For Arizona and New Mexico, Climate Change and a Mangled Jet Stream Means Fire Season Now Starts in February

Isleta-Pueblo-Fire

(500 acre wildfire burns near Isleta in New Mexico on February 19th. Image source: KOAT)

It’s late winter in Arizona and New Mexico. Or at least that’s what the calendar says. During this time of year, snow packs should grace the mountain peaks and cool breezes should blow down into the valleys. A train of west coast moisture should be riding over the mountains of California, bringing with it the occasional snow or rainstorm.

Not so this winter. The blocking pattern over the west coast has mostly held strong — pumping warm, dry air up from the southwest. This warm flood has resulted in continued severe drought conditions ranging from Texas through New Mexico, Arizona and Nevada. Most of California still reels under the worst drought seen in at least a century. While according to reports from the US Drought Monitor, New Mexico experienced its driest January on record. And though the 10 month long blocking pattern barring the Pacific moisture flow briefly fluttered in early February, it has since reasserted itself.

Drought monitor west February 18

(Drought Monitor showing 60% of the Western US suffering from some level of drought. Image source: United States Drought Monitor.)

The result, for Arizona and New Mexico, is unprecedented. For all across these states, weather conditions are pointing toward the beginning of an entirely different season. Humidity levels are excessively low. Temperatures are warm or abnormally warm. And abundant dessicated vegetation covers the hills and valleys. It is a set of conditions that usually don’t begin to ramp up until May. The season of burning and of combustive heat — fire season. In February.

0.1 Inches of Rainfall, Brush Fires Encroaching on Cities

One needn’t look too far to find causes for an early emerging fire hazard. The region of Tuscon, for example, only received a tenth of an inch of rainfall throughout the entire month of January. Throughout February, moisture levels have remained exceptionally low with relative humidity often ranging into the single digits. The result is that vegetation which briefly exploded during a period of abnormally intense rainfall this summer has become withered and dessicated, providing ample and highly combustible fuel should any ignition source emerge.

These are the conditions we should expect as a result of human caused climate change — very intense precipitation followed by very intense dryness along with Jet Stream patterns that tend to become stuck as Arctic sea ice loss and polar amplification in the Arctic accelerates.

Arizona New Mexico February

(Smoke from sporadic brush fires visible over regions of central and southern Arizona and New Mexico that are now virtually devoid of any snow pack, even in February. Image source: Lance-Modis/NASA.)

Even worse, the snow packs for the region, which for years have been steadily receding under a regime of increasing temperatures, are now practically non-existent. Snow pack usually aids in the suppression of ridge and mountain fires until late spring by locking in soil moisture, adding moisture to dry air, and creating runoff that is a natural barrier to fires. Not so for 2014 as there is simply no snow pack to speak of.

In addition to the 500 acre Isleta New Mexico fire, such dry conditions have already led to a spate of brush fires that have encroached on major cities in the region, prompting officials to warn of the, above mentioned, very early start to fire season. According to reports from the Arizona Daily Star:

The recent warm weather, dry conditions and a spate of brush fires on the outskirts of major cities of Arizona and New Mexico are prompting warnings that the 2014 wildfire season is already underway.

The result is that fire warnings have been raised as tinder-box conditions of low humidity, temperatures ranging into the upper 70s, strong winds, and amply abundant fuel persist and intensify. And given that the fire risk began in February, we can expect a very, very long fire season ahead.

Winter Fires Ranged from California to the Arctic in 2014

Unfortunately, Arizona and New Mexico were not the only regions suffering from winter fire seasons during early 2014. California, suffering its worst period of drought in at least 100 years, saw a set of powerful fires rage through Colby near Los Angeles in January. Meanwhile, freakish fires burned near the Arctic Circle in Norway just a week later. Now Arizona and New Mexico add an initiation of fire season in February to the unprecedented tally.

Links:

Fire Season Already Underway in Arizona

Isleta Fire Now 466 Acres

United States Drought Monitor

Lance-Modis/NASA

2000 Acre Colby Fire Rages Near Los Angeles in Winter

Arctic Wildfires in Winter

Hat tip to Collapse of Industrial Civilization

Hat tip to Miep

World Food Security in the Cross Hairs of Human-Caused Climate Change: Mangled Jet Stream, Ocean Heat and Melting Sea Ice To Deliver 500 Year Drought to California? Brazil, Turkey, Australia and More to Follow?

California snow pack January 18 2013California snow pack January 18 2014

(California Snow Pack for January 18 2013 vs the California Snow Pack for January 18 2014. Note the near-zero snow cover for this drought-impacted region. Image source: NASA/Lance-Modis)

“We are on track for having the worst drought in 500 years.” — B. Lynn Ingram, professor of earth and planetary sciences at the University of California, Berkeley.

Remember the historic drought that swept the US in 2011-2013? It was the worse drought in 50 years for some areas. Thankfully, the blocking pattern, excess heat and evaporation that set off this drought and that almost ran the Mississippi River dry abated and lessened, shifting westward and, instead delivered wave after wave of wet and stormy weather to the Eastern US.

Not so with the American West. There the high amplitude Jet Stream pattern remained, keeping regions locked in warm, dry conditions throughout the winter of 2012-2013, on through the end of 2013 and into the early months of 2014.

Looking further back, it was not just these years that had delivered dry weather to the US West Coast. California, ground zero for the current climate change related emergency, has endured dry, hot weather ever since the Pacific Decadal Oscillation (PDO) went negative ten years ago suffering drought years with almost bi-annual frequency.

Now, as Dr. Ingram notes above, California is currently ramping up to its worst drought in 500 years.

A long emergency for California

We only have to scratch the surface for the symptoms of systemic climate crisis in California to crop up. California water authorities failed to honor contracts for the first time in 54 years. Sacramento, as of December was experiencing its worst drought in 130 years even as conditions continued to worsen through January and February.

According to the New York Times, as of February 1rst, 40,000 people were at risk of losing access to water within the next 60 to 120 days. And State officials warned that this number was likely to rapidly rise as The State Water Project announced on January 31rst that it did not have enough water to supplement the fading supplies of local providers to a total of 25 million customers. Meanwhile, State emergency planners were laying out contingencies that included shipping water over land by truck to parched communities.

The drought is also having a devastating impact on local farmers with about 1/3 of California’s farmland expected to lay fallow, at least 25,000 farm laborers expected to be laid off work, and agricultural businesses expecting losses to mount into the tens of millions of dollars. Already, livestock owners in both New Mexico and California, unable to support their animals, have been forced to sell, as fields that used to support four foot high grass are brown and cracked.

Tim Quinn, executive director of the Association of California Water Agencies noted:

“I have experienced a really long career in this area, and my worry meter has never been this high. We are talking historical drought conditions, no supplies of water in many parts of the state. My industry’s job is to try to make sure that these kind of things never happen. And they are happening.”

Climate change, climate change, and climate change

Far flung and dynamic changes to the Earth System appear to have resulted in a variety of factors that have amplified the California drought. First, increasing global temperatures have amped up the rate at which water evaporates into the atmosphere by about 6%, this increased rate of evaporation results in more extreme conditions when heat and dryness do occur. So a drought that may last a year is likely to be even more intense, due to enhanced evaporation, than a comparable drought that occurred 50 or 100 years ago.

In addition, loss of sea ice, snow, and permafrost plays a key roll in re-shaping the Jet Stream. According to Dr. Jennifer Francis and other polar researchers, receding sea ice cover is likely to result in more powerful and long-lasting Rossby Wave type blocking patterns. This happens as more heat becomes concentrated in the polar regions, causing the Jet Stream to meander in great swoops and whirls. These large waves can become fixed into blocking patterns for extended periods. In the up-slope of these waves, warmth and heat predominate. In the trough or down-slope, stormy, wet and cool conditions prevail.

And just such a blocking pattern has dominated the US West Coast for 11 months running. The result is extraordinarily intense dryness, even during the rainy season of November through March.

PNAS drought model US southwest

(Image source: PNAS)

Sadly, according to climate models, we can expect this kind of dryness to intensify over the US Southwest as human caused global warming grows more extreme. A report conducted by PNAS in 2010 and authored by Seager and Vecchi confirmed other model findings that the US Southwest would continue to dry as the climate warmed — the upshot being that the wet season for the West would eventually evaporate.

Above, the PNAS drought model shows evaporation beginning to increase during the first two decades of the 21rst Century. Then, by about decade 2, precipitation rates rapidly fall and evaporation rates gradually rise through to 2100. The red line shows the compounding effects of evaporation increase and precipitation decrease over 24 separate climate model essays.

Rossby wave over West Coast Weakens

(Rossby Wave over West Coast Weakens. Image source: University of Washington)

It is worth noting that on a positive, and slightly hopeful, note, the current blocking pattern over the US West Coast and related Pacific Ocean waters has weakened somewhat. This should allow some moisture to flow into the parched west over the coming days and weeks. And, in the forecast, we do see a proper storm or two emerging from this new pattern. Unfortunately, we’d typically expect about 20-30 storms of this kind during a typical winter season and with March bringing in the end to this year’s rainy season, along with the northward retreat of the moisture flow, it appears likely that California will have to endure at least another 6 months of dry conditions before seeing any hope of major storms returning next fall/winter. A remote potential to say the least given both long-term trends and current conditions.

‘Like a microwave on full blast drying the Earth:’ drought, drought, and more drought

Dr. Kevin Trenberth, one of the world’s premier climatologists, in an email to Joe Romm recently noted:

“The extra heat from the increase in heat trapping gases in the atmosphere over six months is equivalent to running a small microwave oven at full power for about half an hour over every square foot of the land under the drought. No wonder wild fires have increased! So climate change undoubtedly affects the intensity and duration of drought, and it has consequences.”

Under such conditions, we would expect both drought and wildfires to proliferate. And, in fact, this is exactly what we are seeing. As major wildfires impacted both California and Arctic Norway during winter time, Brazil, Turkey, China, Argentina and Australia were also all experiencing some of their worst or most intense droughts on record.

In Brazil, the least rain in two decades is spurring a cattle sell-off that would be very familiar to livestock farmers in California and New Mexico. The expected summer rains did not come and Brazil, a heavily meat-dependent nation was left with soaring food prices after the sell-off as stocks first surged, then plummeted. The epic drought for this region is also causing a number of other impact such as coffee shortages and a related reduction in hydro power as rivers run dry.

Nearby Argentina also saw severe drought-related shocks in recent months as a December drought inflicted serious harm upon Argentina’s corn crop. In a typical year, Argentina produces about 32 million tons of corn. But this year’s drought is estimated to have wiped out about between 7 and 14 million tons of the crop. Argentina is the third largest producer of corn and with the US revising estimates down for its 2013-2014 crop, supplies of the grain are being drawn ever-lower. Though very intense, the December drought had abated by mid-January, providing a respite for other crops such as soybeans.

In Turkey, Lake Sapanca, which provides water for hundreds of adjacent farms, was within a half meter of ‘dying’ as a combination of drought and water drilling had pushed the lake to its limits. Local farmers have, for decades, drilled the land to provide irrigation water for farms and livestock. Now, the drilling is sapping the lake bed. A period of drought had, as of late January, left the lake in such a state that local officials were claiming the lake would be dead after another half-meter fall. The lake which is nourished both by springs and ground water has been deprived of flows both by human climate change induced drought and by human drilling into the lake’s spring-bed.

In Australia, drought conditions are now worse for some locations than at any time since 2003, a tall order since the 2003 to 2009 drought was Australia’s worst in 1,000 years. For Sydney, that means the lowest rainfall totals in more than 70 years. This particular drought hit both hard and fast with Australia seeing normal conditions before Christmas, but after, very intense heat and dryness resulted in a rapid scorching of farmlands, crops, and grazing fields. The dire drought situation has resulted in government relief funds being released to affected farmers. NSW Minister for Primary Industries, Katrina Hodgkinson noted to the Sydney Morning Herald:

“Seasonal conditions are now deteriorating at a rapid rate across a large portion of NSW and both the severity and speed at which this drought is moving is astonishing. Primary producers in some parts of NSW have simply not had the opportunity to prepare for another severe downturn in seasonal conditions so quickly after the Millennium drought broke.”

Lake Poyang May 2014Lake Poyang Jan 2014

(A mostly full Lake Poyang as seen from Satellite on the left during May of 2012. A parched and almost completely dry lake Poyang as seen from Satellite during January of 2014. Image source: NASA/Lance-Modis.)

And, in China, the largest lake for that populous nation has now dried up. Poyang, a massive lake usually spanning 3,500 square miles has been turned into a sprawling field of earth parched and cracked by a combination of drought and water diversions resulting from the construction of the Three Gorges Dam. According to reports from The Guardian and Chinese News Sources, a drought stretching from 2012-2014 in the region of Poyang is now the worst in at least 60 years leaving lake refill almost non existent as upstream river flows to the lake were periodically cut off by water storage operations at the Three Gorges Dam. The result was an extreme lowering of lake levels and dry bed conditions that have driven farmers and fishermen in the region out of business.

Implications for world food security

Major droughts during 2011-2012 impacted many of the world’s primary agricultural basins, resulting in forward food supply dropping to as low as 72 days. Since that time, food supplies have slightly recovered but are well below previous levels last seen in the 1990s at 104 days. Food insecurity and failure to distribute food to the malnourished remains a priority at international agencies like the UN which has identified numerous countries including Cameroon, the Central African Republic, Somalia, Syria, Mali, Sudan and Nigeria, among others, as extreme risks for hunger and famine. Relief agencies have allocated billions of dollars to address this problem but the UN continues to identify climate change as a major threat to global food security with the potential to wipe out all previous progress moving forward.

The droughts in California, Turkey, Australia, China, Argentina and Brazil so far for 2014 put the world at risk for another bout of food insecurity later this year should major weather and climate related crop disruptions emerge in other primary food producers such as the bread baskets of the US, Russia, and Europe (The US, Brazil, China, Russia, and Europe are top food producers). It is worth noting that, in large part due to the ongoing southwestern drought, the US has revised a number of its crop projections downward for end 2014.

With polar amplification playing havoc with the Northern Hemisphere’s weather systems, with Australia sitting in a pool of expanding warm Pacific Ocean water that makes drought more likely there, and with the Eastern Pacific edging closer to La Nina, conditions warrant a continued monitoring of both weather and the state of world food supplies. The added global heat engine also impacts soils and crop growth in ways to which we are currently unaccustomed, resulting in more extreme instances of flash drought as well as flash flood. In this respect, the examples of Australia and Argentina are of particular concern.

Though global crisis has not yet returned, it lurks at the edges as drought, extreme weather and over-use of ground water supplies continues to threaten a wide swath of productive zones. So, at this point, the situation is one best described as tenuous with ongoing regional impacts over the Sahel region of Africa and in other sporadically vulnerable locales.

Links:

Historic Drought of 2011-2013

Winter 2013-2014: Sea Ice Loss Locks Jet Stream into Severe Winter Storm Pattern For Most of US

It happened to Europe last year. A persistent erosion of Arctic sea ice set off changes to the polar jet stream that locked in place a severe winter weather pattern that pummeled the central and western European countries for much of the winter. Storm after storm piled snow high in locations that typically saw only modest winter precipitation while other areas were simply buried. The US also took a glancing blow from this extreme storm configuration. But now, with a large trough in the polar Jet remaining locked in place for almost a year, the US from the Rockies eastward appears to be in the line of fire for some very severe winter weather.

In other regions from Alaska to Eastern Europe, record or near record warmth and dryness have settled in with a large swath of eastern Europe showing average temperatures more than 6 degrees Celsius above the seasonal average. Over the extreme northern Pacific, adjacent to Alaska and the Bering Sea, seasonal temperature range from 4-12 degrees Celsius above average. And it is this extreme northward invasion of warm air that is displacing polar and Arctic air masses toward the east and south, putting much of the US in the firing line for strange and severe winter weather.

Just this week, the tale was one of record ice storms throughout the central and eastern US with hundreds of flights cancelled, deadly traffic pile-ups, and holiday shopping disrupted. On the east coast, from Virginia to Maine, workers and shoppers alike were treated to three days straight of snow turning to sleet and freezing rain and then turning back again to snow. With storms like these hitting in early December and with the pattern in the Jet Stream taking on such an extreme configuration, it appears possible that the winter of 2013-2014 could be a very, very stormy one indeed.

A Tale of Jet Streams and Melting Sea Ice

To understand how human caused global warming can make winter storms more severe in some areas while other areas hardly experience winter at all, one should first take a look at two major governors of Northern Hemisphere weather: the circumpolar Jet Stream and Arctic sea ice.

An extreme difference between the temperatures at high northern latitudes and at more temperate latitudes has driven a very rapid flow of upper level air called the Jet Stream for almost all of human meteorological reckoning. This high temperature difference drove powerful upper level winds from west to east. These winds tended to modulate only slightly and when they did, powerful weather events tended to occur.

Locking a greater portion of this cold air in place was the northern hemisphere ice cap, most of which was composed of a large swath of sea ice covering much of the northern oceans. This high volume of cold, reflective ice kept temperatures up north very, very low and provided the massive temperature differences which kept the Jet Stream predominantly flat with only occasional and more moderate severe weather causing ripples and bulges.

But since 1979, massive volumes of sea ice have been lost due to an immense and ongoing human caused warming trend taking hold in the Arctic. As human greenhouse gas emissions sky-rocketed, Arctic temperatures rapidly increased far faster than the global average. By this year, human greenhouse gas emissions had driven CO2 levels to the highest seen in more than 3 million years while Arctic temperatures are now warmer than at any time in the past 150,000 years. Sea ice retreat has been equally unprecedented with average winter values now 15-20% below extent measures seen during 1979 and with end summer sea ice extent values now a stunning 35-50% below that of 1979. Sea ice volume, the measure of total ice including its thickness, has shown even more stunning losses since 1979 with seasonal winter values 30-35% lower than in 1979 and end summer values between 65 and 80% lower during recent years.

JAXA sea ice Dec 9 2013

(Sea ice extent measure composed by JAXA. The light gray dotted line on the top shows sea ice extent averages during the 1980s. The three record lowest years — 2007, 2011 and 2012 — are shown in green, blue, and orange. The most recent year, 2013, is shown in red. Note the persistent and rapid melt trend.)

The loss of hundreds of thousands of square kilometers of sea ice radically reduces the Arctic Ocean’s ability to keep the Arctic cold. To the contrary, we see larger areas of open water that, in turn, radiate ocean heat into the atmosphere throughout winter. As a result the temperature difference between the Arctic and temperate regions is less and this, in turn, slows down the Jet Stream.

When the Jet Stream slows, it tends to meander. And when it meanders it creates very deep troughs and very large ridges. In the ridges, we get unseasonably hot temperatures along with increased risk of drought. And in the troughs, Arctic air swoops down to collide with warmer, moist air in a series of powerful storms. During the summer time, the hot, dry zones can bring deadly heat waves, record droughts, and major wildfires while the cooler stormier zones can bring epic rainfall events or even link up with tropical cyclones to result in highly severe hybrid storms. During the winter time, the hot zones can almost completely obliterate the winter season, while the stormy cooler zones can result in snow storm after snow storm.

Don’t believe me? Then take a look at what weather experts Jeff Masters and Jennifer Francis have to say on the matter:

Polar Warmth and Rossby Wave Pattern Going into Winter 2013-2014

As noted above, a powerful and continuous ridge in the Jet Stream over the north eastern Pacific near Alaska has persistently provided an equally powerful down-sloping trough over much of the US over the past year. The December 10 Jet Stream configuration map shows this pattern remaining locked in place:

Northern Hemisphere Jet Stream 10 Dec 2013

(Image source: California Regional Weather Server)

Note the strong multi-channel ridge to the south of Alaska and to the west of Canada diving down into a deep trough with convergent upper level air flows over the central and eastern US.

On the map, we also see powerful ridges and correlating warmer regions over Europe, Central Asia, and the western Pacific. These large meanders are now typical to the highly weakened Jet Stream pattern we have seen in recent years due to loss of polar sea ice.

Global temperature maps also show anomalously warm temperature departures for much of the Arctic as well as for regions beneath these powerful jet stream ridges. Note that the only northern hemisphere region showing strong anomalously cool conditions is a large swath adjacent to the large trough over North America and southern Greenland.

Global Temperature Averages Dec 1-7 2013

(Global Temperature Averages and Anomalies vs 1981-2010 mean. Image source: NOAA)

Temperature averages in the Arctic region of Kamchatka, the Bering Sea, the Chukchi Sea and Alaska have ranged between 11- and 12 degrees Celsius above average for the first week of December with much of the Arctic showing 4-12 degrees Celsius above average readings. The US and southern Canada, conversely, have shown temperatures 4-10 degress Celsius below average. It is also worth noting the massive swath of 3-12 C above average temperatures stretching all the way from the Middle East to the west coast of Greenland.

Overall, the prevalence of high latitude warmth and a continued high amplitude Rossby wave pattern trough over much of the US is a very conducive pattern for severe winter weather over the coming weeks. Most likely, this pattern will continue to persist through at least early to mid winter. So for the US and especially from the Rockies to the east coast, a progression of strong storms is likely to continue as winter advances.

Links:

California Regional Weather Server

NOAA

PIOMAS

Supporting Research:

Evidence linking Arctic amplification to extreme weather in mid-latitudes

Impact of sea ice cover changes on Northern Hemisphere atmospheric winter circulation

Impact of declining sea ice on winter snowfall cover

Weather extremes provoked by trapping giant waves in the atmosphere

Quasi-resonant amplification of planetary waves and recent Northern Hemisphere weather extremes.

Drought, Burning Rings of Fire out West, Severe Flooding in the East: How Climate Change and a Mangled Jet Stream Wrecked US Weather

Earlier this summer, I had a weather conversation with my mother. She was excited about a new business venture my sister had undertaken (Adventure Kayaks) and for an upcoming trip to Yosemite in August to celebrate her and my father’s 45th wedding anniversary. She wondered about the weather, hoping it would be a good summer for both the new business and the trip. Without thinking too much, I said:

‘Rain, cooler weather, and storms in the east, drought, heat and fires in the west.’

Immediately after saying this, I felt reticent. Perhaps I shouldn’t have spoken? Maybe I would scare my mom. What good would it do to ruin her enjoyment or her looking forward to both the trip and to my sister’s potential success?

It’s worth noting that, thankfully, the storms and cooler weather that did emerge with fury and flood in the east did not ruin my sister’s kayaking venture (although it did result in numerous interruptions both during spring and throughout summer). Should a tropical storm or hurricane make landfall on the US east coast this August, September or October, however, the devastation could be vast, perhaps exceeding a 1 billion dollar disaster event (more on this below).

But as my mother boarded her plane to California and a potential date with Yosemite yesterday morning, these were the satellite images I was looking at:

Yosemite Fire NASA Earth Observatory

Yosemite Fire NASA Earth Observatory

Image source: Earth Observatory

The vast Rim fire that had grown to consume over 192,000 acres as of today was steadily devouring the western border of Yosemite. You can see it on the above infrared satellite picture provided by NASA as a ring of bright white steadily inching into the indicated yellow border of Yosemite.

Jennifer Francis, Stu Ostro and How I Knew

Earlier this summer, my mother chided me on my ‘attempts to predict the weather.’ In a phone conversation last night, she asked ‘how did you know?’

It’s fair to say that in the overall prediction of more storms and rains in the US east, with more risk of flooding, and more heat and dryness out west, with more risks of fire, that I wasn’t entirely certain. However, I’d recently read the work of climatologist Jennifer Francis and had been listening to and following the statements of Stu Ostro. During early spring and summer, I observed a Jet Stream pattern setting up over the US that appeared to be settling into a ‘stuck position’ that would result in the high likelihood of the conditions I communicated with my mother. It’s worth noting that in looking at these Jet Stream patterns it’s not difficult to make such predictions because the patterns change slowly, they lumber and tend to remain stuck for long periods. Once a pattern settles into place, it’s a good bet that it will stick around for at least a few months these days, a fact that the models nail but which meteorologists, in general, have failed to communicate. In short, this is a climate change driven change in the weather.

In fact, some meteorologists and climatologists seem entirely reticent to accept this new weather pattern, despite the fact that it is a powerful tool for weather prediction and will tend to result in less surprises. The big troughs equal record floods sticking around for a long time and the big ridges equal record heat, drought, and probably fires sticking around for long periods of time.

In an example of this reticence, a recent paper by a University of Colorado researcher concluded that Jennifer Francis did not have enough evidence to support her claims of an observed slowing in the Jet Stream. Unfortunately, the paper included, as a part of its findings, a cross section of the atmosphere in which the Jet Stream does not typically reside even while the paper included a sample during which changes were already occurring, which would have likely biased its results. Despite these biases and errors, where the paper actually did measure Jet Stream flows, it corroborated Francis, showing Jet Stream slowing during the periods measured. This is odd considering the fact that the concluding statement contradicts the papers own findings, a point which Dr. Francis, herself, provides.

It’s easy to understand why reticence still lives in the science. As I noted above, it’s understandable to feel reticent when being the bearer of bad news. No one wants to be the messenger that gets metaphorically ‘killed.’ But without making use of the clear understanding provided by Francis and Ostro, we will continue to be surprised by extreme floods, storms, fires, heatwaves and droughts that can be easily predicted by simply looking at how the Jet Stream sets up and where it gets stuck. Instead, ‘surprise’ after ‘surprise’ just keeps coming our way.

When Rossby Waves Get Stuck: Changing to a More Radical Jet Stream

Dr. Jennifer Francis has observed that loss of sea ice and snow cover in the Northern Hemisphere has resulted in a slowing of the Jet Stream in recent years. Sea ice volume, the measure of total ice in the Arctic Ocean, since 1979 had declined by as much as 80% when measured at its low during 2012 (this measure may rally back to around 75 to 78 percent lower than 1979 this year, but the overall trend remains a death spiral). Greenland melt is unprecedented at 500 gigatons per year and with Arctic heatwaves blasting the tundra both permafrost and snow cover are at record and near record lows. 80 to 90 degree temperatures now often advance to the shores of the Arctic Ocean, with the coldest air pushed back above the 80 degree north latitude line, confining it to a shrinking region that, increasingly, huddles closer to the remaining large ice sheets in Greenland. Overall rates of warming for much of the Arctic are about .5 degrees C temperature increase each decade, more than twice the global average.

A more quickly warming Arctic results in changes to the atmosphere’s heat balance. According to Francis, the height of the atmosphere over the Arctic is rising relative to atmospheric heights in the lower lattitudes, this loss of slope results in lower gradients from north to south and since temperature, atmospheric height and pressure gradient drive Jet Stream speed, the Jet Stream slows down. And as the Jet Stream slows, it tends to seek out the highest gradients it can find. The result is more northward invasions of the polar region of the Jet Stream ridges and more southward invasion of the Jet Stream troughs. This amplification creates a rather large and elongated sine wave called a Rossby wave pattern.

Jet Stream Pattern Change. Image source: NOAA.

Jet Stream Pattern Change. Image source: NOAA.

In the sequence above, we see the progression of a flat Jet Stream to a Rossby wave ridge/trough configuration to, eventually, cut off lows and highs. In the past, such waves tended to set up for briefer periods, extending for days or weeks before returning to the usual, more flattened motion of the Jet. In more recent years, large Rossby type waves have been the typical pattern, one that transitions to cut off lows before it returns to a configuration more similar to (b) in the diagram, before setting up as a Rossby-type wave again.

Perhaps more importantly, this b, c, d progression has tended to occur again and again and again over the same geographical region for months and months on end. And, looking back at Jet Stream maps over the past months, this is exactly what we find.

Below is a progression of images I’m providing from this blog’s archive. It includes either direct temperature measures that indicate Jet Stream patterns or a mapping of air flow speed indicating the Jet Stream’s path.

Clover leaf Jet Stream Pattern April, 2013.

Clover leaf Jet Stream Pattern April, 2013.

(Image source: ECMWF)

In ‘For Central US, Climate Change and a Mangled Jet Stream Means Drought Follows Flood Follows Drought’ I described how the Jet Stream pattern had consistently switched from large trough to large ridge configurations over the past few years bringing either heatwaves and droughts or storms and floods. But the left hand portion of the image provides a good record of the Jet Stream configuration as of mid April this year. Following the temperatures, on the west coast we see a large, hot ridge and in the central and eastern US we see a deep, cool and stormy trough.

Wednesday July 3, Rossby wave still in effect over US.

Wednesday July 3, Rossby wave still in effect over US.

(Image source: ECMWF)

Throughout May and into June, this ridge over west, trough over east, pattern continued. By late June, a massive, record-shattering heatwave had set up over the US southwest. I described this highly anomalous event in ‘Mangled Jet Stream and Global Warming to Shatter Earth’s Highest Recorded Temperature This Week?’

Looking at the ECMWF image above we again see the highly exaggerated ridge/trough dichotomy setting up over the US with very hot, dry conditions out west and cooler, wet and stormy conditions in the east.

At this point, I want to tap Stu Ostro’s own observations to add to the Jennifer Francis mix. What Stu has found is that large, powerful high pressure systems have tended to develop more and more often. These extraordinarily dense systems seem to be exploding to new heights in a thickening atmosphere. Primarily, these monsters are driven by heat and so they tend to live in the massive ridges provided by our new, exaggerated and slowed, Jet Stream pattern. That said, these beasts can spring up almost anywhere there is a massive abundance of heat to tap, as one did over a super-heated region of ocean near Shanghai this summer sparking its own monstrous heat wave.

These large heat domes have major and far reaching effects. To understand them, we must first step back to think about the broader effects of human caused warming before looking at how heat domes manifest in the atmosphere. Based on models of the Earth’s atmosphere, we know that for each 1 degree Celsius of Earth temperature increase we get a corresponding 8% amplification of the hydrological cycle. What this means is that evaporation happens 8% faster and condensation happens 8% faster — OVERALL.

Since 1998, we have observed temperatures that are, on average, .8 degrees Celsius above those seen during the 1880s. What this means is that the hydrological cycle has amplified by 6% over this same time period. Because of this dynamic, droughts are more intense, but rainfall events are also more intense. Yet since the atmosphere is uneven we can expect this 6% amplification to manifest in somewhat more extreme fashion at the locations where more extreme Jet Stream patterns set up.

Mangled Jet Stream Dumps Deluge on US Midwest

Mangled Jet Stream Dumps Deluge on US Midwest

(Image source: California Regional Weather Server)

What goes up must come down. And that massive heat dome over the western US and Canada had been baking moisture out of the soil at unprecedented rates over an extended period from April to August. The moisture injected into the heat dome rose and rose, The high pressure system suppressed cloud formation so the moisture had no where to go but up and out. Eventually, this moisture found the edge of the massive high and spilled over into the storms riding along the Jet Stream trough rushing down from the Arctic Ocean and into eastern Canada and the US (hat tip to Colorado Bob).

The result was multiple flood events starting with the Midwest floods of April, then the massive Canadian floods (Calgary) of June, then the Toronto floods, then the Midwest floods of early August, and lastly the east coast floods of mid to late August. The Calgary floods were the worst ever recorded in Canada, the Toronto floods were the worst recorded for that region, and in the Midwest floods of early August, four months worth of rain fell in just one week.

Monthly rainfall estimates August 2013.

Monthly rainfall estimates August 2013.

(Image source: The Weather Channel)

On 8 August, the time of the second barrage of major Midwest floods this year, we find the Jet Stream in the same elongated configuration with a large northward ridge extending all the way from the southwestern US to the Arctic Ocean and with a deep trough diving back down into the central and eastern United States. As noted above, the mangled Jet Stream delivered its overburden of moisture directly to the US Midwest, dumping four months worth of rain in just one week.

A second pulse of moisture rode far south along this Jet Stream flow to dump massive amounts of rain over the southeastern US about a week after pummeling Missouri. This flow combined with a compromised tropical system to saturate the southeast, with some regions receiving as much as 300 percent their annual rainfall totals by late August.

One of the hardest hit areas is Lake Okeechobee. Water levels there as of mid August hit 16 feet at the Hoover Dike, a level that requires weekly monitoring for cracks or ruptures. The dike stretches over 140 miles along the perimeter of lake Okeechobee and was intended to keep the lake in check during major storms and hurricanes after large outburst events in the early 20th Century resulted in thousands of lives lost. The dike is 25 to 30 feet high and is as wide as a football field. The US Army Corps of Engineers has been working feverishly to shore up the dike in a project that will take years to complete.

At 16.5 feet water level, the dike will require daily monitoring. For each inch of increase above that level, the pressure put on the dike would greatly increase risks of catastrophic failure. The causes of such high water, this year, were neither tropical storms nor hurricanes. Florida has been, thus far, spared the wrath of these strong storms. Deep Jet Stream troughs and a constant Atlantic moisture flow have, instead, resulted in day after day rain events for much of southern Florida, pushing August totals near Lake Okeechobee above 16 inches, filling the massive lake and putting the dikes at risk. Should a hurricane or tropical storm strike Florida during late August, September, or October, the dike could overtop or rupture, unleashing the massive lake on communities sitting beneath it. (Hat tip to Colorado Bob).

As the threat of massive floods continued to increase in the east, the west was erupting with wildfires. Fire containment efforts went into high gear both exhausting the Forest Service Fire budget and briefly pushing the national fire alert level to 5. The Rim Fire, so close to my parents’ vacation site, expanded to 192,723 acres today making it the 6th worst in California history.

Rim Fire on August 28th, 2013

s Rim Fire on August 28th, 2013

(Image source: Lance-Modis)

You can see this massive fire, now 23% contained, burning to the west of Yosemite in the Modis shot below. A more detailed report of this major wildfire is provided by WeatherUnderground here and here.

Mangled Jet Stream Temporarily Edges Eastward

My parents wanted to see Yosemite’s amazing waterfalls. A major source of my reticence in telling them the likely pattern for this summer was that the heat and drought out west would probably dry out many of those magnificent falls. And, sadly, this has happened. So even if they brave the smoke and fires to reach Yosemite, the one attraction my mom had been most excited to see will likely be somewhat less magnificent.

But a cloud has suddenly appeared in this wrinkle. For the Jet Stream had edged slightly east.

As of the middle of last week, reports of heatwave conditions had emerged throughout the US Midwest with North Dakota, South Dakota, Nebraska, Illinois, Wisconsin, Iowa, Minnesota and Missouri experiencing temperatures in the range of 20 degrees (Fahrenheit) above average. With heat index values hitting as high as 110 degrees, communities sweltered and school systems declared closings. In California, where temperatures had remained in the upper 90s to lower 100s for much of summer, the trough advanced, pushing temperatures back down to the 70s. An upper level low flirting with the west coast may even toss a few fog clouds and rain showers toward California. Such an event would be a welcome change for both my parents and for beleaguered fire fighters in the region.

In any case, the shift is expected to be short lived with ECMWF models showing the Jet Stream again backing up and reforming a hot and dry ridge pattern over the US west. So the Midwest can expect cooling and a return to more stormy, rainy conditions while the US west, after only a brief respite, continues to bake:

Mangled Jet Stream Early September

(Image source: ECMWF)

The September 7 ECMWF forecast again shows a large and powerful Rossby-type wave pattern with a very large and hot ridge setting up over the US and Canadian West with a deep trough digging down toward the US East Coast. It is the same pattern we’ve seen since at least April, a pattern that has delivered numerous rounds of heat and drought to the US west and an equally vicious and persistent pattern of storms and flooding from the central US to the east coast. The Jet Stream has, essentially, been stuck these past 5 months and there is no end in sight. For even if this configuration of the Jet were to move, it would likely simply re-distribute the locations of heatwaves and droughts and storms and floods.

If anything, this past summer has been yet one more validation in evidence of the work of Dr. Francis. And it is because of her work that I, a relatively untrained observer, can make the accurate prediction that a large region from the Mississippi west to California will continue to stay hot and dry and will continue to see risk for large fires, while the region to the east will remain cooler and stormier so long as the current Jet Stream configuration continues to persist. The western region will risk periods of record heat, continued drying of lands, rivers and aquifers, and fires of record size. The eastern region will continue to risk record floods and storm events. As summer proceeds to fall, shifts in these weather patterns have the potential to grow violent with the possibility of powerful nor-easters or hybrid storms developing near the US East Coast. Both the southeast and Florida remain very vulnerable to continued large rain events or tropical storms and hurricanes as time moves forward and in the event of pattern persistence. Meanwhile, long range model forecasts show this general pattern continuing to persist until at least early to mid September.

At this point, the current US Jet Stream pattern will have been in place for at least 6 months.

 

 

 

Arctic Heat Wave Re-Intensifies Over Central Siberia Setting off Rash of Tundra Fires

Siberian Fires July 23

Large fires break out over Siberia during renewed Arctic heat wave.

(Image source: NASA)

 

UPDATE: LARGE METHANE PULSE OCCURS IN CONJUNCTION WITH ARCTIC HEATWAVE

 

Over the past week, temperatures have been building throughout Central Siberia. A broad swath of heat pushed thermometers into the upper 70s to upper 80s (with isolated spots showing 90+ degree readings, Fahrenheit) in a broad region stretching from Siberia’s forests all the way to the Arctic Coast. These heatwave conditions set off more than a score of large fires that raged through both Arctic forest and across broad areas of tundra. The largest of these fires covered areas up to 1000 square miles and numerous smoke plumes were visible from satellite, some of which stretched more than 800 miles in length. A larger pall of smoke from this region covered areas of North-Central Russia, the Arctic Coast and sections of Europe more than 2,000 miles away.

You can view these fires and related smoke plumes in the NASA Aqua Satellite image provided by Lance-Modis above.

The scorching Arctic heat wave and massive burning has been set off, once again, by a high amplitude northward bulge in the polar Jet Stream and related ‘heat dome’ high pressure system resting just beneath the bulge. As you can see in the below image, provided by the California Regional Weather Service, this particular heat bulge extends past the 80 degree North Latitude line, nearly reaching the North Pole. This extraordinary upward sweep in the Jet has completely compromised the polar vortex, allowing hot air to build far north and pass deep into the Arctic Ocean environs.

jetstream_northern July 23

(Image source: California Regional Weather Service)

Arctic coastal temperatures usually average less than 50 degrees Fahrenheit at this time of year, but the region beneath this Arctic heat dome has averaged about 15-20 degrees hotter over the past week. Further south, where the tundra fields and arboreal forests of Siberia lay, temperatures have been even warmer with highs stretching into the middle and upper 80s and even lower 90s in some isolated locations. The added heat and the occasional thunderstorm that will typically form under such highly unusual Arctic conditions enhances the chance of wildfires. Now, after a week of such conditions, more than a score of large fires rage.

Siberian Heatwave July 23

Tuesday daytime temperatures for Siberia. Red indicates temperatures ranging from 77-86 degrees Fahrenheit. Note the broad swath of these temperatures riding up from Russia all the way to the Arctic coastline. These measures represent daytime temperatures at the point recorded and do not necessarily record daily maximum temperatures for a given location.

(Image source: Arctic Weather Maps)

Unfortunately, forecasts call for hot conditions to persist over this region of the Arctic at least until Saturday. Then, the heat dome and related Jet Stream bulge is predicted to slowly shift toward Europe, bringing heat, dryness and related risk of wildfires along with it.

This particular heat wave is the most recent of many to plague the Arctic during 2013. Large Arctic regions from Siberia, to Europe, to Canada to Alaska experienced periods of extreme heat where temperatures rose 10, 15, 20 degrees or more (Fahrenheit) above average. The added heat and evaporation in one region appeared to aid in the formation of record floods in another with both Europe and Canada experiencing some of their worst floods on record.

Strange changes to the Jet Stream and the water cycle driving these extreme events are directly related to human-caused global warming. In the first instance, human-caused warming has set off a series of events that have caused a major erosion of Northern Hemisphere sea ice. Since 1979, more about 50% of sea ice extent and 80% of sea ice volume has been lost. Since the 1900s, more than 60% of sea ice extent has melted away. The sea ice, which tends to lock cold air in the Arctic, is thus dramatically weakened. The result is that more warm air tends to pool in the Arctic. As this happens, the temperature difference between the North Pole and temperate regions lessens. This loss of differential causes the Jet Stream to slow down. As the Jet Stream slows, it tends to move more like a lazy river, creating big loops, large high amplitude waves and numerous cut off flows. The net result is that weather systems move more slowly, causing weather patterns to persist over longer periods.

The high amplitude waves that have tended to form in the Jet Stream also result in warmer air being transported toward the North Polar region. In the case of the current Siberian heatwave and wildfires, this is exactly what is happening. What we have seen, this summer, is a ring of very hot conditions developing in the higher Latitude regions from about 60 degrees North to about 80 degrees North. This is the zone where much of the extreme Arctic heating has emerged.

This second factor, added atmospheric heat, causes greater evaporation to occur, especially in regions where the heat is most intense. On average, the global hydrological cycle, which is the net rate at which water evaporates and then comes back to the Earth in some form of precipitation, increases its intensity by 8% for each degree Celsius of warming. Currently, average global temperatures are about .8 degrees Celsius hotter than the 1880s average. So the rate at which water evaporates and the rate at which it falls from the skies as rain and snow has increased by more than 6%. In the hot regions under the Jet Stream bulges and related heat dome high pressure systems this means far more intense soil drying and risk of wildfires. In the wet regions of cut off lows and down-slopes in the polar Jet Stream this means more intense rainfall events.

In essence, this is how human caused global warming is helping to drive extreme weather events now. And the current Siberian heatwave and related wildfires is just one case in point.

Links:

NASA

California Regional Weather Service

Arctic Weather Maps

The Arctic Heat Wave, Heat Domes, and a Mangled Jet Stream

With ‘Warm Storm’ at Its Heart and Heatwaves Rushing in From The Sides, Arctic Sea Ice Braces for Major Blow

Over the past month, warmth and energy have been building in the Arctic. All around, from Siberia to Scandinavia to Alaska, heatwaves have flared beneath anomalous long-wave patterns in the Jet Stream. Patterns, that in many cases have persisted for months. The Alaskan heat dome sent temperatures there to 98 degrees (Fahrenheit). Temperatures in Siberia flared to the low 90s. And heat built and flared again in Scandinavia and Northeastern Europe, sending Arctic temperatures first into the 80s and then to 92.

This building and highly anomalous heat was coupled by another unusual event — a long duration series of Arctic storms that have thinned and weakened large sections of sea ice near the North Pole. This Persistent Arctic Cyclone has flared and faded, remaining in the Arctic since late May.

Now, with central sea ice weakened and with heat circling in from all around, the Arctic appears to be bracing for a period of rapid sea ice loss.

Part 1: The Monitors Start to Go Sharply Negative

The first hint that the Arctic may be at the start of a precipitous fall in sea ice came when the major monitors all went negative. Cryosphere Today, Jaxa, NSIDC — all these key monitors show Arctic sea ice coverage falling sharply over the past two days.

Cryosphere Today showed a substantial loss of more than 200,000 square kilometers of sea ice area in its most recent 24 hour period. Jaxa and NSIDC showed similar extent losses with NSIDC following a steeply declining curve to 10.6 million square kilometers and JAXA diving down to 10.1 million square kilometers.

You can vividly see this declining curve in the most recent NSIDC graph:

The Cliff Starts NSIDC

(Image source: Pogoda i Klimat, Data Source: NSIDC)

And you can see the stunning near-vertical recent decline in the Cryosphere Today graph here:

Sea Ice Cliff Area CT

(Image source: Pogoda i Klimat, Data source: Cryosphere Today)

Together, these monitors begin to show what could well be the emergence of a potential ‘sea ice cliff’ resulting from rapid loss of ice during a time of escalating impacts. And these impacts appear to be emerging in rapid succession. Most notably, a Warm Storm now melts the central ice even as massive heatwaves threaten to inject hot air into the Arctic’s perimeter.

Part 2: PAC 2013 Now a ‘Warm Storm’

We find that even as these sharp sea ice declines began to emerge, temperatures in the Central Arctic Basin are now all above freezing. Meanwhile, a 995 mb low churns almost directly over the North Pole. This low is part of the same complex of storms that has remained in the Central Arctic since about May 26. Though storms, even strong, long duration storm events like this one, have been known to occur in this region during June, a persistent storm thinning and melting the Central Arctic Basin ice is unprecedented. And this is exactly what has been happening.

Now, it appears this storm has shifted into a new phase that is likely to further enhance central sea ice thinning and melting. The Warm Storm appears to have taken hold.

In a previous post, I defined a ‘Warm’ Arctic Storm as a storm occurring in the Central Arctic in conjunction with average atmospheric temperatures in the range of 0 to 6 degrees Celsius. We are now decisively in the lower end of that temperature range as you can see in the current DMI temperature measure:

Warm Storm Temp June 28

(Image source: DMI)

Note the wide area of above freezing temperatures now dominating all but isolated portions of the Central Arctic. And, for reference, we have the position of our Warm Storm given in the DMI image below.

Warm Storm Pressure June 28

(Image source: DMI)

Here we can see our Warm Storm now hovering almost directly over the North Pole.

These Warm Storm conditions provide an added surface stress to the sea ice by burdening the ice will above freezing precipitation, winds, fog and air with higher moisture content. These forces add to the churning mechanism of the storm which tends to break the fresh water cap that protects the sea ice and pull up warmer, saltier water from below. It is a combined stress that has already greatly eroded and melted the Central Arctic’s sea ice.

A vivid modeling of current and projected impacts of this Warm Storm are graphically displayed in the US Navy CICE/HYCOM thickness monitor below:

Warm Storm Turns Central Arctic Into Puddle

(Image source: US Navy)

In this vivid model history we can see our ‘Warm Storm’ turning a growing section of the Central Arctic sea ice into one enormous melt puddle even as it continues to shove sea ice along the north coast of Greenland and out through the Fram Strait. It is also worth noting the speed and violence with which edge melt is projected to proceed between now and July 5th. Hudson Bay, Baffin Bay, the waters of the Canadian Archipelago, The Kara Sea, The East Siberian Sea, The Chukchi, and even the edges of the Beaufort are all projected (in this model) to see rapid to extraordinarily rapid melt.

As noted before, a ‘Warm Storm’ event is a potential nightmare scenario for sea ice loss. And we’re experiencing the early phase of such an event now.

Part 3: Mangled Jet Stream Delivers Major Arctic Heat Spike

As if the formation of a ‘Warm Storm’ in the Central Arctic wasn’t enough…

Today, the Jet Stream set up to begin to deliver an enormous heat spike based in the Western US, which is predicted to see blast furnace temperatures that challenge Earth’s all time record of 134 degrees (Fahrenheit), extending up across a Canada that I’m not sure is prepared for this level of heat, stretching over the Canadian Archipelago, and finally dumping an enormous heat load into the Beaufort Sea.

We can see the current Jet Stream configuration, which can well be described as a freaky hydra-head pattern with multiple rapid upper air flows converging on the high Arctic, in the image below:

Mangled Hydra-Headed Jet Stream June 28

(Image source: California Regional Weather Service)

In particular, we note the high amplitude Rossby Wave pattern emerging over the western US and reinforced by a second echoing pattern extending up over the Beaufort Sea. The wave height for this massive blocking pattern in the Jet is expected to jump northward over the coming days even as a terrific heat dome intensifies with a center near the ‘Devil’s Armpit’ (Hat Tip to X-Ray Mike over at Collapse) of the US (Southern California, Nevada, Arizona).

By Wednesday, we see extraordinary 35 degree Celsius (95 degrees Fahrenheit) average 5,000 foot temperatures at the heat dome’s heart in the US Southwest (translating into 105 to 123+ degree surface highs over a broad area), and a long pulse of hot air jumping all the way up to the Beaufort Sea where it appears near 80 degree (F) high temperatures could emerge near or even over the sea ice.

You can view this uncanny record hot air pulse in the ECMWF weather model forecast below:

Mangled Jet Stream Delivers Severe Heat Pulse

(Image source: ECMWF)

Note the angry hot pink heat dome over the US Southwest and the long, hot arm extending from it and all the way into the Beaufort. It is also worth noting that a secondary, though somewhat less intense, heat surge also emerges above Scandinavia and extends deep into the Arctic from its opposite end, creating a kind of pincher of hot air keeping the Arctic in its grip.

By Thursday, this hot air gets wrapped into a 990 mb ‘Warm Storm’ that then goes traipsing through the Beaufort. Not a pleasant prospect, if one wishes to see sea ice preserved…

Worst Case Melt Scenario May be Emerging

So by late June, it appears that the worst case melt scenario — with a storm hollowing out and melting the Arctic sea ice from the center and powerful warm air pulses delivered by a mangled Jet Stream rapidly melting the sea ice from its edges — may be emerging. A start to a ‘melt cliff’ that occurred this week, therefore, may extend and rapidly advance over the coming days. Model ensembles seem to support this forecast even as atmospheric heat delivery to the Arctic ramps up. It is an extreme situation that is well worth monitoring.

Links:

NSIDC

Cryosphere Today

DMI

US Navy

California Regional Weather Service

ECMWF

Heat, Humidity, A Disrupted Jet Stream: How Climate Change Puts Mid-West Tornadoes on Steriods

oklahoma-tornado

(Image source: Basehunters)

On Earth, there is no other tornado breeding ground like the US Mid-West. To the south, the Gulf of Mexico provides heat and moisture, to the north, Arctic air masses regularly plunge down over the heating plains of spring and summer, and to the west, mountains provide both dry air and instability. These features combine annually to spawn hundreds of tornadoes over this region.

In the more stable climate of the 20th century, risk posed by these powerful storms was a regular part of Mid-Western life. But now, with humans inducing the world’s climate system to rapidly change, the world’s most violent tornadoes are being put on the extreme weather equivalent of steroids. This amping up the atmosphere to produce more violent storms occurs through three processes: added heat, added moisture, alterations to the jet stream.

Tornado Fuel: Added Heat, Moisture, Instability and a Mangled Jet Stream

Since the 1880s, world temperatures have risen by .8 degrees Celsius. This increase is roughly equivalent to 1/6th the difference between now and the last ice age, but on the side of hot. Moreover, more than half of this increase has occurred over the past three decades. Added heat goes to providing more energy instability in the atmosphere and instability is one of the key ingredients of the supercell thunderstorms that spawn tornadoes.

Another key ingredient to thunderstorm strength is moisture. As the oceans warm, more moisture ends up in the atmosphere. This added moisture held aloft goes to feed many of the thunderstorms that do spawn, making them, on average, larger and more powerful. Larger and more powerful storms, like the 60,000 foot tall and 100 mile wide behemoth that pummeled Oklahoma last Friday, tend to spawn more destructive tornadoes.

The final ingredient adding to the strength of storms over the US Mid-West are changes to the polar jet stream. Over the past decade, massive losses of sea ice in the Arctic have led to a slowing of the polar jet stream. This slowing has caused the jet to, more and more often, stretch out in elongated wave patterns. These high amplitude meridonal waves (Rossby waves) reach higher into the Arctic and dip lower into the tropics. The result is that warm and cold air masses meet more often. This confluence of air masses further adds to the instability already created by higher temperatures.

The image of the jet stream below provides an illustration of this kind of amplified wave in the jet stream. It is exactly the kind of dip that emerged during mid-to-late spring of 2013 and has persisted through early June. While serving as a conveyer belt for the storms plaguing the Mid-West throughout this spring, it was also a source of enhanced atmospheric instability. One that has aided in the spawning of numerous severe tornado outbreaks.

jet stream map

(Image source: Climate Sight)

A Clear Record of Increasing Damage

In total, added heat, added moisture, and added instability, all elements caused by human global warming, increase the power of thunderstorms and the intensity of tornadoes. According to Dr. Kevin Trenberth, these changes have resulted in storms being more severe, adding about 5-10% to their intensity. This, in turn has had a compounding effect on thunderstorm and tornado damage.

Trenberth notes:

Warmer and moister conditions are the key for unstable air.

The climate change effect is probably… a 5 to 10 percent effect in terms of the instability and the subsequent rainfall, but it translates into up to a 32% effect in terms of damage.

(It is highly nonlinear).

Trenberth’s observations are born out in Munich Re damage assessments from thunderstorms over the past few decades. In fact, Munich Re tracking shows that Dr. Trenberth’s estimates may well be conservative. What Munich Re has found is that damage from thunderstorms has more than tripled since 1980 :

MunichRe1

(Image source: Munich Re)

More intense and severe thunderstorms result in more intense and severe tornadoes. These numbers and assessments by some of the world’s top climate and hazard experts have now been born out in one of the worst episodes of tornado damage in the US. It follows numerous similar episodes that have happened with greater and greater frequency over the past decade. And these events, most certainly, have been made worse by a combination of factors caused by climate change.

What To Expect: Increasing Periods of Intense Storms Broken Primarily by Drought

The heating of the atmosphere, its added moisture content, and the alterations to the northern polar jet stream will result in a number of severe impacts for the US Mid-West. The first is that we can expect the weather to, increasingly, whip-saw between extended periods of hot and dry weather back to periods of increasingly severe weather.

Such whip-sawing will be brought about by the increasing prevalence of high amplitude Rossby-type waves forming over the central US. During periods when the wave pattern is south to north, hot and dry conditions will dominate, leading to more extreme droughts and heat-waves. During periods when the wave pattern is north to south, stormy conditions will dominate, leading to more extreme floods and tornadoes.

This period will likely intensify over the next two to four decades until large pulses of Greenland melt dump massive volumes of cold water into the North Atlantic. At this time, weather will, likely, again shift into an even more extreme pattern dominated by massive and powerful frontal storms scouring the Northern Hemisphere.

These extreme events can be moderated, and possibly prevented, by a rapid reduction and elimination of worldwide greenhouse gas emissions. But under business as usual ‘growth,’ they are almost certain to continue to worsen.

Links:

Tornadoes, Extreme Weather, and Climate Change

Climate Change and Jet Stream

Munich Re Natural Disasters

Mangled Jet Stream Serves Up Scandinavian Heat Wave

Over the past three days, a northward bulge in the polar Jet Stream has resulted in extraordinarily high temperatures over a large region of Scandinavia and Russia north of the Arctic Circle.

In Arctic Utsjoki, Finland temperatures Friday reached a scorching 87 degrees Fahrenheit, the highest temperature ever recorded for that city. At Inari and Ylitornio, temperatures exceeded 84 degrees, also a record highs. Saturday saw a spreading of hot air north and eastward into Russia with regions within 50 miles of Arctic sea ice recording temperatures near 80 degrees Fahrenheit.

Thoughout this broad region, record or near record high temperatures were breached as a pulse of hot air expanded north and eastward. Temperatures in the 80s were common for an area whose average highs for this time of year range in the high 30s to mid 40s.

You can see this powerful concentration of hot air on the Arctic map below:

synNNWWarctis

(Image source: Uni Koeln)

See that vast region of pink in the lower left-hand corner of the map? There’s your heat wave.

Ever since 2007, loss of sea ice has had an increasing impact on the polar jet stream. Research first conducted by Dr. Jennifer Francis and confirmed by a growing body of climate scientists has found that loss of sea ice and summer snow cover results in a slower jet stream. This slowing of the jet causes it to dip and bulge in big north-south loops. This high amplitude meridonal flow can create blocking patterns that generate persistent weather over a given region. Where weather patterns may have lasted for days or weeks before, now they can last for months. Meanwhile, storms can also persist for longer periods over these regions.

A good explanation for this process is described by Dr. Francis in the below video:

A bulging blocking pattern in the region of Scandanavia and western Russia emerged last week and has since strengthened. This large bulge is dredging up and concentrating warmer air from the south and east and keeping it in place even as it gathers more heat.

You can see this bulge on the below map of the polar Jet Stream:

jetstream_norhem_00

(Image Source: California Regional Weather Service)

The large bulge extends up from Norway toward the Greenland coastline, then cuts across Svalbard before flowing down into Russia.

Northern Hemisphere Jet Stream a Complete Mess

A cursory examination of this Jet Stream’s disposition over the Northern Hemisphere gives testament to how much of a mess it is. Huge dips, breaks, and vortices in the circumpolar wind flow are now common. In large areas, the wind speed has slowed to a crawl, giving the Jet its broken and scattered appearance. One other feature of note, which I’ll examine more in another blog, is the large dip running down through the central US. The persistence of this dip has resulted in a very stormy spring for the US midwest, depositing record rainfall in many regions even as it spawned one of the most damaging tornadoes in US history. So this visibly mangled jet stream is also implicated in extremely severe weather outbreaks in the US midwest.

Weather forecasts show a continuation of the weather pattern currently involved in Scandinavia’s heat wave at least through this weekend. We’ll have to wait to see if conditions persist beyond the current forecast and whether or not this heat becomes an imbedded pattern for this region over late spring and early summer.

Echoes of 2008?

The current heat wave is a few days earlier, quite a bit hotter, and far more widespread than a similar heat-wave that occurred during June 2-10 of 2008. This particular heat wave appeared after the 2007 season of record melt hammered the sea ice. Since 2012 was also a period of record low ice, one wonders if this particular late spring heat wave is related to major sea ice losses seen last year.

NASA provides an in-depth explanation of the 2008 event here. As you can see from the map below, high temperatures during the heat wave five years ago were not quite as hot and no-where near so wide-spread.

neeurope_tmo_2008153

(Image source: NASA)

Indirect Implications For Sea Ice?

Forecast maps also show a finger of this warm air plunging deep into the Arctic. Should such an event occur, it could impact the sea ice from Svalbard and regions further north toward the pole. Models have shown the potential for temperatures of 5-10 degrees Celsius in this extreme northern region. Should high temps arise and persist, we can expect an accelerating impact on sea ice.

So long as hot air remains so wide-spread over Scandanavia and Russia, it can serve as a launching pad for warm air invasions of the Arctic as well as provide fuel for Arctic cyclones. So this weather situation is certainly one worth watching for potential future developments.

Links:

California Regional Weather Office

Uni-Koeln

Hurricane Sandy, The Storm that Climate Change Wrought; How Global Warming Made Sandy Far, Far Worse

(Earth. See that massive swirl of clouds with arms stretching up into the Arctic and back across the Atlantic Ocean? Yes, that’s Sandy.)

This year was already the worst extreme weather year ever recorded. Fires, heatwaves, a monster Derecho and a devastating drought together would have made 2012 one for the record books. The one saving grace, it seemed, was that hurricane season hadn’t significantly added to an already severe problem. That was before Hurricane Sandy slammed into the US Northeast causing what many think will be in the range of 10-20 billion dollars in damage. If total damage estimates exceed 20 billion, Sandy will be one of the five most costly hurricanes in US history.

Sandy was nothing if not unprecedented. Never has the Northeast seen this kind of storm so late in the season. Never has New York and New Jersey been subject to such a high level of ocean flooding over such a broad area. According to CNN’s chief meteorologist: “There’s no one that’s not 300 years old that has seen anything like this.” That’s just a finer way of saying that there is no record for a storm like Sandy ever occurring in this region of the country. And, in many cases, there’s no record for a storm like Sandy occurring period.

What made Sandy so unique? In two words: climate change. We’ve seen northeastern Atlantic Ocean storms where powerful troughs combine with hurricanes in ways that create a much stronger storm. The last time such a thing happened was during the 1991 ‘Perfect Storm.’ But that storm formed over the open waters of the Atlantic and only caused damage as it brushed New England with the powerful squall lines and heavy surf it cast off. In the case of Sandy, the Perfect Storm came ashore far further south and west than is usually possible.

Sandy’s Global Warming Ingredients

Since 1991, atmospheric changes and alterations to the Earth’s physical characteristics have been taking place that make storms like Sandy more and more possible. These ‘ingredients’ include increasing ocean temperatures, changes in the jet stream, and the receding boundary of Arctic Sea Ice.

To understand how these changes made it possible for a storm like Sandy to have such a devastating effect on the US Northeast and Mid-Atlantic so late in the season, it helps to follow the life of the storm that became Sandy…

Like so many other hurricanes, Sandy was born of the tropical Atlantic. She started as a pulse of thunderous rain storms swirling off the coast of Africa. This tropical wave slowly gathered energy from the hot tropical Atlantic as she moved west, gradually twisting into the classic coma shape as she entered the central Caribbean.

(GOES weather satellite Image of Sandy from October 22. Sandy is already large for a tropical system. But Sandy will soon grow even larger by combining with other storms to the north.)

Ocean heat content for the South Atlantic and Caribbean was abnormally high this year. Most of this added heat content came from human caused global warming. In many regions, temperatures were 2-3 degrees above average. This meant that, for a storm like Sandy, these waters were about as warm as they would have been two to three weeks earlier during a typical season of the 20th century. This added energy increased the likelihood that the storm would form in the first place. It also gave the storm more capacity to strengthen even in an environment of increased wind shear.

As Sandy tracked northward, she plowed through Jamaica and hopped over the eastern tip of Cuba. Maintaining significant strength as a category two storm, Sandy grew to a large size, boasting a tropical storm wind field in excess of five hundred miles in diameter. Hovering off the coast of Florida, Sandy was about to enter the second stage of her development.

Two systems to the north would play key roles in Sandy’s growth and path. Both were products of new ‘blocking patterns’ that have emerged as regular weather events during the past decade. ‘Blocking patterns’ occur when the jet stream makes deep swoops down from the Arctic and into the mid and lower latitudes. These swoops make giant wave-like patterns in the jet stream. They also create a huge amount of atmospheric inertia. The result is that weather patterns tend to be more persistent. In the under-belly of a blocking pattern, one can expect abnormally hot and dry conditions to persist over long periods of time. In the frontal down-slope of the blocking pattern, one can expect abnormally cool, wet, and stormy conditions. The peaks of these blocking patterns tap the tropics and the troughs tap the Arctic.

According to Dr. Jennifer Francis, these blocking patterns have emerged as a result of sea ice loss in the Arctic. The receding edge of the sea ice pulls air northward changing the shape of the jet stream from that of a rippling halo to that of a circle of sine waves.

The new blocking pattern that had established itself over the central US allowed a powerful cold front to sweep southward, both lending energy to Sandy via strong temperature and pressure gradients and steering Sandy first northward, then pulling her in toward the Mid-Atlantic coast. A second aspect of the blocking pattern emerged in the form of a new high pressure system that has tended to form recently over Greenland. This particular high pressure system blocked the path of Sandy northeastward, shoving Sandy back up against the frontal trough that ended up lending her so much strength.

(A visible satellite shot of Sandy beginning to combine with a powerful Arctic cold front. The massive trough of cold air is outlined in blue. Sandy is in the red circle. To the northeast is a blocking high backing in over Newfoundland. Note the extraordinary size of the combined trough and Sandy.)

As Sandy began to touch the trough’s strong, cooler winds, her tropical storm wind field spread out, eventually reaching 900 miles in diameter. In addition, Sandy found herself cloaked in the trough’s rain shield. This shield helped to prevent the worst effects of wind shear which, at times, was powerful enough to rip a normal storm apart.

Sandy’s encounter with the Arctic-born cold-air trough caused her to explode in size and as she moved north, she pummeled the Outer Banks of North Carolina and Coastal Virginia from 300 miles off shore. What strength she lost at her core was multiplied manifold in the expanding reach of her effect. North Carolina and Virginia coasts experienced impacts usually reserved for those in the direct path of a Hurricane — powerful winds, heavy rains, and storm surge flooding. Roads were washed out, dunes were breached, homes were flooded. Water rises exceeded seven feet in some places.

(Sandy taps hotter than normal Atlantic Ocean water in final rush to the coast. At this point, Sandy is the largest tropical cyclone ever recorded in the Atlantic Ocean.)

Yet Sandy was still hundreds of miles away, biding her time for the final rush to shore. And in this critical time period, global warming again played its hand. Sandy was now moving parallel to the Virginia coast. In normal years, water temperatures would begin to drop off here, sucking energy from the storm. This year, though, water temperatures had heated to 5 degrees Fahrenheit above normal through, the year after year, heat trapping effects of human emitted greenhouse gasses. Sandy drank deep from this added heat and, as the Arctic-born trough began to pull Sandy in to shore, she intensified.

Maximum sustained winds reached 90 mph, tropical storm force wind diameter reached 1000 miles, hurricane force wind diameter reached 200 miles, and the pressure fell to an unprecedented 940 millibars. Sandy was now a storm for the record books. A storm that was the largest tropical cyclone ever to form in the Atlantic. A storm never seen before in this region of the world. A storm powerful enough to push ocean water nearly a mile inland up and down the Jersey coast. A storm mighty enough to create a nearly 14 foot water rise in New York City.

Without climate change, the storm may not have formed in the first place, the storm probably wouldn’t have reached category 2 strength or grown to such a large size, the storm would have not combined with such a powerful trough sweeping so far south, the storm would have not been blocked from going out to sea by the new Greenland/Newfoundland high pressure, the storm would not have strengthened so far north over abnormally hot waters, and the storm would have not been pulled into the coastline by the powerful blocking pattern caused by melting sea ice.

Sandy was, in all ways, the storm that climate change wrought. And since the pattern is now established for this kind of storm to happen now, it is likely that this kind of ‘300 year storm’ will happen again. Almost certainly with growing force and almost certainly within the next decade or two.

I’ll leave you with the following quote from Time Magazine:

“Perhaps, if you are in your 60s or 70s or 80s, Sandy’s destructive forces are a once in your lifetime event. But younger generations—those of us in our fifties, and our children—will likely be looking at flooded coastal cities, devastated infrastructure, blownout power, and storm surges for the rest of our lives.”

(Graffiti scrawled on the side of a house flooded by Sandy. Image credit: here.)

Links:

http://science.time.com/2012/10/30/climate-change-and-sandy-why-we-need-to-prepare-for-a-warmer-world/

http://www.newyorker.com/online/blogs/newsdesk/2012/10/watching-hurricane-sandy-ignoring-climate-change.html

http://blogs.scientificamerican.com/observations/2012/10/30/did-climate-change-cause-hurricane-sandy/

http://www.huffingtonpost.com/sunita-narain/sandy-climate-change_b_2044339.html

NOAA’s Global Warning: Arctic Tipping Point Reached, Extreme Weather, Rapid Melt, Ecological Damage to Follow

For years now, scientists have been concerned that a global warming tipping point would soon be reached in the Arctic. The worry was that heat would eventually erode the Arctic’s ability to self-insulate. Once this happened, a number of feedbacks would come into play that not only more rapidly increase warming in the Arctic, but that accelerate warming on a global scale.

Now, in a study that can only be called a bombshell, NOAA is saying that we are past the tipping point and an age of unprecedented global change is to follow. The study, entitled “The Recent Shift in Early Summer Arctic Atmospheric Circulation,” examines how wind patterns have changed in the Arctic. It shows that winds which once blew from east to west have now consistently altered to a north-south orientation.

The study notes that these wind changes have been brought on by an erosion of Arctic sea ice. This loss results in a climate impact that pushes the polar jet stream into its new orientation. That new orientation transports warm air into the Arctic environment from the south accelerating the loss of sea ice and creating a dangerous situation of amplifying Greenland ice melt and rapidly accelerating changes to the Arctic environment.

The NOAA press release stated:

“Our research reveals a change in the summer Arctic wind pattern over the past six years. This shift demonstrates a physical connection between reduced Arctic sea ice in the summer, loss of Greenland ice, and potentially, weather in North America and Europe,” said Overland, a NOAA research oceanographer.

The shift provides additional evidence that changes in the Arctic are not only directly because of global warming, as shown by warmer air and sea temperatures, but are also part of an “Arctic amplification” through which multiple Arctic-specific physical processes interact to accelerate temperature change, ice variability, and ecological impacts.

The bolded line is very word and detail dense. In short, what it amounts to is a sort of scientific primal scream.

I’ll do my best to summarize for you.

The first point is that the Arctic is being impacted by global warming, which is increasing Arctic melt. This results in hotter sea and air temperatures.

But the second and most critical point is that the Arctic changes are also part of what is called Arctic amplification. Arctic amplification is a kind of tipping point that, when reached, the physical nature of the Arctic is such that it creates a heating feedback loop. The qualities of the Arctic that cause such a feedback include: the change in wind patterns dredging hot air up from the south, the loss of ice and snow reflectivity or albedo, and the increased production of methane from melting tundra and warming seas.

In short, what NOAA is saying is that now not only will the melt rates in the Arctic increase, but the rates of temperature rise in the Arctic and around the world will likely start to increase as well. Further, these changes are likely to result in severe weather extremes the likes of which we are completely unaccustomed to. I’ll repeat the relevant part of the bolded line by restating that changes in the Arctic, according to NOAA, will accelerate temperature change, ice variability, and ecological impacts.

This is NOAA’s way of saying it’s likely going to get hotter faster, the ice will likely melt faster, and more of Earth’s life, including humans, will be impacted.

NOAA’s research follows a ground-breaking study recently published by Jennifer Francis of Rutgers which identified the changes in wind patterns and noted that these changes created a high risk of extreme weather in the temperate zones. To this point, Francis noted:

“What we’re seeing is stark evidence that the gradual temperature increase is not the important story related to climate change; it’s the rapid regional changes and increased frequency of extreme weather that global warming is causing. As the Arctic warms at twice the global rate, we expect an increased probability of extreme weather events across the temperate latitudes of the northern hemisphere, where billions of people live,” said Jennifer Francis, Ph.D, of Rutgers.

The pace of change is increasing and with each new study stark revelations are being made about how the Arctic is falling into a phase of rapid warming and radical change. The results of this transition will be that humans will experience changes with a speed not seen since the first days of civilization. These changes were preventable. But we did not reduce our use of fossil fuels fast enough. Now, the best response will be a rapid transition to renewable energy and away from fossil fuels lest we further aggravate a situation that is already very dangerous.

Links:

http://www.noaanews.noaa.gov/stories2012/20121010_arcticwinds.html

http://thinkprogress.org/climate/2012/10/11/989231/noaa-bombshell-warming-driven-arctic-ice-loss-is-boosting-chance-of-extreme-us-weather/

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