(Image source: NOAA)
ENSO, the global regulator for, generally, how much heat the world ocean system dumps into the atmosphere, remained on the cool side of neutral for much of August 2013. Ocean surface temperatures in the Eastern Equatorial Pacific remained 1 to 2 degrees Celsius below the 1981-2010 average for most of the month. In a normal year, such departures would tend to depress both global ocean and land surface temperature averages. But, for the world’s global oceans and related land atmospheric system, all was well outside the range of normal.
For beyond the Eastern Equatorial Pacific, most of the world’s oceans ranged from .5 C to up to 4 C hotter than average. A particularly hot region dominated an area east of Shanghai in the Pacific bordering China, Japan and the Korean Peninsula. The hot surface water extended under the powerful influence of an anomalous heat dome that brought dangerous 100-110+ degree (F) temperatures to these countries throughout much of August. This hot zone stretched eastward across the Pacific and on toward the US west Coast — a vast swath of water measuring 2-4 C hotter than the 1981 to 2010 average for much of the month.
These anomalously hot conditions outside of the region normally responsible for governing ocean temperature trends resulted in global ocean temperatures tying 2009 for the record high of .57 degrees Celsius above the global average. But 2009 was an El Nino year. With the Eastern Pacific remaining rather cool, one has to wonder what the hell is going on? Everywhere but in the Eastern Pacific, the ocean surface appears to have heated up. The more rapidly spinning gyres and the greater rate of up welling aren’t doing their usual job of cooling down both the ocean surface and the Earth’s atmosphere. For August, record hot ocean surface temperatures pushed global averages higher. Should ENSO switch to hot under such conditions — prepare for world temperature records to start dropping like dominoes.
Land-Ocean 4th Hottest on Record
All that said, It appears the huge volume of water vapor dredged up from the record hot oceans had done its work in marginally cooling off the continents. Heat pumped huge volumes of ocean water into the atmosphere where it formed powerful storm systems that, during event after event, dumped record amounts of rain. In deluge after deluge, regions saw 100, 200, 500 and even 1000 year floods. The most recent, in Colorado, resulted in thousands of homes lost, tens of thousands displaced, and yet one more major disaster response effort from the US federal government. The US inundation was mirrored this summer by events in the Amur region of Russia and China, massive rainstorms spurring a deadly glacial outburst flood event in India, record floods in Canada, immense floods in Europe, major floods in Pakistan, and a consistent set of record floods striking the central and Eastern US. If we hadn’t also seen major floods in 2009 and 2010, we could call 2013 the year of the flood. Others are calling such events ‘the new normal.’ But normal it is not.
All this rainfall over the world’s continents appears to have resulted in land surface temperatures ‘only’ in the range of 11th hottest on record with land surface temperatures at .62 C hotter than the 20th Century average (NOAA/NCDC). These record hot temperatures combined with all time hot ocean temperatures to make August 2013 the 4th hottest in the 134 year climate record.
Ocean Heat/Moisture Dump Showing Up in Sea Level Record
Whenever the oceans heat up, we begin to see evaporation and rainfall rates rising. Record flood events over the Continents is just one visible effect of this heightened rate of evaporation. It is now also starting to show up as large cyclical dips in the rate of sea level rise. Note the start of this volatile shark tooth pattern in the graph, provided by AVISO, below:
(Image source: AVISO)
In the above graph we can clearly see the large counter-trend drop in sea level during the major flood events of 2010 (See “It Rained So Hard The Oceans Fell“). Subsequent very rapid sea level rise from 2011 to end 2012 easily made up the difference, keeping ocean rise on the 3.19 mm per year track its been following over the past couple of decades. By 2013, a similar ocean to atmosphere to land-mass water dump became again visible in the sea level charts. Observed major flood events throughout 2013 provide a final corroboration of this massive and volatile amplification of the water cycle.
The Ocean-Atmosphere-Cyrosphere system appears to be moving into a period of wider and more powerful fluctuations. The hydrological cycle, primarily governed by the pace of ocean water evaporation and rate of rainfall, is receiving larger moisture dumps from heating seas. As such, it is beginning to encounter periods of extreme rainfall during major evaporation years. Record ocean heat, a primary driver to this amplified and erratic hydrological cycle, is increasingly occurring outside of the typical pattern of hot El Nino and cool La Nina cycles. The fact that we have record ocean warmth during an ENSO neutral pattern that is leaning toward cool is yet one more out of boundary condition and should be cause for serious concern.
Any return to El Nino conditions will likely result in larger volumes of heat transferred from Ocean to atmosphere. With global temperatures testing new limits even as the Equatorial Pacific remains cool, we can only surmise that any new return to ENSO will result in another leap to record hot conditions.