This is a quick attempt to summarize what appears to have happened (is happening) in the North Atlantic Ocean
based on data published on the web page
www.climate4you.com/Heat content anomalies in GJ/m2, 0-700 m depth for 1979-2015 are published for three major geographic subareas in the
North Atlantic. These cover areas from the equator east of 60 degrees W to the Arctic east of 20 degrees W. The Arctic is divided
into 3 area: the E. Greenland Sea, the W. Swalbard Sea, and the W. Barents Sea. From the equator north, these are ...
1. Equatorial N. Atlantic - 30-60 degrees west, 5-20 degrees north.
2. North Atlantic - 0-60 degrees west, 30-65 degrees north.
3. Arctic Gateway Seas - 20 degrees west - 40 degrees east, 70-80 degrees north.
East Greenland Sea - 0-20 degrees west, 70-80 degrees north
West Svalbard Sea - 0-20 degrees east, 70-80 degrees north
West Barents Sea - 20-40 degrees east, 70-80 degrees north
Number one above was on the web site as of a few days ago, but is not currently ... but I copied the data then.
I have no data for the North Atlantic west of 60 degrees west, the Caribbean Sea and the Gulf of Mexico. Since these data
are derived from continuous numeric measures, the change in their anomalies from their means are also continuous.
Current temperature in degrees C from Argo data for 0-800 m depths along a transect 0-30 west at 59 degrees north
for 2004-2015. This transect is located along the northern edge of area number 2 above.
So what has happened?
1. The heat content anomalies of all the above areas increased from 1979 to between 2005 and 2011 and have
declined or remained relatively steady since. The following represent visual approximations of chart values.
The
North Atlantic anomaly increased steadily from -0.5 in 1979 to 1.2 in 2006; an avg. annual increase of 0.06
per year. Since 2006 it has decreased from 1.2 to 0.4; an avg. annual decrease of -0.09, or 1.5 times the
previous increment of increase. This corresponds with what we've seen in the emerging 'blue blob' and what is being
published regarding the emerging negative AMO.
The
current temperature transect embedded in this are has declined from 8.8 C in 2005 to ~7.8 C in 2015.
The
Equatorial North Atlantic anomaly increased from -0.4 in 1985 to 0.5 in 2011; an avg. annual increase of
0.04. Since 2011 it has decreased from 0.5 to -0.2; and avg. annual decrease of -0.18, or 4 times the previous
increment of increase. This corresponds with what we saw in the extension of the 'blue blob' into the equatorial areas
of the North Atlantic earlier in the year. Surely someone can explain better than me why, and via what mechanisms'
this area of the Atlantic is going cold.
The
Arctic Gateway Seas anomalies for its three sub-areas increased to about 1.0 by 2005-2007. There is an
eastward regression in their 1979 starting values from 0 degrees C in the East Greenland Sea, to -0.5 degrees C
in the west Swalbard Sea, to -1.0 degrees C in the west Barents Sea. This likely has something to do with the
mean heat content value across the 1955-2015 base period, but my brain is too cloudy right now to tackle the
explanation
However, since the 2005-2007 peak anomaly year, the W. Swalbard Sea and W. Barents Sea
have declined only slightly, while the E. Greenland Sea has remained relatively flat.
This is curious as the current-driven waters that supposedly feed this area have been declining rather dramatically.
Is there another heating source in these areas?
Perhaps of geothermal origin??? Or does any one have
another explanation?
The
Western Atlantic-Caribbean-Gulf of Mexico area has no similar data posted on Climate4you. We know
from looking at the anomaly maps that these are currently well above the average in many areas.
Where is this heat
going??? And for that matter ... where is it coming from? Without comparison values similar to the ones put
together for the other areas, I simply may not be catching changes visually ... but, how can these anomalies
stay so high when their source areas(?), the Equatorial North Atlantic(?) seem to have cooled? Confusing!
Perhaps there are heat content or temperature data available from the the instrumentation arrays across the
Florida Straights and eastward, but I don't remember seeing any.