Accuracy of Water Temperature Measurements cont.
This is a quote from research by Uni of Alabama and and UK met (Differential trends in tropical sea surface and atmospheric temperatures since 1979 published Geophysical Research Letters 2001
http://www.agu.org/pubs/crossref/2001.../1999GL011167.shtml) regarding accurate water temperature readings as they relate to sea temperatures. You can go to either sites to read the full studies, which is pretty detailed.
"The authors looked at the tropicswide difference between the sea water temperatures and upper air temperatures not only from the satellite data but from balloons and global weather maps. All three records indicated the tropical air between the surface and five miles actually cooled at a rate of about 0.05 degrees C per decade, while the sea water was warming by about 0.13 degrees C per decade."
The disparity is clearly a problem for those that rely on such data to "prove" global warming.
The study is interesting because it also looks at just how water temperature figures have been gathered and such things as whether this is a good indicator of air temperatures.
I rather like the summary of this study because it is precisely on point to Daniel's suggestion that water temperatures are the key to determining global warming. To quote some more:
"The supposed link between sea surface temperatures and air temperatures is an integral part of both the historic surface temperature record and the computerized models used to predict what Earth's climate might do in the future.
Because reliable low-level air temperature data from over the oceans are more scarce and more difficult to assess than water temperatures, scientists monitoring Earth's climate have used sea surface temperatures as a proxy for air temperatures, assuming that the two rise and fall proportionally.
"We found that in the short term, they go up and down essentially simultaneously," said Christy. "Over the long term, however, we start to see differences.""
And just how bad are the long term records. Again I quote from the study:
"By comparison, much of the historic sea water temperature record was generated by military and commercial ships, which recorded the temperature of sea water as it was taken aboard as an engine coolant. While calculated into the temperature record as sea "surface" temperatures, most modern ships draw in cooling water from as much as ten meters below the surface."
Now this is not a study that was designed by those that do not agree with global warming. Far from it, the authors still conclude that they was a warming trend of about 0.06 degrees per decade in the tropics but the study was one that was specifically aimed at looking at just how accurate modelling was for global warming studies using very accurate measurments both above and below the water. Since 0.06 degrees is not a great deal and the measurements only go back 20 years (pretty much the same as for satellites which show an overall warming trend of 0.045 degrees per decade for that period) all anyone can conclude from this is for twenty years the earth has warmed a tiny bit. Since we know it cooled substantially twice in the last century (although by how much there is nothing accurate enough to really say), such warming really is an indication of nothing other than proof of a warming fluctuation, IMHO.
Regards
Richard
