Another Hit for the Climate Models
Its not everyday that the climate models take it on the proverbial chin. It just seems like it. In a paper presented at the Annual Meeting of the American Meteorological Society, Dr. Junhong Wang with the National Center of Atmospheric Research discussed his research teams findings that the amount of water vapor in the upper atmosphere is much greater than previously thought at least over Oklahoma and Kansas.
The researchers have built a new radiosonde instrument, called Snow White (SW), which measures relative humidity more accurately than the old instruments, which have been the basis for all upper atmosphere climate records. The new radiosonde will serve as the new reference case from which all previous measurements will be calibrated.
In test runs over Kansas and Oklahoma, the researchers found that below six kilometers the old and new radiosondes agree reasonably well but then diverge at altitudes above six kilometers. At about 11.4 to 12.7 kilometers, SW found a supersaturation layer, which could be the cirrus cloud layer. Previous measurements found relative humidity of below 30 percent.
This finding is important because high altitude cirrus clouds do not block sunlight, indeed they are often invisible to the naked eye, but very efficiently block outgoing infrared radiation (heat), causing a net warming. Where humidity is high, however, the relative effect of greenhouse gases, such as carbon dioxide, on temperature is smaller than in low humidity areas.
Thats why most anthropogenic warming is predicted to take place in extraordinarily dry (and cold) regions such as Siberia. If the humidity data used in a computer model is too low, then the model will overestimate the effect of greenhouse gases. And, the climate models will predict too much warming. The paper is available at www.ametsoc.org/AMS/index.html.
Melting in Arctic May be Natural
Researchers from the Norwegian Polar Institute and the Norwegian Meteorological Institute have compiled data from the ship logs of early Arctic explorers and whalers to determine the sea ice extent from 1553 to 2002.
What they have found is that the current retreat of ice observed in the Arctic occurred before in the early 1700s. While this evidence doesnt rule out that the current melting is due to mans greenhouse gas emissions, it certainly suggests that it may be entirely natural. “If you go back to the early 1700s you find that sea ice extent was about the same as it is now,” said Chad Dick of the Arctic Climate Systems Study.
The researchers also found that sea ice has declined by about 33 percent over the past 135 years, but that most of that retreat occurred before significant manmade emissions of greenhouse gases. This also means that the current melting could be due to natural cycles. “The evidence at the moment is fairly inconclusive,” said Mr. Dick. “The fact is there are natural cycles in sea ice extent and were not outside the range of those natural cycles at the moment.”
Mr. Dick also noted that if the current warming is indeed due to natural cycles, we should begin to see ice thickening again in the near future. It will take about ten more years at the current rate of thinning to get beyond the range that wed expect if the decline in sea ice is due to natural cycles (Globe and Mail, February 27, 2003). The World Wildlife Fund is publishing the sea charts on CD-ROM (www.panda.org).