Blog about UN Climate Change Conference in Bali 3-14 December 2007 and other related issues

Sunday, May 11, 2008

Antarctic Temperatures Lower in Contrast to Climate Change Computer Models

In a recent paper published by researchers at the National Center for Atmospheric Research, scientists report that computer models of climate change specific to the Antarctic may not be as accurate as they were originally believed. Computer models based on data of Earth’s climate help scientists make predictions of climate change over time. From these mathematical models, scientist run simulations based on data collected in order to assess potential outcomes such as warming or cooling trends around the Earth. While computer models representing climate in the other continents are accurately depicting the phenomenon of increasing temperatures, the models used in Antarctica inaccurately point to larger increases in temperatures than is actually being observed. (The models show an increase of 1.4 degrees Fahrenheit or 0.2 degrees Celsius in the Antarctic versus the actual increase of 0.4 degrees Fahrenheit or 0.75 degrees Celsius).
Why the discrepancy in the Antarctic? Scientists point to a number of reasons, all of which are excellent examples to show students the ongoing investigative nature of scientific study. For starters, the conditions in Antarctica make it difficult to take weather readings (or any kind of readings for that matter) in the first place. This recent report came as a result of improved measurements in the Antarctic region that will provide more accurate data in the future. Using ice core data samples and the increased ability to take actual climate observations and comparing these to the models gives scientists a better idea of how these data compare. That said, scientists still caution that the models used today still may not be as accurate as they are in other parts of the world. NCAR scientist David Schneider states, “The current generation of climate models has improved over previous generations, but still leaves Antarctic surface temperature projections for the 21st century with a high degree of uncertainty.”
Another factor in the discrepancy between models and actual data deals with the ozone hole over Antarctica. Because of the hole, the upper layers of atmosphere over Antarctica are cooler, creating cooler temperatures in the central part of the continent. This is in contrast to warming trends in other continents, as well as the warming trend in the Antarctic Peninsula. This cooler air reduces the amount of water vapor present, something that the computer models point to as a source of increase temperatures in the region that are in contrast to actual readings.
Scientist Andrew Monaghan, a co-author of this recent report, states, “We can now compare computer simulations with observations of actual climate trends in Antarctica. This is showing us that, over the past century, most of Antarctica has not undergone the fairly dramatic warming that has affected the rest of the globe. The challenges of studying climate in this remote environment make it difficult to say what the future holds for Antarctica’s climate.”

Dr. Monaghan is a guest columnist for the upcoming June issue (Weather and Climate: From Home to the Poles) of Beyond Penguins and Polar Bears.

Source: expertvoices

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