An article in the November 1, 2005 Integrated Land Ecosystem-Atmosphere Processes Study (iLEAPS) Newsletter by Professor Bert Holtslag of Wageningen University in the Netherlands entitled âStable boundary layers and land surface climateâ? summarizes serious difficulties in the accurate representation of near surface processes at night, including temperature. This topic was presented with further updates by Professor Holtslag at the iLEAPS meeting this week in Boulder, Colorado.
The abstract states,
âGABLS refers to the GEWEX Atmospheric Boundary Layer Study. The project aims to improve the understanding and the representation of the atmospheric boundary layer in regional and large-scale climate models. Results of a recent GABLS model intercomparison highlighted large model errors due to an inadequate representation of small-scale and near surface processes. These errors effect prediction of local and regional representations of land-atmosphere exchange and may impact on global scale climate studies as well.â?
The identification of this problem with climate models provides further support for the conclusion made in the January 23 2006 weblog that,
âThis raises the possibility that those GCMs that appear to accurately represent global average temperature trends over recent decades may be obtaining results that look right when compared to data, but for the wrong physical reasons. If so, this would call into question their ability to accurately predict the future evolution of the climate system.â?
There are significant remaining uncertainties in the modeling of long-term surface temperature trends, as well as uncertainties in the accurate observational monitoring of these trends.