2008 MAR 17 - (VerticalNews.com) -- "A satellite-derived (NOAA Advanced Very High Resolution Radiometer) cloud climatology over the Scandinavian region covering the period 1991 - 2001 has been used to evaluate the performance of cloud simulations of the Swedish Meteorological and Hydrological Institute Rossby Centre regional climate model (RCA3). Several methods of adapting the satellite and model data sets to allow a meaningful comparison were applied," scientists writing in the Journal of Geophysical Research - Atmospheres report ...read more

  2008 MAR 3 - (VerticalNews.com) -- "In this paper we discuss temperature anomalies that develop in the shallow subsurface as a result of localized deforestation in combination with shallow horizontal groundwater flow. Model results show how a patch-wise pattern of deforestation at the surface induces significant lateral temperature gradients in the subsurface," scientists in Norwich, the United Kingdom report.

  "Results also indicate that lateral heat transport by advection via horizontal groundwater flow becomes significant above flow rates of about 10(-8) m/s. In a steady state situation, reached 1750 a after deforestation, an anomaly of 0.1 K is still present at a distance of similar to 2.5 km downstream of the deforested patch at depths between 200 and 575 m for horizontal groundwater flow velocities between 10(-7) m/s and 10(-8) m/s, respectively. We carried out transient simulations to examine the impact of deforestation on subsurface temperatures during the last century. These experiments include a study of the effects of regional surface warming on the thermal regime of the subsurface. In these scenarios, 100 a after localized deforestation, significant temperature anomalies occur hundreds of meters downstream of the deforested areas. Results show that ground surface temperature history reconstructions based upon synthetic temperature versus depth profiles up- and downstream of the deforested patches fail to recover the timing and magnitude of the warming event imposed at the surface," wrote V. Bense and colleagues, University of East Anglia ...read more

  2008 FEB 18 - (VerticalNews.com) -- According to a study from the United States, "Daily ozonesondes were launched from 14 North American sites during August 2006, providing the best set of free tropospheric ozone measurements ever gathered across the continent in a single season. The data reveal a distinct upper tropospheric ozone maximum above eastern North America and centered over the southeastern USA."

  "Recurring each year, the location and strength of the ozone maximum is influenced by the summertime upper tropospheric anticyclone that traps convectively lofted ozone, ozone precursors and lightning NOx above the southeastern USA. The North American summer monsoon that flows northward along the Rocky Mountains is embedded within the western side of the anticyclone and also marks the westernmost extent of the ozone maximum. Removing the influence from stratospheric intrusions, median ozone mixing ratios (78 ppbv) in the upper troposphere (> 6 km) above Alabama, near the center of the anticyclone, were nearly twice the level above the U. S. west coast. Simulations by an atmospheric chemistry general circulation model indicate lightning NOx emissions led to the production of 25-30 ppbv of ozone at 250 hPa above the southern United States during the study period," wrote O.R. Cooper and colleagues, National Oceanic and Atmospheric Administration ...read more