The Arctic and Subarctic Winter Temperature Inversion Layers as seen by GPSRO

The earth radiation balance is significantly affected by the ubiquitous presence of the atmospheric boundary layer (ABL). This region of the atmosphere plays a fundamental role in coupling the atmospheric flows to land and ocean surfaces and regulating radiative and turbulent flux exchanges. In winter, the high latitude ABL remains mostly in stable phase due to the absence of diurnal cycle while experiencing some periods under neutral conditions. Depending upon synoptic flow, deep and steeped temperature inversion layers can be present. These layers are called Elevated Temperature Inversion Layers (EI) to differentiate them from the locally developed Surface Based Inversion (SBI) layer, whose temperature inversion base is anchored at the surface.

This week’s Lunch Lecturer Dr. Javier Fochesatto will give an analysis of GPS-Radio Occultation (GPSRO) datasets and comparison to radiosonde observations (RAOBS) from October 01 to March 31 of each winter season from 2006 to 2015 will be presented. GPSRO sounding having the deepest penetration level close to surface were considered in a region of 4o by 4o centered in Fairbanks and Barrow stations in Alaska.

The GPSRO statistical sampling of SBIs and EIs inversions layers was analyzed using RAOBS information and was scrutinized for anticyclone and cyclone driven EI layers. This seminar describes convergences and divergences obtained in the density distributions when comparison between localized RAOBS and spatially distributed GPSRO data. We prove that the more likely sampling parameter when using GPSRO in Arctic and subarctic continental atmospheres is for EI layers.

Dr. Fochesatto is Associate Professor of Atmospheric Sciences at the Geophysical Institute & College of Natural Science and Mathematics at the University of Alaska Fairbanks and Deputy Group Leader Geophysical Institute Atmospheric Science Research Group. Dr. Fochesatto is editor of the Journal of Atmospheric and Oceanic Technology, American Meteorological Society. Among his present research interests are Land-Surface interaction and Atmospheric Coupling across Spatial and Time Scales, Atmospheric Boundary Layer Turbulence, Composition, Dynamics and Meteorology, Micrometeorology. Eddy-Covariance, Laser Scintillometry and Lidar Spectroscopy, Biogeochemical Cycles in High Latitudes and Polar Meteorology.

This semester, Dr. Fochesatto teaches the Methods of Global Climate Change course on the Climate Change and Global Sustainability program, a new graduate program run in collaboration between the the School for International Training (SIT), Vermont USA, and the University Centre of the Westfjords. 

Lunch Lectures take place in the University Centre cafeteria 12:10-13 and are open to all.