Observation and model comparison of the thermodynamic environment using the microwave radiometer profiler

Poster PDF

Description

It is anticipated that the knowledge gained through analysis of ARM Mobile Facility (AMF) observations will be utilized by efforts to increase the accuracy of global climate models (GCMs) in under-sampled regions of interest. In pursuit of one such effort, the purpose of this study is to investigate the feasibility and utility of observation and model comparisons that employ thermodynamic profiles derived from the AMF’s 12-channel microwave radiometer profiler (MWRP) to assess the profiles generated by GCMs in the corresponding vertical column of grid cells. Although radiosondes are widely accepted as the preferred instrument for obtaining atmospheric profiles, they are not suitable for the present application because assimilation techniques are required to resolve the scales discordance between radiosonde launches and GCM time steps. Profiles with spatial and temporal characteristics that are appropriate for comparison with GCM output are available, however, from the MWRP. To demonstrate the accuracy and capability of radiometric retrievals for the present application, profiles obtained from the MWRP are compared with radiosonde soundings from the one-year AMF deployment in Niamey, Niger, in 2006. Key variables that characterize the thermodynamic environment are then used to assess the performance of four GCMs. Analyses of the links between clouds, precipitation, and the thermodynamic environment are explored and are found to have the potential to provide a unique and valuable opportunity to assess the performance of parameterized physics in GCMs.