Characteristics of radiosonde observations and their impact in satellite sounding product validation

Conventional radiosonde observations (RAOBs) from global operational upper air network have historically been used as a commonly accepted ground-truth data set in satellite measurements and derived products monitoring and validation. Issues, however, may be present in this application, in terms of RAOB measurement quality and the consistency of RAOB profile resolution/atmospheric structure with expected satellite sensor sensitivity.

In this work, we provide a summary of the major characteristics of RAOB data based on the analysis of three years (2010-2012) of global RAOB collocations with NOAA IASI/AMSU retrieval profiles collected at the NOAA Products Validation System (NPROVS), a near-real-time satellite EDR monitoring/validation system, supported by the NOAA Joint Polar Satellite System (JPSS). These include the overall accuracy of RAOB temperature and humidity measurements and the capability of RAOB profiles to detect atmospheric structure features including surface temperature inversion, planetary boundary layer height and tropopause height of interest in satellite product applications in weather monitoring and forecasting. We show how these characteristics are reflected in satellite product evaluation and in their consistency with expected satellite sensor sensitivity and constraints. We also show the overall usefulness of conventional RAOBS in satellite product validation by assessing the thermodynamic relationship between cloud, temperature and humidity in the NOAA IASI/AMSU sounding retrieval system (also adopted for Suomi-NPP NOAA-Unique CrIS/ATMS Processing System, NUCAPS).