Assessing the Value of Satellite Observations as Part of an IR Sounder Concept for NOAA Satellite Observing System Architecture (NSOSA) Study

Satellite observations are routinely assimilated into numerical weather prediction models to improve the initial conditions and ultimately the forecast. Experimental designs to assess the value of satellite observations in a numerical forecast include Observing System Simulation Experiments (OSSE), Observing System Experiments (OSE) and Forecast Sensitivity and Observation Impact (FSOI) studies. In this work we use an OSE to perform a focused and relatively rapid-turnaround investigation of the implications of an IR sounder to proposed architectures with IR/GSST and IR/LSST platforms. We utilize the Weather Research and Forecasting (WRF) numerical model to explore the sensitivity of 24-hour forecasts over the CONUS to shortwave IR sounder data from IASI. The MIT Lincoln Laboratory supercomputer was used to perform a one-month OSE in which a series of forecasts was run that assimilated all available observations and these forecasts were compared to forecasts with IASI shortwave IR data withheld from the data assimilation. The inclusion of the IASI shortwave IR measurements resulted in reductions in forecast error for temperature and moisture in the lower troposphere and for winds in the mid-troposphere. The impact of the shortwave IR observations was greatest for six-hour forecasts and the least for the 24-hour forecasts. The OSE results and the use of focused data assessment studies in the context of proposed architectures will be discussed.

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This material is based upon work supported by the National Oceanic and Atmospheric Administration under Air Force Contract No. FA8721-05-C-0002 and/or FA8702-15-D-0001. Any opinions, findings, conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Oceanic and Atmospheric Administration.