Assimilating data from a simulated global constellation of stratospheric balloons

Abstract

AbstractIn order to evaluate the effect of assimilating data from proposed stratospheric balloon networks, a variation of the standard Observation Systems Simulation Experiment (OSSE), called a Partial (or Poor‐man's) OSSE, was developed. This technique was used to assimilate five different simulated balloon constellations. Increasing the constellation density increased the analysis and forecast accuracy, predominately near the balloon flight level (30 hPa) in the tropics and throughout the depth of the stratosphere at higher latitudes. However, the potential impact may be greater, since the saturation point, where assimilating extra observations produces no additional analysis benefit, was not reached for the range of constellation densities tested. Unrealistic analysis increments were produced during a sudden stratospheric warming period. This weakness arises from the use of climatological background‐error statistics in assimilation schemes. Overall, the results are very encouraging and suggest that proposals to add a permanent constellation of stratospheric balloons to the global observing system are realistic and beneficial to the scientific community. © Crown copyright, 2004. Royal Meteorological Society