The Increasing Benefit to NWP from Higher Resolution Earth Observations from Space

In recent experiments the importance and economic value of earth observations from space (EOS) have been documented. For example in a study using both the NCEP and Australian operational forecast systems the life of a high quality numerical forecast is extended by a factor of four over the southern hemisphere by using EOS. That is a one-day operational forecast not using satellite data is of the same quality as a four-day operational forecast which used satellite data when both are verified against the all data (satellite) analysis. Considerable benefit has also been documented in the northern hemisphere. The importance of EOS for extreme weather prediction such as tropical Cyclone and heavy rainfall forecasting has also been shown.

Increasingly, technology development has enabled higher spatial temporal and spectral resolution observations from space and this has resulted in more accurate, higher resolution inferred geophysical parameters and more accurate forecasts. Here we examine the benefit of these high resolution observations in areas such as current and future hyperspectral infrared sounding, microwave sounding, radio occultation sounding and high resolution wind estimation from space. We show the considerable benefit from the high resolution observations from instruments such as AIRS, IASI, CrIS and Himawari and the potential to improve current capability by both extended use of the current observational capacity and by use of future high resolution observation platforms. For example in the case of hyperspectral infrared sounding the benefits of using increased channel numbers, cloudy radiance data and accurate estimates of the emissivity will be shown (Noting for instance the accurate estimate of emissivity requires an increased availability of surface viewing channels). In the case of microwave sounding, radio occultation sounding and high resolution wind estimation, again the link between high resolution observations and high quality forecasts has been established. Examples of these will also be provided.

In summary EOS form a vital part of NWP and climate monitoring. The benefits now being demonstrated by the improving spatial spectral and temporal resolution observations available from current and future space-based platforms indicate considerable potential for providing significant increase in social and economic benefits to the community.