Straw-person:The impact of new in-situ observations in a world crowdedwith satellite data.Tom Hamill
Concerns • Do cost / benefit of field programs vs. other ways of spending THORPEX funds. Do field programs only to extent they’re a research bargain. • Non-parochial: need to have field program that will garner international support and participation. Proceed under assumption that the following is of value
The impact of new in-situ observations in a world crowdedwith satellite data.
If we add no new in-situ, what will be the changes to NWP 10 years hence? Presumably better, because … • New satellite platforms • Hyperspectral sounders • GPS-Met occultations • … many more. • Better models and assimilation systems • Higher resolution, less representativeness error • Better fidelity, better background forecasts. • 4D-Var with weak constraint, allowing model errors
Then again … • New systems still mostly will observe where the clouds are not. • Tough to develop efficient H operators, so a new satellite doesn’t necessarily mean new obs into NWP models • Singular-vector (energy norm) literature suggests that crucial errors are often in the cloudy, precipitating baroclinic zones.
Will new in-situ have the impact 10 years hence they do now? • Assumption: Only “cheap” new in-situ platforms are likely to be deployed. • Hypothesis: Cheap in-situ platforms will still have a substantial impact on forecast accuracy 10 years hence, when flooded with sounder data.
Proposed program • Method: limited field program with cheap observations. • Extensive OSSE development so they provide realistic assessments of observation impact. • Compare/validate impact from OSSEs to impact from real observations. • OSSEs of impact given network 10 years hence.