1. Opportunities for Satellite Observations in Validation and Assessment Barbara Brown NCAR/RAL 19 November 2008

2. Importance of validation and assessment for aviation safety Why evaluate forecast performance? For developers: For developers: Improve forecasts, NWP models, and algorithms – through feedback into forecast development processImprove forecasts, NWP models, and algorithms – through feedback into forecast development process For forecast users: For forecast users: Assure reliability and meaningfulness of informationAssure reliability and meaningfulness of information Particularly important for 4D Data Cube and Single Authoritative Source (SAS) Particularly important for 4D Data Cube and Single Authoritative Source (SAS) Provide information for decisions and decision-making systemsProvide information for decisions and decision-making systems Forecast quality information is an integral component of decision making processes Forecast quality information is an integral component of decision making processes

3. Traditional observations used for evaluation of aviation forecasts Ground-based (ASOS, radar, etc.) Ground-based (ASOS, radar, etc.) Upper air (i.e., rawinsondes) Upper air (i.e., rawinsondes) Pilot reports Pilot reports Automated observations (in situ edr, TAMDAR) Automated observations (in situ edr, TAMDAR)

4. Limitations of Traditional observations used for verification of aviation forecasts Ground-based (ASOS, radar, etc.) Ground-based (ASOS, radar, etc.) They are “ground-based” – i.e., limited views of upper atmosphereThey are “ground-based” – i.e., limited views of upper atmosphere Limited coverage (e.g., ASOS)Limited coverage (e.g., ASOS) Selected variables onlySelected variables only Interpretation uncertainties (e.g., radar)Interpretation uncertainties (e.g., radar) Upper air Upper air Selected variables Infrequent Pilot reports Pilot reports Spatial biases Not systematic Subjective Limited coverage Automated observations Automated observations Limited coverage Limited variables Uncertainties

5. New opportunities from satellites… Satellite observations provide Satellite observations provide Wide spatial coverage – including oceanic and polar regions, and other data sparse areasWide spatial coverage – including oceanic and polar regions, and other data sparse areas Measurements of things that matter for aviationMeasurements of things that matter for aviation Observations that are relatively independent of the forecastsObservations that are relatively independent of the forecasts A-train instruments provide many diverse opportunities A-train instruments provide many diverse opportunities Characteristics that make satellite obs difficult to integrate into operational products are an asset for forecast evaluation

6. Benefits of satellite observations for forecast evaluation Measure cloud- scale features – the scale of importance for aviation Measure cloud- scale features – the scale of importance for aviation Relatively independent of datasets used in the forecast Relatively independent of datasets used in the forecast Feb 5, 2008 Credit: NASA/JPL/CIRA/CSU

7. Challenges for use of satellite observations for forecast evaluation Single instruments don’t always tell the complete story Single instruments don’t always tell the complete story Taking into account parallax, other attributes unique to satellite obs Taking into account parallax, other attributes unique to satellite obs Methods for matching forecasts and observations Methods for matching forecasts and observations Development and adaptation of forecast evaluation tools Development and adaptation of forecast evaluation tools Development and application of new features-based toolsDevelopment and application of new features-based tools Moving beyond POD and FARMoving beyond POD and FAR From Miller and Stephens, 2001

8. Summary Forecast evaluation techniques have developed sufficiently to have the potential to make excellent use of new satellite observations Forecast evaluation techniques have developed sufficiently to have the potential to make excellent use of new satellite observations Satellite-based measurements represent weather situations that are of particular importance for aviation safety Satellite-based measurements represent weather situations that are of particular importance for aviation safety Use of these observations provide an incredible opportunity to improve forecasts and models of aviation-related variables… Use of these observations provide an incredible opportunity to improve forecasts and models of aviation-related variables… But challenges still exist in developing tools and applications to make the best use of the dataBut challenges still exist in developing tools and applications to make the best use of the data Opportunities exist for making satellite obs an integral part of evaluation of NWP and aviation weather forecasts.