AIRS Products for the National Weather Service Brad Zavodsky

1. AIRS Products for the National Weather Service Brad Zavodsky SPoRT Science Advisory Committee: June 12, 2007

2. Overview Relevance to SPoRT: Taking real-time AIRS L2 profile data and creating useful tools to assist NWS forecasters improve 0 – 24h forecasts • AIRS Instrument Review • SPoRT/SOO workshop and AIRS Science Team collaborations • Current Work • Point Location Skew-Ts • Gridded AIRS product for WFO • Boundary Layer Height • Summary/Future Plans

3. AIRS Instrument Review • Aboard Aqua polar orbiter with early afternoon equator crossing • 2378 spectral channels from 3.7 to 15.4 μm) (650 – 2675 cm-1) • 3 x 3 footprints (golfball; L1B: 15km; L2: 50 km spatial resolution) • L2 products have: • V4 (current version) 0.9-1.3K global ocean and land (in 1 km layers); <15% RH (in 2 km layers) • quality indicators (QIs) based on how deep the sounding goes in the atmosphere • V5 (available S07) will have improved accuracy (WV profile and over non-frozen land) and level-by-level error estimates for better QIs

4. Outcome of SPoRT/SOO Workshop and AIRS Science Team Visit • AIRS L2 products beneficial because they provide upper air information in spatial and temporal data voids • Feedback from SPoRT/SOO workshop determined that AIRS L2 products could help solve specific forecast problems: • atmospheric destabilization leading to convective storms • diagnoses of 4D moisture variability in the mesoscale (particularly ahead of developing weather) • improved 0 – 24 hr prediction of sensible weather elements • fog, smoke, and low cloud detection (boundary layer) • Visit by AIRS Science Team members from JPL to discuss operational use of AIRS with WFO yielded three potential products: • L2 soundings at specific points (used as RAOBS) • L3 gridded product (generated from L2 profiles; used as model) • Boundary layer height product

5. Current Work: AIRS Skew-Ts at Point Locations • Provide WFO sounding information for nearest high-quality AIRS sounding • Overlay AIRS and RAOB data at RAOB locations (e.g. BNA) • Produce just AIRS profiles at latitude/ longitude for locations lacking RAOB (e.g. HUN) • Introduce into AWIPS as RAOB data 00Z RAOB 12Z RAOB AIRS AIRS Sample AIRS/RAOB overlain Skew-T for Nashville, TN (BNA) Sample AIRS Skew-T for Huntsville, AL (HUN) (no available RAOB)

6. Let’s look at how AWIPS displays a cross section of AIRS data Current Work: Gridded AIRS Product for WFO AWIPS display of AIRS 1000 hPa T AWIPS display of AIRS 1000 hPa Td • “Proof of concept” prototype using V4 standard AIRS profiles and Cressman analysis • Produces smooth, realistic looking field of temperatures and dew points with no discontinuities from land to water

7. Current Work: Gridded AIRS Product for WFO (cnt’d) AWIPS display of AIRS T cross section AWIPS display of AIRS Td cross section • Easily generates vertical cross sections • Able to create point soundings with calculated indices (e.g. CAPE, LCL, etc.) at any location there are data

8. Current Work: Boundary Layer Height Product AIRS MIPS • Important to validate AIRS lower layers in order to use product (assist JPL in this task) • Comparison between UAH MPR data collocated in space and time • Preliminary results indicate AIRS and MPR show similar structure of lower atmosphere—should lead to similar boundary layer height • Product for WFO would convey boundary layer height on a pixel-by-pixel basis • forecasters could view plan view of boundary layer or cross section (similar viewing to gridded product) Same lower atmosphere structure

9. Summary • AIRS profiles are a valuable asset to the operational community by providing upper air information in spatial and temporal data voids • The SPoRT/SOO workshop and meetings with members of the AIRS Science Team helped identify three possible products that could assist forecasters with specific forecasting problems • L2 soundings at specific points • L3 gridded product • Boundary Layer height product • Continued collaboration with the AIRS Science Team and NWS will help determine best possible products for operational use

10. Future Work • Eagerly awaiting implementation of V5 AIRS algorithm sometime this summer—working closely with JPL and University of Wisconsin to get AIRS V5 on direct broadcast as quickly as possible • Add AIRS point soundings as an additional RAOB type in AWIPS • Adapt the prototype gridded product to use V5 support product and get further assistance from JPL in producing a regional, gridded product in near-real-time (perhaps a new L3 product in V6 release) • Produce files in real-time and transfer to WFOs for forecaster use • Assist JPL with validation of AIRS boundary layer using UAH MIPS, which could lead to a boundary layer height product for WFOs