Dual Frequency Scatterometer (DFS) Partnership with JAXA Michael Brennan National Hurricane Center Richard Knabb Central Pacific Hurricane Center 2009 NOAA Hurricane Conference Miami, Florida 2 Dec 2009

QuikSCAT Update QuikSCAT failed early on 23 November Spinning antenna stopped after a gradual degradation in performance over the past few months A remarkable mission of over 10 years in orbit

NOAA/NASA/JAXA Partnership Japanese Space Agency (JAXA) planning GCOM- Carbon cycle (GCOM-C) and GCOM-Water cycle (GCOM-W) missions – 13-year mission; three satellites in series, each with 5-year lifetime, 1-year overlap with follow-on satellites for calibration – GCOM-W1 planned for launch late 2011, GCOM-W Since June 2008 NOAA, NASA/JPL, and JAXA have been discussing a potential partnership – U.S. would provide Dual Frequency Scatterometer (DFS), designed by NASA/JPL on GCOM-W2 mission

NOAA/JAXA Partnership Mary Kicza, assistant administrator for NESDIS, signed a Letter of Intent with Yasushi Horikawa, executive director of JAXA, agreeing to exchange data, conduct joint research, and develop advanced integrated products. Both agencies plan to continue discussing the possibility of flying NOAA instruments on future JAXA satellite missions.

Dual Frequency Scatterometer (DFS) Builds on QuikSCAT and ASCAT heritage Ku-band (H-pol and V-pol) and C-band (H-pol) – Mitigates rain contamination Instrument design constrained by GCOM-W2 bus and AMSR instrument designs 1.8 to 2-m antenna – Basic resolution ~ 10 km 1800-km wide swath (identical to QuikSCAT) AMSR onboard with DFS provides opportunity to improve surface products (wind and SST) from both Slice resolution 16km x 3km 25-34km x 3km HH VV

DFS Design and Capabilities C-band channel retrievals much less affected by rain Experience with ASCAT and DFS simulations show that adding C-band channel will yield substantial improvements over QuikSCAT retrievals in rain DFS has capability to provide accurate retrievals in nearly all weather conditions, including Cat 1 and 2 hurricanes

DFS vs. QuikSCAT and XOWVM Simulated Retrievals based on Katrina (2005) XOVWMQuikSCATDFS TS H1 H2 H3 H4 H5 50 DFS better captures true wind signal where QuikSCAT high winds are tied to rain DFS accurately depicts hurricane-force wind radii and retrieves winds into category 2 range, but not into category 3 range DFS cannot identify small scale wind maxima seen by XOVWM “Truth”

DFS vs. QuikSCAT and XOWVM Katrina Simulated Retrievals DFS captures true wind signal well into hurricane-force range Significant improvement over QuikSCAT, where rain degrades quality of retrievals above around 50 kt QuikSCATDFS

DFS vs. QuikSCAT and XOWVM Coastal Retrievals – Shelikof Strait, Alaska DFS provides retrievals slightly closer to the coast compared to QS Work underway that could provide retrievals from QuikSCAT and DFS within 6 km of the coast DFS does not show large improvement seen in coastal XOVWM retrievals Higher resolution of DFS does capture smaller-scale wind features not seen by QS QuikSCATDFSXOVWM

DFS Expected Performance Highest resolution of DFS  10 km compared to  12.5 km for QuikSCAT DFS will improve wind retrieval accuracy over QuikSCAT by at least 20% – Increased power, number of looks, frequency diversity, larger aperture size At high wind speeds, DFS can improve accuracy up to 50% – Small-scale wind maxima in TCs still cannot be resolved, but rain contamination mitigated No significant improvement in the distance to the coast achievable between QuikSCAT and DFS

Progress so far… DFS accepted as a baseline instrument for GCOM-W2 Research and Operational Users Working Group (ROUWG) established (5 NOAA members) – Define mission requirements – Provide guidance on mission trade-offs between instruments – Represent interests of research and operational user communities – Advocate for mission, organize user meetings, conference sessions, and solicit community input

DFS Timeline GCOM-W1 launch scheduled for Jan GCOM-W2 launch scheduled for Jan Timeline and funding uncertain from JAXA side due to recent change in Japanese government – JAXA Mission Definition Review (MDR) for GCOM-W2 has been postponed due to budget uncertainties Originally scheduled for Dec Likely to now be held early in 2010

Moving Forward Meeting scheduled launch date for GCOM‐W2 requires significant funding for DFS in FY11 FY10 House appropriations for NOAA and NASA instructs agencies to work together to continue funding studies and instruct NOAA to make a request for funding in FY11 to build and fly a new operational scatterometer – Senate appropriation has no such language NWS and NOAA have briefed Congressional staffers on status of QuikSCAT and stated preference for DFS as a replacement

Scatterometry and Climate Workshop held in DC during August 2009 – Participation from NOAA (NWS, NESDIS, OAR), NASA, JAXA, universities Goals – Provide a comprehensive case for the importance of continued scatterometer measurements for climate studies and applications (including TC-climate relationships) – Refine the climate requirements for the next-generation U.S. scatterometer, akin to the weather requirements already established by NOAA/NWS Workshop report nearing completion, and is intended for wide public distribution to help advocate for a next- generation U.S. scatterometer

Oceansat-2 Indian Space Research Ogranisation (ISRO) launched a research satellite, Oceansat-2, earlier this year, with a scatterometer on board similar to QuikSCAT NOAA, NASA, and ISRO signed a letter of intent on Nov. 18 to share Oceansat-2 data NOAA has agreed to explore making data downlink sites in Fairbanks and Wallops available to collect the data in near-real time Some hope that near-real time data could be available within a couple of years from this instrument Gulfnews.com

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ROUWG Activities Define the GCOMW-2 Level 1 requirements – Address research and operational goals for the two payload components (AMSR and DFS), and joint goals for both instruments Provide guidance to GCOMW-2 project on mission trade-offs which may require assessing impact of mission design on payload performance – Trade and prioritize among mission objectives when there are competing payload accommodation requirements – Conduct scientific studies related to performance of mission and ability to meet Level 1 requirements Represent interests of research and operational user communities Advocate for GCOMW-2 mission and organize user meetings/conference sessions and solicit community input

DFS vs. QuikSCAT and XOWVM Katrina Simulated Retrievals DFS shows underestimation of winds ≥ kt that is not seen in XOVWM, likely result of limited resolution compared to XOVWM XOVWM DFS