1 / 14

Masahiro Kazumori Japan Meteorological Agency

Recent activities on utilization of microwave imager data in the JMA NWP system - Preparation for AMSR2 data assimilation -. Masahiro Kazumori Japan Meteorological Agency. AMSR-E Joint Science Team Meeting, Portland, OR, U.S.A. 11 & 12 September 2012. Introduction.

yetta-skinner
Download Presentation

Masahiro Kazumori Japan Meteorological Agency

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Recent activities on utilization of microwave imager data in the JMA NWP system- Preparation for AMSR2 data assimilation - Masahiro Kazumori Japan Meteorological Agency AMSR-E Joint Science Team Meeting, Portland, OR, U.S.A. 11 & 12 September 2012

  2. Introduction • Microwave imager data has been assimilating in JMA Global Data Assimilation (DA) system and Meso scale DA system. • The radiance assimilation provides atmospheric moisture information for initial state of NWP models. • The assimilated Microwave imager data • Clear Sky radiance data for Global DA system • Radiance and Retrieved Rain Rate for Meso scale DA system • In Use • TMI/TRMM • AMSR-E/Aqua(by Oct. 6, 2011) • SSMIS/DMSP F-16, F-17, F-18 • In Preparation • Windsat/Coriolis • AMSR2/GCOM-W1 • V-pol. channels (19, 23, 37 and 89) are assimilated in JMA NWP system. (since Dec. 6, 2011)

  3. Impact of microwave imager data in JMA NWP • MW imager data is one of the essential data to produce realistic moisture fields as initial conditions of NWP. • The initial fields are updated (four times per day for Global DA, eight times for Meso scale DA) to capture change of weather conditions. • Use of multiple MW imager data is necessary for the frequent update of the initial field. New MW imager data should be used. Short-range precipitation forecast TRMM observed rain Without Microwave Imager data Operational JAXA

  4. Recent updates of MW radiance assimilation in JMA • Oct. 6, 2011 Stop of AMSR-E observation • Dec. 1, 2011 Start of TMI ver. 7 Tb data use • Dec. 6, 2011 Start of DMSP F-18 SSMIS Tb use Time sequence of O-B statistics Start of TMI ver. 7 (Dec. 1) [K] Stop of AMSR-Eobservation (Oct. 6) Introduction of F-18 SSMIS (Dec. 6 )

  5. Used MW radiance data in Global DA Time sequence of Data Counts Available data number of DMSP F-17 SSMIS is decreasing since June 2011. [Counts] Decrease of DMSP F-17 SSMIS data

  6. In the data assimilation, satellite data are thinned spatially and temporally (e.g. , 200km and hourly). Satellite data in separate orbit are preferred because they increase the data coverage in six-hour analysis time window. Equator crossing time F-16 The orbit of SSMIS (F-16 and F-17) are becoming very close. F-17 12UTC Jun. 10, 2011 Both F-16 and F-17 data can be used because they are in the different thinning box. F-18 12UTC Sep. 4, 2012 One satellite (F-16) data can be used because they are in the same thinning box. Aqua

  7. Cal/Val collaboration with JMA and JAXA • JAXA successfully launched GCOM-W1. And AMSR2 is working in very good condition. • For early use of satellite data in operational NWP, Space agency and NWP center are collaborating in Cal/Val activities (e.g., AMSU-A/Metop-A, ECMWF and EUMETSAT, SSMIS/DMSP F-16, UK Met Office, NESDIS and NRL, ATMS/Suomi-NPP,NCEP, NESDIS, and NASA ) • Comparison of observed Tb and NWP model’s calculated Tb reveals Tb calibration issues. • For early use of AMSR2 data in JMA NWP, JMA and JAXA started Cal/Val collaboration. • Preliminary un-calibrated AMSR2 L1B product has been delivering to JMA since Sep. 3, 2012. O-B Monitoring of AMSR2 is ongoing. A pre-processor for the data assimilation is being developed.

  8. Microwave Imager data’s coverage in JMA NWP Global DA Meso scale DA 06UTC 18UTC AMSR2 is a unique Microwave Imager in PM Orbit. The data fill the gap in the 6-houly global data coverage. In Meso scale DA system, 06UTC and 18 UTC analysis has little microwave imager data. The data cut-off time for the receiving is 50 min. after the analysis time. Direct receiving AMSR2 data by JAXA can be used in real time. Light blue: AMSR2

  9. Development of pre-processor for AMSR2 radiance assimilation • Main function • Data thinning and ocean data selection • Removal of cloud and rain affected data →Clear sky radiance assimilation • QC with TPW and CLW retrievals • TPW: Consistency check of retrieval and NWP model • CLW: Cloud and rain screening. Used as one of predictors of variational bias correction • Scan position dependent bias correction (static) • Radiative transfer calculation with NWP model’s profiles (RTM: RTTOV-10.2) • Monitoring of AMSR2 data quality with O-B. • The biases in O-B are corrected by variational bias correction scheme (VarBC). The biases are estimated using a linear function with some predictors and those coefficients are optimized in the analysis and updated every analysis cycle. Bias correction term is in the observation operator Predictors : TPW, SST, SST^2, SSW, CLW, ORBIT,CONST

  10. Preliminary O-B Comparison with other MW imagersTMI and AMSR-E(ocean and clear sky condition) Red: W BC Green: WO BC AMSR2 19V 23V 37V 89V July 2012 ME5.02 0.03 STD 1.651.61 ME5.62 0.09 STD 2.432.45 ME3.63 0.02 STD 1.69 1.55 ME2.95 0.05 STD 2.342.20 [K] TMI Ver.7 ME1.22 -0.10 STD 1.551.48 ME-0.31 -0.15 STD 2.272.20 ME-0.63 -0.09 STD 1.29 1.27 ME0.47 -0.12 STD 1.76 1.71 July 2011 AMSR-E ME1.67 -0.06 STD 1.43 1.38 ME1.44 -0.11 STD 2.12 2.14 ME0.14 -0.06 STD 1.331.31 ME-0.67 -0.1 STD 2.152.11

  11. Preliminary O-B Comparison with other MW imagersSSMIS(ocean and clear sky condition) Red: W BC Green: WO BC AMSR2 19V 23V 37V 89V July 2012 ME5.02 0.03 STD 1.651.61 ME5.62 0.09 STD 2.432.45 ME3.63 0.02 STD 1.69 1.55 ME2.95 0.05 STD 2.362.20 [K] SSMISF-18 ME-0.29 0.01 STD 1.431.36 ME0.64 0.02 STD 2.272.14 ME-0.71 0.01 STD 1.29 1.28 ME-2.08 -0.01 STD 1.98 1.50 SSMISF-16 ME1.03 -0.06 STD 1.52 1.41 ME1.80 -0.10 STD 2.39 2.20 ME0.36 -0.06 STD 1.291.26 ME-0.55 -0.10 STD 1.951.53

  12. Preliminary L1B Comparison between AMSR2 and AMSR-E One month O-B orbit dependent bias July 2012 AMSR2 19V 23V 37V 89V Descending [K] Ascending July 2010 AMSR-E 19V 23V 37V 89V Latitude Local Time

  13. Preliminary assimilation experiment (single case) Q925 AMSR2 19GHz V-pol. O-B Q925 analysis increment AMSR-2 data assimilation experiments are in preparation.

  14. Summary • Microwave imagers data have large positive impacts in JMA NWP system. The data are essential for accurate humidity analyses and precipitation forecasts for Japan. • Current satellite microwave observing configuration is not optimal for NWP. Due to no PM orbit microwave imager, the data sparse area and period exist. AMSR2 can fill the gap. • JMA and JAXA started collaboration in Cal/Val activities for the early use of AMSR2 data in JMA NWP system. • Preliminary un-calibrated AMSR2 L1B data show positive biases in the comparison with calculated Tb. And our bias correction scheme can correct the bias globally. AMSR2 bias corrected O-B departure are comparable with other MW imager data (F16, F18 SSMIS and TMI). • AMSR2 orbit dependent bias looks different from AMSR-E. • Preliminary assimilation experiment (single case) was performed. Global and Meso scale data assimilation experiments are planned to confirm the impacts of AMSR2 data assimilation for the weather forecast.

More Related