FY2-IASI and FY3C-IASI towards Demo Na XU, Hanlie XU, Chengli QI, Tao ZHANG, Zhe XU, Xiuqing HU Thanks to : Masaya Takahashi and Tim Hewison CMA NSMC 2015-03-19

Outline FY2-IASI towards Demo FY3-IASI towards Demo NetCDF Products content Method for Correction Coefficients and TB Bias calculation Data sharing and web publication FY3-IASI towards Demo Briefly introduction to FY-3C IR sensors LEO-LEO intercalibration method Samples of IR calibration assessments for FY-3C Current situation and plan of FY3-IASI products

1. FY-2 NetCDF Products (Demo) File Names and contents all follow the GSICS convention, from https://gsics.nesdis.noaa.gov/wiki/Development/NetcdfConvention Filename: W_CN-CMA-NSMC,SATCAL+NRTC+GEOLEOIR,FY2E+SVISSR-MetOpA+IASI_C_BABJ_20150120000000_demo_01.nc Contents: Global attributes ; Variations Smoothing period: NRTC ： t-5d to t-0 RAC ： t-5d to t+0 Refer to https://gsics.nesdis.noaa.gov/wiki/Development/NetcdfConvention Near Real Time Correction (NRTC) Re-Analysis Correction (RAC) Correction Coefficients TB Bias @STD Scene

Method- Correction Coefficients Weighted linear regression are used based on collocated radiances. The inverse of the sum of the spatial and temporal variance of the target radiance and the radiometric noise provide an estimated uncertainty on each dependent point, and is used as a weighting. Uncertainty

Method- TB Bias Uncertainty Standard scene for FY-2 IR Channels WV6.9 IR3.7 Tb_std (K) 286 285 247 RAD_std mW m-2 sr-1(cm-1)-1 90.4 104 8 0.37 Uncertainty

Data Sharing NRTC products (Demo) against MetopA IASI are available. RAC products (Demo) will be releases before this month ends. They are downloadable from CMA’s GSICS Data and Products Server: http://gsics.nsmc.cma.gov.cn/thredds/catalog.html

Web publication 1. Daily Near Real Time 2. TB bias re-analysis Regression Scatterplots Collocation map 2. TB bias re-analysis Monthly Regression Scatterplot Temp-dependence variation Time series variation 3. Double difference sequence (under building) (FY2-IASI_A)- (FY2-IASI_B); (FY2-IASI)- (FY2-CRIS); http://gsics.nsmc.cma.gov.cn/

2. FY-3C instruments GSICS products for three instruments of FY-3C are ongoing. IRAS: InfraRed Atmospheric Sounder MERSI: Medium Resolution Spectral Imager VIRR: Visible and Infra-Red Radiometer

LEO-LEO Intercalibration method Weighted linear regression are used based on collocated radiances. Products are generate monthly. Spatial distributions of cross points FY-3C~METOP-A ATBDs are ready, and will be submitted for review. Collocation criteria: Observation time difference < 300s Spacial Distance <1km geometry difference |cos(FY_zen)/cos(REF_zen)-1| < 5% Environment uniformity check RSTD (FY3 in ENV_BOX) < 0.005

Products towards demo Three kinds of figure products are planned to generate like FY-2. At present, the monthly regressions for the three sensors are available. NC and TB re-analysis products are under building follow GEO GSICS convention . 1. Monthly Near Real Time Regression Scatterplots Collocation map IRAS VIRR MERSI

Summary FY2-IASI FY3-IASI FY2-IASI to Demo plan in 2015 Daily NRTC products of Demo version are ready and downloadable from CMA data server; RAC products of Demo version are ready, and will online in two weeks; CMA GSICS web can provide two kinds of figure products, daily NRT regression and TB re-analysis. Double difference sequence is under building. FY3-IASI GSICS LEO-LEO intercalibration are applied to VIRR, MERSI and IRAS. ATBDs are ready, and will be submitted for review. CMA GSICS web can provide monthly regression results. NC and TB re-analysis products are under building follow GEO GSICS convention, and will be finished by the end of summer 2015. FY2-IASI to Demo plan in 2015 Upload FY2-MetopA/IASI RAC ; Complete FY2-MetopB/IASI NRTC and RAC products; Test GSICS Plotting tool based on RAC; Complete ATBDs and user guides

Thanks for your attention Email: Xuna@cma.gov.cn