Long-term Water Cycle Observation by the Advanced Microwave Scanning Radiometer (AMSR) Series: AMSR-E, AMSR2 and Follow-on

Transcription

1 Long-term Water Cycle Observation by the Advanced Microwave Scanning Radiometer (AMSR) Series: AMSR-E, AMSR2 and Follow-on M. Kachi 1), H. Fujii 1), T. Kubota 1), T. Maeda 1), N. Ono 1), M. Kasahara 1), and N. Ebuchi 1),2) 1) Japan Aerospace Exploration Agency 2) Hokkaido University 5 October, Seoul, South Korea 9th International Precipitation Working Group Workshop

2 JAXA Earth Observation Satellite missions Targets (JFY: Apr-Mar) Disasters & Resources [Land and disaster monitoring] JERS1/OPS, SAR ( ) ADEOS-I/AVNIR ALOS-2 / PALSAR-2 ALOS-4 ALOS/AVNIR2, PALSAR (2006- ALOS-2CIRC 2011) ALOS-3 ISS/CIRC Climate System Water Cycle ADEOS-I/AMSR ( ) Aqua/AMSR-E ( ) Climate change ADEOS-I/OCTS ( ) ADEOS-II/GLI (2003) Greenhouse gases JMA meteorological satellites Mission status TRMM / PR [Precipitation 3D structure] with NASA GPM / DPR with NASA [Wind, SST, water vapor, precipitation] On orbit [CO 2, CH 4, GCOM-W / AMSR2 GOSAT / FTS, CAI 2009~ MTSAT-1R (Himawari-6) MTSAT-2 (Himawari-7) [Cloud, SST] Development [Vegetation, aerosol, cloud, SST, ocean color] with MOE Study GCOM-C / SGLI [Cloud and aerosol 3D structure] with ESA [CO 2, CH 4, CO] [Cloud, aerosol, SST] Himawari-8/AHI Himawari-9 (standby) GOSAT-2 Feasibility study DPR F/O Pre-phase-A AMSR2- F/O EarthCARE GOSAT -3

3 Development of AMSR Series Sensor MOS-1/MSR ADEOS-II/AMSR Aqua/AMSR-E GCOM-W/AMSR2 Coverage Direct receive only Global Global Global Swath 317km 1600km 1450km 1617km Frequencies (GHz) 2 (23,31) 9 (6.9,10,18,23, 36,50,52,89) 6 (6.9,10,18,23, 36,89) Polarization Mixed V and H V and H V and H V and H Antenna Size 0.5m 2.0m 1.6m 2.0m 7 (6.9,7.3,10,18, 23,36,89) Spatial Res. AMSR3? GCOM-W 3

4 Overview of GCOM-W and AMSR2 Instrument Altitude Orbital inclination Local sun time at Ascending node Launch vehicle Advanced Microwave Scanning Radiometer 2 (AMSR2) 705 km 98.2 deg 13 :30 H-IIA Launch May 18, 2012 Designed lifetime 5 years üsuccessor of Aqua/AMSR-E (launched in May 2002), providing continuous data for climate studies and operational applications üjoining A-train constellation (same as Aqua) and also GPM constellation ücarrying AMSR2, a multi-polarization and multi-frequency microwave imager üobserving various water-related ECVs at highspatial resolution üimproving on-board calibration target has resulted reduction of annual TB variation due to calibration and improvement of TB stability üachieved designed mission life (5-year) on May 18, 2017, and continues observation üenough fuels to keep current orbit for more than 15 years 4

5 Descending orbit on 8 May AMSR2 Geophysical Parameters Total Precipitable Water Integrated Cloud Liquid Water Precipitation Sea Surface Temperature Sea Surface Wind Speed Sea Ice Concentration Snow Depth Soil Moisture Content

6 G E O Product Coverage Resolution Brightness Temperature Total Precipitable Water Cloud Liquid Water Precipitation Sea Surface Temperature Sea Surface Wind Speed Sea Ice Concentration AMSR2 Standard Products Release Accuracy Standard Accuracy Global 5-50km 1.5K 1.5K Global Ocean Global Ocean Global (except high latitude) Global Ocean Global Ocean Ocean in high latitude 15km 15km 15km 3.5 kg/m kg/m 2 Ocean 50 % Land 120 % Target Accuracy 1.0K (bias) 0.3K(random) Validation Result Latest version < 1.4 K Ver kg/m kg/m kg/m 2 Ver kg/m kg/m kg/m 2 Ver.2.1 Ocean 50 % Land 120 % 50km 0.8 ºC 0.5 ºC 15km 1.5 m/s Ocean 20 % Land 80 % 0.2 ºC (zonal mean) Ocean 48% Land 86% 0.5 ºC < 0.2 ºC (zonal) Ver.2.1 Ver.3.0 Soil Moisture Land 50km 10 % 10 % 5 % 4 % Ver m/s 1.0 m/s 1.0 m/s Ver km 10 % 10 % 5% 9 % Ver.3.0 Snow Depth Land 30km 20 cm 20 cm 10 cm 18 cm Ver.2.1

7 AMSR2 Research Products and Accuracy Products Area Resolution Target accuracy Status All-weather sea surface ± 7 m/s for strong Ver.3.0 released Ocean 60 km wind speed wind (>17m/s) 4.07 m/s High-resolution Ver.3.0 released Ocean 30 km ± 0.8 ºC (10-GHz) SST 0.55 ºC Soil moisture and vegetation soil moisture: ± 8% Africa, Australia water content based on the 25 km vegetation water: Under development (at first stage) land data assimilation ± 1 kg/m 2 Land surface temperature Land 15 km forest area: ± 3 ºC nondense vegetation: ± 4 ºC Ver.1.0 released 3 ºC (forest) 4 ºC (nondense vegetation) Vegetation water content Land 10 km ± 1 kg/m 2 Under evaluation High resolution sea ice concentration Ocean in high latitude Thin ice detection Global 15 km Sea ice moving vector Total Precipitable Water over Land Ocean in high latitude Land (except ice and vegetation) 5 km ± 15 % Under evaluation 50 km ± 80 % (answered correctly) 2 components: 3 cm/s Consideration to release 92.4 % for Okhotsk sea Under evaluation 15 km 6.5 kg/m 2 Newly Proposed 2.59 kg/m 2 vs. GPS Released to public To be released Newly proposed 7

8 Land Surface Temperature Product Algorithm provided by Tom Jackson (USDA) based on Holmes et al. (2009) Retrieval of LST by single equation using 36 GHz V TB Equation is obtained by using linear regression between AMSR2 LST and LST at ground observation sites in Europe and US Observing top of forest over forest area Capable to obtain frequent LST for both day & night Released in February 2018 through Detailed validation results are also available at the web site DAY June 2017 NIGHT June

9 AMSR-E Reprocess Product Status Toward consistent dataset between AMSR2 and AMSR-E for long-term analysis, JAXA has reprocessed AMSR-E product applying the latest AMSR2 algorithms. Level 1 & 3 (brightness temperature): Released from G-Portal Level 1B & 1R in AMSR2 format (HDF5) Level 2 & 3 (geophysical parameters): Preparation for public release Applying the current (latest) AMSR2 L2 algorithms and format (HDF5) Validation is underway (to be released by early 2019) SST Total Precipitable Water 9

10 AMSR-E L1 Product Ver. 4 L1 reprocessing summary Brightness temperature (TB) between AMSR-E and AMSR2 is not adjusted Swath width of AMSR-E (1450km, 196 pixels for low-freq. Ch. / 392 for high-freq. Ch.) is extended to be equivalent to that of AMSR2 (1620km, 243 pixels for low-freq. Ch. / 486 for high-freq. Ch.) AMSR-E L1R (resampling) product, which is highly requested by users, are newly developed Improvements in L1B Algorithm Bias correction of TB is applied to scan edges to extend swath width Improved method to calculate hot load temperature correction by using two orbit paths to resolve gaps between Ascending and Descending orbit products Improved geometric parameters AMSR-E L1 products (ver.4) has been released to public through G- Portal since April

11 AMSR-E L1 Ver.4: Extend Swath Width 0 deg. Satellite flight direction -61 deg. -75 deg. Antenna rotating direction +61 deg. +75 deg. AMSR-E original Equivalent to AMSR2 Swath width 1450km (193 pix for low-freq. / 392 for high-freq.) Swath width 1620km (243 for low-freq. / 486 for high-freq.) 11

12 Status of AMSR2 follow-on sensor (AMSR3) AMSR2 is now flying more than six years exceeding designed life. In response to users requests, AMSR2 follow-on mission has been in pre-project phase (Phase A) since September 1, Mission Definition Review (MDR): April to June 2018 Project Preparation Review: July 2018 The new satellite will become a joint mission of AMSR2 follow-on sensor and GOSAT-2/TANSO-2 successor sensor (advanced spectrometer to monitor greenhouse gases). Orbit definition is currently under negotiation with TANSO-2 successor mission but we will keep early afternoon orbit around 13:00 or 13:30 in LT AMSR2 follow-on sensor (AMSR3) specification Almost equivalent sensor specification to the current AMSR2 (antenna size, channels) except additional higher frequency channels of 166 & 183 GHz for snowfall retrievals and water vapor analysis in NWP New products including snowfall, TPW over land, high-resolution SST, allweather sea surface wind speed & high-resolution sea ice concentration 12

13 JAXA Research Announcement (RA) The next RA was just announced for the three-year period JFY The JAXA integrated Research Announcements for various missions and release Research Announcements on the Earth Observations. This RA includes almost all EO missions in the JAXA (GPM, GCOM-W, AMSR3, GCOM-C, EarthCARE, ALOS-2/3/4, and MOLI). Deadline is the end of November àthe next RA includes not only GCOM-W, but also AMSR3!

14 Summary JAXA s GCOM-W mission is now flying more than 6-years without any serious problem. Satellite and sensor (AMSR2) is in healthy condition. AMSR2 products are distributed to public via internet. Transfer to G-Portal ( has completed in June standard geophysical parameters and 3 research products are now available, and 2 research products (including candidate) are close to release AMSR-E reprocessing products applying AMSR2 format and algorithms are in preparation, expecting contribution to CDRs L1B and L1R (resampling: new) products are already available at G-Portal L2 products are now validated and show accuracy equivalent to AMSR2 AMSR2 follow-on sensor (AMSR3) and TANSO-2 successor sensor will be joint mission and has been in Phase A since Sep. 1, Will keep early afternoon orbit Sensor specification of AMSR3 will be equivalent to AMSR2 except additional 166/183 GHz channels for solid precipitation retrievals and water vapor analysis in NWP 14

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16 AMSR-E L1 Ver.4: Hot Load Correction Parameters to correct hot load temperature are calculated using half orbit data previously, but gaps are found at boundary of A/D products. In new version, two orbits path data (1 orbit before and after) are used for calculation and gaps are resolved. Previous method New method Hot Load temperature Ascending Descending Ascending Ascending Descending Ascending 16

17 AMSR-E L2 Ver.8: Current Validation Status Product (ID) Total Precipitable Water (TPW) Integrated Cloud Liquid Water (CLW) Precipitation (PRC) Sea Surface Temperature (SST) Sea Surface Wind Speed (SSW) Sea Ice Concentration (SIC) Snow Depth (SND) Soil Moisture Content (SMC) Ver.7 (Current ver) Ver.8 (Reprocess ver.) 1.89 kg/m kg/m / 2.0 kg/m kg/m 2 (Jan./Jul ) Ocean 94.87% Land % kg/m 2 (Whole period) kg/m 2 (Jan./Jul. 2003) Ocean 65.92% Land 91.13% Accuracy definition of AMSR2 (Standard/Target) * RMSE of instantaneous observation 0.05 / 0.02 kg/m 2 * Data spread (total accuracy including parameter dependency: CLW accuracy = Worst STD. + Worst Bias) Ocean 50 / 20 % Land 120 / 80 % * Relative error at 50km average (RMSE ratio against averaged precipitation rate) RMSE 0.62 deg.c RMSE 0.54 deg.c 0.5deg.C@RSME / 0.2deg.C@Bias * Standard: Global monthly average of RMSE * Target: Monthly bias average at each 10-deg lat m/s m/s 1.0 / 1.0 m/s * Global monthly average of RMSE N.H. 6.66% S.H. 8.10% N.H. 7.01% S.H. 8.02% 10 / 5 % * RMSE of instantaneous observation GSOD 17.0cm GSOD 17.7cm 20 / 10 cm * MAE of instantaneous observation Mongolia 3.07%vol U.S. LR 3.87%vol Mongolia 2.16%vol U.S. LR 4.88%vol 10 / 5 %vol * MAE of instantaneous observation 17