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 Extension and application of an AMSR global land parameter data record for ecosystem studies

 Extension and application of an AMSR global land parameter data record for ecosystem studies. Jinyang Du, John S. Kimball, Lucas A. Jones , Youngwook Kim, Matt Jones, Jennifer Watts (UMT);

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 Extension and application of an AMSR global land parameter data record for ecosystem studies

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  1.  Extension and application of an AMSR global land parameter data record for ecosystem studies Jinyang Du, John S. Kimball, Lucas A. Jones,Youngwook Kim, Matt Jones, Jennifer Watts (UMT); Numerical Terradynamic Simulation Group, College of Forestry and Conservation and Flathead Lake Biological Station, Division of Biological Sciences, The University of Montana Collaborators: Kyle McDonald, Eni Njoku & Steven Chan (JPL); Rolf Reichle (GSFC); Rama Nemani (NASA Ames). AMSR Joint Science Team Meeting 4-5 September 2013 Oxnard, CA

  2. OVERVIEW • The global satellite microwave record from the AMSR sensors has strong utility for ecosystem studies, including retrievals of vegetation optical depth, surface temperature & moisture, landscape freeze/thaw dynamics, open water inundation & Atm. water vapor changes. • Synergistic satellite observations include AMSR-E (2002-2011), AMSR2 (from Jun-2012) & similar sensor data (e.g. WindSat) • Calibration & extension of the global land parameter record is desirable for Ecological studies & applications, including land-atmosphere carbon, water, and energy fluxes; • In this study, recalibration of the University of Montana Global Land algorithms has been carried out using reprocessed (V7) AMSR-E & L1R AMSR2 swath data.

  3. Algorithm Flowchart Tb 18.7, 23.8 V & H pol. Tb 6.9 or 10.7 V & H pol. Estimate emissivity Temperature Algorithm Estimate slope parameter: 30-day running smoother 30-day running smoother Invert for VOD (assume dry baseline soil conditions) Invert for SM

  4. Pre-Screening Input Tb. • Hierarchy of conditional flags (those with lower numbers displace higher) • Derived from Tb ratios & differences (will require re-tuning for new datasets) (0) Good Tb; Do retrieval! (3) Coastal/Mountain Snow & Ice (6) 6.9 and 10.7 GHz RFI (5) 18.7 GHz RFI (7) 10.7 GHz RFI only (1) Tb not collected by instrument (4) Precipitation (8) 6.9 GHz RFI only (2) Snow & Frozen Soil

  5. Data Preparation AMSR-E / AMSR Swath Brightness Temperature Gridded brightness Temperature Algorithm Parameters Calibration • Subset Brightness Temperature and AIRS products for WMO Stations • Screening Datasets for RFI, Snow, Precipitation and High DEM variations • Adjust Algorithm Parameters based on WMO measurements and AIRS products • WMO Stations Temp. • AIRS Water Vapor • MODIS Land Cover • DEM Algorithm Re-Calibration Land Surface Products

  6. Daily Maximum/Minimum Temperature – Selection of the WMO stations Training (red dots) and Validation (green dots) Datasets from WMO Summary-of-the-Day weather stations

  7. Daily Max/Min Temperature Retrievals AMSR-E Tmaxvs WMO Obs Tmax (May 29, 2010) Training sites UMT (V7) Validation sites UMT (V6)

  8. Daily Maximum/Minimum Temperature – Comparison of the two UMT product versions Comparisons between Recalibrated Products and the previous products (Left: Correlation between the retrievals of year 2009-2010; Right: RMSD (K) of the two products)

  9. Retrieval of Total Water Vapor – Validation Comparisons between AMSR-E Retrieved Total Water Vapor and AIRS (V6) product (Left: using Training site data; Right: using Validation sites).

  10. Water Vapor– Comparison of the two version UMT products Comparisons between Recalibrated Products and the previous products (Left: Correlation between the retrievals of year 2009-2010; Right: RMSD (mm) of the two products)

  11. Vegetation Optical Depth (X-band)– Comparison of the two UMT product versions Comparisons between Recalibrated Products and the previous products (Left: Correlation between the retrievals of year 2009-2010; Right: RMSD of the two products)

  12. AMSR2 --- Extended Land Surface Parameter Record

  13. AMSR2: Extended Daily Maximum/Minimum Temperature Records – Validation AMSR2 Tmaxvs WMO Obs Tmax (May 29, 2010 / May 30,2013) UMT (V7) UMT (AMSR2)

  14. Water Vapor – Validation AMSR2 vs AIRS Water vapor (May 29, 2010 / May 30, 2013) UMT (V7) UMT (AMSR2)

  15. Recent Ecological Application Studies

  16. Documenting Alaska Boreal Forest Wildfire Recovery using AMSR-E VOD record VOD results show 3-7 year post fire recovery determined by burn severity; VOD (10.7 GHz) recovery from Large Boreal Fires in 2004 VOD recovery proportional to fire severity indicated by relative tree cover loss (MOD44B) Source: Jones, M.O. et al., 2013. Global Change Biology.

  17. Comparing Land Surface Phenology between AMSR-E Vegetation Optical Depth (VOD) and GPS Normalized Microwave Reflectance Index (NMRI) network VOD and NMRI Correspondence • VOD and NMRI are responsive to changes in vegetation water content • Significant correlations (p<0.05) were found at 276 of 305 sites (90.5%). • VOD and NMRI Start of Season metrics (r2=0.73, P<0.001, RMSE=36.8 days) were also in agreement. Jones MO, Kimball JS, et al. (2013) International Journal of Biometerology

  18. Summary • Initial re-calibration of UMT Global Land Parameter algorithms using reprocessed (V7) AMSR-E & AMSR2 L1R 1swath Tb data records. • Both UMT AMSR-E product versions are generally well correlated, but large differences occur in some areas. • Water vapor retrievals highly correlated except over dense vegetation; V7 results show higher water vapor over rainforest; • Temperature retrievals show larger differences for dense vegetation areas and southern-hemisphere; • VOD retrievals well correlated, though V7 results show higher VOD levels for dense vegetation; • Soil moisture retrievals show lower correspondence and need further evaluation. • Algorithm calibration also carried out using AMSR2 data. Results similar to AMSR-E, but AMSR2 temperature and water vapor accuracy is slightly lower. • Continuing calibration & extension of UMT record planned in support of several global ecosystem studies. 1AMSR-E V7 reprocessed Tb record provided by Remote Sensing Systems; AMSR2 L1R data are from JAXA

  19. Thanks! 1

  20. Related Equations 1

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