Pan-Arctic Land and Lake Surface Temperature from AATSR and MODIS: Products Development and Evaluation Homa Kheyrollah Pour Claude Duguay University of Waterloo 1 st Arctic Products Validation & Evolution Workshop Ottawa, 12-13 November 14
Content Arctic land surface temperature (LST) from satellite observations Arctic lake surface water temperature (LSWT) from satellite observations Generation of products Evaluation of products Concluding remarks
Arctic land surface temperature (LST) from satellite observations Why? Long term changes in surface temperature Evaluation of regional climate models Assimilation into permafrost models Arctic lake surface water temperature (LSWT) from satellite observations Why? Long term changes in water temperature Evaluation of lake models Assimilation into weather prediction models
Arctic LST from satellite observations UW-L3 LST weekly and monthly (25 km) products derived from combination of Terra and Aqua L2 data (top) 25 km x 25 km grid cells Soliman et al., 12
Arctic LST/LSWT from satellite observations Monthly MODIS (Terra and Aqua combined- 1km) LST/LSWT. Great Slave Lake/ Great Bear Lake, NWT (July 02-).
Arctic LSWT from satellite observations Monthly MODIS (Terra and Aqua combined-1km) LSWT Great Slave Lake, NWT (Jan-Dec 06)
Generation of products MODIS L2 files (MOD/MYD) Interpolated L2 files 1 km EASE-Grid Polar Projection Spatial Aggregation 1-25 km Processing chain of MODIS UW-L3 LST/LSWT products Temporal Aggregation Update day and night averages Day observations count, File 4 Day LS(W)T day/ week/monthaverage, File 3 Night LS(W)T day/ week/month- average, File 5 Night observations count, File 6 Day/Night LS(W)T daily/ weekly/monthlyaverage File 1 Total observations count, File 2
Evaluation of LST products UW-L3 LST monthly product intercomparison Monthly MODIS (Terra and Aqua combined-1km) and clear-sky monthly average of NARR and SSM/I LST, and AMSR-E screen-height air temperature for July 07. Mean difference in the order of 1-2 K between MODIS and other products during snow-free conditions. 25 km x 25 km grid cells Soliman et al., 12 SSM/I: Royer and Poirier, AMSR-E: Jones et al.,
LST vs 2-m air temperature Evaluation of LST products Daily averaged (MOD/MYD) Hourly overpasses(mod/myd) Deline_Station MODIS Deline_Station MODIS 30 40 30 Temperature ( C) 0 - - Temperature ( C) 0 - - -30-30 -40-40 -50 07 08-50 07 08 30 Deline_Hourly Air Temperature ( C) 0 - - -30-40 R 2 = 0.97 n= 708 I a = 0.987 MBE= 1.12 RMSE= ± 4.53-50 -50-40 -30 - - 0 30 MODIS_LST ( C)
Evaluation of LSWT products LSWT vs surface water temperature Temperature ( C) 25 ΔT (MODIS - In situ) In-situ (0m) MODIS LST 15 5 0-5 I a = 0.94 MBE = - 0.90 RMSE = ±1.36 - June July August September ST3 Great Slave Lake (June to Sep 03) In-situ data obtained from buoys 0 In-situ Axis LWST Title (0m) ( C) 15 5 ST4 ST7 n = 175 MBE = - 1.00 RMSE = ± 1.55 0 5 15 MODIS LWST ( C)
Evaluation of LSWT products AATSR LSWT vs surface water temperature a) AATSR-L2-NCC ( C) 30 25 15 Jaasjarvi NuasiJarvi Inari Pyhajarvi Haukivesi Lappa Pielinen Oulujarvi Rehja-Nuas n = 31 MBE = -0.63 RMSE = 4.60 b) AATSR-L2-PR ( C) 30 25 15 Jaasjarvi NuasiJarvi Inari Pyhajarvi Haukivesi Lappa Pielinen Oulujarvi Rehja-Nuas n = 32 MBE = -0.45 RMSE = 3.46 c) AATSR_L2 ( C) 5 5 15 25 30 30 25 15 Jaasjarvi NuasiJarvi Inari Pyhajarvi Haukivesi Lappa Pielinen Oulujarvi Rehja-Nuas SYKE ( C) 5 5 15 25 30 SYKE ( C) n = 19 MBE = 3.18 RMSE = 5.24 5 5 15 25 30 SYKE ( C) a) AATSR_L2_NCC b) AATSR_L2_PR c) ESA s AATSR L2 In-situ data from Finnish Lakes (August 09)
Evaluation of LSWT products LSWT vs 1-D lake models 30 CLIMo FLake MODIS Temperature ( C) 0 - - -30-40 -50 Jan-02 Jan-03 Jan-04 Jan-05 Jan-06 Jan-07 Jan-08 Jan-09 Jan- Great Slave Lake (02-) LST-CLIMo (02-) 30 0 - CLIMo - I a = 0.956-30 MBE = 4.25-40 RMSE = 6.27 n = 1154-50 -50-40 -30 - - 0 30 LST-MODIS (02-) CLIMo: Canadian Lake Ice Model FLake: Freshwater Lake model 1:1 LST-FLake (02-) 30 0 - FLake - I a = 0.949-30 MBE = 3.03-40 RMSE = 6.30 n = 1154-50 -50-40 -30 - - 0 30 LST-MODIS (02-) Kheyrollah Pour et al., 12 1:1
Evaluation of LSWT products LSWT vs 3-D lake model POM (Aug 08) MODIS (Aug 08) POM: Princeton Ocean Model Great Bear Lake (Aug 08). POM: Yerubandi et al., 11 Mean difference in the order of 1 ºC between MODIS (MYD/MOD) and POM simulation.
Evaluation of LSWT products MODIS/AATSR LWST & MERIS ice fraction a) MODIS visible image b) MERIS ice fraction c) AATSR surface temperature (between 8- AM local time) d) MODIS day time (between AM -12 PM local time) e) MODIS night time (between PM - 3 AM local time) a) b) c) d) e) 12 April 11 Kheyrollah Pour et al., 14
Concluding remarks Differences are in the order of 1-2 ºC between in-situ LST/LSWT, modeled LSWT and satellite-derived observations. MODIS Level 2 (Aqua/Terra) and derived products (e.g., UW-L3) allow for the examination of yearly/monthly and seasonal changes over the last decade. Two new algorithms (Key and Prata algorithms) were applied with the objective of improving the accuracy of LSWT product from AATSR. The newly developed AATSR products provide comparable results and minimize land contamination effects of existing product from ESA. More frequent satellite observations will be available (e.g. Sentinel-3 SLSTR, GCOM-C1 SGLI) with 1-km and 500-m spatial resolutions respectively.
Questions? Churchill, MB. Feb. 11
Evaluation of LST products Daily/hourly MODIS LST vs. Air Temperature (Hay River 07-08) 30 Daily Hay River_Station MODIS 40 Hourly Hay River_Station MODIS 30 Temperature ( C) 0 - - Temperature ( C) 0 - - -30-30 -40-40 -50 07 08-50 07 08 Daily Deline_Hourly Air Temperature ( C) 30 0 - - -30-40 Hourly R 2 = 0.96 n= 1435 I a = 0.985 MBE= -1.48 RMSE= ± 4.35-50 -50-40 -30 - - 0 30 MODIS_LST ( C)
LST vs air temp. Imnavait Basin, AK Arctic LST from satellite observations: validation/comparison Kuujjuaq, QC Hachem et al., 12
Arctic LST from satellite observations: validation/comparison Imnavait Basin, AK Kuujjuaq, QC LST vs ground temp. (3-5 cm below the surface) Hachem et al., 12
HIRLAM forecasting results without LSWT data with LSWT data Simulated 2m air temperature Simulated 2m air temperature MODIS visible image Simulated cloud cover 28 January 12, 00 UTC Simulated cloud cover
Recent variations observed by MODIS (00-12) Spring (MAM) anomaly (12 vs mean 02-11) March April May Derived from UW-L3 LST (25 km x 25 km)
MODIS-derived UW-L3 LST (1 km x 1 km) Nov. 11-1km
MODIS-derived UW-L3 LSWT (1 km x 1 km) 1-7 Jan. -1km Weekly June 12-1km Monthly