Satellite-based Lake Surface Temperature (LST) Homa Kheyrollah Pour Claude Duguay
Lakes in NWP models Interaction of the atmosphere and underlying layer is the most important issue in climate modeling and numerical weather prediction (NWP). Lakes influence the regional heat, moisture content and circulation of the atmosphere. Ice cover and lake temperature have important effects on regional weather and climate in the vicinity of the lakes. A good representation of lake ice/temperature-climate interactions is necessary for improved weather forecasting and climate modelling. Lake Surface Temperature (LST) Satellite data Modeling In situ
MODIS Land/Lake Surface Temperature Produce Hourly, Daily, Weekly, and Monthly Land/Lake Surface Temperature products, - At different scales: PanArctic at 25 km of resolution. All territories above 55 N. Regional area at 6km resolution. Regional area at 1km resolution. - Period of time: 2002-2010.
Source of Observations From the NASA earth observation system MODIS sensor Level 2 LST product - Two satellites : Terra (2000) and Aqua (2002). Morning and evening overpasses 4 observations per day. - Calculated from thermal infrared wavelength in 2 different spectral ranges (11 and 12 mm). - All atmospheric temperature and water vapour profiles are used to calculate the LST. - Split window algorithm from Wan and Dozier (1997) From ESA, the Level 2 LST product from AATSR. - One satellite : Envisat (2002). - LST retrieved from thermal infrared. - Split window algorithm from Prata (2002)
Data Processing MODIS Terra & Aqua (Level 2, 1 km 2 resolution, version 5) day/night time land surface temperature and emissivity products (MOD/MYD11_L2), from the thermal-infrared channels 31 and 32 used through NASA s Land Processes Distributed Active Archive Center (LP DAAC) for the period 2002-2010. Two arrays are produced, one containing the average of all observations during the day and the other during the night. Average is produced for each pixel during the day and night. These values are averaged together to produce the final LST average with equal weighting between day and night values.
PanArctic (2010) 25 km resolution Jan Feb March April May June July Aug Sep
Regional (2010) 1km resolution Mackenzie River Basin, Canada MODIS Terra/Aqua
Yellownife_LST ( C) Agreement btw. MODIS Land Surface temperature and weather station air temperature 30 20 10 0-10 -20-30 -40-50 R 2 = 0.97 n= 1244 I a = 0.987 MBE= -2.67 RMSD= 4.12-50 -40-30 -20-10 0 10 20 30 MODIS_LST ( C) 2002-2009 R 2 I a MBE RMSD Jan-Dec 0.97 0.987-2.67 4.12 June-Sep LST > 0 Oct-May LST < 0 0.77 0.994-1.56 2.74 0.94 0.983-3.29 4.73
Lake Models FLake Fresh water Lake model (Mironov 2008). 1-D lake model. Developed for NWP & climate modeling. Based on a two-layer water temperature profile. Predict the surface temperature in lakes of various depths on the time scales. FLake does not consider the snow cover over the lake ice. CLIMo Canadian Lake Ice Model (Duguay et al. 2003). 1-D thermodynamic ice model. Simulate ice phenology on lakes of various sizes and depths. Five different scenarios for snow and mixed layer depth. Mixed layer depth kept constant during simulations.
Models LSTs vs. MODIS (Back Bay, GSL, 10m depth) Whole Season CLIMo FLake Open Water Season Ice Growing Season
Models LSTs vs. MODIS (Main Basin, GSL, 40m depth) Whole Season CLIMo FLake Open Water Season Ice Growing Season
MODIS-based LST over Finnish Lakes
Why am I here? Study the thermal variability of lakes and their responses to climate using MODIS (Moderate-Resolution Imaging Spectroradiometer) & AATSR (Advanced Along-Track Scanning Radiometer) data. Validating satellite temperature data (MODIS, AATSR data) with in-situ and SYKE over Finnish lakes. Using satellite temperature data in NWP models as data assimilation method.
MODIS Mean Monthly Temperature
MODIS Mean Monthly Temperature
MODIS-derived LST (Jan 2009 - Dec 2010) Temperature C High Low
MODIS Mean Monthly Temperature
MODIS Mean Monthly Temperature
Validation of MODIS LST with In-situ Obs. & SYKE (Päijänne Lake) MODIS values are averaged during days (6 AM 6 PM).
LST- In Situ (2010) Temperature ( C) LST- In Situ (2010) Validation of MODIS LST with In-situ Obs. & SYKE (Lappajarvi Lake) 26 24 SYKE MODIS DailyAve. Insitu Obs. 25 20 22 20 15 18 16 14 10 5 Ia = 0.99 MBE = - 1.46 RMSE = 2.68 n = 59 12 10 8 0 0 5 10 15 20 25 LST-MODIS (2010) 6 4 2 25 20 0 May June July August September 2010 MODIS value are averaged during whole day (6 AM - 6 PM,6 PM - 6 AM). 15 10 5 0 0 5 10 15 20 25 LST-MODIS (2010) Ia = 0.99 MBE = - 2.11 RMSE = 2.61 n = 59
Limitations Temporal discontinuity in data due to: - Cloud contamination: less than 100 days without cloud in one year for some regions. - Number of overpasses over the exact same location: every 16 days Aqua and Terra and 30 days with AATSR
Ladoga Lake
Temperature (K) Ladoga Lake 265 260 255 250 245 240 1-Jan 6-Jan 11-Jan 16-Jan 21-Jan 26-Jan 31-Jan Ladoga Lake - 2010 61.736419 30.798418 61.736419 30.810129 61.736419 30.821839 61.736419 30.83355 61.736419 30.84526 61.736419 30.85697 61.736419 30.868681 61.727413 30.83355 61.727413 30.84526 61.727413 30.85697 61.727413 30.868681
Ladoga Lake (15 Clusters) 1 2 3 4 5 8 6 7 9 11 10 12 13 15 14
Temperature Ladoga Lake (15 Clusters/April-Day time) 276 274 272 270 268 266 264 Cluster1 Cluster2 Cluster3 Cluster4 Cluster5 Cluster6 Cluster7 Cluster8 Cluster9 Cluster10 Cluster11 Cluster12 Cluster13 Cluster14 Cluster15 262 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 Ladoga-April 2010
Temperature Ladoga Lake (15 Clusters/Aug-Day time) 300 295 290 285 280 275 270 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 Ladoga-Aug 2010 Cluster1 Cluster2 Cluster3 Cluster4 Cluster5 Cluster6 Cluster7 Cluster8 Cluster9 Cluster10 Cluster11 Cluster12 Cluster13 Cluster14 Cluster15