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Satellite Remote Sensing and Applications in Hydrometeorology. Xubin Zeng Dept of Atmospheric Sciences University of Arizona Tucson, AZ 85721. http://www.atmo.arizona.edu/~zeng/zeng.html Fractional cover (Zeng et al. 2000, 2003) and green
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Satellite Remote Sensing and Applications in Hydrometeorology Xubin Zeng Dept of Atmospheric Sciences University of Arizona Tucson, AZ 85721
http://www.atmo.arizona.edu/~zeng/zeng.html • Fractional cover (Zeng et al. 2000, 2003) and green • vegetation cover (Miller et al. 2006) • Albedo/BRDF (Wang et al. 2004, 2005, 206) and snow • albedo (Barlage et al. 2005, 2006) • Vegetation root (Zeng et al. 1998; Zeng 2001) • Precip intensity and freq. (Kursinski and Zeng 2006) • Precip, water vapor, and monsoon (Zeng and Lu 2004) • Veget. pattern and growth (X.D. Zeng et al. 2006a,b)
FVC vs LAI NCAR/CLM3: FVC(x,y), LAI(x,y,t) NCEP/Noah: GVF(x,y,t),LAI=Const Validation: 1-3m spy sat data, 1-5m aircraft data, 30m Landsat data, Surface survey data Histogram of evergreen Broadleaf tree NDVIveg = 0.69
FVC (x,y) LAI (x,y,t) Versus FVC (x,y,t) LAI = 4
Interannual variability and decadal trend of global fractional vegetation cover from 1982 to 2000
NLDAS GVF Data Noah 1/8 degree monthly MODIS 2km 16-day
Application of MODIS Maximum Snow Albedo to WRF-NMM/NOAH • up to 0.5 C decreases in 2-m Tair in regions of significant albedo change • > 0.5 C increase in 2-m Tair in several regions
Land Surface albedo and its SZA dependence ECMWF: no SZA dependence NCEP: simple formulation NCAR (CLM3): two stream NASA (Catchment): simple fitting to two-stream In satellite remote sensing retrieval of solar fluxes, including ISCCPFD, UMD (Pinker; ISCCP C1), CERES TRMM: surface albedo adjusted to match computed TOA solar flux with satellite measurements
The comparison of the MODIS blue-sky albedos with CERES/TRMM broadband albedos at 8 locations with different vegetation types from July 11-26, 1998. The MODIS BSA at 60 SZA for the 16-day period starting from Julian day 193 averaged from 2000 to 2004 are used.
Maximum snow albedo • Maximum snow albedo is used as an end member of the interpolation from snow- to non-snow covered grids • Current dataset is based on 1-year of DMSP observations from 1979 • Current resolution of 1° • Create new dataset using 4+ years of MODIS data with much higher resolution
MODIS Albedo Data (a) 1 km data in 10 deg tiles; global 0.05 deg (vs. 1 deg in RK) (b) seven narrow bands, VIS (0.4-0.7 microns), NIR (0.7-5 microns), SW (0.4-5 microns) (vs. SW from 0.4-1.1 microns in RK) (c) Day 49 of 2000 - Day 177 of 2004 (vs. 75 images in 1979 and 5 images in 1978) (d) Quality flags (e) MODIS data from both Terra and Aqua (f) Both albedo and BRDF
Current Logic Structure 0.05o MODIS Albedo MODIS QC = good NDSI > 0.4 Band 2 > 0.11 Global Maximum Snow Albedo Land Cover
* Application of MODIS Maximum Snow Albedo to NCEP Land Surface Model Up to 0.2 difference in high/mid latitudes can greatly affect surface energy balance, snow depth, and snow melt timing *Note: 0.05° maximum albedo dataset downscaled to 1° to compare with NOAH data
Application of MODIS Maximum Snow Albedo to WRF-NMM/NOAH • WRF-NMM Model: 10min(0.144°) input dataset converted from 0.05° by simple average; model run at 12km; initialized with Eta output; • Winter simulation: 24hr simulation beginning 12Z 31 Jan 2006
Offline simulation over the Amazon (deep roots maintain dry season ET)
Monsoon Onset/Retreat Indexes Normalized precipitable water (PW) index: NPWI = (PW – PWmin)/(PWmax – PWmin) where PWmax and PWmin are the ten-year averages of the annual max and min daily PW at each grid cell. Proposed objective criterion: The monsoon onset (or retreat) date for grid cell G is defined as the first day (d) when NPWI is greater (or less) than the Golden Ratio (0.618) for 3 consecutive days in 7 of the 9 cells centered at cell G in day d or d±1. Explanations: `3 consecutive days’, `9 cells’, `Golden Ratio’
Vegetation Pattern and Diversity (1) (2) (3) (4) (5) (6) (7)
Annual Precipitation: 297mm Annual Precipitation: 342 mm
Annual Precipitation: 484mm Annual Precipitation: 542mm