1. Downscaling of forcing data Temperature, Shortwave (Solar) & Longwave (Thermal) CHARIS meeting, Dehra Dun, India, October 2014 Presented by: Karl Rittger

2. Spatial variability in forcing variables Temperature and precip. gradients North and south facing slopes Kanjin, Langtang Himal, November 2013 Along valley gradients 2CHARIS meeting, Dehra Dun, India, October 2014

3. Snow heterogeneity Wind redistribution (D. Marks) Differential ablation (E. Bair) 3CHARIS meeting, Dehra Dun, India, October 2014

4. Meteorological stations Sparse coverage Few high elevation stations Possibly short series How representative are they Need to be “upscaled”/extrapolated Needs knowledge of lapse rates for P and T. 4CHARIS meeting, Dehra Dun, India, October 2014

5. Snow cover from Landsat 5 & in-situ data 5 July 02 Fractional snow cover July 18 Fractional snow cover Automated SWE observations Streamflow observations CHARIS meeting, Dehra Dun, India, October 2014

6. Climate reanalysis 6 Numerical description of the recent climate Combines models of physical processes in the atmosphere and oceans with observations Observations Air temperature, pressure, wind Rainfall, soil moisture, sea-surface temp Simplified topography May be biased Needs to be downscaled Globally complete Long time series consistent CHARIS meeting, Dehra Dun, India, October 2014

7. Atmospheric reanalysis used in NASA’s Land Data Assimilation System (LDAS) 7 http://ldas.gsfc.nasa.gov/index.php GLDAS-1: Current Higher resolution GLDAS-2: Long time scale Consistent CHARIS meeting, Dehra Dun, India, October 2014

8. Atmospheric reanalysis used in NASA’s Land Data Assimilation System (LDAS) 8 http://ldas.gsfc.nasa.gov/index.php Drives multiple land surface models from simple to complex CHARIS meeting, Dehra Dun, India, October 2014

9. Downscaling of forcing data Temperature  Based on lapse rates and elevation differences between coarse and fine DEMs Shortwave and Longwave  Scale (time and space)  Elevation  Topography  Forest 9CHARIS meeting, Dehra Dun, India, October 2014

10. Downscaling of forcing data Temperature  Based on lapse rates and elevation differences between coarse and fine DEMs Shortwave and Longwave  Scale (time and space)  Elevation  Topography  Forest 10CHARIS meeting, Dehra Dun, India, October 2014

11. GLDAS-1-NOAH: air temperature 11CHARIS meeting, Dehra Dun, India, October 2014

12. Sierra Nevada, California (Elevation) 12 500m (1/8° or about 14km) CHARIS meeting, Dehra Dun, India, October 2014

13. Sierra Nevada, California (Elevation) 13 500m scale (1/8° or about 14km) CHARIS meeting, Dehra Dun, India, October 2014

14. Downscaling temperature using a lapse rate and change in elevation 14CHARIS meeting, Dehra Dun, India, October 2014 Air Temperature, 1999-01-01 0100

15. Air Temperature (T a ), 1999-01-01 0100 (Video) 15CHARIS meeting, Dehra Dun, India, October 2014

16. But environmental lapse rates change through time and from place to place. Reanalysis data has air temperatures for many levels in the atmosphere Atmospheric profile can be used to estimate lapse rate. A more rigorous approach to the lapse rate, γ 16 Simplest approach is to use a standard lapse rate to disaggregate model temperature to finer grid. CHARIS meeting, Dehra Dun, India, October 2014

17. Downscaling of forcing data Temperature  Based on lapse rates and elevation differences between coarse and fine DEMs Shortwave and Longwave  Scale (time and space)  Elevation  Topography  Forest 17CHARIS meeting, Dehra Dun, India, October 2014

18. GLDAS: incoming solar 18CHARIS meeting, Dehra Dun, India, October 2014

19. Net Shortwave Radiation: Tuolumne-Merced River basins March 1, 2006 12:00 Painter et al., 2009; Dozier et al., 2008 Link and Marks, 1999; Garren and Marks, 2005 Dozier and Frew, 1990 Erbs et al., 1982; Olyphant et al., 1984 Dubayah and Loechel., 1997 Cosgrove et al., 2003; Pinker et al., 2003; Mitchell et al., 2004 19CHARIS meeting, Dehra Dun, India, October 2014

20. GLDAS: incoming thermal 20CHARIS meeting, Dehra Dun, India, October 2014

21. Net Longwave Radiation: Tuolumne-Merced River basins March 1, 2006 12:00 Dozier and Frew, 1990 Link and Marks, 1999; Garren and Marks, 2005 Dubayah and Loechel, 1997 21CHARIS meeting, Dehra Dun, India, October 2014

22. Summary Need to capture processes at small scale in modeling snow accumulation and melt Global re-analysis data available from several sources Coupled with land surface models to provide surface fluxes Downscaling based on  Elevation, slope, aspect, solar angles, vegetation, shading, dynamic lapse rates 22CHARIS meeting, Dehra Dun, India, October 2014

23. ERA-Interim estimates lapse rates 23CHARIS meeting, Dehra Dun, India, October 2014