1. Phil Arkin, ESSIC University of Maryland
Satellite Observations in Support of NAME Diagnostic Studies
Phil Arkin, ESSIC
University of Maryland

2. Outline Mean seasonal cycle in precipitation in the NAME region
Seasonal and diurnal variability in precipitation in the NAME region during the 2003 monsoon season
Issues for NAME Diagnostic Studies

3. Seasonal variability in precipitation in the NAME region from CMAP
CMAP is composite product using several satellite-derived estimates and gauge observations (Xie and Arkin, 1997)
Monthly, 2.5ºx 2.5º used here
Averaged over 1987 – 1997 (full dataset is )

4. CMAP Precipitation
April – June
July - August
Ratio – percentage increase from AMJ to JA

5. CMAP precipitation (1987-1997) for AMJ (top) and JA (bottom)
Tip of Baja California goes from <0.2 to 2-3 mm/day; coastal point to the south goes from 1 to >6 mm/day

6. Ratio (JA/AMJ)
Annual cycle of precipitation averaged over the two boxes

7. Details of the diurnal cycle during the 2003 monsoon season using CMORPH
CMORPH is composite product using all available passive microwave-derived estimates with interpolation by advection inferred from geostationary IR (Joyce et al., 2003, submitted)
Basic dataset is 30 minute/8 km – 3 hour totals for 0.25ºx 0.25º areas used here
Pingping Xie made the figures I will show here; thanks also to Robert Joyce, John Janowiak, Mingyue Chen and Yelena Yarosh

22. Conclusions: Part 4
CMORPH allows us to visualize details of the influence of the terrain of the diurnal cycle of precipitation that probably have not been seen before
Precipitation dies away quickly to the west of the Sierra Madre Occidental; only a little rain makes it offshore
ITCZ south of Mexico has weak diurnal cycle with peak just after midnight; sharp demarcation right at coastline
Over the U.S., CMORPH exhibits clear eastward propagation from the Rockies, quite similar to Carbone et al. findings from several years of radar data

23. Issues for NAME Diagnostic Studies
Precipitation products that utilize satellite observations (such as, but not limited to, CMAP and CMORPH) will be very useful for NAME diagnostics studies:
However, the link to surface-based observations (gauges, radars) is still to be made for fine scales
The (likely) loss of TRMM and AMSR (on ADEOS-2) is a significant handicap