Phil Arkin, ESSIC

1
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
  1979-2003)

4
CMAP Precipitation 1987 - 1997
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 lt0.2 to 2-3
mm/day coastal point to the south goes from 1 to
gt6 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

8
(No Transcript)
9
(No Transcript)
10
(No Transcript)
11
(No Transcript)
12
(No Transcript)
13
(No Transcript)
14
(No Transcript)
15
(No Transcript)
16
(No Transcript)
17
(No Transcript)
18
(No Transcript)
19
(No Transcript)
20
(No Transcript)
21
(No Transcript)
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