Transcript 070507Atlanta_TRMMStormStructureV05_Houze.ppt

Using the TRMM Precipitation Radar for
Storm Structure Analysis
Robert A. Houze
University of Washington
Precipitation Measuring Mission Science Team Meeting, Atlanta, 7-10 May 2007
Question:
Can we use TRMM PR to do traditional storm
structure analysis, like we might do with a
NEXRAD or an airborne radar like the
ELDORA?
Limitation of PR is temporal
Temporal--TRMM can’t be used to track mesoscale precipitation systems
Advantage is spatial
• TRMM goes everywhere in the tropics and views storms the same
way--so we can understand differences in mesoscale structure ion
different regions
• PR gets fully 3D reflectivity coverage where ever it goes
• Excellent vertical resolution
Stumbling block
Appropriate analysis tools and related data format issues--hard to do
meteorologist’s analysis
Re-map and interpolate the PR reflectivity field
Satellite
Interpolate
Geolocate
West Africa and Adjacent Atlantic
Off the coast of West
Africa
shallow-to-moderate
cells
mergers form
stratiform regions
Over land, just south
of the Sahara
deep convection with
anvil echo aloft
huge squall line
systems
Himalayan Region
°N
Western
Subregion
Central
Subregion
Arabian
Sea
INDIA
Eastern
Subregion
Bay of
Bengal
°E
Sawyer 1947
A case of deep isolated 40 dBZ core
14 June 2002
0900 UTC
A case of wide 40 dBZ echo core
22 July 2002
1300 UTC
Carlson et al. 1983
A typical case of wide 40 dBZ echo core with line
organization
2208 UTC
3 Sep 2003
A wide 40 dBZ echo core with squall-line
organization—rare!
2017 UTC
5 June 2003
A of wide 40 dBZ echo core with squall-line
organization—rare!
500 mb jet over
and parallel to the
Himalayas
10 meter level
500 mb level
5 June 2003
Deep cores over the Tibetan Plateau
14 July 2002
1227 UTC
Western
Central
Deep Intense Cores
40 dBZ echo
> 10 km in height
Wide Intense Cores
40 dBZ echo
> 1000 km2 area
Broad Stratiform Echo
stratiform echo
> 50,000 km2
Eastern
Intraseasonal Variation of the Monsoon
Webster & Tomas 1997
Day 0:
8 mm/d
5N-5S
80-90E
39 events
1985-95
“Break”
“Active”
Broad stratiform case
11 Aug 2002
0252 UTC
Broad stratiform case
Upstream of mountains
0455 UTC
CFADs can be used to summarize the storm
structures statistically
Reflectivity data for 2 monsoon seasons
Convection is
stronger &
deeper in west
Stratiform more
pronounced in
east
Reflectivity data for 2 monsoon seasons
Convection is
slightly deeper &
stronger over the
lowlands than
the foothills
Hurricane Rita as Seen by the TRMM PR
1445 UTC
22 Sep 2005
Summary
• Re-mapping, geo-locating, and interpolating the
TRMM PR data allows them to displayed in analysis
tools using Cartesian gridding
• Takes full advantage of both spatial coverage and
fine vertical resolution of PR
• Makes it possible to contrast and compare storm
structures in detail in various regions--Africa, India,
hurricanes, etc.
Thanks