# Presentation: 209812

## Overview of TRMM Ground Validation

*Robert F. Adler & David B. Wolff*
*NASA/GSFC*

## Overview of TRMM Ground Validation

Description of Primary TRMM GV Sites

Comparing GV & TRMM Rain Intensities

Other Activities

Greater NASA Wallops GV Network

Florida Keys as a complementary GV site for TRMM

TRMM 3B42 vs. Atoll Gauge Data (Huffman et al.)

MELB PR/GV Comparisons (Meneghini et al)

*Description of Primary TRMM GV Sites*
*Comparing GV & TRMM Rain Intensities*
***Other Activities***
*Greater NASA Wallops GV Network*
*Florida Keys as a complementary GV site for TRMM*
*TRMM 3B42 vs. Atoll Gauge Data (Huffman et al.)*
*MELB PR/GV Comparisons (Meneghini et al)*

*Overview*

## TRMM GV Processing Status

## KWAJ: Kwajalein Atoll, RMI

*KPOL: S-band dual-pol 10 cm radar.*
*Seven gauge sites (co-located gauges at each site).*
*X-array gauge site at Roi Namur*
*Disdrometers on Kwajalein and Roi Namur islands.*

*KWAJ: Kwajalein Atoll, RMI*

## MELB: Melbourne, Florida

*WSR-88D 10 cm Doppler radar*
*Multiple gauge networks (STJ, SFWMD, KSC)*

*MELB: Melbourne, Florida*

## DARW: Darwin, Northern Territory, Australia

*CPOL: C-band dual-pol 10 cm radar.*
*30+ gauge sites*
*Significantly enhanced by BMRC support*

*DARW: Darwin, Northern Territory, Australia*

## HSTN: Houston, Texas

*WSR-88D Radar located in League City*
*150+ gauges operated by the Harris County Office of Emergency Management*

*HSTN: Houston, Texas*

## The NASA TRMM Office is responsible for collecting, processing and distributing GV data products

Level I: 1B-51, 1C-51

Level II: 2A-53, 2A-54, 2A-55, 2A-56

Level III: 3A-54

Data is processed using the Ground Validation System (GVS) and the Radar Software Library (RSL), both of which are available on the web.

*Level I: 1B-51, 1C-51*
*Level II: 2A-53, 2A-54, 2A-55, 2A-56*
*Level III: 3A-54*
***Data is processed using the Ground Validation System (GVS) and the Radar Software Library (RSL), both of which are available on the web.***
_***[	](http://trmm-fc.gsfc.nasa.gov/trmm_gv/software/software.html)***_

- _[http://trmm-fc.gsfc.nasa.gov](http://trmm-fc.gsfc.nasa.govhtml/)_

*GV Data Processing*

## 1B-51
All sites: radar reflectivity (DZ) and radial velocity (VR), polar coordinates
Darwin: Also ZDR
Kwajalein: Also ZDR and KDP
Data truncated at 230 km
All volume scans (VOS) packaged into hourly granules in HDF format

1C-51
Observed radar reflectivity + corrective mask
Maximum range 150 km

*All sites: radar reflectivity (DZ) and radial velocity (VR), polar coordinates*
*Darwin: Also ZDR*
*Kwajalein: Also ZDR and KDP*
*Data truncated at 230 km*
*All volume scans (VOS) packaged into hourly granules in HDF format*
***1C-51***
*Observed radar reflectivity + corrective mask*
*Maximum range 150 km*

*Level I GV Products*

## Radar

Remove non-precipitating echoes that may impact quality of higher level products

Anomalous propagation (AP), insects, birds, chaff, wildfires

Algorithm originally developed by Rosenfeld et al 1995.
8 adjustable parameters
Manually intensive -> algorithm not fully automated except at Kwajalein

*Remove non-precipitating echoes that may impact quality of higher level products*
*Anomalous propagation (AP), insects, birds, chaff, wildfires*
*Algorithm originally developed by Rosenfeld et al 1995.*
*8 adjustable parameters*
*Manually intensive -> algorithm not fully automated except at Kwajalein*

*Radar Data Quality Control*

## Gauge

Fully automated algorithm (Amitai et al. 2000) 
Applied to the combined radar and rain gauge data to determine which rain gauges (on a monthly scale) are unreliable for the purposes of Ze-R development.

If a gauge is considered unreliable, then all data for that month and gauge/(radar window) are ignored in Ze-R development.

*Fully automated algorithm (Amitai et al. 2000) *
*A**pplied to the combined radar and rain gauge data to determine which rain gauges (on a monthly scale) are unreliable for the purposes of Z**e**-R development.*
*If a gauge is considered unreliable, then all data for that month and gauge/(radar window) are ignored in Z**e**-R development.*

*Gauge Data Quality Control *

## 2A-52i: Rain existence

2A-53: Instantaneous rain rate†

2A-54: Stratiform/convective rain type†

2A-55: Three-dimensional reflectivity††

***2A-53: Instantaneous rain rate******†***
***2A-54: Stratiform/convective rain type******†***
***2A-55: Three-dimensional reflectivity******††***

- †151 x 151 grid at 2 km horizontal resolution
- † †151 x 151 x 13 grid at 1.5 km vertical resolution

*Level II GV Products*

## 3A-53: Five day (pentad) rainfall map †

3A-54: Monthly rainfall map †

3A-55: Three dimensional structure with vertical profiles

***3A-54: Monthly rainfall map ******†***
***3A-55: Three dimensional structure with vertical profiles***

- †151 x 151 grid at 2 km horizontal resolution

*Level III GV Products*

## Level I & II Processing Flowchart

*Level I & II Processing Flowchart*

## Using TRMM GV data

*Applications*

## V6r Biases - KWAJ 1999-2004

## V6r Monthly Means - KWAJ 1999-2004

## Greater Wallops Island GV Network

## Wallops Island Gauge/Disdrometer Radar “Farm”

## The TRMM Project has conducted field activities during August-September 2001-2003.

2001: Keys Area Microphysics Program (KAMP/CAMEX-III)

2002: Keys Area Precipitation Project (KAPP 2002, TRMM Project)

2003: Keys Area Precipitation Project (KAPP 2003, TRMM Project)

*2001: Keys Area Microphysics Program (KAMP/CAMEX-III)*
*2002: Keys Area Precipitation Project (KAPP 2002, TRMM Project)*
*2003: Keys Area Precipitation Project (KAPP 2003, TRMM Project)*

*Florida Keys as a Complimentary GV Site for TRMM*

## Keys Gauge Network

*Keys Gauge Network*

## TRMM Multi-Satellite Precipitation Analysis

***Huffman et al. 2005***
**The MPA primarily depends on input from two different sets of sensors.  **
- Passive microwave data
- Low-Earth-orbit (LEO) satellites
- TMI, SSM/I, AMSR-E (Aqua) AMSU-B (NOAA)
- Infrared (IR) data
- geosynchronous-Earth-orbit (GEO) satellites

## TRMM MPA Early Results - Atolls

## Radar Measurements 

*Meneghini et al.*

## Scatter Plots of Mean Reflectivity

*Scatter Plots of Mean Reflectivity*

## Scatter Plots of Mean Reflectivity

*Scatter Plots of Mean Reflectivity*

## Scatter Plots of Mean Rain

## TRMM GV data processing is fully up-to-date.

Routine comparisons between GV and TRMM estimates is now underway.

Utilization of other data sets/analyses (atolls, buoys, research gauge networks) for comparison with TRMM continues

Studying sites and techniques to improve overall validation program for TRMM, for the near future (AMSR, multi-satellite), and for transitioning into GPM

***Routine comparisons between GV and TRMM estimates is now underway.***
***Utilization of other data sets/analyses (atolls, buoys, research gauge networks) for comparison with TRMM continues***
***Studying sites and techniques to improve overall validation program for TRMM, for the near future (AMSR, multi-satellite), and for transitioning into GPM***

*Summary and Plans for the Future*