Tropical Rainfall Measuring Mission (TRMM) LBA
NOAA AL Profiler Observations in Support of TRMM-LBA, Rondonia Province, Brazil
The Large Scale Biosphere Atmosphere Experiment (LBA) is an international field program led by Brazilian scientists. The aim of LBA is to explore the effects of deforestation in Amazonia on regional climate. TRMM LBA is an important part of the hydrology component of LBA.
The primary objective of TRMM-LBA is to provide ground validation for the TRMM satellite. The data base developed in TRMM-LBA will be suitable for validation of numerical simulation of mesoscale convective systems using cloud-resolving models and forward radiative transfer models to understand and improve the performance of the satellite and ground validation algorithms. TRMM-LBA was conducted jointly by U.S. and Brazilian scientists.
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| Figure 1. AL Profiler pair located at Ji Parana municipal airport. | Figure 2. Map showing locations of AL Profilers in relation to scanning radars and other ground-based instruments (map courtesy of Colorado State University). |
TRMM-LBA was led by Colorado State University. The ground-based component of TRMM-LBA includes two scanning Doppler radars operated in dual Doppler mode (the NCAR S-pol radar and the TOGA radar operated by NASA). The Aeronomy Laboratory profilers were located at the Ji Parana municipal airport surrounded by a network of rain gages and disdrometers.
The TRMM-LBA data archive resides at the GSFC DAAC.
NOAA AL Profiler Observations from TRMM-LBA, Rondonia Province, Brazil
The NOAA Aeronomy Laboratory has used two collocated Doppler radar profilers in support of TRMM-LBA field campaign. The profilers are vertically directed and operate at 915 MHz and 2835 MHz respectively and are used to observe the hydrometeors in precipitating cloud systems in the vertical column over the profilers. The Doppler spectra are processed to yield the three moments of the spectrum: the reflectivity (in units of dBZe), Doppler velocity of the hydrometeors in the ambient air (m/s) and spectral width (m/s).
For TRMM-LBA the profilers (See Figure 1) were located at the Ji Parana municipal airport which places them between the TOGA radar and the S-pol radar (See Figure 2). The profilers were operated in a time synchronous manner each alternating between two modes with dwell periods of 30 seconds each. During the first dwell period the profilers observed with 105 meter pulse length up to 10 km and during the second dwell period the 915 MHz profilers observed with 250 meter pulse length up to 18 km while the 2835 MHz profiler observed with 60 meter pulse length up to 6 km.
Links to AL TRMM-LBA profiler archives:
- Browse archive of profiler images (a new window will open). This link provides images of the profiler observations.
- Profiler calibration. This link describes the profiler calibration using the collocated surface Joss-Waldvogel disdrometer.
- Calibrated profiler data archive. This link contains the calibrated profiler observations of reflectivity, Doppler velocity, and spectral width.
- Surface Meteorological data archive. This link contains the observations from the collocated surface met observations.
- Joss-Waldvogel Disdrometer. This link contains the observations from the collocated Joss-Waldvogel disdrometer.