NOTE: This item is not available outside the Texas A&M University network. Texas A&M affiliated users who are off campus can access the item through NetID and password authentication or by using TAMU VPN. Non-affiliated individuals should request a copy through their local library's interlibrary loan service.
A census of precipitation features in the tropics using TRMM: radar, ice scattering, and lightning observations
Abstract
The observation of precipitation in the tropics has been greatly enhanced trough the launch of the Tropical Rainfall Measuring Mission (TRMM) satellite n 1997. TRMM'S ability to continuously and simultaneously observe precipitation processes with the first quantitative space-borne radar (the 13.8 5Hz Precipitation Radar), the TRMM Microwave Imager, and the Lightning Imaging Sensor has created a large database of high-resolution data for intercomparison. Focusing on the TRMM data set in two land and two ocean regions during August, September and October 1998, this study used radar retrievals and 85 GHz Polarization Corrected Temperatures (PCTs, which passively measure relative concentrations of precipitation-sized ice particles within a cloud system) to identify TRMM Precipitation Features (TPFs) greater than 75 km: in size. These features were classified by intensity criteria to identify Mesoscale Convective Systems, precipitation with PCTs below 250 K, and other features without PCTs below 250 K. Analysis of the TPFs revealed similar areas of features when the entire distribution was taken into account. However the TPFs with MCSs had significantly larger rain areas over the ocean than over land. Despite the larger rain areas, the ice scattering signatures < 250 K were similar over land and ocean, meaning more rain is falling outside of the ice scattering MCS area. Oceanic systems were much less intense in terms of their maximum height of the 30 dBZ contour and maximum reflectivity at 6 km altitude. Rainfall distributions for land and ocean storms were found to be very different when classified by intensity. Despite similar total rainfall over the four regions, the rainfall patterns differ among the land and ocean regions. Oceanic storms have a bimodal contribution to rainfall from two types of systems: very weak systems with little ice scattering and moderately strong systems that do not produce high lightning flash rates. Continental systems that produce the bulk of the rainfall as sampled are likely to have higher lightning flash rates, which is shown to be linked to stronger radar and ice scattering intensities.
Description
Due to the character of the original source materials and the nature of batch digitization, quality control issues may be present in this document. Please report any quality issues you encounter to digital@library.tamu.edu, referencing the URI of the item.Includes bibliographical references (leaves 83-85).
Issued also on microfiche from Lange Micrographics.
Collections
Citation
Nesbitt, Stephen William (1999). A census of precipitation features in the tropics using TRMM: radar, ice scattering, and lightning observations. Master's thesis, Texas A&M University. Available electronically from https : / /hdl .handle .net /1969 .1 /ETD -TAMU -1999 -THESIS -N49.
Request Open Access
This item and its contents are restricted. If this is your thesis or dissertation, you can make it open-access. This will allow all visitors to view the contents of the thesis.