The effects of orography in indochina on wind, cloud, and rainfall patterns during Typhoon Ketsana (2009)

Abstract

The objective of this study is to i) investigate the effects of orography on the rainfall, wind, and cloud systems of the Typhoon Ketsana (2009) in Indochina, ii) determine rainfall distribution patterns and which parts of Indochina were most affected during Typhoon Ketsana, iii) identify trends in the cloud and rainfall distribution patterns and wind flow patterns in the synoptic scale on orographic effects during Typhoon Ketsana. Remote sensing techniques have been used to study the impacts of TCs. Using data from the remote sensing data such as Fengyun 2D (FY-2D) satellite, Global Digital Elevation Model (GDEM) from the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) satellite, wind information from the Navy Operational Global Atmospheric Prediction System (NOGAPS), and radiosonde data were applied in this study to determine the relationship of the typhoon with the orographic effect. This study provides examples of how the orographic effect is important to weather forecasters, as high mountain ranges were able to influence the distribution of the cloud, rainfall and even wind flow patterns during the typhoon season. This remote sensing technique allows tropical cyclones to be forecasted and their impacts to be defined, and it allows disaster zones to be determined.