IARC Seminar Announcement

Submitted by Kimberly Hayes
Phone: 907-474-7176
10/07/05

Cloud Detection and Cloud Distribution Characteristics over the Antarctic from Satellite Data

Presentor: Gaku Kadosaki

Earth Observation Research and application Center, JAXA

Wednesday, October 26, 2005

IARC, Conference Room #401 11 a.m.

ABSTRACT

Over the past few decades, a considerable number of studies have been conducted on techniques to determine cloud coverage over the Antarctic using satellite images. One recent and notable technique presumes the particle size, temperature, and optical depth of cloud from the distribution of small brightness temperature differences (BTDs) between near infrared data (3.7 micrometer region) and thermal infrared data (11 micrometer region), and between two thermal infrared data (11 and 12 micrometer region) obtained from AVHRR onboard the polar orbital satellite NOAA. Although this method can discriminate clouds from snow and ice surface by using the slight BTD, the temperature difference between clouds and snow and ice surface may become less during polar night, making it especially difficult to distinguish clouds from the other surface in the Antarctic. For this reason, cloud detection over the Antarctic has been limited to certain regions and seasons; there are no quantitative cloud detection data for year-round analysis. In this study, an algorithm has been developed using the AVHRR data from NOAA-14 for cloud detection over the Antarctic, and the cloud distribution properties have been analyzed for the period from March 1997 to January 1998.