Production of globally uniform ISCCP Convection Tracking (CT) dataset
and preliminary analysis results
Abstract
The International Satellite Cloud Climatology Project (ISCCP)’s
Convection Tracking (CT) database was designed to track the evolution of
deep convective cloud systems throughout their life cycle. The database
is produced in 3 steps. The first step determines whether a particular
image pixel is cloudy and determines the cloud top temperature and
optical thickness. The second step clusters up all adjacent cold IR
pixels with brightness temperature (TBIR)< 245 K and stores
the summary information about cloud structural and radiative properties.
Such clusters are referred to as Convective Systems (CSs). A further
test identifies Convective Clusters (CCs) as adjacent cloud pixels with
TBIR < 220 K. The third step tracks each individual CS over
time to form families and produces the CT database. Previous version of
the CT data covered the period from 1983-2008 and treated one
geostationary satellite at a time. Recently, we started producing a new
version of CT data that are built upon the new, H-version ISCCP data
(HXG). Improvements from this new CT data include: 1) globally uniform
coverage, 2) higher spatial sampling/resolution (from 30 km down to 10
km), and 3) longer data record (1983-2015). This presentation will
introduce the new ISCCP CT database and show some preliminary results
including comparison with the old CT data and some essential global
statistics of deep convective cloud systems.