TITLE:
Characteristics of Central Southwest Asian Water Budgets and Their Impacts on Regional Climate
AUTHORS:
Khalid M. Malik, Peter A. Taylor, Kit Szeto, Azmat Hayat Khan
KEYWORDS:
Water Budgets; Drought over Central Southwest Asia; Moisture Flux Convergence; Principle Component Analysis; Climate Change
JOURNAL NAME:
Atmospheric and Climate Sciences,
Vol.3 No.2,
April
30,
2013
ABSTRACT: Water budgets terms, evapotranspiration (E), precipitation (P), runoff (N), moisture
convergence (MC) and both surface as
well as atmospheric residual terms have been computed with National Centers for
Environmental Prediction (NCEP) (1948-2007) and European Centre for Medium-Range Weather Forecasts (ECMWF) ERA-40 (1958-2001) reanalysis
data sets for Central Southwest Asia (CSWA).The domain of the study is 45° - 75°E
& 25° - 40°N. Only the land area has been used in these calculations. It is
noted in the comparison of both reanalysis data sets with Global Precipitation
Climatology Centre (GPCC) that all three data sets record different
precipitation before 1970. The maximum is from NCEP and the minimum with
ERA-40. However, after 1970 all the data sets record almost the same
precipitation. ERA-40 computes two phases of MC. Before 1975, the domain acts as a moisture source, whereas
after 1975 it behaves as a moisture sink. The region CSWA is divided into six
sub areas with rotational principle factor analysis and we distinguish them by
different approached weather systems acting on each area. Finally, NCEP yearly
precipitation is further divided into seasons; winter (November to April) and
summer (May to October) and two phases have been noted. The variation in winter
precipitation is more than summer during last 60-year analysis.