contributor author | Sun, Bomin | |
contributor author | Groisman, Pavel Ya | |
date accessioned | 2017-06-09T16:20:06Z | |
date available | 2017-06-09T16:20:06Z | |
date copyright | 2004/05/01 | |
date issued | 2004 | |
identifier issn | 0894-8755 | |
identifier other | ams-6596.pdf | |
identifier uri | http://onlinelibrary.yabesh.ir/handle/yetl/4207244 | |
description abstract | Several changes in U.S. observational practice [in particular, the introduction of the Automated Surface Observing System (ASOS) in the early 1990s] have led to a challenging heterogeneity of time series of most ground-based cloud observations. In this article, an attempt is made to preserve/restore the time series of average low cloud cover (LCC) over the country up to the year 2001 using cloud sky condition and cloud-base height information collected in the national archive data and to describe its spatial and temporal variability. The switch from human observations to ASOS can be bridged through the use of frequency of overcast/broken cloudiness. During the past 52 yr, the nationwide LCC appears to exhibit a significant increase but all of this increase occurred prior to the early 1980s and thereafter tends to decrease. This finding is consistent with similar changes in the frequency of days with precipitation. When the cloud-type information was still available (i.e., during the pre-ASOS period), it was found that the overall LCC increase was due to the increase in stratiform and cumulonimbus cloud occurrences while cumulus cloud frequency decreased. | |
publisher | American Meteorological Society | |
title | Variations in Low Cloud Cover over the United States during the Second Half of the Twentieth Century | |
type | Journal Paper | |
journal volume | 17 | |
journal issue | 9 | |
journal title | Journal of Climate | |
identifier doi | 10.1175/1520-0442(2004)017<1883:VILCCO>2.0.CO;2 | |
journal fristpage | 1883 | |
journal lastpage | 1888 | |
tree | Journal of Climate:;2004:;volume( 017 ):;issue: 009 | |
contenttype | Fulltext | |