Diurnal variations of cloud cover and their relationship to climatological conditions

Journal Article · Fri Nov 01 04:00:00 EST 1996 · Journal of Climate

DOI:https://doi.org/10.1175/1520-0442(1996)009<2802:DVOCCA>2.0.CO;2· OSTI ID:433058

Bergman, J W; Salby, M L ^[1]

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1. Univ. of Colorado, Boulder, CO (United States)

The ISCCP-C2 cloud climatology is used to describe the three-dimensional structure of cloud diurnal variations and to investigate their relationship to local climatological conditions. The latter follows from the regression of diurnal components onto climatological state variables. Four important diurnal cloud categories are identified. The diurnal variation of maritime high-cloud fraction C{sub hi} maximizes at 1700 local solar time (LST) and is strongest over maritime convective locations where the mean high-cloud fraction is C{sub hi} > 0.1. The diurnal variation of maritime low-cloud fraction maximizes at 0400 LST and is strong over maritime nonconvective locations where C{sub hi} < 0.1. Diurnal variations of high-cloud fraction (persistent during the night, minimum at 1100 LST) and low-cloud fraction ( 1300 LST maximum) are strong over all continental locations in the latitude band 40{degrees}S-40{degrees}N. In each cloud category, most of the diurnal amplitude and phase at individual locations is explained by the regression of diurnal amplitude onto only three climatological state variables. For most categories, the diurnal amplitude has its strongest relationship with mean cloud fraction. 31 refs., 15 figs., 8 tabs.

• OSTI ID: 433058
• Journal Information: Journal of Climate, Journal Name: Journal of Climate Journal Issue: 11 Vol. 9; ISSN JLCLEL; ISSN 0894-8755
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
AMBIENT TEMPERATURE
CLIMATES
CLOUD COVER
CORRELATIONS
DAILY VARIATIONS
STATISTICS