Show simple item record

contributor authorPeña, MalaquÍas
contributor authorDouglas, Michael W.
date accessioned2017-06-09T16:14:42Z
date available2017-06-09T16:14:42Z
date copyright2002/12/01
date issued2002
identifier issn0027-0644
identifier otherams-64049.pdf
identifier urihttp://onlinelibrary.yabesh.ir/handle/yetl/4205120
description abstractThis paper describes the mean atmospheric conditions associated with synoptic-scale rainfall fluctuations over Central America during the rainy season. The study is based on composites of wet and dry spells; these composites are generated from six years (1990?94 and 1997) of daily rainfall observations from select Central American stations, one year (1997) of upper-air wind data from an enhanced sounding network over the region, National Center for Environmental Prediction (NCEP) reanalysis data, and outgoing longwave radiation (OLR) data. Wet spells, defined as days when 75% or more of the stations along the Pacific side of Nicaragua, Costa Rica, and Panama reported rainfall, are associated with weaker trade winds over the Caribbean and stronger cross-equatorial flow northward over the eastern Pacific. During wet spells the intensity of eastern Pacific cross-equatorial flow exceeds by several meters per second the seasonal mean in the lower and middle troposphere, and is strongest and deepest one day before the wettest day. Dry spells, defined as the days when 35% or less of these stations reported rainfall, are associated with stronger trade winds over Central America and weaker and shallower cross-equatorial flow. The basic flow patterns seen in the observation-based composites agree well with similar composites produced using reanalysis data, except that the observations show stronger cross-equatorial flow in the lower-mid troposphere over the eastern Pacific. OLR data shows that convective cloudiness anomalies associated with the wet and dry spells extend westward from Central America into the eastern tropical Pacific.
publisherAmerican Meteorological Society
titleCharacteristics of Wet and Dry Spells over the Pacific Side of Central America during the Rainy Season
typeJournal Paper
journal volume130
journal issue12
journal titleMonthly Weather Review
identifier doi10.1175/1520-0493(2002)130<3054:COWADS>2.0.CO;2
journal fristpage3054
journal lastpage3073
treeMonthly Weather Review:;2002:;volume( 130 ):;issue: 012
contenttypeFulltext


Files in this item

Thumbnail

This item appears in the following Collection(s)

Show simple item record