On the Controls of Daytime Precipitation in the Amazonian Dry SeasonSource: Journal of Hydrometeorology:;2016:;Volume( 017 ):;issue: 012::page 3079DOI: 10.1175/JHM-D-16-0101.1Publisher: American Meteorological Society
Abstract: he Amazon plays an important role in the global energy and hydrological budgets. The precipitation during the dry season (June?September) plays a critical role in maintaining the extent of the rain forest. The deployment of the first Atmospheric Radiation Measurement (ARM) Mobile Facility (AMF-1) in the context of the Green Ocean Amazon (GOAmazon) field campaign at Manacapuru, Brazil, provided comprehensive measurements of surface, cloud, precipitation, radiation, and thermodynamic properties for two complete dry seasons (2014 and 2015). The precipitation events occurring during the nighttime were associated with propagating storm systems (nonlocal effects), while the daytime precipitation events were primarily a result of local land?atmosphere interactions. During the two dry seasons, precipitation was recorded at the surface on 106 days (43%) from 158 rain events with 82 daytime precipitation events occurring on 64 days (60.37%). Detailed comparisons between the diurnal cycles of surface and profile properties between days with and without daytime precipitation suggested the increased moisture at low and midlevels to be responsible for lowering the lifting condensation level, reducing convective inhibition and entrainment, and thus triggering the transition from shallow to deep convection. Although the monthly accumulated rainfall decreased during the progression of the dry season, the contribution of daytime precipitation to it increased, suggesting the decrease to be mainly due to reduction in propagating squall lines. The control of daytime precipitation during the dry season on large-scale moisture advection above the boundary layer and the total rainfall on propagating squall lines suggests that coarse-resolution models should be able to accurately simulate the dry season precipitation over the Amazon basin.
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contributor author | Ghate, Virendra P. | |
contributor author | Kollias, Pavlos | |
date accessioned | 2017-06-09T17:17:13Z | |
date available | 2017-06-09T17:17:13Z | |
date copyright | 2016/12/01 | |
date issued | 2016 | |
identifier issn | 1525-755X | |
identifier other | ams-82423.pdf | |
identifier uri | http://onlinelibrary.yabesh.ir/handle/yetl/4225536 | |
description abstract | he Amazon plays an important role in the global energy and hydrological budgets. The precipitation during the dry season (June?September) plays a critical role in maintaining the extent of the rain forest. The deployment of the first Atmospheric Radiation Measurement (ARM) Mobile Facility (AMF-1) in the context of the Green Ocean Amazon (GOAmazon) field campaign at Manacapuru, Brazil, provided comprehensive measurements of surface, cloud, precipitation, radiation, and thermodynamic properties for two complete dry seasons (2014 and 2015). The precipitation events occurring during the nighttime were associated with propagating storm systems (nonlocal effects), while the daytime precipitation events were primarily a result of local land?atmosphere interactions. During the two dry seasons, precipitation was recorded at the surface on 106 days (43%) from 158 rain events with 82 daytime precipitation events occurring on 64 days (60.37%). Detailed comparisons between the diurnal cycles of surface and profile properties between days with and without daytime precipitation suggested the increased moisture at low and midlevels to be responsible for lowering the lifting condensation level, reducing convective inhibition and entrainment, and thus triggering the transition from shallow to deep convection. Although the monthly accumulated rainfall decreased during the progression of the dry season, the contribution of daytime precipitation to it increased, suggesting the decrease to be mainly due to reduction in propagating squall lines. The control of daytime precipitation during the dry season on large-scale moisture advection above the boundary layer and the total rainfall on propagating squall lines suggests that coarse-resolution models should be able to accurately simulate the dry season precipitation over the Amazon basin. | |
publisher | American Meteorological Society | |
title | On the Controls of Daytime Precipitation in the Amazonian Dry Season | |
type | Journal Paper | |
journal volume | 17 | |
journal issue | 12 | |
journal title | Journal of Hydrometeorology | |
identifier doi | 10.1175/JHM-D-16-0101.1 | |
journal fristpage | 3079 | |
journal lastpage | 3097 | |
tree | Journal of Hydrometeorology:;2016:;Volume( 017 ):;issue: 012 | |
contenttype | Fulltext |