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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Evolution of the Planetary Boundary Layer on the northern coast of Brazil during the CHUVA campaign

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Author(s):
da Silva Ramos, Diogo Nunes [1] ; Reyes Fernandez, Julio Pablo [1] ; Fisch, Gilberto [2]
Total Authors: 3
Affiliation:
[1] Inst Nacl Pesquisas Espaciais, Ctr Previsao Tempo & Estudos Climat, Cachoeira Paulista, SP - Brazil
[2] Inst Aeronaut & Espaco, Dept Ciencia & Tecnol Aeroespacial, Sao Jose Dos Campos, SP - Brazil
Total Affiliations: 2
Document type: Journal article
Source: ATMOSPHERIC RESEARCH; v. 203, p. 298-310, MAY 1 2018.
Web of Science Citations: 0
Abstract

This study aims to characterize the wind and thermodynamic structure of the Planetary Boundary Layer (PBL) on the northern coast of Brazil (NCB) via the CHUVA datasets. Three synoptic conditions were present in the NCB region between March 1 and 25, 2010: a dry period, the Upper Tropospheric Cyclonic Vortex (UTCV) and the Intertropical Convergence Zone (ITCZ). Nighttime precipitation accounted for 78% of the total precipitation observed in the month, mainly during the ITCZ. In general, the surface meteorological fields were few changed by intense weather events due to proximity to the ocean and the predominant contribution of the northeasterly trade winds. There was also a weak sea breeze signal that maintained the horizontal moisture flow in the studied area. On dry days, the PBL depth was higher, drier, and warmer, resulting in stronger winds below 500 m. Moreover, trends throughout the period suggest that PBLs are near-neutral below 500 m. However, the wind variability was intensified by up to 20% due to downdrafts and higher wind shears during the deep convection mechanisms derived by UTCV. Furthermore, ITCZ mixed rainfall cooled the PBL at approximately 2 K, making it very stable according to the Richardson number classification adopted. The observed temporal and spatial scale represent challenges to the physical parameterizations used to improve numerical weather prediction models over tropical coastal areas. (AU)

FAPESP's process: 09/15235-8 - Cloud processes of the main precipitation systems in Brazil: a contribution to cloud resolving modeling and to the GPM (Global Precipitation Measurement)
Grantee:Luiz Augusto Toledo Machado
Support type: Research Projects - Thematic Grants