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Sea breeze and precipitation over Hainan Island
Author(s) -
Liang Zhaoming,
Wang Donghai
Publication year - 2017
Publication title -
quarterly journal of the royal meteorological society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.744
H-Index - 143
eISSN - 1477-870X
pISSN - 0035-9009
DOI - 10.1002/qj.2952
Subject(s) - orography , sea breeze , stratification (seeds) , climatology , precipitation , geology , wind shear , mesoscale meteorology , convection , humidity , atmospheric sciences , prevailing winds , warm front , environmental science , oceanography , wind speed , meteorology , geography , seed dormancy , botany , germination , dormancy , biology
The relationship between sea breeze and precipitation over Hainan Island is investigated, along with consideration of the effects of orography, synoptic wind and environmental conditions, using a period (2011–2015) of high‐resolution observational data, ERA‐Interim reanalysis data, and numerical experiments. The results show that the combined effect of mountain–plain and plain–sea thermal contrasts plays a major role in promoting sea‐breeze occurrence on Hainan Island. Although the sea‐breeze convergence tendency favours precipitation formation during October to March, the low humidity and convective available potential energy (CAPE), stable atmospheric stratification, high free convection level (LFC) and strong vertical wind shear in northeasterlies during this period notably inhibit the occurrence of heavy precipitation on Hainan Island. On the contrary, large amounts of precipitation over Hainan Island during April to September arise from high humidity and CAPE, unstable atmospheric stratification, low LFC and weak vertical wind shear associated with southwesterlies; additionally, the sea‐breeze front (SBF) has a convergence tendency under weak synoptic winds. In the context of the synoptic wind, these strong precipitations are prone to occur on the mountain leeward side, likely because of a strong leeward‐side SBF, which could be enhanced considerably by the orography; however, heavy precipitation seldom occurs on the mountain windward side, likely due to weak lifting motion associated with weak synoptic winds and a less significant windward‐side SBF. Because of these effects, pronounced precipitation is apt to occur over the east and west coasts, and propagates northeastward or northward with the steering of the southwesterlies and the development of SBFs in the north part of the island, during April to August. Whereas in September similar amounts of precipitation tend to occur over the southeast and southwest coasts, and expand locally with the influence of the easterlies and the inland penetration of SBFs.