Premium
Diurnal winds around lake Tanganyika
Author(s) -
Savijärvi Hannu
Publication year - 1997
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.49712354006
Subject(s) - mesoscale meteorology , sea breeze , global wind patterns , prevailing winds , climatology , geology , trade wind , diurnal cycle , rift valley , structural basin , oceanography , atmospheric sciences , geomorphology , paleontology
Regular diurnal variations of coastal winds are observed around Lake Tanganyika during the dry season, when insolation is intense and the prevailing trade winds are weak. the long deep lake is at the bottom of the East African rift valley. A two‐dimensional mesoscale model across the schematic rift‐valley topography is used to study these local tropical winds. the full model gives a good simulation when compared with the observed winds on the east coast. It turns out that about half of the strong diurnal wind variation there, in the form of slope winds, is due to the sloping mountains. Roughly one quarter is due to the thermal lake effect (sea breeze), and one quarter is due to the existence of the south‐easterly trade wind, which enhances the sea‐breeze circulation component considerably during daytime, and adds on to the downslope winds during night‐time. the wind field across the lake is quite variable from hour to hour and from place to place, yet predictable to a good extent during the dry season, when the external conditions are rather similar from day to day.