Open AccessLand use change impacts on regional climate over Kilimanjaro
Author(s) -
Fairman Jonathan G.,
Nair Udaysankar S.,
Christopher Sundar A.,
Mölg Thomas
Publication year - 2011
Publication title -
journal of geophysical research: atmospheres
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.67
H-Index - 298
eISSN - 2156-2202
pISSN - 0148-0227
DOI - 10.1029/2010jd014712
Subject(s) - orographic lift , environmental science , precipitation , orography , cloud cover , climatology , atmospheric sciences , deforestation (computer science) , climate change , land cover , land use , geography , meteorology , geology , oceanography , civil engineering , engineering , cloud computing , computer science , programming language , operating system
Glacier recession on Kilimanjaro has been linked to reduction in precipitation and cloudiness largely because of large‐scale changes in tropical climate. Prior studies show that local changes in land cover can also impact orographic cloudiness, precipitation, and terrain‐generated circulation patterns. This study uses the Regional Atmospheric Modeling System to simulate dry season orographic cloudiness, rainfall, and orographic flow patterns over Kilimanjaro for current deforested and reforested land cover scenarios. The simulations for current land cover show satisfactory performance compared to surface meteorology and satellite‐observed cloudiness. Clouds occur less frequently in response to deforestation, with the magnitude of decrease increasing with deforestation. On the windward side, cloud liquid water path (LWP) and precipitation both show decreases at lower elevations (∼1000–2000 m) and increases at higher elevations (2000–4000 m) in response to deforestation. This pattern is caused by decreased aerodynamic resistance, leading to enhanced wind speeds and convergence at higher elevations. On the lee regions, LWP deficits found in deforested simulations coincide with regions of reduced moisture while precipitation increased slightly at lower elevations (1000–1800 m) and decreased at higher elevations (1800–4000 m). Kilimanjaro offers less obstruction to background airflow, and reduced moisture transport to the lee side is found for deforested conditions, causing reduced LWP and rainfall. However, land use change has little effect on cloudiness and rainfall at elevations in excess of 4000 m and is not expected to impact glaciers in the summit zone of Kilimanjaro during the dry season. The effect in other seasons requires further investigation.