Knowledge Resource Center for Ecological Environment in Arid Area
DOI | 10.1007/s00382-015-2522-4 |
Impact of burned areas on the northern African seasonal climate from the perspective of regional modeling | |
De Sales, Fernando1; Xue, Yongkang1,2; Okin, Gregory S.1 | |
通讯作者 | De Sales, Fernando |
来源期刊 | CLIMATE DYNAMICS
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ISSN | 0930-7575 |
EISSN | 1432-0894 |
出版年 | 2016 |
卷号 | 47期号:11页码:3393-3413 |
英文摘要 | This study investigates the impact of burned areas on the surface energy balance and monthly precipitation in northern Africa as simulated by a state-of-the-art regional model. Mean burned area fraction derived from MODIS date of burning product was implemented in a set of 1-year long WRF-NMM/SSiB2 model simulations. Vegetation cover fraction and LAI were degraded daily based on mean burned area fraction and on the survival rate for each vegetation land cover type. Additionally, ground darkening associated with wildfire-induced ash and charcoal deposition was imposed through lower ground albedo for a period after burning. In general, wildfire-induced vegetation and ground condition deterioration increased mean surface albedo by exposing the brighter bare ground, which in turn caused a decrease in monthly surface net radiation. On average, the wildfire-season albedo increase was approximately 6.3 % over the Sahel. The associated decrease in surface available energy caused a drop in surface sensible heat flux to the atmosphere during the dry months of winter and early spring, which gradually transitioned to a more substantial decrease in surface evapotranspiration in April and May that lessened throughout the rainy season. Overall, post-fire land condition deterioration resulted in a decrease in precipitation over sub-Saharan Africa, associated with the weakening of the West African monsoon progression through the region. A decrease in atmospheric moisture flux convergence was observed in the burned area simulations, which played a dominant role in reducing precipitation in the area, especially in the months preceding the monsoon onset. The areas with the largest precipitation impact were those covered by savannas and rainforests, where annual precipitation decreased by 3.8 and 3.3 %, respectively. The resulting precipitation decrease and vegetation deterioration caused a drop in gross primary productivity in the region, which was strongest in late winter and early spring. This study suggests the cooling and drying of atmosphere induced by burned areas caused the strengthening of subsidence during pre-onset and weakening of upward atmospheric motion during onset and mature stages of the monsoon leading to a waning of convective instability and precipitation. Monthly mid-tropospheric vertical wind showed a strengthening of downward motion in winter and spring seasons, and weakening of upward movement during the rainy months. Furthermore, precipitation energy analysis revealed that most of precipitation decrease originated from convective events, which supports the hypothesis of reduced convective instability due to wildfires. |
英文关键词 | Impact of burned areas on regional climate Regional climate modeling Wildfire Sahel precipitation Sahel land cover change |
类型 | Article |
语种 | 英语 |
国家 | USA |
收录类别 | SCI-E |
WOS记录号 | WOS:000389349000002 |
WOS关键词 | DOWNSCALING ABILITY ; SURFACE ALBEDO ; FIRE ; SAHEL ; DESERTIFICATION ; DEFORESTATION ; EMISSIONS ; DYNAMICS ; FEEDBACK ; SCALES |
WOS类目 | Meteorology & Atmospheric Sciences |
WOS研究方向 | Meteorology & Atmospheric Sciences |
来源机构 | University of California, Los Angeles |
资源类型 | 期刊论文 |
条目标识符 | http://119.78.100.177/qdio/handle/2XILL650/192082 |
作者单位 | 1.Univ Calif Los Angeles, Dept Geog, Los Angeles, CA 90024 USA; 2.Univ Calif Los Angeles, Dept Atmospher & Ocean Sci, Los Angeles, CA USA |
推荐引用方式 GB/T 7714 | De Sales, Fernando,Xue, Yongkang,Okin, Gregory S.. Impact of burned areas on the northern African seasonal climate from the perspective of regional modeling[J]. University of California, Los Angeles,2016,47(11):3393-3413. |
APA | De Sales, Fernando,Xue, Yongkang,&Okin, Gregory S..(2016).Impact of burned areas on the northern African seasonal climate from the perspective of regional modeling.CLIMATE DYNAMICS,47(11),3393-3413. |
MLA | De Sales, Fernando,et al."Impact of burned areas on the northern African seasonal climate from the perspective of regional modeling".CLIMATE DYNAMICS 47.11(2016):3393-3413. |
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Impact of burned are(4106KB) | 期刊论文 | 出版稿 | 开放获取 | CC BY-NC-SA | 浏览 |
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