Global S&T Development Trend Analysis Platform of Resources and Environment
DOI | 10.1175/JCLI-D-17-0702.1 |
Reduced Wet-Season Length Detected by Satellite Retrievals of Cloudiness over Brazilian Amazonia: A New Methodology | |
Sena, Elisa T.1,2; Silva Dias, M. A. F.1; Carvalho, L. M. V.3; Silva Dias, P. L.1 | |
2018-12-01 | |
发表期刊 | JOURNAL OF CLIMATE |
ISSN | 0894-8755 |
EISSN | 1520-0442 |
出版年 | 2018 |
卷号 | 31期号:24页码:9941-9964 |
文章类型 | Article |
语种 | 英语 |
国家 | Brazil; USA |
英文摘要 | This study investigates the variability of the seasonal cycle of convection in the Brazilian Amazon basin during the last decades, and examines physical mechanisms that potentially trigger these modifications. A new methodology to evaluate the onset and length of the rainy season using long-term cloud fraction observations from geostationary satellites is proposed and the connection between cloud cycle variability, surface properties, and thermodynamic and dynamic conditions is explored. The results show that cloud cover has significantly decreased over the last decades. The decline in cloudiness is steeper at 1200 UTC (0800 LT), when a trend of up to -6% decade(-1) is observed over the central and eastern Amazon. High-cloud-cover reduction is the major contributor to the observed decline in total cloud fraction. Delayed onsets and a reduction of up to 4 days yr(-1) in the northern and central Amazon wet-season length are observed. Correlation analyses indicate that the El Nino phenomenon affects the interannual variability of cloudiness in the Amazon, leading to delayed onset and early demise of the rainy season. The tropical South Atlantic, the Pacific warm pool, and the North Atlantic tripole also play a small, but significant, role in the Amazon's cloudiness variability. The decrease in cloudiness over the Amazon basin reduces the amount of solar radiation reflected back to space while increasing irradiance at the surface. This local warming alters surface heat fluxes and the atmospheric thermodynamic profile, further affecting cloud development. The strong tendencies reported here indicate a significant shift in the Amazonian hydroclimate during the last few decades. |
英文关键词 | Amazon region Climate variability Cloud cover Hydrologic cycle Satellite observations |
领域 | 气候变化 |
收录类别 | SCI-E |
WOS记录号 | WOS:000450565300002 |
WOS关键词 | LAST 2 DECADES ; SOUTH-AMERICA ; RAINY-SEASON ; INTERDECADAL VARIABILITY ; REGIONAL VARIABILITY ; DEEP CONVECTION ; MONSOON SYSTEM ; LAND-SURFACE ; MAJOR FLOODS ; WATER-VAPOR |
WOS类目 | Meteorology & Atmospheric Sciences |
WOS研究方向 | Meteorology & Atmospheric Sciences |
引用统计 | |
文献类型 | 期刊论文 |
条目标识符 | http://119.78.100.173/C666/handle/2XK7JSWQ/20660 |
专题 | 气候变化 |
作者单位 | 1.Univ Sao Paulo, Inst Astron Geofis & Ciencias Atmosfer, Sao Paulo, Brazil; 2.Univ Fed Sao Paulo, Escola Paulista Polit Econ & Negocios, Dept Multidisciplinar, Osasco, Brazil; 3.Univ Calif Santa Barbara, Santa Barbara, CA 93106 USA |
推荐引用方式 GB/T 7714 | Sena, Elisa T.,Silva Dias, M. A. F.,Carvalho, L. M. V.,et al. Reduced Wet-Season Length Detected by Satellite Retrievals of Cloudiness over Brazilian Amazonia: A New Methodology[J]. JOURNAL OF CLIMATE,2018,31(24):9941-9964. |
APA | Sena, Elisa T.,Silva Dias, M. A. F.,Carvalho, L. M. V.,&Silva Dias, P. L..(2018).Reduced Wet-Season Length Detected by Satellite Retrievals of Cloudiness over Brazilian Amazonia: A New Methodology.JOURNAL OF CLIMATE,31(24),9941-9964. |
MLA | Sena, Elisa T.,et al."Reduced Wet-Season Length Detected by Satellite Retrievals of Cloudiness over Brazilian Amazonia: A New Methodology".JOURNAL OF CLIMATE 31.24(2018):9941-9964. |
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