DOI: 10.1002/2015JD024303
论文题名: Trends of mean temperatures and warm extremes in northern tropical Africa (1961-2014) from observed and PPCA-reconstructed time series
作者: Moron V. ; Oueslati B. ; Pohl B. ; Rome S. ; Janicot S.
刊名: Journal of Geophysical Research: Atmospheres
ISSN: 2169897X
出版年: 2016
语种: 英语
英文关键词: ENSO
; Global warming
; Tropical Africa
; Tropical night
; Very hot day
; Warm extremes
英文摘要: Trends in daily maximum (TX) and minimum (TN) temperatures and indices of warm extremes are studied in tropical North Africa, west of the eastern African highlands, from 1961 to 2014. The analysis is based on the concatenation and cross-checking of two observed databases. Due to the large number of missing entries (~25%), a statistical infilling using probabilistic principal component analysis was applied. Averaged over 90 stations, the linear trends of annual mean TX and TN equal respectively +0.021°C/yr and +0.028°C/yr. The frequency of very hot days (TX>35°C) and tropical nights (TN>20°C), as well as the frequency of daily TX and TN above the 90th percentile (p90) ("warm days" and "warm nights"), roughly follows the variations of mean TX and TN, respectively. Heat spells of TX or TN>p90 are often short (usually <2-3days), and the interannual variation of their mean duration is noisier than for the other indices. Nevertheless, heat spells tend to last longer, with almost constantly positive anomalies since the mid-1990s. The trends in March-June, the warmest season across the Sahelian and Sudanian belts, show similar variations as annual means. Overall, the local-scale warming in annual temperatures, and in March-June, may be viewed merely as a simple shift of the probability distribution function of daily TX and TN. The correlations between the thermal indices and the 2m temperatures suggest that the low-frequency (>8years) variations may be viewed as a regional-scale fingerprint of the global warming, with largest correlations in the tropical Atlantic and Indian basins, while the high-frequency (<8years) variations should be mostly viewed as a delayed remote impact of El Niño-Southern Oscillation (ENSO) events over the region, with warm (cold) anomalies tending to follow warm (cold) ENSO events. © 2016. American Geophysical Union. All Rights Reserved. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/62936
Appears in Collections: 影响、适应和脆弱性 气候减缓与适应
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作者单位: Aix-Marseille University, UM 34 CNRS, CEREGE Aix en Provence France; IRI Columbia University Palisades New York USA; CRC, UMR 6282 Biogéosciences CNRS/Université de Bourgogne-Franche-Comté Dijon France; LTHE UMR 5564 CNRS/UJF/IRD/G-INP Université Grenoble Alpes Grenoble France; UMR7159 LOCEAN Sorbonne Universités UPMC-CNRS-IRD-MNHN Paris France
Recommended Citation:
Moron V.,Oueslati B.,Pohl B.,et al. Trends of mean temperatures and warm extremes in northern tropical Africa (1961-2014) from observed and PPCA-reconstructed time series[J]. Journal of Geophysical Research: Atmospheres,2016-01-01