Unraveling East Africa's Climate Paradox
Unraveling East Africa's Climate Paradox
复制标题
解开东非的气候悖论
DOI：
10.1002/9781119068020.ch16
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发表时间：
2017
影响因子：
4.9
通讯作者：
N. Vigaud
中科院分区：
文献类型：
--
作者：
B. Lyon;N. Vigaud
几个东非国家目前正面临某种气候悖论[里昂，2014]。十多年来，该地区经历的干旱频率不断增加（图16.1a），最近发生的最严重的干旱事件（2010-2011年）引发了人道主义危机，并促使国际社会做出重大反应[FEWSNET，2011]。这种降雨量的下降导致了不可避免的猜测，即该地区已经开始出现人为气候变化的信号。然而，矛盾的是，气候模型预测显示了一个普遍的共识，即温室气体的增加实际上将导致东非的气候在本世纪变得更加湿润（图16.1 b）[Christensen等人，2007; Shongwe等人，2011年]。混淆了这一看似矛盾的现象，在东非的许多地方，降雨季节周期是双峰的，最近降雨量下降的大部分发生在3月至5月的“长雨”季节（MAM;其他季节表示类似），而12月至12月的“短雨”（OND）在过去三十年中显示出上升趋势[例如，Liebmann等人，2014年]。这些不同的结果突出表明，需要确定与东非气候观测和预测变化相关的物理机制。从物理学的角度来看，一个真正的悖论当然是虚幻的，可以考虑几个假设来解释不同的趋势。例如，用于预测未来气候的耦合气候模型（CMIP 5）可能会遗漏或歪曲对东非降雨重要的关键物理过程。未来可能确实会变得更干燥，模型预测完全错误。或者，最近的干旱可能是东非气候变化的一个解开
Several East African countries are currently facing something of a climate paradox [Lyon, 2014]. For well over a decade, the region has been experiencing an increased frequency of drought (Fig. 16.1a), the most recent and severe of these events (in 2010–2011) triggering a humanitarian crisis and prompting a major international response [FEWSNET, 2011]. This rainfall decline has led to inevitable speculation that an anthropogenic climate change signal has begun to emerge in the region. Yet, paradoxically, climate model projections show a general consensus that increasing greenhouse gasses will in fact result in East Africa’s climate becoming wetter during the current century (Fig. 16.1b) [Christensen et al., 2007; Shongwe et al., 2011]. Confounding this seeming paradox, in many parts of East Africa the rainfall seasonal cycle is bimodal, with the bulk of the recent rainfall decline occurring during the “long rains” season of March–May (MAM; other seasons denoted similarly) while the “short rains” of October–December (OND) show an upward trend over the past three decades [e.g., Liebmann et al., 2014]. These divergent outcomes highlight the need to identify the physical mechanisms associated with both the observed and projected changes in East African climate. From a physical perspective, a true paradox is of course illusory and several hypotheses can be contemplated to account for the differing trends. For example, the coupled climate models (CMIP5) used to project the future c limate may be missing, or misrepresenting, key physical processes important to East African rainfall. The future may indeed become drier and the model projections are simply wrong. Alternatively, the recent drying may be a Unraveling East Africa’s Climate Paradox
影响因子：
4.6
作者：
Bayr, Tobias;Dommenget, Dietmar;Power, Scott B.
通讯作者：
Power, Scott B.