Pacific decadal oscillation hindcasts relevant to near-term climate prediction
Pacific decadal oscillation hindcasts relevant to near-term climate prediction
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DOI：
10.1073/pnas.0906531107
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发表时间：
2010-02-02
影响因子：
11.1
通讯作者：
Mori, Masato
中科院分区：
文献类型：
--
作者：
Mochizuki, Takashi;Ishii, Masayoshi;Mori, Masato
太平洋及其周边地区的年代际气候变化与所谓的太平洋年代际涛动（PDO）密切相关，而太平洋年代际涛动（PDO）与北美冬季气候和亚洲季风一致，对海洋生态系统和渔业产生重要影响。在覆盖到2030年的近期气候预测中，我们需要了解气候系统内部变化的未来状态，例如PDO以及全球变暖信号。我们使用一个耦合的大气-海洋气候模式进行集合后报和预测实验，以研究十年时间尺度上内部变化的可预测性，以及对温室气体和气溶胶浓度变化，火山活动和太阳周期变化引起的外部强迫的响应。我们的研究结果强调，使用历史观测的上层海洋状态的初始化是有效的PDO的成功后报，并对未来的预测有很大的影响。对20世纪世纪的模拟结果表明，在近十年的时间里，特别是在观测到PDO信号最强的黑潮-俄亥俄延伸区（KOE）和副热带海洋锋区附近，上层海洋温度具有预测能力。未来10年PDO位相的负向变化趋势将加强东亚和KOE地区地面气温的上升趋势，并抑制沿着南北美洲西海岸和赤道太平洋的上升趋势。这种抑制将有助于减缓全球平均SAT的上升。
Decadal-scale climate variations over the Pacific Ocean and its surroundings are strongly related to the so-called Pacific decadal oscillation (PDO) which is coherent with wintertime climate over North America and Asian monsoon, and have important impacts on marine ecosystems and fisheries. In a near-term climate prediction covering the period up to 2030, we require knowledge of the future state of internal variations in the climate system such as the PDO as well as the global warming signal. We perform sets of ensemble hindcast and forecast experiments using a coupled atmosphere-ocean climate model to examine the predictability of internal variations on decadal timescales, in addition to the response to external forcing due to changes in concentrations of greenhouse gases and aerosols, volcanic activity, and solar cycle variations. Our results highlight that an initialization of the upper-ocean state using historical observations is effective for successful hindcasts of the PDO and has a great impact on future predictions. Ensemble hindcasts for the 20th century demonstrate a predictive skill in the upper-ocean temperature over almost a decade, particularly around the Kuroshio-Oyashio extension (KOE) and subtropical oceanic frontal regions where the PDO signals are observed strongest. A negative tendency of the predicted PDO phase in the coming decade will enhance the rising trend in surface air-temperature (SAT) over east Asia and over the KOE region, and suppress it along the west coasts of North and South America and over the equatorial Pacific. This suppression will contribute to a slowing down of the global-mean SAT rise.