Rectification of El Nino-Southern Oscillation as a Mechanism for the Tropical Pacific Decadal Variability: A Diabatic and Time-Dependent View

在逐年的基础上，热带太平洋海表温度（SST）的变化主要是由厄尔尼诺/南方涛动（ENSO）事件，这是众所周知的影响全球天气模式，并对美国有重大影响。 但是热带太平洋SST也可以变化得更慢，热带太平洋年代际变率（TPDV）也被认为是全球影响的原因，包括20世纪30年代的大沙尘暴干旱和最近的全球变暖中断。 目前的工作审查的可能性，TPDV的一部分是有关ENSO活动通过一种机制被称为整流，其中洋流和海洋温度异常与ENSO事件，尽管其短暂的性质，但产生持久的热重新安排整个热带太平洋。 的意义上的重新安排是这样的，ENSO整流导致较冷的温度在西太平洋的“暖池”，海洋大陆周围的最大SST的区域，和“冷舌”区域沿着赤道在东太平洋。 PI假设，如果ENSO异常活跃的一段时间内的整流效应将导致一个平均状态，较弱的东西海洋温度对比赤道太平洋，这是不利于ENSO。 其结果将是厄尔尼诺/南方涛动活动减少，导致较弱的整流效应，从而导致更强的东西温度对比。 较强的温度对比更有利于ENSO活动，使ENSO活动恢复到更大的水平，并重复循环。 一套实验使用的气候模式在各种配置，包括一些与表面风的海洋组件模型和其他与SST施加在大气组件模型，将被用来测试hypothes. Although它的科学利益，TPDV起源的问题有实质性的社会影响。 如果这一机制有助于TPDV和ENSO活动的年代际调制，它可能会导致更好的预测ENSO事件和太平洋SST的变化缓慢。 考虑到热带太平洋SST变化对全球的影响，此类预测将具有重要价值。 这项工作也可能有助于理解全球变暖的中断和预测其终止。 此外，这项工作将支持和培训一名研究生，从而发展这一研究领域的未来劳动力。

On a year-to-year basis the variability of sea surface temperature (SST) in the tropical Pacific is dominated by El Nino/Southern Oscillation (ENSO) events, which are known to influence weather patterns worldwide and have significant impacts on the US. But tropical Pacific SSTs can also vary more slowly, and tropical Pacific decadal variability (TPDV) has also been proposed as the cause of worldwide impacts including the great Dust Bowl drought of the 1930s and the recent global warming hiatus. The present work examines the possibility that some portion of TPDV is related to ENSO activity through a mechanism referred to as rectification, in which the ocean currents and ocean temperature anomalies associated with ENSO events, despite their transient nature, nevertheless produce a lasting rearrangement of heat across the tropical Pacific ocean. The sense of the rearrangement is such that ENSO rectification leads to cooler temperatures in the West Pacific "warm pool", the region of maximum SSTs around the Maritime Continent, and the "cold tongue" region along the equator in the eastern Pacific. The PI hypothesizes that if ENSO is unusually active for an extended period the rectification effect will lead to a mean state with a weaker east-west ocean temperature contrast across the equatorial Pacific, which is less favorable to ENSO. The result will be a reduction in ENSO activity, resulting in a weaker rectification effect that will lead to a stronger east-west temperature contrast. The stronger temperature contrast is more favorable to ENSO activity, producing a return to greater ENSO activity and repeating the cycle. A suite of experiments using a climate model in various configurations, including some with surface winds imposed on the ocean component model and others with SSTs imposed on the atmospheric component model, will be used to test the hypothesis.In addition to its scientific interest, the question of TPDV origins has substantial societal implications. If the proposed mechanism contributes to TPDV and decadal modulation of ENSO activity, it may lead to improved prediction of ENSO events and slower variations of Pacific SST. Such predictions would be of great value given the worldwide impacts of tropical Pacific SST variations. The work may also be helpful in understanding the global warming hiatus and anticipating its termination. In addition, the work will support and train a graduate student, thereby developing the future workforce in this research area.