SGER: Role of the Indian Ocean in Causing the Excessive Biennial El Nino-Southern Oscillation (ENSO) Tendency in NCAR's Community Climate Modeling System (CCSM3) Simulations

许多耦合的气候模式，那些充分代表大气和海洋，无法准确地模拟厄尔尼诺/南方涛动（ENSO）现象的空间结构和时间演变。厄尔尼诺/南方涛动是影响世界大部分地区区域天气和气候的主要气候变化模式。美国国家大气研究中心（NCAR）的社区气候系统模式（CCSM 3）的当前版本产生了ENSO变率，但具有不切实际的两年或两年周期。用于预测全球气候变化的主要模式之一的这一缺陷降低了这种预测的可靠性及其预测区域气候变化的效用。根据他早期的模式研究，PI假设ENSO中这种不切实际的时间变化是热带太平洋和印度洋之间相互作用的结果。他将通过进行模型实验来检验这一假设，在模型实验中，不是模拟印度洋的海面温度，而是强加该盆地的温度;强加的温度将遵循生成的模型和观测到的年周期。如果在这些实验中减少或消除厄尔尼诺/南方涛动两年期的过度变率，将表明印度洋气候是整个模式中问题的一个重要来源。这项工作将有助于纠正一个广泛使用的最先进的气候模型中的一个重要问题，并将有助于培训一名研究生助理。

Many coupled climate models, those with full representations of the atmosphere and ocean, are unable to simulate accurately the spatial structure and time evolution of the El Nino/Southern Oscillation (ENSO) phenomenon. ENSO is a leading mode of climate variability that affects regional weather and climate over much of the world. The current version of the Community Climate System Model (CCSM3) at the National Center for Atmospheric Research (NCAR) produces ENSO variability, but with an unrealistically strong two-year, or biennial, cycle. This deficiency, in one of the leading models used for projections of global climate change, reduces the reliability of such projections and their utility for predicting changes in regional climates. Based on his earlier model studies the PI hypothesizes that this unrealistic temporal variability in ENSO is a result of interactions between the tropical Pacific and Indian Oceans. He will test this hypothesis by conducting model experiments in which, rather than simulating sea-surface temperatures in the Indian Ocean, temperatures in this basin are imposed; the imposed temperatures will follow both a model generated and an observed annual cycle. If the excessive biennial variability of ENSO is reduced or eliminated in these experiments, it will indicate that the Indian Ocean climate is a significant source of the problem in the full model. This work will help to correct an important problem in a widely used, state-of-the-art, climate model and will contribute to training a graduate research assistant.