Impact of Atmospheric 30-60 Day and Quasi-biweekly Oscillation on Tropical Indian Ocean Dynamics, Heat Transport, and Upper Ocean Heat Content

0452917热带印度洋大气季节内振荡（ISOs）的气候重要性已受到越来越多的关注。反映了这一重要性，广泛的建模研究，加上一些新部署的系泊观测，显着提高了我们的认识，在过去几年中引起的大气ISO印度洋变化的各个方面。然而，这一认识远未完成，许多悬而未决的科学问题仍未得到解决。（i）赤道印度洋的表层和次表层纬向流如何和为什么对大气ISO作出反应（特别是30-60天和准双周振荡），这种反应如何影响跨赤道热传输的多时间尺度变化？(ii)上印度洋对大气ISO响应的季节性和年际变化是什么？(iii)大气ISO如何影响热带印度洋（特别是暖池）热含量的变化？该项目的主要工具是海洋环流模式。卫星数据与欧洲中期天气预报中心的每日再分析相结合，将被用作模式强迫场。海洋模式中物理学的现实表示允许直接调查海洋如何响应季节内大气强迫。为了深入了解所涉及的关键海洋过程，还将使用一个线性连续分层模式和一个非线性中间海洋模式。印度洋的现有数据将进行分析，与模式解决方案进行比较和解释。拟议的研究具有重要的科学意义，因为人们对热带印度洋（独立于厄尔尼诺/南方涛动的部分）的年际变化还没有很好的了解，而且有人提出了大气ISO的跨时间尺度影响。该项目涉及气候研究的一个中心主题，对于理解大气ISO在引起热带多尺度气候变率方面的作用至关重要。拟议项目的智力价值在于它的贡献，促进我们的理解，并提供新的见解，如何以及为什么热带印度洋响应季节内大气强迫，一项研究，将建立一个坚实的基础，确定大气ISO在热带耦合海洋/大气系统中造成气候变率的作用。通过将研究与教育相结合，该项目将通过推进气候研究和促进研究生教育对我们的社会产生更广泛的影响。

0452917The climatic importance of atmospheric IntraSeasonal Oscillations (ISOs) in the tropical Indian Ocean has been receiving increasing attention. Reflecting this importance, extensive modeling studies, together with a few newly deployed mooring observations, have significantly advanced our understanding of various aspects of Indian Ocean variability induced by atmospheric ISOs in the past a few years. This understanding, however, is far from complete and many outstanding science issues remain unaddressed.The objectives of the proposed project are to explore: (i) How and why do the surface and subsurface meridional currents in the equatorial Indian Ocean respond to atmospheric ISOs (especially the dominant 30-60 day and quasi-biweekly oscillations), and how does that response impact multi-timescale variability of cross-equatorial heat transport? (ii) What are the seasonality and interannual variability of the upper Indian Ocean response to atmospheric ISOs? (iii) How do atmospheric ISOs affect the variability of tropical Indian Ocean (especially the warm pool) heat content?The primary tool for this project is an ocean general circulation model. Satellite data combined with daily reanalysis from the European Center for Medium range Weather Forecasts will be used as the model forcing fields. The realistic representation of physics in the ocean model allows for a direct investigation of how the ocean responds to the intraseasonal atmospheric forcing. To provide insights into the key oceanic processes involved, a linear continuously stratified model and a nonlinear intermediate ocean model will also be used. Available data in the Indian Ocean will be analyzed, compared with, and interpreted by the model solutions. The proposed research is scientifically important because interannual variability of the tropical Indian Ocean (the part that is independent of ENSO) is not well understood, and the cross-timescale impact of atmospheric ISOs has been suggested. The project addresses a central theme of climate research and is essential for understanding the role of atmospheric ISOs in causing multi-scale climate variability in the tropics. The intellectual merit of the proposed project lies in its contribution to advancing our understanding of, and providing new insight into, how and why the tropical Indian Ocean responds to intraseasonal atmospheric forcing, a study that will build a solid foundation for identifying the role played by atmospheric ISOs in causing climate variability in the tropical coupled ocean/atmosphere system. By integrating the research with education, the project will have a broader impact on our society through both advancing climate research and promoting graduate education.