Measurements of the Diurnal Warm Layer and Biologically-Induced Heating during the CIRENE Campaign

印度洋的大气对流对季风有很强的影响。在冬季，对流的最大振幅位于赤道和20s之间，通常称为麦登-朱利安涛动（MJO）。最近基于卫星数据的研究表明，该地区的季节内活动与大的海表温度（SST）变率（高达3℃）有关，并表明海气相互作用起着重要作用。迄今为止，只有卫星数据和数值模拟用于研究这些地区的变率。建议参加法国的一项运动，其目的是了解印度洋这一地区在季节内时间尺度上的海洋-大气耦合，并解释海温变率的机制及其对大气演变的影响。测量将使用海气相互作用分析器（ASIP）进行，该分析器配有5个拉格朗日浮子，附有24个节点温度链。ASIP先前由美国国家科学基金会海洋技术项目资助，将以亚厘米空间分辨率提供混合层全深度的温度、电导率、剪切、荧光/浊度和PAR剖面，重复间隔为5分钟。这一建议将解决下列基本问题：局地海温条件和暖层日循环与大尺度大气条件的相对重要性。近地表生物对热量捕获的贡献及其在整体热量收支中的作用。通过解决与印度洋大气对流有关的一些问题，这些目标的更广泛影响涉及气候变化；MJO与厄尔尼诺-南方涛动、季风和温带天气相互作用，因此具有全球重要性。

Atmospheric convection in the Indian Ocean has a strong impact on the monsoon. During winter, the maximum amplitude of convection is located between the equator and 20 S, and is generally referred to as the Madden-Julian oscillation (MJO). Recent studies based on satellite data have shown that the intraseasonal activity in this region is associated with large sea surface temperature (SST) variability (up to 3 C), and it has been suggested that air-sea interaction plays an important role. Heretofore there have been only satellite data and numerical modelling used to investigate the variability in these regions. It is proposed to participate in a French Campaign the objective of which is to understand ocean-atmosphere coupling at the intraseasonal timescale in this region of the Indian Ocean, and to explain the mechanisms of the SST variability and its influence on the atmospheric evolution. Measurements will be made using the Air-Sea Interaction Profiler (ASIP), augmented with 5 Lagrangian floats, with 24-node temperature chains attached. ASIP, previsouly funded by the NSF Oceanographic Technology program, will provide profiles of temperature, conductivity, shear, fluorescence/turbidity, and PAR over the full depth of the mixed layer at sub-centimeter spatial resolution and repeat intervals of 5 minutes. This proposal will address the following fundamental problems: 1. the relative importance of local SST conditions and the diurnal cycle of the warm layer versus large scale atmospheric conditions 2. the biological contribution to heat trapping in the near-surface layer, and its role in the overall heat budget. The broader impacts of the objectives relate to climate change by addressing some of the issues pertinent to atmospheric convection in the Indian Ocean; the MJO interacts with the El Nino-Southern Oscillation, the monsoons, and extratropical weather, and therefore of global importance.