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大影响。冬季对流的最大振幅位于赤道至S之间，一般称为马登-朱利安振荡。最近基于卫星资料的研究表明，该区域的季节内活动与大的海表面温度变率(高达3℃)有关，并表明海-气相互作用起着重要作用。到目前为止，只有卫星数据和数值模拟用于调查这些区域的变异性。拟参加法国的一项活动，其目的是在印度洋这一区域的季节内时间尺度上了解海-气耦合，并解释海温变化的机制及其对大气演变的影响。测量将使用海-气相互作用剖面仪(ASIP)进行，该剖面仪增加了5个拉格朗日浮子，附加了24个节点的温度链。ASIP由NSF海洋技术计划预先资助，将以亚厘米的空间分辨率和5分钟的重复间隔提供混合层全深度的温度、电导率、切变、荧光/浊度和PAR的剖面。这项提议将解决以下基本问题：1.当地SST条件和暖层与大尺度大气条件的日循环的相对重要性；2.生物对近地面层热量捕获的贡献，及其在总热量收支中的作用。这些目标的更广泛影响涉及气候变化，解决了与印度洋大气对流有关的一些问题；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.