Isopycnal Intrusions in Doubly Diffusive Fluids

0236304斯特恩二维双扩散侵入体将研究分析和数值锋面模式。对于手指有利的垂直温度和盐度梯度（盐度向上增加）的情况下，小尺度通量将参数化先前获得的（数值）校准。有限横向宽度模型的应用将给出一个最小的临界值的横向盐度变化的二维侵入不稳定的发病。对于超临界横向盐度变化，本征函数将初始化数值积分，该数值积分将给出平均横向梯度的修改和等密度翻转的条件。一个稳定的盐梯度加热从下面的情况下，也将在一个横向有界的锋面模型进行检查，和垂直尺度的侵入不稳定性将有关的最小温跃层步骤中观察到的威德尔海。在这些步骤中向上的热通量可能有助于维持在南极冰中观察到的大的间隙（冰穴），这可能会影响大气Climate.This项目将有助于我们理解的水平混合的水团通过使用一个非常复杂和精确的盐指参数化模拟入侵发生在一个密度补偿温盐锋和回答问题，如首选的入侵规模和规模。这项研究将提供给气候模拟界的演示和出版物，以便将结果纳入一般海洋环流模型。此外，博士后和博士。学生将获得使用最先进的科学计算设备和技术来解决具有重大实际意义的流体动力学问题的宝贵经验。PI还将参加伍兹霍尔海洋研究所的地球物理流体动力学（GFD）夏季课程。

0236304 SternTwo dimensional doubly diffusive intrusions will be investigated analytically and numerically in a frontal model. For the case of finger favorable vertical temperature and salinity gradients (salinity increasing upward) the small scale fluxes will be parameterized by previously obtained (numerical) calibrations. Application to the finite lateral width model will give a minimum critical value of the lateral salinity variation for the onset of a two-dimensional intrusive instability. For supercritical lateral salinity variation the eigenfunctions will initialize a numerical integration which will give the modification of the mean lateral gradients and the condition for isopycnal overturns. The case of a stable salt gradient heated from below will also be examined in a laterally bounded frontal model, and the vertical scale of the intrusive instability will be related to the smallest thermocline steps observed in the Weddell Sea. The upward heat flux in these steps may help to maintain the large gaps (polynyas) observed in the Antarctic ice which could affect the atmospheric climate.This project will contribute to our understanding of the horizontal mixing of water masses by using a very elaborate and precise salt finger parameterization to model the intrusions occurring on a density-compensated thermohaline front and answer questions such as preferred intrusion scales and magnitudes. This research will be made available to the climate modeling community with presentations and publications so that the results can be incorporated into the general ocean circulation models. In addition, the post doc and Ph.D. student will gain invaluable experience in using state-of-the art scientific computational equipment and techniques to solve fluid dynamical problems of significant practical interest. The PI will also participate in the Summer Program in Geophysical Fluid Dynamics (GFD) at Woods Hole Oceanographic Institution..