Collaborative Research: The Maud Rise Nonlinear Equation of State Study (MaudNESS)

该项目是对一种机制的研究，通过这种机制，深海对流可以从稳定的初始条件演变而来，达到足以将温暖的水带到表面并在冬末甚至可能是仲冬融化现有冰盖的程度。 具体研究将研究海水密度对温度和盐度（状态方程）的非线性依赖性如何在典型的南极条件下增强垂直对流。当密度相似但温度和盐度差异较大的海水层相互作用时，存在许多可能的非线性不稳定性，这些不稳定性可以将现有的势能转换为湍流能。 在威德尔海，冷的表面混合层通常通过薄而弱的重斜斜与下面温暖的、含盐量更高的水分开，使得水柱特别容易受到与温压（热膨胀系数的压力依赖性）相关的不稳定性的影响。 该项目是纽约大学、地球与空间研究中心、华盛顿大学、海军研究生院和麦克菲研究公司之间的合作项目。这项工作在解释威德尔冰湖的存在方面具有很强的实际应用价值，威德尔冰湖是威德尔海季节性海冰内面积达 30 万平方公里的开放水域，大约从 1975 年到 1979 年。此后，这种情况就没有再出现过，尽管有迹象表明威德尔湖冰湖规模要小得多，持久性也较差。莫德隆起海山附近确实存在开放水域。 实验部分将于 2005 年 7 月至 9 月在 RVIB Nathaniel B. Palmer 上进行。

This project is an investigation into one mechanism by which deep ocean convection can evolve from stable initial conditions, to the extent that it becomes well enough established to bring warm water to the surface and melt an existing ice cover in late, or possibly even mid-winter. The specific study will investigate how the non-linear dependence of seawater density on temperature and salinity (the equation of state) can enhance vertical convection under typical antarctic conditions. When layers of seawater with similar densities but strong contrasts in temperature and salinity interact, there are a number of possible non-linear instabilities that can convert existing potential energy to turbulent energy. In the Weddell Sea, a cold surface mixed layer is often separated from the underlying warm, more saline water by a thin, weak pycnocline, making the water column particularly susceptible to an instability associated with thermobaricity (the pressure dependence of the thermal expansion coefficient). The project is a collaboration between New York University, Earth and Space Research, the University of Washington, the Naval Postgraduate School, and McPhee Research Company.The work has strong practical applications in contributing to the explanation for the existence of the Weddell Polynya, a 300,000 square kilometer area of open water within the seasonal sea ice of the Weddell Sea, from approximately 1975 to 1979. It has not recurred since, although indications of much smaller and less persistent areas of open water do occur in the vicinity of the Maud Rise seamount. The experimental component will be carried out on board the RVIB Nathaniel B. Palmer between July and September, 2005.