Mixed Layer Depth in the Australian Region

Mixed layer depth was calculated from the oceanographic temperature and salinity cast data used to generate CARS2000. It was defined to be the minimum (shallower) depth of depths zt and zs, where zt and zs are the shallowest depths such that abs(T(zt)-T(10m)) >= .4C and abs(S(zs)-S(10m)) >= 0.03 PSU. These values were then mapped onto a regular .5 degree grid using a loess filter, as used in CARS2000, simultaneously fitting quadratic spatial functions and annual harmonics. These fields were then linearly interpolated to the required 1/10th degree spatial resolution. The provided "annual amplitude" is simply the magnitude of the fitted annual sinusoid. CARS is a set of seasonal maps of temperature, salinity, dissolved oxygen, nitrate, phosphate and silicate, generated using Loess mapping from all available oceanographic data in the region. It covers the region 100-200E, 50-0S, on a 0.5 degree grid, and on 56 standard depth levels. Higher resolution versions are also available for the Australian continental shelf. The data was obtained from the World Ocean Atlas 98 and CSIRO Marine and NIWA archives. It was designed to improve on the Levitus WOA98 Atlas, in the Australian region.

混合层深度（Mixed layer depth）通过用于生成CARS2000的海洋温盐剖面观测数据计算得到。其定义为深度zt与zs中的较小值（更浅者），其中zt和zs分别为满足|T(zt)-T(10m)|≥0.4℃与|S(zs)-S(10m)|≥0.03实用盐度单位（PSU）的最浅深度。随后采用CARS2000所使用的局部加权回归（Loess）滤波器，将上述混合层深度值映射至规则的0.5°网格，同时拟合二次空间函数与年谐波项。随后将这些场数据通过线性插值处理至所需的0.1°空间分辨率。本次提供的“年振幅”即为拟合得到的年度正弦曲线的幅值。CARS是一套区域季节分布图集，涵盖温度、盐度、溶解氧、硝酸盐、磷酸盐与硅酸盐要素，通过对研究区域内所有可用海洋观测数据进行Loess映射生成。该图集覆盖东经100°至200°、南纬50°至0°的海域，采用0.5°网格与56个标准深度层。针对澳大利亚大陆架区域，另有更高空间分辨率的数据集版本可供获取。本数据集的数据来源于《世界海洋Atlas98》（World Ocean Atlas 98）以及澳大利亚联邦科学与工业研究组织（CSIRO）海洋分部与新西兰国家水与大气研究所（NIWA）的档案库。该数据集旨在针对澳大利亚海域优化莱维图斯（Levitus）编制的WOA98海洋图集。