Estimating the Mean Diapycnal Mixing Using a Finescale Strain Parameterization
Estimating the Mean Diapycnal Mixing Using a Finescale Strain Parameterization
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DOI：
10.1175/jpo-d-14-0167.1
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发表时间：
2015-04
影响因子：
3.5
通讯作者：
C. Whalen;J. MacKinnon;L. Talley;A. Waterhouse
中科院分区：
文献类型：
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作者：
C. Whalen;J. MacKinnon;L. Talley;A. Waterhouse
摘要精细尺度方法在区域和全球尺度上被广泛应用于湍流平均耗散率和扩散率的估算。本研究通过比较赤道、山脊上方、海山附近和强流等六种不同环境的平均微观结构剖面，评估了由等压应变得出的细尺度估计。精细尺度的应变估计来自至少10个附近的Argo剖面（通常距离小于60公里），没有时间限制，包括以季节或几十年为间隔的测量。在这些情况下没有时间限制是合理的，因为作者发现在所考虑的纬度（0°-30°和40°-50°），耗散率在季节时间尺度上是稳定的。相比之下，在两个半球的风暴路径（30°-40°）下，在1000米以上的季节周期为2-5倍。Argo剖面计算的平均耗散率与微观结构剖面计算的平均耗散率一致。
AbstractFinescale methods are currently being applied to estimate the mean turbulent dissipation rate and diffusivity on regional and global scales. This study evaluates finescale estimates derived from isopycnal strain by comparing them with average microstructure profiles from six diverse environments including the equator, above ridges, near seamounts, and in strong currents. The finescale strain estimates are derived from at least 10 nearby Argo profiles (generally <60 km distant) with no temporal restrictions, including measurements separated by seasons or decades. The absence of temporal limits is reasonable in these cases, since the authors find the dissipation rate is steady over seasonal time scales at the latitudes being considered (0°–30° and 40°–50°). In contrast, a seasonal cycle of a factor of 2–5 in the upper 1000 m is found under storm tracks (30°–40°) in both hemispheres. Agreement between the mean dissipation rate calculated using Argo profiles and mean from microstructure profiles is wi...