A new river discharge and river temperature climatology data set for the pan-Arctic region
A new river discharge and river temperature climatology data set for the pan-Arctic region
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泛北极地区新的河流流量和河流温度气候数据集
DOI：
10.1016/j.ocemod.2014.12.012
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发表时间：
2015
期刊：
影响因子：
3.2
通讯作者：
D. Menemenlis
中科院分区：
文献类型：
--
作者：
J. Whitefield;P. Winsor;J. McClelland;D. Menemenlis
大多数使用流量作为强迫的一部分的区域海洋模型使用相对粗糙的河流流量数据集（1°或110 km），与模型分辨率（通常为1/4°或更低）相比，并且不考虑河流水温的季节性变化。本文介绍了一个新的北极地区河流流量和河流水温的气候数据集（Arctic River Discharge and Temperature; ARDAT），该数据集采用1/6°网格间距，包含了30条北极河流的观测数据。所有河流的年平均流量为2817 ± 330 km 3 yr −1。河流水温在冬季0 °C至7月14.0-17.6 °C之间，导致所有河流的长期平均月热通量为3.2 ± 0.6 TW，其中31%来自阿拉斯加河流，69%来自欧亚河流。这条河流的热通量相当于白令海峡通流相关的海洋热通量估计值的44%，但在春季期间，可能是白令海峡通流相关的海洋热通量的10倍，这表明与北极河流相关的热通量是北极季节时间尺度上热收支的重要组成部分。并将结果与使用1°分辨率放电数据集的模型积分进行比较。在ARDAT强迫模式运行中，北极大陆架（<200 m）上的综合淡水含量与较粗的强迫相比增加了3600 km 3，这表明在使用ARDAT数据集强迫时，北极大陆架上的河流排放量被包含在内。当包括河水温度时，模拟的夏季大陆架热通量增加了8 TW，从而使整个流域9月的海冰范围减少了10%。区域差异较大，例如，博福特陆架海冰面积减少了36%。使用非线性自由面参数化沿着与ARDAT数据集，我们发现河口附近的海面高度梯度的增加。地转速度增加，形成准连续的、快速移动的近岸边界流，使用1°分辨率数据集无法再现。因此，忽略河水温度或使用较低分辨率的数据集可能导致对沿海运输、海冰形成/融化速率以及其他区域和流域尺度过程的不正确模型估计。建议在今后的建模工作中使用高分辨率的排放数据集，并考虑到北极河流携带的大量热量。
Most regional ocean models that use discharge as part of the forcing use relatively coarse river discharge data sets (1°, or ∼110 km) compared to the model resolution (typically 1/4° or less), and do not account for seasonal changes in river water temperature. We introduce a new climatological data set of river discharge and river water temperature with 1/6° grid spacing over the Arctic region (Arctic River Discharge and Temperature; ARDAT), incorporating observations from 30 Arctic rivers. The annual mean discharge for all rivers in ARDAT is 2817 ± 330 km3yr−1. River water temperatures range between 0 °C in winter to 14.0–17.6 °C in July, leading to a long-term mean monthly heat flux from all rivers of 3.2 ± 0.6 TW, of which 31% is supplied by Alaskan rivers and 69% is supplied by Eurasian rivers. This riverine heat flux is equivalent to 44% of the estimated ocean heat flux associated with the Bering Strait throughflow, but during the spring freshet can be ∼10 times as large, suggesting that heat flux associated with Arctic rivers is an important component of the Arctic heat budget on seasonal time scales.We apply the ARDAT data set to a high-resolution regional ocean-ice model, and compare results to a model integration using a 1° resolution discharge data set. Integrated freshwater content on the Arctic shelves (<200 m) increases by ∼3600 km3in the ARDAT forced model run compared to the coarser forcing, suggesting that river discharge is contained on the Arctic shelves when forced with the ARDAT data set. Modelled summer heat fluxes over the shelves increase by 8 TW when river water temperature is included, which subsequently reduces basin-wide September sea ice extent by ∼10%. Regional differences are larger, where e.g., sea ice extent on the Beaufort shelf is reduced by ∼36%. Using a non-linear free surface parameterization along with the ARDAT data set, we find an increase in the sea surface height gradient around river mouths. Geostrophic velocities increase to form quasi-continuous, fast-moving near-shore boundary currents not reproduced using the 1° resolution data set. Omitting river water temperature, or using a lower resolution data set, can therefore lead to incorrect model estimates of coastal transport, sea ice formation/melt rates, and other regional and basin scale processes. Using a high-resolution discharge data set, and accounting for the considerable heat carried by the Arctic rivers is recommended for future modelling efforts.
影响因子：
3.2
作者：
Losch, Martin;Menemenlis, Dimitris;Hill, Chris
通讯作者：
Hill, Chris