Development of the Surface Urban Energy and Water Balance Scheme (SUEWS) for cold climate cities
Development of the Surface Urban Energy and Water Balance Scheme (SUEWS) for cold climate cities
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DOI：
10.5194/gmd-7-1691-2014
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发表时间：
2014-01-01
影响因子：
5.1
通讯作者：
Strachan, I. B.
中科院分区：
文献类型：
--
作者：
Jarvi, L.;Grimmond, C. S. B.;Strachan, I. B.
地表城市能量和水平衡方案（SUEWS）的发展包括雪。研究的过程包括不同城市地表类型的积雪积累：雪的反照率和密度老化、雪的融化和融水的再冻结。利用赫尔辛基和蒙特利尔这两个寒冷气候城市的长期观测资料，对个别模式参数进行了评估和独立评估。涡旋相关方差感热通量和潜热通量以及雪深观测在蒙特利尔有两个站点，在赫尔辛基有一个站点。还分析了赫尔辛基两个集水区（24公顷和45公顷）的地表径流以及蒙特利尔两个地点的雪特性（反照率和密度）。由于两个城市有多个不同土地覆盖特征的观测点，因此模型开发独立于评价。开发的模型很好地模拟了与融雪有关的径流（在赫尔辛基的两个集水区，当地面有雪时，径流在19%和3%之间），并正确地估计了春季的峰值。然而，观测到的径流峰值往往比模拟的更平滑，这可能是由于集水区的持水量以及模型中集水区与观测点之间的时间滞后。对于所有三个站点，该模型很好地模拟了积雪和融化事件的时间，但低估了赫尔辛基的18-20%和蒙特利尔的29-33%的总雪深。该模式能够再现冷雪期、融雪期和无雪期的净辐射和感热和潜热湍流通量的日变化。最大的模式不确定性与融雪期的时间和融雪的参数化有关。结果表明，该模型能较好地模拟不同地表覆盖条件下寒冷气候城市的能量和水的交换。
The Surface Urban Energy and Water Balance Scheme (SUEWS) is developed to include snow. The processes addressed include accumulation of snow on the different urban surface types: snow albedo and density aging, snow melting and re-freezing of meltwater. Individual model parameters are assessed and independently evaluated using long-term observations in the two cold climate cities of Helsinki and Montreal. Eddy covariance sensible and latent heat fluxes and snow depth observations are available for two sites in Montreal and one in Helsinki. Surface runoff from two catchments (24 and 45 ha) in Helsinki and snow properties (albedo and density) from two sites in Montreal are also analysed. As multiple observation sites with different land-cover characteristics are available in both cities, model development is conducted independent of evaluation. The developed model simulates snowmelt related runoff well (within 19% and 3% for the two catchments in Helsinki when there is snow on the ground), with the springtime peak estimated correctly. However, the observed runoff peaks tend to be smoother than the simulated ones, likely due to the water holding capacity of the catchments and the missing time lag between the catchment and the observation point in the model. For all three sites the model simulates the timing of the snow accumulation and melt events well, but underestimates the total snow depth by 18-20% in Helsinki and 29-33% in Montreal. The model is able to reproduce the diurnal pattern of net radiation and turbulent fluxes of sensible and latent heat during cold snow, melting snow and snow-free periods. The largest model uncertainties are related to the timing of the melting period and the parameterization of the snowmelt. The results show that the enhanced model can simulate correctly the exchange of energy and water in cold climate cities at sites with varying surface cover.