Dust radiative forcing in snow of the Upper Colorado River Basin: 2. Interannual variability in radiative forcing and snowmelt rates
Dust radiative forcing in snow of the Upper Colorado River Basin: 2. Interannual variability in radiative forcing and snowmelt rates
复制标题
DOI：
10.1029/2012wr011986
复制
发表时间：
2012-07
影响因子：
5.4
通讯作者：
S. Skiles;T. Painter;J. Deems;A. C. Bryant;C. Landry
中科院分区：
文献类型：
--
作者：
S. Skiles;T. Painter;J. Deems;A. C. Bryant;C. Landry
在这里，我们提出了辐射和积雪融化的影响，灰尘沉积积雪覆盖使用6年的能量平衡记录（2005-2010年）在高山和亚高山微气象塔在参议员贝克盆地研究区（SBBSA）在西南部科罗拉多，美国。这些结果来自第一部分中描述的测量。我们模拟了在观测和无尘条件下，以及+2 ° C和+4 ° C融化季节温度扰动这些情况下，每个站的雪水当量的演变。在有记录的6年中，日平均沙尘辐射强迫介于0到214 W m−2之间，每小时峰值可达409 W m−2。在此期间，高山地区的平均春季沙尘辐射强迫为31至49 W m−2，亚高山地区为45至75 W m−2，从而使积雪持续时间缩短了21至51天。尽管沙尘暴暴露和太阳辐照度存在时间变化，但沙尘提前积雪损失（天数）与积雪结束时的总沙尘浓度呈线性关系。在干净的雪条件下，温度升高会使积雪缩短5-18天，而在有灰尘的情况下，它们只会缩短0-6天的降雪时间。沙尘辐射强迫也会导致更快和更早的峰值融雪流量与日平均积雪流量加倍最重的沙尘条件下。平均而言，在多尘条件下，塔上的积雪在峰值流出后2.5天消失，在清洁条件下，峰值流出后1-2周消失。
Here we present the radiative and snowmelt impacts of dust deposition to snow cover using a 6‐year energy balance record (2005–2010) at alpine and subalpine micrometeorological towers in the Senator Beck Basin Study Area (SBBSA) in southwestern Colorado, USA. These results follow from the measurements described in part I. We simulate the evolution of snow water equivalent at each station under scenarios of observed and dust‐free conditions, and +2°C and +4°C melt‐season temperature perturbations to these scenarios. Over the 6 years of record, daily mean dust radiative forcing ranged from 0 to 214 W m−2, with hourly peaks up to 409 W m−2. Mean springtime dust radiative forcings across the period ranged from 31 to 49 W m−2 at the alpine site and 45 to 75 W m−2 at the subalpine site, in turn shortening snow cover duration by 21 to 51 days. The dust‐advanced loss of snow cover (days) is linearly related to total dust concentration at the end of snow cover, despite temporal variability in dust exposure and solar irradiance. Under clean snow conditions, the temperature increases shorten snow cover by 5–18 days, whereas in the presence of dust they only shorten snow duration by 0–6 days. Dust radiative forcing also causes faster and earlier peak snowmelt outflow with daily mean snowpack outflow doubling under the heaviest dust conditions. On average, snow cover at the towers is lost 2.5 days after peak outflow in dusty conditions, and 1–2 weeks after peak outflow in clean conditions.