Blowing Snow at McMurdo Station, Antarctica During the AWARE Field Campaign: Surface and Ceilometer Observations
Blowing Snow at McMurdo Station, Antarctica During the AWARE Field Campaign: Surface and Ceilometer Observations
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DOI：
10.1029/2020jd033935
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发表时间：
2021-04
期刊：
影响因子：
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通讯作者：
Nicole A. Loeb;A. Kennedy
中科院分区：
文献类型：
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作者：
Nicole A. Loeb;A. Kennedy
吹雪（BLSN）是寒冷气候中的一种影响过程，影响区域热力学，辐射特性和雪的表面质量平衡。虽然它对气候有重大影响，但人们对这一过程的了解仍然很少，也没有广泛纳入天气和气候模型。2016年，AWARE实地活动在南极洲的麦默多站部署了一套大型原位和遥感仪器，以便对BLSN进行调查。在南极洲其他地方使用的基于云高计的BLSN检测算法应用于AWARE的数据，产生的BLSN频率为14.1%，而人类观测者检测到的频率为8.2%。为了增加检测的置信度，该算法被更新为具有较短的时间平均值，并包括各种气象阈值，以限制由于雾引起的错误检测。将激光粒度仪纳入算法的努力没有成功。粒子大小分布对风速的非物理依赖性被发现，这表明在风速大于10 m s−1时观测是有问题的。修订后的算法检测到BLSN频率为7.4%，增加了与人类观察的一致性，并相信该过程正在观察地点积极发生。这些观测结果被纳入2002-2018年在麦默多站对BLSN进行人类观测的气候学背景中。估计年平均值为8.0%-14.0%，总的年范围为3.4%-21.3%。无论BLSN是由人类还是仪器观测到的，该地点的大多数病例都与持续降水有关。
Blowing snow (BLSN) is an impactful process in cold climates, affecting regional thermodynamics, radiation properties, and the surface mass balance of snow. Though it has significant climatic impacts, the process is still poorly understood and not widely included in weather and climate models. In 2016, the AWARE Field Campaign saw the deployment of a large suite of in situ and remote sensing instruments to McMurdo Station, Antarctica allowing for investigation of BLSN. A ceilometer‐based BLSN detection algorithm used elsewhere in Antarctica is applied to data from AWARE, yielding a BLSN frequency of 14.1% compared to 8.2% as detected by human observers. To increase confidence in detections, the algorithm is updated to have shorter temporal averaging and to include a variety of meteorological thresholds to limit false detections due to fog. Efforts to incorporate a laser disdrometer into the algorithm were unsuccessful. An unphysical dependence of particle size distributions on wind speed is found suggesting observations are problematic at wind speeds greater than 10 m s−1. The revised algorithm detected a BLSN frequency of 7.4%, increasing agreement with human observations and confidence that the process is actively occurring at the observation site. These observations are put into context of a climatology of human observations of BLSN at McMurdo station from 2002–2018. An annual average of 8.0%–14.0% is estimated, with a total annual range of 3.4%–21.3%. Regardless of whether BLSN is observed by humans or instrument, the majority of cases at this location are associated with ongoing precipitation.