RAPID: Cold Air Pool Exchange Processes during the Utah Wintertime Fine Particulate Study

持续冷气池是一种现象，在冬季高压事件期间，空气有效地被困在盆地或山谷中。它们在美国西部的高海拔盆地中尤其普遍。冷气池的影响之一是颗粒污染物积累，并影响犹他州盐湖城等地的空气质量。该奖项为研究人员提供资金，以便在现有的基于飞机的空气质量实地活动期间进行地面气象测量，以更好地详细说明影响冷气池内空气运动和影响相关化学过程的过程。仅在盐湖城，就有100多万人受到这些事件的影响，研究结果可能会延伸到其他地形相似的地方，如洛杉矶和科罗拉多前线。研究人员将加入美国国家海洋和大气管理局领导的犹他州冬季细颗粒物研究，该研究将于2017年1月至2月在盐湖城地区进行。NSF资助的研究人员将通过对犹他州山谷和盆地冬季建立的持续冷池的气象测量来加强这项专注于空气质量的研究。在冷空气汇集事件中，垂直混合被抑制，颗粒污染物积累并影响人类健康。多个天花板、激光雷达、声雷达、温度传感器、地面通量站和无线电探空仪发射器将作为地面资产部署，以补充NOAA飞机行动。此次部署将针对影响颗粒物空气污染形成的化学成分和化学途径的大气混合和气团交换的关键过程和问题。具体过程包括：1)持续冷空气池内的垂直混合，2)夜间沿盆地侧壁和峡谷下气流注入清洁但富含氧化剂的空气，3)沿盆地侧壁的白天通风过程，以及4)气团与大盐湖的湖泊边界层交换。

Persistent cold-air pools are a phenomena where air is effectively trapped in a basin or valley during high pressure events in wintertime. They are especially prevalent in high altitude basins in the western United States. One of the impacts of cold air pools is that particulate pollutants accumulate and affect the air quality for places like Salt Lake City, Utah. This award provides funding for researchers to take surface-based meteorological measurements during an existing aircraft-based air quality field campaign to better detail the processes that affect air movement within the cold air pools and impact the relevant chemical processes. In Salt Lake City alone there are over 1 million people affected by these events, and the research results may extend to other locations with similar topography such as Los Angeles and the Front Range of Colorado.The researchers will join the NOAA-led Utah Wintertime Fine Particulate Study which will take place in Jan-Feb 2017 in the Salt Lake City region. The NSF-funded researchers will augment the air quality focused study with meteorological measurements of the persistent cold pools that set up in the valleys and basins of Utah in the wintertime. In cold air pooling events vertical mixing is inhibited and particulate pollutants accumulate and affect human health. Multiple ceilometers, a lidar, sodar, temperature sensors, a surface flux station, and radiosonde launches will be deployed as ground-based assets to complement the NOAA aircraft campaign. The deployment will target key processes and questions regarding atmospheric mixing and airmass exchange that affect chemical composition and chemical pathways of particulate air pollution formation. The specific processes include: 1) vertical mixing within the persistent cold-air pool, 2) nighttime injections of clean, but oxidant-rich air along the basin sidewalls and through down-canyon flows, 3) daytime ventilation processes along the basin sidewalls, and 4) airmass exhanges with the lake boundary layer of the Great Salt Lake.