发表机构
Arizona State University; University of Illinois – Urbana-Champaign; NorthWest Research Associates; University of Alaska, Fairbanks; National Center for Atmospheric Research（亚利桑那州立大学; 伊利诺伊大学厄巴纳-香槟分校; 西北研究协会; 阿拉斯加大学费尔班克斯分校; 国家大气研究中心）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
利用阿拉斯加钠激光雷达观测，研究了太阳极小期冬季MLT经向风中的12小时波，发现其振幅在12月至1月显著增大，超过130米/秒，且高于流星雷达测量值，并与SSW同期出现。
AI 中文摘要
利用位于阿拉斯加查塔尼卡波克平坦研究场（PFRR，64°N，147°W）的钠激光雷达观测，研究了2018-2019年太阳活动极小期北极冬季中间层和低热层（MLT）经向风中的12小时波。12月至1月期间，夜间12小时波振幅显著增加，在97公里以上高度，多日振幅超过130米/秒。这比该时段之外观测到的12小时波振幅高出一倍多。查塔尼卡上空的流星雷达风也显示，在此期间82至97公里高度经向风12小时波振幅显著增加，但振幅低于激光雷达测量值。12小时波振幅的强烈变化与SME指数不相关，尽管最大振幅与1月初的平流层突然增温（SSW）同时发生。测量结果与季节性WACCM-X模型运行和四天的HIAMCM数据进行了比较。在可用的HIAMCM数据对应的四个日期，查塔尼卡上空的12小时波振幅在HIAMCM、WACCM-X和激光雷达在97公里以下高度相似，而激光雷达在97-105公里高度测量的振幅超过模型。所有测量结果都遵循类似的季节性趋势，振幅在12月底/1月初增加。WACCM-X的SW2拟合显示，SW2潮汐振幅与12小时波测量结果具有相似的季节性趋势。这些高分辨率激光雷达测量表明，局地12小时波振幅大于先前使用流星雷达测量的研究报告的值。
英文摘要
The 12-h wave in meridional winds in the mesosphere and lower thermosphere (MLT) during the solar minimum 2018-2019 Arctic winter is investigated using sodium lidar observations at Poker Flat Research Range (PFRR), Chatanika, Alaska (64N,147W). Nightly 12-h wave amplitudes increased significantly during December-January, with amplitudes exceeding 130 m/s above 97 km on several days. This was more than double the 12-h wave amplitudes observed outside this time period. Meteor radar winds over Chatanika also showed significant increase in meridional wind 12-h wave amplitudes at altitudes between 82 and 97 km during this time period with lower amplitudes than lidar measurements. The strong variation in 12-h wave amplitudes was not correlated with SME index, though the largest amplitudes coincided with the sudden stratospheric warming (SSW) in early January. Measurements were compared to a seasonal WACCM-X model run and four days of HIAMCM. For the four dates of available HIAMCM data, 12-h wave amplitudes over Chatanika were found to be similar between both HIAMCM and WACCM-X and the lidar below 97 km, with amplitudes measured by lidar exceeding the models at altitudes between 97-105 km. All measurements followed a similar seasonal trend with increasing amplitudes at the end of December/early January. Fits of SW2 from WACCM-X show the SW2 tidal amplitude following similar seasonal trends to 12-h wave measurements. These high-resolution lidar measurements indicate that localized 12-h wave amplitudes are larger than previously reported by studies using meteor radar measurements.
Comments30 pages, 6 figures. Submitted to Journal of Geophysical Research: Atmospheres
