Collaborative Research: An investigation of wave dynamics in the Arctic mesosphere and coupling between the lower and upper polar atmosphere

The research objective is to utilize a suite of instruments, including an airglow imager, to investigate short-period gravity waves in the Arctic atmosphere over Alaska. Short-period gravity waves are an important component of the larger atmospheric circulation as these waves are believed to transport a large amount of vertical moment flux into the mesosphere and lower thermosphere (MLT) region. While the propagation nature and sources of these waves have been studied extensively at low- and mid-latitudes, little is known about their behavior at high latitudes. Recent efforts have begun to characterize the waves over the Antarctic continent, while the project proposed here will focus on the Arctic. Specifically, the proposed research will establish a long-term winter time series of short-period gravity waves in the Arctic, including their dominant source regions, and influences of large-scale tidal and planetary wave motion. The co-located Rayleigh LIDAR will provide essential high vertical resolution temperature measurements to help elucidate the vertical wave propagation, individual wave contribution to the Eliassen-Palm (EP) flux, and coupling between the lower and upper atmosphere during stratospheric warming events.

本研究的目标为采用包括气辉成像仪（airglow imager）在内的整套观测仪器，对阿拉斯加上空北极大气中的短周期重力波（short-period gravity waves）开展研究。短周期重力波是大尺度大气环流的重要组成部分，据信可将大量垂直动量通量输送至中间层与低热层（mesosphere and lower thermosphere，MLT）区域。目前，低纬度与中纬度地区已针对这类波的传播特性与源区开展了大量研究，但高纬度地区的相关波系特征仍鲜有报道。此前已有研究开始对南极大陆上空的短周期重力波进行系统表征，而本项拟实施的研究将聚焦北极区域。具体而言，本研究将建立北极地区短周期重力波的长期冬季时间序列，涵盖其主要源区，以及大尺度潮汐与行星波活动的影响。与此同时，共址部署的瑞利激光雷达（Rayleigh LIDAR）将提供高垂直分辨率的温度测量数据，助力阐明垂直波传播特性、单波对埃利亚森-帕尔姆（Eliassen-Palm，EP）通量的贡献，以及平流层增温事件期间低层与高层大气之间的耦合过程。