The Hemispheric Asymmetry of Gravity Wave Impact on the Polar Mesospheric Cloud, Based on the Aeronomy of Ice in the Mesosphere Satellite

In this research, we analyze the gravity wave (GW) energy density, ice water content (IWC), particle radius, and cloud albedo data of 16 polar mesospheric cloud (PMC) seasons in the Northern Hemisphere (NH) from 2007 to 2014 and Southern Hemisphere (SH) from 2007/2008 to 2014/2015, based on observations from the Cloud Imaging and Particle Size and Solar Occultation For Ice Experiment instruments. The influence of GW activity on the formation of PMCs is studied by hemispheric contrast. In the NH, the GW flux generally starts to increase significantly around the summer solstice during the 8 PMC seasons. In 6/8 of these seasons, the IWC is positively correlated with the variation of GW. When the GW activity is enhanced to reach the maximum, the IWC will start to increase and reach the peak within 0-23 days. In comparison, in the SH, the GW peaks around 55 days after the solstice. The timing of PMC appearance also varies, with the IWC starting to grow 20 days after the solstice and the GW increasing in 55 days after the solstice. In particular, the IWC starts even earlier than the solstice in the seasons of 2012/2013 and 2013/2014.