Characteristics of aerosol distribution in mountainous regions obtained from AERONET/DRAGON/J-ALPS

In order to investigate atmospheric aerosol properties in the mountainous regions of Japan, aerosol observations by the NASA/AERONET field campaign were conducted around Nagano prefecture in Japan since March 2020. This field campaign is called DRAGON/J-ALPS because the target area includes the mountains known as the Japanese Alps. One of the objectives of DRAGON/J-ALPS is to understand the spatial distribution of aerosol properties in mountainous regions. The aerosol concentration levels in the J-ALPS sites are usually not too high. Possible reasons are low local emissions and aerosol advection blocked by the high mountains. However, there are days when the concentration is higher than usual. One of the reasons for this is the advection of “yellow dust” from the continent. Another factor is the local emissions. The shape of the basin surrounded by mountains and meteorological conditions may also promote the retention of aerosols. This work is expected not only to introduce the results of the J-ALPS, but also to provide insights into aerosol advection and local emission in closed mountain areas.