9:15 AM - 9:30 AM
[MIS10-02] Characteristics of Vertical Structure of Temperature on the South Slope of Mt. Myojindake, Kamikochi
Keywords:mountainous region, cold air pool
Cold-air pool, an atmospheric phenomenon, tend to occur in basins and valleys in mountainous regions. There have been few studies on cold-air pool phenomena based on actual measurements of cold air pool formation and its layered structure(layer thickness). In addition, in recent years, there has been much interest in how the formation of cold-air pool in mountainous regions is affected by climate change, and long-term, detailed observations are required. In this study, we will conduct temperature observations on the south slope of Mt. Myojidake, Kamikochi over several years to clarify the characteristics of the vertical structure (layer structure) of cool-air lakes in mountain regions. For this, temperature loggers were installed at every 50 m elevation from the valley floor in Kamikochi, and hourly temperatures were observed.
Cold-air pool events were formed more than 10 times per month and tended to increase during the summer season. The number of events varied greatly from year to year during the summer months, while the number of events varied little during the winter months. In the winter of 2019-2020;the warmest winter on record in the country, the number of events and the height of the cold-air layer did not change, although a similar trend was observed in the mountain regions. The total duration of each elevation cold-air lake formation for all cold-air lake events in each month showed a small difference in duration between the 1700 m point and the upper level in winter and a large difference in duration in summer. The total duration of each elevation cold-air lake formation for all cold-air lake events in each month showed a small difference in duration between the 1700 m point and the upper level in winter and a large difference in duration in summer.
The steep valley topography of the site allows the formation of cold-air lakes throughout the year. Differences in the formation process of the cold-air pool may affect the duration of formation and the altitude of the cold-air layer, and one of the possible factors is the change in the amount of radiative cooling associated with changes in surface conditions.
Cold-air pool events were formed more than 10 times per month and tended to increase during the summer season. The number of events varied greatly from year to year during the summer months, while the number of events varied little during the winter months. In the winter of 2019-2020;the warmest winter on record in the country, the number of events and the height of the cold-air layer did not change, although a similar trend was observed in the mountain regions. The total duration of each elevation cold-air lake formation for all cold-air lake events in each month showed a small difference in duration between the 1700 m point and the upper level in winter and a large difference in duration in summer. The total duration of each elevation cold-air lake formation for all cold-air lake events in each month showed a small difference in duration between the 1700 m point and the upper level in winter and a large difference in duration in summer.
The steep valley topography of the site allows the formation of cold-air lakes throughout the year. Differences in the formation process of the cold-air pool may affect the duration of formation and the altitude of the cold-air layer, and one of the possible factors is the change in the amount of radiative cooling associated with changes in surface conditions.