Weekday-Holiday Differences in Atmospheric Pressure and Surface Wind Fields in Tokyo and Osaka

Abstract

A statistical study was conducted on weekday-holiday differences in atmospheric pressure in the central part of Tokyo and Osaka, and on surface wind fields in surrounding areas. The analysis for pressure was based on 33-year data from stations of the Japan Meteorological Agency (JMA). The analysis of winds was based on 44-year data from the Automated Meteorological Data Acquisition System (AMeDAS) of the JMA and 28-year data from the Air Pollution Monitoring System (APMS) of the Tokyo Metropolis. It was found that the pressure in central Tokyo was higher during the daytime on holidays than on weekdays, by approximately 0.045 hPa at 1500 JST. The daytime surface winds had a divergent anomaly within several tens of kilometers of the city center, corresponding to a wind speed anomaly of the order of 0.1 m s⁻¹. Similarly, a pressure anomaly of approximately 0.015 hPa was found in the afternoon on holidays in central Osaka, as well as a divergent anomaly in surface winds in the surrounding area.