Relation between Long-term Temperature and Wind Speed Trends at Surface Observation Stations in Japan

Abstract

In order to detect microscale influences on observed surface air temperature changes, 29 years’ data on the AMeDAS network were used to identify the relation between temperature trends and wind speed trends, which were regarded as reflecting the changes of site exposure. The results were found to differ according to time of the day and the mean wind speed of the site. For stations with relatively high mean wind speed (≥ 1.5 m s^-1), a significant negative correlation is found between daytime temperature trends and wind speed trends. For stations with low wind speed (< 1.0 m s^-1), evening temperature trends are negatively correlated with wind speed trends, whereas daytime temperature trends tend to be positively correlated with them. These facts give statistical evidence of the dependence of temperature trends on microscale environmental changes, with complications according to the degree of site exposure.