An observational study on the influence of wind ventilation changes on surface air temperature, induced by nearby plants and artificial structures.

Abstract

We studied the influence of surrounding plants and artificial structures on air temperature, on the basis of parallel observation from two thermometers in the meteorological enclosure of JMA in central Tokyo. One of the thermometers is for operational observation and is located at a well-ventilated place in the center of the enclosure, whereas the other is installed for our research at a spot: surrounded by plants and artificial structures at about 20m distant from the operational one. The two thermometers are of the same specification, and are installed at a height of 1.5m from ground. We also installed an ultrasonic anemometer at a height of 2.5m near each thermometer. It was found that the temperature at the spot surrounded by plants was higher than the operational temperature in the early afternoon of the warm season, by about 0.5^oC on the average. The temperature difference became larger on sunny days with higher solar radiation, but decreased under high wind speed.