A Study of the Decline of Air Temperature in the Small Grove in Summer

Abstract

In this study we have measured the temperature difference between the inside and the outside of a small size grove in the park and analysed with relation to some meteorological elements by the means of multivariate analysis. And at the same time, the precision of the measurement of temperature at moving observation method is calculated. The result is summarised as follows.
(1) A decline of the air temperature in the grove is clear in every observations and the most cooling part appears at the rear part in the grove from the wind direction.
(2) A maximum decline value of air temperature (Δt^max) and an average decline value (Δt_av) in the grove is shown by these regression equations.
Δt^max=-0.0878X₁+0.0007X₂-0.3114X₃-0.0196X₄+4.9002
Δt^av=-0.0587X₁+0.0004X₂+01834X₃-0.0172X₄+3.6595
(X₁: air temperature, °C X₂: illumination intensity of a light saturation point, ×100 lux X₃: wind speed at 1.5m hight, m/s X₄: relative humidity, %)
(3)Δt_av value of the small size grove (500 m²) is calculated 1.1°Cand the value in the more large size grove (15, 000m²) is 2.1°Con midday and clear in summer of Tokyo.
(4) The precision of the measurement is calculated from the short time dispersion of air temperature and the result is ±0.53°C at this observation.