Feasibility of the Lapse Rate Prediction at an Hourly Time Interval

Abstract

Temperature lapse rate within the planetary boundary layer shows a diurnal cycle with a substantial variation. The widely-used lapse rate value for the standard atmosphere may result in unaffordable errors if used in interpolating hourly temperature in complex terrain. We propose a simple method for estimating hourly lapse rate and evaluate whether this scheme is better than the conventional method using the standard lapse rate. A standard curve for lapse rate based on the diurnal course of temperature was drawn using upper air temperature for 1000hPa and 925hPa standard pressure levels. It was modulated by the hourly sky condition (amount of clouds). In order to test the reliability of this method, hourly lapse rates for the 500-600m layer over Daegwallyeong site were estimated by this method and compared with the measured values by an ultrasonic temperature profiler. Results showed the mean error -0.0001℃/m and the root mean square error 0.0024℃/m for this vertical profile experiment. An additional experiment was carried out to test if this method is applicable for the mountain slope lapse rate. Hourly lapse rates for the 313-401m slope range in a complex watershed ('Hadong Watermark 2') were estimated by this method and compared with the observations. We found this method useful in describing diurnal cycle and variation of the mountain slope lapse rate over a complex terrain despite larger error compared with the vertical profile experiment.

Improving the Usage of the Korea Meteorological Administration's Digital Forecasts in Agriculture: V. Field Validation of the Sky-condition based Lapse Rate Estimation Scheme

“…환경기온감률의 월변동 또는 계절변동에 대하여 많 은 연구가 진행되어 왔으며 (Kirchner et al, 2013;Minder et al, 2010;Yun et al, 2001), 최근 Kim and Yun(2016) Kim and Yun(2016) (Fig. 1).…”

“…The diurnal change in temperature lapse rate on an equinox and the minimum value Γ min , the maximum value Γ max of the temperature lapse rate in each interval (1, 2, 3). 'Standard' represents the average weather condition (Adopted from Kim and Yun, 2016). 경우와 유사한 수준으로 유지되었다 (Fig.…”