基于分段三次样条函数逐时气象资料模拟方法研究

Modeling method of hourly meteorological data based on piecewise cubic spline function

精细化的逐时气象资料是气候可行性论证的基础,本文利用河南省5个气象观测站逐日4次定时气温观测资料及日最高气温和日最低气温观测资料,基于分段三次样条函数插值法模拟计算逐时气温,并以2006—2015年郑州气象观测站气温观测资料为例分析观测气温与模拟气温之间的差异。结果表明:分段三次样条函数插值法可以有效模拟实际气温的变化特征,但考虑日最高气温和日最低气温后,"六点"插值法模拟效果优于"四点"插值法,2006—2015年郑州气象观测站模拟气温与观测气温之间呈极显著的正相关关系(R^2=0.99,n=73 040);特别是在气温要素没有连续跃变时,利用分段三次样条函数插值法可以使4次气温观测资料有效转换为逐时气温资料,三次样条函数插值法也适宜于其他连续性变化的气象要素(如水汽压、相对湿度和风速等)的逐时模拟,且模拟效果基本不受地域影响;从郑州气象观测站模拟气温与观测气温之间的偏差及其变化幅度来看,计算结果可以满足气候可行性论证对气象要素时间精度的要求和气候应用服务的需求。

Fine hourly meteorological data are the basic for the studying climate feasibility. Based on the four times a day of observational data and daily maximum and minimum air temperature data at five meteorological stations in He＇nan province, the hourly air temperature was calculated using a cubic spline interpolation method, and the differences between observed and simulated air temperature were analyzed based on the observations of Zhengzhou meteorological station from 2006 to 2015. The results show that the cubic spline interpolation method can effectively represent the variation of the actual air temperature. Through considering the daily maximum and minimum air temperature, the ＂six-point＂ interpolation model is better than the ＂four-point＂ interpolation model. The simulated and observed values of air temperature have a significantly high correlation （ R^2 = 0. 99, n = 730 40 ）. The cubic spline interpolation method can effectively convert the four times observation data into hourly data, especially as temperature values do not have continuous jumps. This method can also be used to simulate hourly variations of other continuously changeable parameters, such as water vapor pressure, relative humidity, wind speed and their simulations are hardly limited by territory. The deviation and variation between the simulated and observed air tem- perature at the Zhengzhou meteorological station prove that the simulation results can meet the requirements of time accuracy of meteorological elements and climate application service.