冰期河湖与大气的热交换模型

Heat exchange model between river-lake and atmosphere during ice age

河湖与大气的热交换模型是计算分析冰凌形成、发展、消融时空变化规律的基础。基于现有太阳辐射、长波辐射、蒸发和对流模型研究成果,以现场冰情要素观测及历史天气资料为依据,建立了适用于冰期计算分析的河湖与大气的热交换非线性模型。提出了考虑晴天散射的太阳辐射计算模型,以Iziomon公式计算大气长波逆辐射,以俄罗斯冬季公式计算蒸发和对流。基于现场观测雪面或冰面温度T_(s)接近于T_(a)的实际,提出了在T_(s)=T_(a)点对河湖与大气的多参数非线性热交换模型线性化,然后利用历史天气资料,采用线性回归的方法确定热交换系数hsa。研究证实:(1)气象站风级或者风速资料一般不能准确估计地势低洼河面的风速;(2)采用典型年历史天气资料得到的hsa可用于预测其他年的热交换;(3)hsa与T_(a)成正比,且北京、沈阳、保定、包头的hsa的平均值>10.0 W(/m^(2)·℃);(4)漠河和拉萨的hsa略小于北京等地区。

The heat exchange model between river-lake and atmosphere is the basis for calculating and ana⁃lyzing the temporal and spatial variation law of ice formation,development and melting.Based on the exist⁃ing research results of solar radiation,long-wave radiation,evaporation and convection models,and on the basis of on-site observation of ice conditions and historical weather data,a nonlinear model of heat ex⁃change between rivers,lakes and atmosphere is established,which is suitable for ice age calculation and analysis.A solar radiation calculation model considering sunny day scattering is proposed.The atmospheric long-wave inverse radiation is calculated by Iziomon formula,and evaporation and convection are calculated by Russian winter formula.Based on the fact that the observed temperature T_(s) of snow or ice surface is close to air temperature T_(a),a multi-parameter nonlinear heat exchange model between rivers,lakes and the atmosphere is linearized at T_(s)=T_(a),and then the heat exchange coefficient hsa is determined by linear regres⁃sion using historical weather data.The research proves that:(1)the wind speed of low-lying river cannot be estimated correctly by the wind level or wind speed data of meteorological stations;(2)hsa obtained from historical weather data of typical years can be used to predict heat exchange in other years;(3)hsa is propor⁃tional to T_(a),and the average value of hsa in Beijing,Shenyang,Baoding and Baotou is>10.0 W(/m·2℃);and(4)the average values of hsa in Mohe and Lhasa are slightly smaller than those in Beijing and other areas.