基于LAS观测的城镇感热通量时空特征及影响因素
投稿时间:2020-03-17  修订日期:2020-04-04  点此下载全文
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作者单位E-mail
刘寿东 南京信息工程大学 lsd123123@163.com 
王璐瑶 南京信息工程大学  
胡凝 南京信息工程大学  
王咏薇 南京信息工程大学  
王亮 南京信息工程大学  
赵翔 南京信息工程大学  
中文摘要:利用2018年4月~2019年4月南京盘城大孔径闪烁仪(Large Aperture Scintillometer,LAS)观测数据,分析了城镇感热通量的时空变化特征及影响因素。结果表明:1)南京城镇感热通量呈单峰型日变化特征,白天明显大于夜间;城镇感热通量白天晴天明显大于阴天,夜间晴天略小于阴天,晴、阴天小时感热通量年平均分别在2.25 ~ 200.53 W?m-2、13.10 ~ 132.52 W?m-2之间波动。2)城镇感热通量夏季明显大于冬季,8月昼、夜分别为112.19、23.54 W?m-2,2月昼、夜分别为35.57、11.57 W?m-2。3)晴天白天条件下,不同风向(通量贡献源区)城镇感热通量存在显著差异,即随着不透水层占比的增加,净辐射分配到感热通量的比例明显提高,当占比大于60%时提高趋势不明显。4)以莫宁-奥布霍夫长度判断大气稳定度为标准,Cn2法在计算感热通量的5种大气稳定度判断方法中的误判率较低且数据源于LAS,是比较适宜城镇夜间大气稳定度的判断方法。5)在影响城镇感热通量的地表参数中,有效高度变化的影响最大,风速变化的影响较大特别在秋冬季节更为明显,波文比变化对城镇感热通量的影响较小,温度、地表粗糙度和零平面位移变化的影响可忽略不计。
中文关键词:城镇  LAS  感热通量  时空特征  环境因子  地表参数
 
Spatial-temporal characteristics and influencing factors of sensible heat flux based on LAS in town
Abstract:The data observed by Large Aperture Scintillometer (LAS) from April, 2018 to April, 2019 in Pancheng town were used to analyze the spatial-temporal characteristics and influencing factors of sensible heat flux. The results show that: 1) In town, the sensible heat flux exhibits a unimodal diurnal variation characteristic, which is significantly larger than that of nighttime. The sensible heat flux during the clear day is significantly larger than that of the cloudy day, and at night are slightly less than the cloudy day. The average hourly sensible heat flux on clear and cloudy days vary between 2.25?200.53 W·m-2 and 13.10?132.52 W·m-2. 2) The sensible heat flux in summer is significantly larger than that in winter. The value for the daytime and night in August is 112.19 and 23.54 W·m-2, respectively. In February, the value for the daytime and night is 35.57 and 11.57 W·m-2, respectively. 3) For the inflows of different directions in clear days, there are evident differences in sensible heat fluxes in town, that is, as the proportion of impervious layers increases, the proportion of net radiation allocated to sensible heat fluxes increases significantly. When the proportion is more than 60%, the upward trend is not obvious. 4) Taking the Monin-Obukhov length as the criterion for judging the stability of the atmosphere, the Cn2 method has a low misjudgment rate among the five methods and the data is derived from LAS. It is a more suitable method for determining the atmospheric stability at night in town. 5) Among the surface parameters that affect sensible heat flux, changes in effective height have the greatest impact. The effect of changes in wind speed is larger, especially in autumn and winter. The change of Bowen's ratio has a small effect. The effects of changes in temperature, roughness length, and displacement height are negligible.
keywords:Town  LAS  sensible heat flux  spatial-temporal characteristics  environmental factors  surface parameters
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