兰州新区近地层风场时空特征分析  

Analysis of Characters of Wind Field in Surface Layer in Lanzhou New District

作　　者：李晓霞[1,2] 黄涛[1,2] 王兴[1,2] 梁东升[1,2] 

机构地区：[1]中国气象局兰州干旱研究所/甘肃省干旱气候变化与减灾重点实验室/甘肃省干旱气候变化与减灾重点开放实验室,兰州730020 [2]西北区域气候中心,兰州730020

出　　处：《高原气象》2017年第4期1001-1009,共9页Plateau Meteorology

基　　金：甘肃省科技支撑计划项目(144FKCA077)

摘　　要：利用兰州新区2014年1-12月秦川金家庙、西岔段家川、新区东南角、黑石川和平4座70 m风塔和新区城区4个10 m高度自动气象站逐10 min风向风速观测资料,分析了兰州新区盛行风向、风速、污染系数时空分布特征。结果表明:新区周围地形复杂,盛行风向、风速及污染系数等要素随高度、时间、位置均有变化。观测年内,新区测风塔70 m高度年盛行风向为东北风及相邻方向,该方向平均风速最大;新区偏北的两个风塔(秦川金家庙和西岔段家川)西北至偏北方向污染系数较小,新区偏南两个风塔(新区东南角和黑石川和平),偏北及相近方向污染系数较小。测风塔10 m高度各观测点盛行风向、风速和污染系数与70 m均有明显差异,4个风塔的风场特征也显著不同。各观测点各高度均有静风天气出现,70 m高度静风频率4.2%~13.5%,10 m高度静风频率5.6%~11.5%;各塔风向有较明显的季节变化特征,秋、冬季盛行风向接近,春、夏季盛行风向接近;新区风向日变化呈现出山谷风特征,白天盛行风向多为东南风或西南风,夜晚多为东北风和偏东风。This paper used wind direction and speed data collected at four anemometer towers（ 70 meters） from Qinchuan-Jinjiamao,Xicha-Duanjiachuan,Heishichuan-Heping and the southeast of Lanzhou NewDistrict,and other four high AWS（ Automatic Weather Station）（ 10 meters） at the newdistrict from January to December2014,to analyze the area＇s prevailing wind direction,speed,characteristics and distributions of air pollution.The reselts showed： The newdistrict exhibited complex geographic variations; Prevailing wind direction,speed,and air pollution index（ API） changed depending on altitude,time,and location. During the period of 2014,the newdistrict anemometer towers（ 70 meters） observed a dominant frequency of northeastern prevailing wind,a direction with the highest average wind speed; As for API,it was the lowest between Qinchuan-Jinjiamiao and Xicha-Duanjiachuan at the west by north,and the lowest API between the southeast of Lanzhou NewDistrict and Heishichuan-Heping is at the north and the near directions. Furthermore,the prevailing wind direction,speed and API had some differences between the 10 meters towers and the 70 meters towers. The wind fields also changed among the four towers. Calm wind weather occurred at each observation point. The Frequency for calm wind was4. 2% ~ 13. 5% at 70 meters,and 5. 6% ~ 11. 6% at 10 meters; Each tower had distinct seasonal differences;Autumn and winter shared a similar prevailing wind direction,and spring and summer shared a similarity at another direction. The daily wind changes at the newdistrict also displayed characteristics of valley wind,with a southeast or southwest prevailing wind in the day,and a northeast or east wind at night.

关 键 词：兰州新区 近地层风场 盛行风向 风速频率 污染系数 

分 类 号：P404[天文地球—大气科学及气象学]