北京地区1963年春季冰核浓度变化特点的观测分析

THE MEASUREMENT AND ANALYSIS OF ICE-NUCLEUSCON CENTRATION AT PEKING DURING THE PERIOD FROM MARCH 18TH TO APRIL 30TH IN 1963

摘要: 1963年3月18日至4月30日在北京利用混合型云室进行了-15℃至-30℃温度范围内冰核浓度的测定。得到了在4个温度下(-15°,-20°,-25°,-30℃)的平均冰核浓度和冰核浓度的逐日变化的观测结果。当能见度变低和测点处于市区的下风方向时,观测到的冰核浓度显然较高,这表示城市污染是造成北京地区冰核浓度逐日变动的一个重要原因。另外,在有风砂现象时也常观测到冰核浓度的相对增加,看来北京地区的土壤可能是冰核的另一个比较次要的来源。

Abstract: The concentration of ice-nuclei active at temperatures of -15°,-20°,-25°,-25℃ and -25℃ was measured with an mixing cloud chamber,during the period from March 18th to April 30th in 1963 at Peking.The average concentration and daily varitions at four temperatures of ice-nucleus concentration counts are given.The results are discussed with reference to the conditions of wind and pollution.