摘要
利用大气气溶胶和云分档模式研究海盐气溶胶和硫酸盐气溶胶在云微物理过程中的作用,计算结果表明:云中液态水含量随高度的分布并不随海盐、硫酸盐的数目以及云团上升速度的变化而变化;随着云滴数目的增加,云滴的有效半径会减小;硫酸盐对云滴数目影响起主导作用,海盐在水汽相对充足情况下增加了云滴数目,在水汽相对不足的情况下减少了云滴数目;硫酸盐粒子浓度特别强的情况下(人类活动污染比较严重时),如果水汽相对不足,云滴数目会明显小于硫酸盐粒子浓度;而海盐粒子的存在,加剧了水汽的供应不足,从而可以在很大程度上进一步降低云滴数目。也就是说,在有些情况下,如果不考虑海盐气溶胶的作用,硫酸盐气溶胶对云特性的影响会被过高估计。
Impacts of nss-sulfate and sea-salt on marine clouds microphysical properties are investigated using a mutil-component size-resolving aerosol model. Numerical results show that the vertical distribution of liquid water content remains almost constant as sea salts number and updrafts increase. The effective radius decreases as cloud drops number increases. The number of cloud drops is dominated by nss-sulfate. Sea-salt plays a critical role in cloud microphysical processes. Due to its large radius sea-salt particles are activated into cloud drops in the initial cloud development. Sea-salt activation decreases supersaturation by consuming water vapor and suppresses nss-sulfate activation. Sea salts can enhance cloud drops number concentration under the case of larger updrafts and decrease under the case of low updrafts. Nss-sulfate indirect forcing may be overestimated in some conditions （such as updraft is low） because of the presence of sea-salt particles.
出处
《应用气象学报》
CSCD
北大核心
2005年第4期417-425,共9页
Journal of Applied Meteorological Science
基金
国家自然科学基金项目40005001和40475003共同资助
