Sullivan R C, Crippa P, Hallar A G, Clarisse L, Whitburn S, Van Damme M, Leaitch W R, Walker J T, Khlystov A, Pryor S C
Department of Earth and Atmospheric Sciences, Cornell University, Ithaca, New York, USA.
COMET, School of Civil Engineering and Geosciences, Newcastle University, Newcastle upon Tyne, UK.
J Geophys Res Atmos. 2016;121(20):12217-12235. doi: 10.1002/2016jd025568.
New particle formation (NPF) can potentially alter regional climate by increasing aerosol particle (hereafter particle) number concentrations and ultimately cloud condensation nuclei. The large scales on which NPF is manifest indicate potential to use satellite-based (inherently spatially averaged) measurements of atmospheric conditions to diagnose the occurrence of NPF and NPF characteristics. We demonstrate the potential for using satellite-based measurements of insolation (UV), trace gas concentrations (sulfur dioxide (SO), nitrogen dioxide (NO), ammonia (NH), formaldehyde (HCHO), and ozone (O)), aerosol optical properties (aerosol optical depth (AOD) and Ångström exponent (AE)), and a proxy of biogenic volatile organic compound emissions (leaf area index (LAI) and temperature ()) as predictors for NPF characteristics: formation rates, growth rates, survival probabilities, and ultrafine particle (UFP) concentrations at five locations across North America. NPF at all sites is most frequent in spring, exhibits a one-day autocorrelation, and is associated with low condensational sink (AOD × AE) and HCHO concentrations, and high UV. However, there are important site-to-site variations in NPF frequency and characteristics, and in which of the predictor variables (particularly gas concentrations) significantly contribute to the explanatory power of regression models built to predict those characteristics. This finding may provide a partial explanation for the reported spatial variability in skill of simple generalized nucleation schemes in reproducing observed NPF. In contrast to more simple proxies developed in prior studies (e.g., based on AOD, AE, SO, and UV), use of additional predictors (NO, NH, HCHO, LAI, T, and O) increases the explained temporal variance of UFP concentrations at all sites.
新粒子形成（NPF）有可能通过增加气溶胶粒子（以下简称粒子）数量浓度并最终增加云凝结核来改变区域气候。NPF出现的大尺度表明，有潜力利用基于卫星（本质上是空间平均）的大气条件测量来诊断NPF的发生情况和NPF特征。我们展示了利用基于卫星的日照（紫外线）、痕量气体浓度（二氧化硫（SO）、二氧化氮（NO）、氨（NH）、甲醛（HCHO）和臭氧（O））、气溶胶光学特性（气溶胶光学厚度（AOD）和埃斯特朗指数（AE））以及生物源挥发性有机化合物排放的一个替代指标（叶面积指数（LAI）和温度（））作为北美五个地点NPF特征预测指标的潜力：形成速率、生长速率、存活概率和超细粒子（UFP）浓度。所有地点的NPF在春季最为频繁，呈现出一天的自相关性，并且与低凝结核汇（AOD×AE）和HCHO浓度以及高紫外线相关。然而，NPF频率和特征以及预测变量（特别是气体浓度）中哪些对用于预测这些特征的回归模型的解释力有显著贡献，存在重要的地点间差异。这一发现可能为简单通用成核方案在再现观测到的NPF技能方面所报告的空间变异性提供部分解释。与先前研究中开发的更简单的替代指标（例如基于AOD、AE、SO和紫外线）相比，使用额外的预测指标（NO、NH、HCHO、LAI、T和O）增加了所有地点UFP浓度的解释时间方差。
