The relationship between cloud condensation nuclei (CCN) concentration and light extinction of dried particles: indications of underlying aerosol processes and implications for satellite-based CCN estimates
Number of Authors: 14
2015 (English)In: Atmospheric Chemistry And Physics, ISSN 1680-7316, E-ISSN 1680-7324, Vol. 15, no 13, 7585-7604 p.Article in journal (Refereed) Published
We examine the relationship between the number concentration of boundary-layer cloud condensation nuclei (CCN) and light extinction to investigate underlying aerosol processes and satellite-based CCN estimates. For a variety of airborne and ground-based observations not dominated by dust, regression identifies the CCN (cm(-3)) at 0.4 +/- 0.1% supersaturation with 10(0.3 alpha+1.3)sigma(0.75) where sigma (Mm(-1)) is the 500 nm extinction coefficient by dried particles and alpha is the Angstrom exponent. The deviation of 1 km horizontal average data from this approximation is typically within a factor of 2.0. partial derivative logCCN / partial derivative log sigma is less than unity because, among other explanations, growth processes generally make aerosols scatter more light without increasing their number. This, barring special meteorology-aerosol connections, associates a doubling of aerosol optical depth with less than a doubling of CCN, contrary to previous studies based on heavily averaged measurements or a satellite algorithm.
Place, publisher, year, edition, pages
2015. Vol. 15, no 13, 7585-7604 p.
Earth and Related Environmental Sciences
IdentifiersURN: urn:nbn:se:su:diva-119770DOI: 10.5194/acp-15-7585-2015ISI: 000357978300028OAI: oai:DiVA.org:su-119770DiVA: diva2:848540