Reports

Evidence for Liquid-Phase Cirrus Cloud Formation from Volcanic Aerosols: Climatic Implications

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Science  24 Jul 1992:
Vol. 257, Issue 5069, pp. 516-519
DOI: 10.1126/science.257.5069.516

Abstract

Supercooled droplets in cirrus uncinus cell heads between -40° and -50°C are identified from Project FIRE [First ISCCP (International Satellite Cloud Climatology Project) Regional Experiment] polarization lidar measurements. Although short-lived, complexes of these small liquid cells seem to have contributed importantly to the formation of the cirrus. Freezing-point depression effects in solution droplets, apparently resulting from relatively large cloud condensation nuclei of volcanic origin, can be used to explain this rare phenomenon. An unrecognized volcano-cirrus cloud climate feedback mechanism is implied by these findings.