Surface Albedo Increase following Massive Pleistocene Explosive Eruptions in Western North America

• Published in: Quaternary Research
• Main Author: Bray, J. R.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Cambridge University Press (CUP) 1979
• Subjects: Arctic; albedo
• Online Access: http://dx.doi.org/10.1016/0033-5894(79)90057-7; http://api.elsevier.com/content/article/PII:0033589479900577?httpAccept=text/xml; http://api.elsevier.com/content/article/PII:0033589479900577?httpAccept=text/plain; https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0033589400030258

The eight massive Pleistocene explosive volcanic eruptions which occurred in western North America produced rhyolitic ash layers estimated to have covered from 0.38 to 2.76 × 10 6 km 2 of the western and central portions of the continent. The surface albedo increases in the Northern Hemisphere resulting from these light-colored ash covers varied from around 0.06 to 0.41% assuming ash albedos based on color of around 53 to 65%. These albedo increases resulted in hemispheric temperature decreases of from around 0.07° to 0.41°C with greater cooling in and adjacent to the ash-covered regions. Such albedo-induced temperature declines lasted for at least several decades and reenforced the substantial posteruption cooling caused by volcanic aerosols and by a feedback decrease in atmospheric precipitable water. The magnitude and critical location of these temperature declines may have contributed to summer snow survival in the sub-Arctic plateaus and to a consequent triggering of major Pleistocene glaciations.