Chemical consequences of Chicxulub impact ejecta reentry
Abstract
The Chicxulub impact 66.0 million years ago initiated the second biggest extinction in the Phanerozoic Eon. The global reentry of material ejected by the impact generated a strong pulse of thermal radiation that wiped out much of the terrestrial biota. The cause of the marine extinction, however, has remained elusive. This report shows that reentering ejecta produces enough NOx to acidify the upper ocean and cause a massive marine extinction. Using non-equilibrium chemically reacting flow simulations coupled with atmospheric transport modeling, it is determined that enough NOx reached the stratosphere and precipitated to overpower the carbonate buffer and acidify the upper ocean down to a pH of 6.7, causing most organisms to perish.
Degree
M.S.A.A.
Advisors
Alexeenko, Purdue University.
Subject Area
Atmospheric Chemistry|Aerospace engineering|Atmospheric sciences
Off-Campus Purdue Users:
To access this dissertation, please log in to our
proxy server.