Naked Science Forum
Life Sciences => The Environment => Topic started by: Muchomank on 20/04/2009 17:33:49
-
HI, I have looked for hours and hours for a graph/image/chart on how the ozone layer was looking at the same time the dinosaurs became extinct. Any help would be much apreciated.
-
I very much doubt you will find one either
-
I dont know of a single proxy for O3, so I think ukmicky is right. You very likely will not find one, and if you do, I would consider it HIGHLY suspect until it is well researched.
-
The title of this thread is actually quite deceiving.
-
See:
The effect of paleoatmospheric ozone on surface temperature
Joel S. Levine and Robert E. Boughner
Atmospheric Environmental Sciences Division, NASA Langley Research Center, Hampton, Virginia 23665, USA
Abstract
Photochemical calculations indicate that the atmospheric O3 column was maximized when the atmospheric oxygen (O2) level was 10−1 of its present atmospheric level (PAL). For this O2 level, the O3 concentration maximum occurred about 10 km below its present peak. Coupled photochemical and radiative-convective calculations indicate that for this level and distribution, O3 may have increased the globally averaged paleosurface temperature by as much as 4.5°K. A major deficiency in our understanding concerns the exact chronology for the evolution of O2; i.e., according to various scenarios, O2 may have reached 10−1 PAL as early as 2 billion years ago or as late as 400 million years ago.