NSF Org:	AGS Division of Atmospheric and Geospace Sciences
Recipient:	WASHINGTON UNIVERSITY, THE
Initial Amendment Date:	November 18, 2015
Latest Amendment Date:	November 18, 2015
Award Number:	1612532
Award Instrument:	Standard Grant
Program Manager:	David Verardo AGS  Division of Atmospheric and Geospace Sciences GEO  Directorate for Geosciences
Start Date:	October 1, 2015
End Date:	October 31, 2016 (Estimated)
Total Intended Award Amount:	$57,715.00
Total Awarded Amount to Date:	$57,716.00
Funds Obligated to Date:	FY 2014 = $57,716.00
History of Investigator:	Ryan Ogliore (Principal Investigator) rogliore@physics.wustl.edu
Recipient Sponsored Research Office:	Washington University 1 BROOKINGS DR SAINT LOUIS MO  US  63130-4862 (314)747-4134
Sponsor Congressional District:	01
Primary Place of Performance:	Washington University MO  US  63130-4862
Primary Place of Performance Congressional District:	01
Unique Entity Identifier (UEI):	L6NFUM28LQM5
Parent UEI:
NSF Program(s):	Paleoclimate, ANT Earth Sciences
Primary Program Source:	01001415DB NSF RESEARCH & RELATED ACTIVIT 0100XXXXDB NSF RESEARCH & RELATED ACTIVIT
Program Reference Code(s):	1530, 4444, 7916, 9150
Program Element Code(s):	153000, 511200
Award Agency Code:	4900
Fund Agency Code:	4900
Assistance Listing Number(s):	47.050

ABSTRACT

There are many ways of reconstructing past environments at the Earth's surface, but reconstructing past conditions in the upper atmosphere has not been possible because of the lack of physical samples from these altitudes. While modern Earth System Models simulate climate dynamics and atmospheric chemistry from the Earth's surface to the stratosphere and beyond, there has been no way to ground-truth the results for the upper atmosphere for conditions that are different from those at present.

This study, a collaboration between a cosmochemist and a climate dynamicist, investigates the feasibility of reconstructing upper atmosphere temperature and composition during past climates using high precision isotopic measurements of the fusion crust of meteorites. Specifically, the work tests the hypothesis that magnetite in the fusion crust of iron meteorites records the isotopic composition of O2 in the atmosphere at the time and altitude that the fusion crust formed, which in turn is a proxy for ozone concentration (a mass-independent signature) as well as variations in the Dole Effect or other mass-dependent stratospheric processes. The work takes advantage of existing collections of meteorites. If this pilot project is successful, the fusion crust paleo-atmosphere proxy could be applied to the vast collection of Antarctic meteorites, which spans the past 3 million years, and could provide tests of Earth System Model results.

PROJECT OUTCOMES REPORT

Disclaimer

This Project Outcomes Report for the General Public is displayed verbatim as submitted by the Principal Investigator (PI) for this award. Any opinions, findings, and conclusions or recommendations expressed in this Report are those of the PI and do not necessarily reflect the views of the National Science Foundation; NSF has not approved or endorsed its content.

We developed a new method to measure the concentration of ozone in the stratosphere during Earth's recent past.

Iron meteorites, during their passage through the atmosphere, interact with oxygen and form a "fusion crust". This fusion crust can be easily distinguished from oxidation that happens after the meteorite lands. Iron meteorites themselves contain little oxygen, so they fusion crust is a sample of stratospheric oxygen at the time and place that the meteorite fell. Ozone in the stratosphere creates a peculiar effect on the isotopes of stratospheric oxygen, a mass-independent fractionation that increases with increased concentrations of ozone. This mass-independent effect is a high-integrity measure of the concentration of ozone, as it cannot be created by other mechanisms (such as heating during atmospheric entry). We measured this mass-indepedent effect in the fusion crusts of iron meteorites that fell in the 1800s, and also in meteorites that fell in the last thirty years. We saw that the meteorites that fell before industrial times recorded a large mass-independent isotope effect, and therefore a higher concentration of ozone, than the meteorites that fell recently.

Our work provides actual evidence that human activity caused some destruction of atmospheric ozone. Long-term anthropogenic ozone destruction has been proposed but never measured before this work using meteorites.

Last Modified: 01/12/2017
Modified by: Ryan Ogliore

Image

  

• 

Please report errors in award information by writing to: awardsearch@nsf.gov.