Two dimensional model study of atmospheric transport using carbon-14 and strontium-90 as inert tracers

Conference · Sat Feb 01 00:00:00 EST 1992

OSTI ID:10153620

Kinnison, D E; Wuebbles, D J ^[1]; Johnston, H S ^[2]

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1. Lawrence Livermore National Lab., CA (United States)
2. Lawrence Berkeley Lab., CA (United States)

This study tests the transport processes in the LLNL two-dimensional chemical-radiative-transport model using recently reanalyzed carbon-14 and strontium-90 data. These radioactive tracers were produced bythe atmospheric nuclear bomb tests of 1952--58 and 1961--62, and they were measured at a few latitudes up to 35 kilometers over the period 1955--1970. Selected horizontal and vertical eddy diffusion coefficients were varied in the model to test their sensitivity to short and long term transpose of carbon-14. A sharp transition of K{sub zz} and K{sub yy} through the tropopause, as opposed to a slow transition between the same limiting values, shows a distinct improvement in the calculated carbon-14 distributions, a distinct improvement in the calculated seasonal and latitudinal distribution of ozone columns (relative to TOMS observations), and a very large difference in the calculated ozone reduction by a possible fleet of High Speed Civil Transports. Calculated northern hemisphere carbon-14 is more sensitive to variation of K{sub yy} than are global ozone columns. Strontium-90 was used to test the LLNL tropopause height at four different latitudes. Starting with the 1960 background distribution of carbon-14, we calculate the input of carbon-14 as the sum of each nuclear test of the 1961--62 series, using two bomb-cloud rise models. With the Seitz bomb-rise formulation in the LLNL model, we find good agreement between calculated and observedcarbon-14 (with noticeable exceptions at the north polar tropopause and the short-term mid-latitude mid-stratosphere) between 1963 and 1970.

• Research Organization: Lawrence Livermore National Lab., CA (United States)
• Sponsoring Organization: USDOE, Washington, DC (United States); National Aeronautics and Space Administration, Washington, DC (United States)
• DOE Contract Number: W-7405-ENG-48; AC03-76SF00098
• OSTI ID: 10153620
• Report Number(s): UCRL-JC-108847; CONF-9202172-1; ON: DE93012547
• Resource Relation: Conference: NASA high speed research program models and measurements workshop,Satellite Beach, FL (United States),2-7 Feb 1992; Other Information: PBD: Feb 1992
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
99 GENERAL AND MISCELLANEOUS//MATHEMATICS, COMPUTING, AND INFORMATION SCIENCE
NUCLEAR EXPLOSIONS
ENVIRONMENTAL EFFECTS
TROPOSPHERE
RADIONUCLIDE MIGRATION
STRATOSPHERE
ATMOSPHERIC EXPLOSIONS
CARBON 14
STRONTIUM 90
MATHEMATICAL MODELS
FALLOUT
TRACER TECHNIQUES
LAWRENCE LIVERMORE LABORATORY
LAWRENCE BERKELEY LABORATORY
BACKGROUND RADIATION
540130
990200
RADIOACTIVE MATERIALS MONITORING AND TRANSPORT
MATHEMATICS AND COMPUTERS