Title: U.S. emissions of HFC-134a derived for 2008-2012 from an extensive flask-air sampling network: US emissions of HFC-134a

Abstract

Abstract U.S. national and regional emissions of HFC‐134a are derived for 2008–2012 based on atmospheric observations from ground and aircraft sites across the U.S. and a newly developed regional inverse model. Synthetic data experiments were first conducted to optimize the model assimilation design and to assess model‐data mismatch errors and prior flux error covariances computed using a maximum likelihood estimation technique. The synthetic data experiments also tested the sensitivity of derived national and regional emissions to a range of assumed prior emissions, with the goal of designing a system that was minimally reliant on the prior. We then explored the influence of additional sources of error in inversions with actual observations, such as those associated with background mole fractions and transport uncertainties. Estimated emissions of HFC‐134a range from 52 to 61 Gg yr ⁻¹ for the contiguous U.S. during 2008–2012 for inversions using air transport from Hybrid Single‐Particle Lagrangian Integrated Trajectory (HYSPLIT) model driven by the 12 km resolution meteorogical data from North American Mesoscale Forecast System (NAM12) and all tested combinations of prior emissions and background mole fractions. Estimated emissions for 2008–2010 were 20% lower when specifying alternative transport from Stochastic Time‐Inverted Lagrangian Transport (STILT) model driven by the Weathermore » Research and Forecasting (WRF) meteorology. Our estimates (for HYSPLIT‐NAM12) are consistent with annual emissions reported by U.S. Environmental Protection Agency for the full study interval. The results suggest a 10–20% drop in U.S. national HFC‐134a emission in 2009 coincident with a reduction in transportation‐related fossil fuel CO ₂ emissions, perhaps related to the economic recession. All inversions show seasonal variation in national HFC‐134a emissions in all years, with summer emissions greater than winter emissions by 20–50%.« less

Authors:

Hu, Lei ^[1]; Montzka, Stephen A. ^[2]; Miller, John B. ^[1]; Andrews, Aryln E. ^[2]; Lehman, Scott J. ^[3]; Miller, Benjamin R. ^[1]; Thoning, Kirk ^[2]; Sweeney, Colm ^[1]; Chen, Huilin ^[4]; Godwin, David S. ^[5]; Masarie, Kenneth ^[2]; Bruhwiler, Lori ^[2]; Fischer, Marc L. ^[6]; Biraud, Sebastien C. ^[6]; Torn, Margaret S. ^[6]; Mountain, Marikate ^[7]; Nehrkorn, Thomas ^[7]; Eluszkiewicz, Janusz ^[7]; Miller, Scot ^[8]; Draxler, Roland R. ^[9] more »; Stein, Ariel F. ^[9]; Hall, Bradley D. ^[2]; Elkins, James W. ^[2]; Tans, Pieter P. ^[2] « less

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+ Show Author Affiliations

1. Univ. of Colorado, Boulder, CO (United States); National Oceanic and Atmospheric Administration (NOAA), Boulder, CO (United States)
2. National Oceanic and Atmospheric Administration (NOAA), Boulder, CO (United States)
3. Univ. of Colorado, Boulder, CO (United States)
4. Univ. of Groningen, (Netherlands). Centre for Isotope Research
5. US Environmental Protection Agency (EPA), Washington DC (United States)
6. Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
7. Atmospheric and Environmental Research, Lexington MA (United States)
8. Harvard Univ., Cambridge, MA (United States)
9. National Oceanic and Atmospheric Administration (NOAA), College Park, MD (United States)

Publication Date:

Wed Dec 17 00:00:00 EST 2014

Research Org.:

Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States)

Sponsoring Org.:

USDOE Office of Science (SC), Biological and Environmental Research (BER)

OSTI Identifier:

1512160

Alternate Identifier(s):

OSTI ID: 1402295

Grant/Contract Number:  

AC02-05CH11231

Resource Type:

Accepted Manuscript

Journal Name:

Journal of Geophysical Research: Atmospheres

Additional Journal Information:

Journal Volume: 120; Journal Issue: 2; Journal ID: ISSN 2169-897X

Publisher:

American Geophysical Union

Country of Publication:

United States

Language:

English

Subject:

54 ENVIRONMENTAL SCIENCES