1 / 11

Atmospheric C2H2 and its Relationship with CO as an Indicator of Air Mass Aging

This study investigates the correlation between C2H2 and CO in the atmosphere to test model emissions, transport, and OH levels. The study concludes that the C2H2/CO ratio is a reliable tracer of air mass aging, reflecting a combined influence of emission, transport, chemistry, and background.

lisawilkerson
Download Presentation

Atmospheric C2H2 and its Relationship with CO as an Indicator of Air Mass Aging

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. ~2 wks CO C2H2 ~2 mons atmosphere Fossil fuel auto Biofuel Biomass burning Atmospheric C2H2 and its relationship with CO as an indicator of air mass aging C2H2 /CO Xiao et al. [2007a]

  2. C2H2-CO correlation: a test of model transport and chemical processes Objective: to determine the information contained in C2H2-CO relationship for testing model emissions, transport, and OH levels

  3. Atmospheric C2H2 sources Tg/year The model shows no significant bias in reproducing the major features of C2H2 observed in atmosphere

  4. C2H2/CO ratio: a tracer of air mass aging Observation (0-2 km): TRACE-P, PEM-Tropics B Model: averaged 0-2 km

  5. C2H2/CO slope: not a robust tracer of air mass aging observations model The variation of C2H2/CO slope reflects a combined influence of emission, transport, chemistry, and background. (1)(2)(3): TRACE-P, March (BL) (4)PEM-West A, September (UT) (5) PEM-Tropics B, March (BL) (6) PEM-Tropics A, September (FT) (7) TRACE-A, September (FT) (8) INTEX-A, Jul-Aug (BL) (8) (4) (8) (1) (3) (4) (3) (1) (2) (2) (7) (5) (6) (7) C2H2 CO

  6. Interpretation of log[C2H2]-log[CO] slope by Ehhalt et al. [1998] β=1 dilution dominates β= dilution ~ chemistry β> chemistry dominates chemistry dominates ~ 1.7-1.9 dilution dominates Narrow range!

  7. Interpretation of log[C2H2]-log[CO] slope by GEOS-Chem chemistry dominates ~ 1.7-1.9 dilution dominates Our model results are generally consistent with Ehhalt et al. [1998]

  8. Regional constraints on U.S. sources of ethane Xiao et al. [2007b] Persistent underestimate of C2H6 emissions in the U.S. EPA National Emissions Inventories, including the latest NEI-99. INTEX-A (July-August, 2004)

  9. Simulation of C2H6 observations in INTEX-A (Jul-Aug,2004) 47% 28% Note different color scales! EPA NEI-99 * 3.5 Industrial solvent Other Industrial (ngas/oil) Biomass burning source of C2H6 is minor compared to fossil fuel source

  10. Optimized C2H6 emissions in the United States x7 in NEI-99 for the southern United States x1.8 in NEI-99 for the northern United States Model [NEI-99 * 3.5] / obs (< 2km) 1.3 1.6 0.7

  11. Estimated CH4 emission from natural gas/oil source in U.S. a major U.S. contribution to greenhouse warming is underestimated! C2H6 emission in U.S CH4/C2H6 ER from fossil fuel 2.4 Tg yr-1 19 mol mol-1 ground samples near natural gas/oil source region in south-central US [Katzenstein et al., 2003] CH4 fossil fuel emission in U.S. 24 Tg yr-1 as compared to: 10.5 Tg estimated by EIA (2005) 20 Tg by Wang et al. [2004]

More Related