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Title: Large CO 2 effluxes at night and during synoptic weather events significantly contribute to CO 2 emissions from a reservoir

CO 2 emissions from inland waters are commonly determined by indirect methods that are based on the product of a gas transfer coefficient and the concentration gradient at the air water interface (e.g., wind-based gas transfer models). The measurements of concentration gradient are typically collected during the day in fair weather throughout the course of a year. Direct measurements of eddy covariance CO 2 fluxes from a large inland water body (Ross Barnett reservoir, Mississippi, USA) show that CO 2 effluxes at night are approximately 70% greater than those during the day. At longer time scales, frequent synoptic weather events associated with extratropical cyclones induce CO 2 flux pulses, resulting in further increase in annual CO 2 effluxes by 16%. Therefore, CO 2 emission rates from this reservoir, if these diel and synoptic processes are under-sampled, are likely to be underestimated by approximately 40%. Our results also indicate that the CO 2 emission rates from global inland waters reported in the literature, when based on indirect methods, are likely underestimated. Field samplings and indirect modeling frameworks that estimate CO 2 emissions should account for both daytime-nighttime efflux difference and enhanced emissions during synoptic weather events. Furthermore, the analysis here canmore » guide carbon emission sampling to improve regional carbon estimates.« less
 [1] ;  [1] ;  [2] ;  [3] ;  [4] ;  [5]
  1. Washington State Univ., Pullman, WA (United States). Dept. of Civil and Environmental Engineering
  2. Duke Univ., Durham, NC (United States). Nicholas School of the Environment
  3. Cary Inst. of Ecosystem Studies, Millbrook, NY (United States)
  4. Univ. of Alaska Fairbanks, Fairbanks, AK (United States). Inst. of Arctic Biology
  5. Univ. of California, Santa Barbara, CA (United States). Dept. of Ecology, Evolution, and Marine Biology
Publication Date:
Grant/Contract Number:
SC0006967; SC0011461
Accepted Manuscript
Journal Name:
Environmental Research Letters
Additional Journal Information:
Journal Volume: 11; Journal Issue: 6; Journal ID: ISSN 1748-9326
IOP Publishing
Research Org:
Washington State Univ., Pullman, WA (United States)
Sponsoring Org:
USDOE Office of Science (SC), Biological and Environmental Research (BER) (SC-23)
Country of Publication:
United States
54 ENVIRONMENTAL SCIENCES; carbon emissions from lakes; eddy covariance flux of CO2; wind-based gas transfer; lake-atmosphere interactions; southern inland water; surface-energy budget; united-states; carbon-cycle; lake; flux; evaporation; exchange; methane; air
OSTI Identifier: