KOPRI Repository

An evaluation of oceanic emissions of CH4 and N2O

Metadata Downloads
Title
An evaluation of oceanic emissions of CH4 and N2O
Other Titles
해양으로부터 메탄과 산화이질소 방출량 추정
Authors
Rhee, Tae Siek
Keywords
Atlantic; CH4; N2O; emission; ocean
Issue Date
2008
Citation
Rhee, Tae Siek. 2008. An evaluation of oceanic emissions of CH4 and N2O. Korean Society of Oceanography. Korean Society of Oceanography. 2008.05.29~.
Abstract
Methane (CH4) and nitrous oxide (N2O) are important greenhouse gases in the troposphere. Ocean environments appear to be an important natural source of atmospheric N2O and a minor source of CH4. However, their emission rates of the ocean show large range due likely to heterogeneous production rates in different water column. A series of IPCC reports describe oceanic emission rate of CH4 as 5 –
25 Tg (CH4) yr-1. However, basin-wide measurements provides utmost ~3 Tg (CH4) yr-1. Regarding N2O, ocean emits at 1 –
7 TgN yr-1, while much higher source strength of 7 –
11 TgN yr-1 has been reported. To provide more concrete source strength of the ocean for these two gases, we steamed the Atlantic in 1998 and measured their concentrations in the surface mixed layer and the overlying air from 50°N to 50 °S. The cruise covers the open ocean, coastal regions, the west Africa upwelling region, the equatorial upwelling zone, and the Rio de la Plata estuarine region. Throughout the cruise track, CH4 and N2O were saturated or supersaturated in the surface waters. Dissolved CH4 was highly supersaturated in the Rio de la Plata estuarine region. The coastal regions are significant CH4 source, but no increase of CH4 concentration was observed in the equatorial upwelling zone. Dissolved N2O concentrations were highly supersaturated in the west Africa upwelling region and the equatorial upwelling zone, which indicates that the upwelled water delivered a large amount of N2O from below the surface mixed layer. Based on the measurements of CH4 and N2O in the surface water and the overlying air, I estimated emission rate from the ocean as 0.3 –
1.9 Tg(CH4) yr-1 for CH4 and 0.5 –
2.6 TgN yr-1 for N2O. The emission rate of CH4 is far lower than the values in IPCC reports, but is comparable to the value estimated by other basin-wide measurements. Our estimate of N2O emission is at the lower bound of the range in IPCC report.
URI
http://repository.kopri.re.kr/handle/201206/7793
Conference Name
Korean Society of Oceanography
Conference Place
Korean Society of Oceanography
Conference Date
2008.05.29~
Files in This Item
There are no files associated with this item.
General Conditions
      ROMEO Green
    Can archive pre-print and post-print or publisher's version/PDF
      ROMEO Blue
    Can archive post-print (ie final draft post-refereeing) or publisher's version/PDF
      ROMEO Yellow
    Can archive pre-print (ie pre-refereeing)
      ROMEO White
    Archiving not formally supported

    qrcode

    Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.

    Browse