Seasonal variation analysis of atmospheric CH4, N2O and CO2 in Tianjin offshore area

Abstract

in order to study the greenhouse gases in the Tianjin offshore area of Bohai Sea. CH 4 concentrations varied from 1.87 to 2.61 ppm with the highest value appearing in summer and the lowest in winter. The concentration range of N 2 O was 319.3 to 347.7 ppb, with the maximal value appearing in winter. CO 2 was higher in the heating season than in non-heating season in this area. Concentrations of the three greenhouse gases in the study area exceeded the 2005 global background values. Backward trajectory model was used to analyze the sources. All three gases were influenced evidently by continental sources in the inshore area during the sampling periods. Every gas was compared with each other by correlation analysis, showing that the correlation of CO 2 and N 2 O was more significant than to CH 4 and their relationship with meteorological factors was consistent. It can be concluded these three greenhouse gases may be influenced by some similar sources, especially for CO 2 and N 2 O.Bohai Sea, greenhouse gas, offshore observation, backward trajectory model, sources Citation: Kong S F, Lu B, Han B, et al. Seasonal variation analysis of atmospheric CH 4 , N 2 O and CO 2 in Tianjin offshore area. Carbon dioxide (CO 2 ), methane (CH 4 ) and nitrous oxide (N 2 O) are three important greenhouse gases (GHGs) with relatively high concentrations, long atmospheric lifetime in the troposphere, and are greatly influenced by anthropogenic emissions. With the development of industries, deforestation, population growth, and other human activities, global concentrations of CO 2 , CH 4 and N 2 O increased to 379.1 ppm, 1783 ppb, 319.2 ppb, respectively, by the year 2005, an increase of 35.4%, 154.7% and 18.2% [1], respectively, compared to the year 1750 levels (pre-industrial times).These three GHGs play an important role in global warming and climate change, although their mass concentrations attributed to less than 0.04% of the atmosphere [2][3][4]. CO 2 is the largest contributor to greenhouse effect. On an equivalent concentration basis, CH 4 and N 2 O have a global warming potential of 200 and 300 times larger than CO 2 . The increasing concentrations of GHGs put the global surface temperature in an ascending trend, being 0.3-0.6°C in last century [5]. Global warming has caused environmental deterioration and increased the frequency of natural disasters, which have seriously affected human society as well as the economic development.Global warming and quantification of global GHGs budgets have attracted increasing attention since the 1960s [6][7][8][9][10][11]. Main sources and sinks of the three GHGs have been confirmed [12]. However, budget balance between CO 2 sources and sinks still has gaps [13]. Recent studies have focused mainly on advanced research methodology, expanded studying areas, responses of GHGs flux to global

Enhanced methane emissions from oil and gas exploration areas to the atmosphere – The central Bohai Sea

“…4). However, our results were consistent with that of Kong et al (2010) (from 1.87 to 2.61 ppmv in the Tianjin nearshore area). The high m atm of CH 4 in the surveying area may indicate local air addition of CH 4 from sea-air emission (see Section 3.4) or from the neighboring industrialized coastal zone (Fig.…”

Features of the annual evolution of CO 2 and CH 4 in the atmosphere of a Mediterranean climate site studied using a nonparametric and a harmonic function

“…Moreover, noticeable differences are observed at Mt. Waliguan, China, where most studies presented ranges of around 0.01 ppm, except Kong et al (2010), who depicted a range of 0.04 ppm taken from Liu et al (2004). Noticeable ranges, reaching up to 0.1 ppm, the greatest amongst those observed in the other places considered, were obtained at Hegyh ats al in Hungary, and Cabaw in The Netherlands.…”

On the performance of satellite-based observations of <i>X</i>CO<sub>2</sub> in capturing the NOAA Carbon Tracker model and ground-based flask observations over Africa's land mass

“…Transport of atmospheric CO 2 is simulated by using the global two-way nested transport model (TM5). TM5 is an offline atmospheric tracer transport model (Krol et al, 2005) driven by meteorology from the European Centre for Medium-Range Weather Forecasts (ECMWF) opera-tional forecast model and from the ERA-Interim reanalysis (Dee et al, 2011) to propagate surface emissions. TM5 is based on a global 3 0 × 2 0 and at a 1 0 × 1 0 spatial grid over North America.…”

“…The model can be used in a wide range of applications, which includes aerosol modelling, stratospheric chemistry simulations, and hydroxyl-radical trend estimates. A detailed description of the TM5 model can be found in the works of Peters et al (2004) and Krol et al (2005).…”