In-situ monitoring method for flux of methane gas on water-air interface

Abstract

The invention relates to an in-situ monitoring method for the flux of methane gas on a water-gas interface, which comprises the following steps of: 1) arranging a circular gasbag at the open of a tank with an open bottom, connecting the gasbag to an anchor through a rope, and filling gas in the gasbag; 2) throwing the anchor to an observation point, and after the tank is stabilized, connecting gas in the tank with a methane concentration measurement instrument through a gas tube; 3) starting the methane concentration measurement instrument, measuring and recording the methane gas concentration X1 on the water-gas interface, and recording the measurement time t1; 4) measuring and recording a water level h in the tank in the step 1) and an actual height H of the tank; 5) after the sampling is finished, measuring and recording the methane gas concentration X2, the temperature T2 and the gas pressure P2 on the water-gas interface, and recording the measurement time t2; and 6) calculating the flux of the methane gas between the water and the air by utilizing the methane gas concentration X1 and X2, the time t1 and t2, the water level h in the tank, the actual height H of the tank, the temperature T2 and the gas pressure P2 recorded in the steps 3), 4) and 5). The in-situ monitoring method is suitable for monitoring the flux of the methane gas between the water which takes paddy field, wetland, marshland, lake surface, river, sea, sewage and the like as an underlying surface and the air.

Description

technical field [0001] The invention relates to a method for measuring gas flux, in particular to an in-situ monitoring method for methane gas flux at the water body-atmosphere interface. Background technique [0002] Methane is one of the major greenhouse gases and is a long-lived greenhouse gas. The radiative forcing value of methane and its contribution to global climate change and impact are second only to carbon dioxide, and the scale involves the global space range, which has attracted widespread attention in recent years (Document 1: IPCC, 2007, Climate Change 2007: the physical science basis, World Environment , 13-22). In order to improve people's understanding of greenhouse gases and cope with global climate change, it is necessary to estimate and evaluate methane gas fluxes at global and regional scales, and to conduct scientific estimates and evaluations, field observations of methane gas fluxes must be carried out first. The existing water body-atmosphere meth...

AI Technical Summary

Problems solved by technology

The existing water body-atmosphere methane gas flux measurement methods are basically replaced by gas box collection, remote sample delivery, and gas-intake gas chromatography (Document 2: Chen Yufen et al., 1996, Measuring rice field methane emissions by gas chromatography Fluxes, Environmental Science Research, (4): 21-24; Document 3: Tongchuan et al., 2008, Methane fluxes and influencing factors of Spartina alterniflora, an invasive species of Spartina alterniflora, in wet-mouthed Minjiang rivers, Geographical Sciences, 28(6) : 826-832), but the above-mentioned devices and methods have the problems of indirection, complicated operation and high cost, and rarely consider the temperature and air pressure at the instant of sampling, so it is difficult to achieve the purpose of real-time monitoring

At present, there are no reports on the methods and devices specially used to observe the water body-atmosphere methane gas flux

Images