Research And Application Of Thin Boundary Layer Model On Greenhouse Gas Transfer Through Air-water Interface

At present,in the use of the thin boundary layer model,there still exsit many limitations and uncertainty.According to review the research results of the thin boundary layer model,evaluating thin boundary layer model parameters sensitivities.After that,using the thin boundary model to research the relationship between air-water greenhouse gas flux and eutrophic water and water quality,to provide theoretical reference for the application and research of thin boundary layer model.According to research the thin boundary layer model,results show that on the base of the differ of the transfer rate.The thin boundary layer model is comprised of the theoretical and empirical model,theoretical model including two-thin-layer model,surface renewal and surface divergence model.Theoretical model is currently still in the stage of research and practical application is rarely.The model based on the experience of the wind speed of the gas diffusion rate is currently the most widely used and most studied and used.The COARE model is a mature model,and has a wide practical application.The model based on the experience of thin boundary layer model based on wind speed,via the EFAST global and local sensitivity analysis of parameters.The results show that,for air-water CO₂,CH₄ and N₂O gas flux,the water surface gas partial pressure and the wind speed in 10 m above water are high sensitive parameters,the high precision is required in monitoring,the gas balanced concentration and water temperature is the second sensitive parameters,and the sensitivity of model index is minimal.Using thin boundary layer model,to use linear regression and correlation analysis on air-water CO₂ and CH₄ gas flux and the total nitrogen concentration,total phosphorus concentration and chlorophyll a concentration.Results show that when the total nitrogen concentration is about 1 mg/L,the total phosphorus concentration is about 0.03 mg/L,the eutrophication limitation is the total phosphorus concentrtion rather than total nitrogen concentration.When eutrophication is more serious,the lower air-water CO₂ and CH₄ gas flux.Using thin boundary layer model,to analyse the correlation of air-water CO₂ and CH₄ gas flux and water quality.Results show that when the water of the total nitrogen concentration of 1 to 10 mg/L,the total phosphorus concentration is 0.03 to 1 mg/L,the water dissolved oxygen concentration,PH,total phosphorus concentration and chlorophyll a concentration and phosphorus concentration is the factors affect air-water CO₂ and CH₄ gas flux.Using correlation and multiple-stepwise regression analysis methods,analyzing the relationship between the model parameter water surface CO₂ and CH₄ gas partial pressure of thin boundary layer model and water quality,the results show that when the water of the total nitrogen concentration of 1 to 10 mg/L,total phosphorus concentration is 0.03 to 1 mg/L,the chlorophyll a concentration,PH,water temperature,the concentration of ammonia nitrogen,dissolved oxygen concentration and phosphorus concentration,and other water quality indexes are affecting the water surface CO₂ and CH₄ gas partial pressure.