The Distribution And Air-sea Exchange Fluxes Of CO₂,CH₄ And N₂O In The Surface Water Of Dalian Bay

In the present dissertation, distribution,controlling factors and fluxes of surface seawater partial pressure of CO2(pCO2),N2O and CH4 were determined during the surveies on Dalian Bay in Nov-2009 and Jan-2010.The main research work is as follows:1. The results show that the pCO2 ranged from 435.68 to 510.41μatm,with an average of 473.01μatm during the survey in Nov-2009.While it ranged from 350.95μatm to 556.52μatm,with an average of 396.53μatm during the survey in Jan-2010.Dalian Bay area acted as a source of atmospheric CO2 in autumn,While it acted as a sink in winter.2. A good positive correlation has been found between pCO2 and Tem or Sal during the survey in Nov-2009,while there were no significant correlation between them during the survey in Jan-2010.In addition, A good correlation has been found between pCO2 and saturation of DO in Nov-2009,while pCO2 and DO had exactly the opposite change.3. The results show that the distributions of CH4 and N2O in the surface waters both illustrate a decrease of CH4 and N2O concentration on shore to offshore.Both CH4 and N2O in the surface waters were supersaturated during the two surveies.CH4 fluxes from the Dalian Bay were 52.88±68.42 and 113.91±146.82μmol·m-2·d-1,respectively by LM86 and W92 during the survey in Nov-2009,and they were 133.07±193.37 and 286.96±416.98μmol·m-2·d-1,respectively during the survey in Jan-2010. CH4 fluxes were higher in winter than they were in antumn by a factor of 2.6.While N2O fluxes were 3.30±4.78 and 10.62±10.74 umol·m-2·d-1(LM86),respectively.N2O fluxes were higher in winter than they were in antumn by a factor of 3.2.