Marine biogenic emission of dimethylsulfide(DMS)has been well recognized as the main natural source of reduced sulfur to the remote marine atmosphere and has the potential to affect climate,especially in the polar regions.We used a global climate model(GCM)to investigate the impact on atmospheric chemistry from a change to the contemporary DMS flux to that which has been projected for the late 21st century.The perturbed simulation corresponded to conditions that pertained to a tripling of equivalent CO2,which was estimated to occur by year 2090 based on current worst-case greenhouse gas emission scenarios.The changes in zonal mean DMS flux were applied to 50°S-70°S Antarctic(ANT)and 65°N-80°N Arctic(ARC)regions.The results indicate that there are clearly different impacts after perturbation in the southern and northern polar regions.Most quantities related to the sulfur cycle show a higher increase in ANT.However,most sulfur compounds have higher peaks in ARC.The perturbation in DMS flux leads to an increase of atmospheric DMS of about 45％in ANT and 33.6％in ARC.The sulfur dioxide(SO2)vertical integral increases around 43％in ANT and 7.5％in ARC.Sulfate(SO4)vertical integral increases by 17％in ANT and increases around 6％in ARC.Sulfur emissions increases by 21％in ANT and increases by 9.7％in ARC.However,oxidation of DMS by OH increases by 38.2％in ARC and by 15.17％in ANT.Aerosol optical depth(AOD)increases by 4％in the ARC and by 17.5％in the ANT,and increases by 22.8％in austral summer.The importance of the perturbation of the biogenic source to future aerosol burden in polar regions leads to a cooling in surface temperature of 1 K in the ANT and 0.8 K in the ARC.Generally,polar regions in the Antarctic Ocean will have a higher offsetting effect on warming after DMS flux perturbation.