| The ice sheet holds the largest amount of water on the planet,and the Antarctic ice sheet accounts for 91%of the world's ice mass,making it the biggest potential contributor to global sea level rise.In recent years,the spatial pattern of mass loss of the East Antarctic and West Antarctic ice sheets has changed significantly.By tracking changes in ice velocity and mass over a long time series,the current and future responses of the East and West Antarctic ice sheets to global climate change can be evaluated.In this study,by means of optical remote sensing observation,the land ice velocity product Golive of Landsat8 was used to conduct velocity statistics on the coastal area of Amundsen Gulf in the Southwest Pole and Lambert area in the Southeast Pole,and the velocity characteristics and velocity changes during 2014-2019 were obtained.Elevation changes in the study area were obtained by using ICESat-2 data from the laser altimetry satellite.The material loss and accumulation of the whole Antarctic from 2003 to 2020 were counted and the elevation changes were verified by using GRACE data.Finally,the relationship between the variation of mass and velocity and the variation of velocity in the southwest and southeast polar regions is analyzed.The conclusions are as follows:(1)From 2014 to 2019,the velocity of the inland ice cover in the coastal area of Amundsen Gulf of the Southwest Pole was 0.04-3 m/d,and the velocity of the coastal ice was 0.8-11.3 m/d.The annual average velocity variation rate was more than 30%,or even more than 40%.The velocity of the inland ice sheet in the southeastern Lambert region ranges from 0.02 m/d to 0.06 m/d,while the velocity of the coastal ice sheet varies from 0.01 m/d to 2 m/d,and the annual average velocity variation rate is less than 30%.The characteristics of the ice velocity of the East and West Antarctic ice sheets are as follows:the basic form of the ice velocity in the coastal zone is greater than that in the inland,and the ice velocity of West Antarctic ice sheet is generally faster,and the inter-annual variation is larger,showing a strong mobility;The velocity of the East Antarctic ice sheet is generally slow,and the inter-annual variation is relatively stable.The regions with greater velocity variation are also concentrated near the coastal zone,and the variation of ice velocity in West Antarctic region is greater than that in the East Antarctic region.(2)The total elevation change of the Amundsen Gulf coastal area in the Southwest Pole in 2004 and 2019 is-4.43±35.29 m,and the annual mean elevation change is-27.69 cm/yr,which is close to the mass change of-464.2 Gt in this area in the past two years as shown by GRACE data.The total elevation change of the Lambert region of the Southeast Pole in 2004 and 2019 is 0.09±17.92 m,and the annual mean elevation change is 0.56 cm/yr,which is close to the mass change of 53.7 Gt in this region in the past two years as shown by GRACE data.The material balance of East and West Antarctica is as follows:there is serious material loss in the southwest polar coastal zone,and there is both loss and accumulation of material in the interior.There is also serious material loss in the Antarctic Peninsula,and the southwest polar region presents a relatively serious material loss state overall.The mass changes in the inland and coastal areas of the Southeast polar region are both increased and decreased,and the range of mass changes is not large,and the mass changes are in a relatively balanced state.(3)The ice flow velocity can reflect the state of mass balance to some extent,but it does not mean that the larger the ice flow velocity is,the more significant the regional mass change will be.The change of ice flow velocity has a significant relationship with the state of mass balance,and the ice flow velocity can reflect the state of mass balance to a certain extent.It is because the change of ice flow velocity that the ice flow velocity changes.Figure[24]table[3]reference[93]... |
PDF Full Text Request