1979—2015年罗斯海海冰运动速度变化

VARIATION OF SEA ICE MOTION VELOCITY IN THE ROSS SEA(1979–2015)

基于美国冰雪数据中心的月平均海冰运动和海冰密集度数据,建立了1979—2015年罗斯海海冰运动速度时间变化序列,揭示了海冰运动速度的年际和季节变化特征,探讨了海冰运动速度和海冰范围之间可能存在的联系,最后对影响海冰运动速度变化的因素进行了分析。结果表明,1979—2015年罗斯海海冰运动速度总体呈现加快趋势,海冰运动速度增加趋势最快的季节为秋季,其次是冬季、春季和夏季。冬季海冰平均运动速度最大,依次是秋季、春季和夏季。海冰运动速度与海冰范围在37年间均呈现上升趋势,海冰范围变化滞后海冰运动速度1—2个月,两者呈显著正相关关系,海冰运动速度的增加导致罗斯海海冰范围不断扩张,进而影响南极整体海冰分布。罗斯海海冰运动速度与风速之间存在显著正相关关系,风场是影响海冰运动速度的一个直接因素。除此之外,海冰运动还受到包括气压场、洋流场以及海洋阻力系数等的影响。

Using data of monthly mean sea ice motion velocity and sea ice concentration, provided by the National Snow and Ice Data Center, we established the temporal variation of sea ice motion velocity in the Ross Sea（1979–2015）. The interannual and seasonal variational characteristics of sea ice motion velocity were revealed, as was the relationship between sea ice motion velocity and sea ice extent. Finally, the factors influencing the variation of sea ice motion velocity were analyzed. The results showed that sea ice motion velocity in the Ross Sea increased during 1979–2015; the rate of increase was fastest in autumn, followed by winter, spring, and summer. The average motion velocity of sea ice in winter was highest, followed by autumn, spring, and summer. The sea ice motion velocity and sea ice extent both showed increasing trends over the 37-year period. Although the variation of sea ice motion velocity lagged sea ice extent by 1–2 months, significant positive correlation was found between them, and the increase of sea ice motion velocity caused the extent of sea ice to expand, affecting the distribution of Antarctic sea ice. Significant positive correlation was found between sea ice motion velocity and wind speed in the Ross Sea, indicating that the wind field was a factor contributing directly to the variation of sea ice motion velocity. In addition, sea ice motion was also affected by the pressure field, ocean currents, and ocean drag coefficient.