National Centre for Polar and Ocean Research, Ministry of Earth Sciences (Govt. of India), Goa, India; Department of Marine Geology, Mangalore University, Mangalore, 574 199, India.
National Centre for Polar and Ocean Research, Ministry of Earth Sciences (Govt. of India), Goa, India.
Environ Res. 2022 Sep;212(Pt D):113481. doi: 10.1016/j.envres.2022.113481. Epub 2022 May 16.
Antarctic sea ice variability is primarily associated with ocean-atmospheric forcing driven by anomalous conditions over the tropical regions of the Pacific and Indian Oceans. The ice-ocean-atmosphere dynamics in the Indian Ocean Sector (IOS) of Antarctica have been studied using monthly satellite and reanalysis observations over four decades (1979-2019). In this study, we revealed that the annual sea ice extent (SIE) in the IOS increases at a rate of 0.7 ± 0.9% decade, with a maximum increase in austral summer (5.9 ± 3.7% decade). The wavelet approach was used to determine the variability in IOS sea ice caused by the El Niño/Southern Oscillation (ENSO) and southern annular mode (SAM). The SIE has a significant association with both indices during the summer and autumn. In comparison to ENSO, the sea ice variability associated with SAM is typically seasonal in nature and lacks distinct patterns. The wavelet coherence analysis revealed a relatively weak relationship between ENSO and SAM but a highly significant coherence between climatic indices and SIE. We observed that sea ice in the IOS is influenced significantly by climatic oscillations during their negative SAM/El Niño or positive SAM/La Niña phases. Furthermore, the study demonstrated a substantial impact of climatic disturbances in determining the sea ice variability in the IOS.
南极海冰的变化主要与太平洋和印度洋热带地区异常条件驱动的海洋-大气强迫有关。利用四十年来（1979-2019 年）每月的卫星和再分析观测数据，研究了南极印度洋扇区（IOS）的冰-海-气动力学。在这项研究中，我们揭示了 IOS 中的年海冰范围（SIE）以每年 0.7±0.9%的速度增加，在南半球夏季增加最快（5.9±3.7%的十年）。我们使用小波方法确定了厄尔尼诺/南方涛动（ENSO）和南方环状模（SAM）引起的 IOS 海冰变化。SIE 在夏季和秋季与这两个指数都有显著的关联。与 ENSO 相比，SAM 引起的海冰变化通常具有季节性，缺乏明显的模式。小波相干分析显示 ENSO 和 SAM 之间的关系相对较弱，但气候指数与 SIE 之间的相干性非常高。我们观察到 IOS 中的海冰受到其负 SAM/厄尔尼诺或正 SAM/拉尼娜阶段期间气候波动的显著影响。此外，该研究表明气候干扰对确定 IOS 中海冰变化具有重大影响。
