Indian Journal of Marine Sciences Vol. 37(1), March 2008, pp. 35-39 Antarctica sea ice variability and southeast Indian Ocean SST: Possible relationship Shailendra Rai 1 , N. Khare 2 & A. C. Pandey 1,* 1 K. Banerjee Centre of Atmospheric and Ocean Studies, University of Allahabad, Allahabad – 211002, India 2 National Centre of Antarctic and Ocean Research, Headland Sada, Vasco-da-Gama, Goa - 403804, India * [E_mail: avinashcpandey@rediffmail.com ] Relationships between the Antarctic sea ice variability and extrapolar climate variables especially the Indian Ocean SST have been explored and we have identified that the southeast Indian Ocean SST shows the most persistence relationship with Antarctic sea ice variability. The SST is the unique precursor for the Australian summer monsoon, Indian summer monsoon and ENSO phenomenon after the 1976-1977 regime shift and is also linked with recently discovered Indian Ocean Dipole event of subtropical Indian Ocean. [Key words: Sea ice, southeast Indian Ocean, Antarctica, Southern Ocean, climate data, SST, sea ice edge] 1. Introduction The cryosphere in the Southern Ocean is an active component in global climate and is influenced by many local, regional and remote climate fluctuations on the synoptic to geological time scales. The signature of teleconnection between Antarctic sea ice variability and climate has been a topic of research for a long time in modeling as well as observational studies 1-4 . White & Peterson 2 discovered the Antarctic Circumpolar Wave (ACW) that propagates eastwards on the El Nino/Southern Oscillation (ENSO) time scales whereas Yuan & Martinson 3, 5 found a quasi- stationary wave named as Antarctic Dipole (ADP) linked to the ENSO variability that also dominates the interannual variability of the sea ice field. Due to accumulation of sea ice data, connection of polar to tropical climate indices such as ENSO have been found statistically significant 3, 6 . In addition to ENSO, Antarctic sea ice is supposed to be linked to other climate indices such as tropical Indian Ocean sea surface temperature (SST), tropical land precipitation 3 , southeast Indian Ocean SST 7 but these studies are at the primitive stage. A number of modeling and observational studies suggest that tropical Indian Ocean SST anomalies can significantly affect Indian summer rainfall variability 8-11 . Some recent studies focus on the Southern Indian Ocean (SIO) SST variability and its relationship with Indian monsoon, Australian monsoon and African rainfall variability 12-16 . Southwest Indian Ocean, off Australia, may supposedly play major boundary forcing for Late Indian Summer Monsoon (LISM) 12 and is also responsible for the transition of whole ENSO- monsoon system 13 . In addition, Mascarene High plays a major role in east Asian summer rainfall 14 . The southeast Indian Ocean and Mascarene high may be influenced by various physical processes. Our knowledge in the Southern Hemisphere high latitudes and Antarctic is still in the infancy, largely due to few observations 17 but in recent past, due to accumulation of data and improvement in statistical techniques the quality of data in high southern latitudes has improved. In the present work, we have tried to establish linear relationships between the sea ice variability and climate variables specially SST for the southeastern Indian Ocean and Mascerene region (Fig. 1). 2. Sea Ice and Climate Data Satellite measurements of polar sea ice enables us for the variability study from seasonal to interannual time scales. In the present study we have used sea ice —————— *Corresponding author: Ph: +91 (532) 2460993 Fax: +91 (532) 2466974