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Clim Dyn (2014) 43:19651972
DOI 10.1007/s00382-013-2020-5
Indian Ocean Dipole and southern high latitude precipitation: possible links
M. Nuncio K. Satheesan
Received: 3 October 2013 / Accepted: 6 December 2013 / Published online: 21 December 2013 Springer-Verlag Berlin Heidelberg 2013
Abstract Southern high latitude precipitation during austral spring in relation to the Indian Ocean Dipole (IOD) and ENSO is investigated in the present study. Both the IOD and ENSO generate Rossby waves trains that create positive and negative pressure anomalies. These anomalous pressure centres generate meridional moisture uxes that impact the precipitation. Inuence of the IOD is detected mainly in the Ross sea region, where the southward moisture transport induced by the low pressure cell enhances precipitation. During strong IOD years, east Antarctica near 100E, is also characterised by enhanced precipitation induced by the southward moisture transport by a high pressure cell located south of Australia. In the Dronning Maud Land, precipitation is linked to the moisture advection through the Atlantic during ENSO years and not during the IOD years.
Keywords Indian Ocean Dipole Precipitation
Antarctica Rossby wave trains Teleconnections
1 Introduction
There is a societal relevance to the mass balance of ice sheets in the Antarctica because it is closely related to the global sea-level rise. Recent estimates show Greenland and Antarctic ice-sheets contribute to *1 mm of sea-level rise
(Jacob et al. 2012). One of the factors governing the mass balance is precipitation. In Antarctica, the most common form of deposition is precipitation in the form of snow which exhibit a wide range of time scales. Though not all regions exhibit elevation changes purely due to snowfall variability, this may be the case in some of the regions (Thompson et al. 1994; Thomas et al. 2008). Yearly snowfall uctuations of 20 mm year-1 of water equivalent would contribute to 0.6 mm year-1 of global sea-level rise (Monaghan et al. 2006). Majority of the east Antarctic, during the time period 19922003, is thickening because of snow fall. Satellite altimeter derived rate of change of surface elevation for East Antarctica is about 06 cm year-1, whereas west Antarctica exhibits substantial spatial variability (Davis et al. 2005). In a reconciled estimate for the mass changes of ice sheets west Antarctica and Antarctic peninsula have lost mass...