Freshening of the Indonesian Throughflow and the Leeuwin Current during the 2010-11 La Niña/Ningaloo Niño

During the 2010-11 La Niña/Ningaloo Niño, excessive precipitations in the Maritime continent and Indonesian-Australia Basin have caused a 0.3 psu freshening of the surface waters in the southeast Indian Ocean. The freshening... [ view full abstract ]

During the 2010-11 La Niña/Ningaloo Niño, excessive precipitations in the Maritime continent and Indonesian-Australia Basin have caused a 0.3 psu freshening of the surface waters in the southeast Indian Ocean. The freshening anomalies are carried westward by the Indonesian Throughflow and the South Equatorial Current, and carried southward along the Western Australia coast by the poleward flowing eastern boundary current, the Leeuwin Current. Salinity anomalies contribute to more than 20% of the anomalous increase of the southward Leeuwin Current transport at the peak of the 2010-11 Ningaloo Niño, resulting unprecedented warming of the coast of Western Australia. Episodically freshening of the Leeuwin Current has been observed at a coastal reference station of Western Australia during extended La Nina conditions over the past several decades.