MACNBR   00242
MUSEO ARGENTINO DE CIENCIAS NATURALES "BERNARDINO RIVADAVIA"
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
CENTENNIAL AND MILLENNIAL-SCALE CHANGES IN THE SOUTHERN WESTERLY WINDS (SWW) IN SOUTHERN PATAGONIA SINCE 15 KA
Autor/es:
RODRIGO VILLA-MARTINEZ; ISABEL VILANOVA; PATRICIO MORENO; RICARDO DE POL-HOLZ
Lugar:
Punta Arenas
Reunión:
Congreso; VIII Southern Connection Congress; 2016
Institución organizadora:
Universidad de Magallanes
Resumen:
fluctuations and tropical climate variability during the Holocene. Stratigraphic records from southwestern Patagonia allow monitoring the SWW at the boundary between mid- and high southern latitudes (50°- 55°S), from the sole continental landmass at this latitude on Earth. Here we present a record from Chilean Patagonia (51°S) that reveals strong SWW during the Antarctic Cold Reversal (ACR), anomalously low wind intensity between 7.5-10.5 ka and stronger SWW since 7.5 ka. We detect 9 positive Southern Annular Mode (SAM)-like events at centennial timescales since 5.8 ka superimposed on a multi-millennial trend such that predominantly positive SAM-like states prevail between 0.6-1.5 and 2.7-4 ka in the LC record, followed by negative SAM-like conditions between 0.2-0.6 and 1.5-2.7 ka. The apparent phasing for the onset and peak SAM-like and ENSO variability in the eastern sectors of the equatorial and southern midlatitude Pacific raises the possibility that coherent variations in the intensity and position of the Hadley and Walker circulation cells, at millennial and centennial timescales, resulted in oscillatory modes in tropical and extratropical sectors of the Pacific basin.