Please use this identifier to cite or link to this item: https://apo.ansto.gov.au/dspace/handle/10238/8281
Title: Equatorial pacific coral ceochemical records show recent weakening of the Walker Circulation
Authors: Carilli, JE
McGregor, HV
Gaudry, JJ
Donner, SD
Gagan, MK
Stevenson, S
Wong, HKY
Fink, D
Keywords: Climates
Seas
Southern oscillation
Corals
Salinity
Kiribati
Issue Date: 10-Nov-2014
Publisher: Americal Geophisical Union
Citation: Carilli, J., McGregor, H. V, Gaudry, J. J, Donner, S. D., Gagan, M. K., Stevenson, S., Wong, H. & Fink, D. (2014). Equatorial Pacific Coral geochemical records show recent weakening of the Walker Circulation. Paper presented at the AGU Fall Meeting, 15-19 December 2014, San Francisco, USA.
Abstract: Equatorial Pacific ocean-atmosphere interactions affect climate globally, and a key component of the coupled system is the Walker Circulation, which is driven by sea surface temperature (SST) gradients across the equatorial Pacific. There is conflicting evidence as to whether the SST gradient and Walker Circulation have strengthened or weakened over the late twentieth century. We present new records of SST and sea surface salinity (SSS) spanning 1959–2010 based on paired measurements of Sr/Ca and δ18O in a massive Porites coral from Butaritari atoll in the Gilbert Islands, Republic of Kiribati, in the central western equatorial Pacific. The records show 2–7 year variability correlated with the El Niño–Southern Oscillation (ENSO) and corresponding shifts in the extent of the Indo-Pacific Warm Pool, and decadal-scale signals related to the Pacific Decadal Oscillation and the Pacific Warm Pool Index. In addition, the Butaritari coral records reveal a small but significant increase in SST (0.39°C) from 1959 to 2010 with no accompanying change in SSS, a trend that persists even when ENSO variability is removed. In contrast, larger increases in SST and SSS are evident in coral records from the equatorial Pacific Line Islands, located east of Butaritari. Taken together, the equatorial Pacific coral records suggest an overall reduction in the east-west SST and SSS gradient over the last several decades, and a recent weakening of the Walker Circulation.© 2014, American Geophysical Union.
Gov't Doc #: 7847
URI: https://agu.confex.com/agu/fm14/webprogram/Paper7318.html
http://apo.ansto.gov.au/dspace/handle/10238/8281
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