1. PROJECTED SEASONALITY IN OCEAN ACIDIFCATION IN THE WESTERN PACIFIC REGION by 2100
Sri Nandini1, 2, Helene Jacot Des Combes1, Andrew Lenton3 and Mareva Kuchinke3
1PACE-SD, University of the South Pacific, Suva, Fiji Islands
2 corresponding author:
3CSIRO Wealth from Oceans National Research Flagship, PO Box 1538, Hobart, TAS 7001, Australia
Abstract
Oceans play a vital role by uptake of atmospheric CO2, thus altering the seawater chemistry. The pH and aragonite saturation state (Ωar) are reduced, collectively known as ocean acidification. Previous studies indicate that coral growth (calcification) rates typically decline as saturation states decrease. Consequently, island nations that rely on coral reefs may be adversely impacted. In this study, we investigate how the seasonal and long-term Ωar and its key drivers (Sea Surface Temperature (SST), Salinity (SALT), Total Alkalinity (TA) and Total CO2 (TCO2) change under the high (A2) and control atmospheric CO2 emission scenarios. We focus on the Pacific region (35°S: 30°N; 120°E: 220°E) and subregions of the West Pacific Warm Pool (WPWP) and the East Equatorial Pacific (EEQ) due to contrasting processes. We also evaluate the coupled carbon Community Climate System Model (CCSM3) against upper ocean seasonal data, where surface Ωar values drop from 3.8 to 2.3 by 2100 for the whole region. The mean seasonal amplitude in Ωar decreases by 4 % from while the seasonal phase remains unchanged till We have found that TCO2 is the main driver in the seasonal variability in Ωar in the different regions and that CCSM3 over estimates the TA response towards Ωar at the equator, WPWP and EEQ. In the WPWP there is a cancellation effect (TA compensates effects of TCO2) due to dilution caused by intensified hydrological cycle by In the EEQ, wind driven seasonal upwelling is the main driver causing seasonal changes in Ωar by 2100.
Introduction
Methods
Results
Further studies
References
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Conclusion
Acknowledgements

2. Caldeira K and Wickett ME. 2005
Caldeira K and Wickett ME Ocean model predictions of chemistry changes from carbon dioxide emissions to the atmosphere and ocean. Journal of Geophysical Research 110: 1-12.