Diagnosing the Causes of Subsurface Ocean Salinity and Temperature Change to Surface Using Idealized Ocean Model Experiments
[26-Feb-2014] Lago, V., Durack, P., Wijffels, S., Bindoff, N., and Marsland, S.
Presented at the 2014 Ocean Sciences Meeting
Previous works have reported coherent and detectable changes to the ocean's subsurface salinity and temperature fields in response to observed climate change. Using idealized ocean model simulations, we investigate the role of surface water cycle (evaporation minus precipitation [E-P]) and temperature changes on subsurface ocean properties. We achieve this by undertaking experiments in which surface temperature, or the surface salinity pattern (inferred E-P changes), or both are linearly increased over 50 years and allow the model to freely respond to these surface-forced changes. We compare the spatial patterns of ocean property changes in three-dimensions to those resolved earlier from observations. A qualitative comparison suggests that the observed salinity change patterns can only be reproduced if both an inferred E-P change and warming are imposed on the model. Similarly, observed temperature change patterns can only be reproduced if both warming and E-P changes are imposed. These new results further extend our understanding of the mechanisms that are responsible for changing the ocean's subsurface salinity and temperature in response to climate change.