Role of mode and intermediate waters in future ocean acidification: analysis of CMIP5 models

Consistently with the past decades observations, CMIP5 Earth System Models project highest acidification rates in subsurface waters. Using 7 ESMs, we find that high acidification rates in mode and intermediate waters (MIW) on centennial timescales (-0.0008 ± 4 × 10–5 yr–1 to -0.0023 ± 0.0001 yr–1 depending on the scenario) are predominantly explained by the geochemical effect of increasing atmospheric CO2, whereas physical and biological climate change feedbacks explain less than 10% of the simulated changes. MIW are characterized by a larger surface area to volume ratio than deep and bottom waters leading to 5 to 10 times larger carbon uptake. In addition, MIW geochemical properties result in a sensitivity to increasing carbon concentration twice larger than surface waters (Δ[H+] of +1.2 mmol.m–3 for every mmol.m–3 of dissolved carbon in MIW vs. +0.6 in surface waters). Low pH transported by mode and intermediate waters are likely to influence surface pH in upwelling regions decades after their isolation from the atmosphere.

Resplandy L., Bopp L., Orr J. C. & Dunne J. P., in press. Role of mode and intermediate waters in future ocean acidification: analysis of CMIP5 models. Geophysical Research Letters. Article.

0 Responses to “Role of mode and intermediate waters in future ocean acidification: analysis of CMIP5 models”



  1. Leave a Comment

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

This site uses Akismet to reduce spam. Learn how your comment data is processed.




Subscribe to the RSS feed

Powered by FeedBurner

Follow AnneMarin on Twitter

Blog Stats

  • 1,283,416 hits

OA-ICC HIGHLIGHTS

Ocean acidification in the IPCC AR5 WG II

OUP book