Report explained - news not good

Station ALOHA data reveal ocean acidification

A few posts back, I had a post updating some recent stuff on ocean acidification, and ended noting a study on waters near Hawaii that examined the 20 year history of pH levels. I said it was kind of hard to understand clearly, as at that time I only had a link to the paper itself, and scientists aren't all that good at writing clear summaries.

Anyhow, my guess as to what it meant was correct, as shown in this easier to understand summary linked above:

.....over the two decades of observation, the surface ocean grew more acidic at exactly the rate expected from chemical equilibration with the atmosphere. However, that rate of change varied considerably on seasonal and inter-annual timescales, and even reversed for one period of nearly five years. The year-to-year changes appear to be driven by climate-induced changes in ocean mixing and attendant biological responses to mixing events.

The authors also found distinct layers at depth in which pH declines were actually faster than at the surface. Dore and colleagues attribute these strata of elevated acidification rates to increases in biological activity and to the intrusion at Station ALOHA of remotely formed water masses with different chemical histories.

This seems to me to be a pretty important study, as it is confirmation from long term measurements that the predicted rate of ocean acidification is correct. (The fact that there are bumps along the way is, I suppose, like the difference between weather and climate.)

To the extent that they note that at depth, acidification at times seems to be happening faster than expected, is not good news.