Proceedings of the National Academy of Sciences of the United States of America, Vol. 106, Issue 30, pp. 12235-12240 (2009)
Research by John E. Dore, Roger Lukas, Daniel W. Sadler, Matthew J. Church, and David M. Karl sheds light on short and long-term modulations of ocean acidification in the central North Pacific. The team of researchers analyzed nearly twenty years worth of time series data (seawater pH and related statistics) at Station ALOHA near Hawaii and came to many important conclusions. In terms of short-term trends, they were able to establish a clear seasonal pattern in the pH of surface waters; the pH hits a peak during the winter (January to April) and hits a minimum during the summer (July to October). They also noted that the swings in pH were mirror images of the swings in water temperature (carbon dioxide is most soluble in water at low temperatures). In terms of long-term trends, they observed a rate of pH decline of about .0019 per year. These findings are quality additions to our knowledge of how ocean acidification functions.
This sounds very similar analysis as to what we will be doing for MP3. Should be a very useful primary article to site to help build your argument. This is also one of the newest studies I have seen modeling pH trends. These types of things need to be updated every so often to see if old projections match new ones.