I'm at the NCSE "Climate Solutions Conference" in Washington, DC this week. I was invited to talk about the lessons we can learn from the 2012 ocean heat wave in a session on "Managing Fisheries Under Climate Change." For my talk, I was curious whether the warming we've seen in the Gulf of Maine is unique. Short answers: it is very unique: since 2004, the Gulf of Maine has warmed faster than 99.85% of the global ocean.
To get to this number, I grabbed the global sea surface temperature (SST) data set from NOAA's optimally interpolated product. I removed the mean annual cycle (1982-2011) to produce daily anomalies. I then selected 2,000 point at random (shown over the mean SST from June):
At each point, I computed the linear trend over the last 10 years (January 2004-September 2013). At this relatively short time scale, I would expect to see a lot of variability--a lot of places warming, but also a lot of places cooling, and this is what I found. The mean trend is 0.006°C/yr and there are slightly more points that are warming (1024 points) than cooling (976).
The distribution of trends is pretty much normal (in the statistical sense):
but the Gulf of Maine is decidedly abnormal. The Gulf is warming at 0.23°C/yr (see my previous post), and from my 2000 randomly selected points, I found only four (FOUR!) that were warming faster (red stars on the map). Turns out one of them was from the Gulf of Maine (go figure), and that the other points were from the Kuroshio extension region northeast of Japan. This makes some sense oceanographically and is probably driven by a northward shift in the Kuroshio (the Pacific's Gulf Stream).
According to this analysis, the warming in the Gulf is remarkable, and frankly, a little scary. However, it is important to remember that this is just a statistical analysis. At some point, the trend will slow, but we don't know when and by how much. There is clearly more work to be done to understand the mechanisms that are driving the current trend. And, there is also an opportunity to use the Gulf of Maine to understand how an ecosystem responds to rapid climate change.