Water Temperature
Data on water temperatures are presented as monthly averages (Figs. 4, S1-S3). At λ values of 20 and 25, the model outputs for the first half of the year were remarkably similar, particularly at the higher hazard rate (λ=25). Two regimes were generally identified with a shift detectable in 1988 for all months from January through June (Fig. 4). The mean temperature increase between regimes ranged between 10 and 20C. As with the first half of the year, two regimes were generally distinguished from July through December, again involving temperature increases of between 10 and 20C (Fig. 4). Interestingly the regime shifts (λ=25) during the latter half of the year tended to occur progressively later than those from January through June: July (1997), August (1994), September (1996), October (1999), November (2005), December (2014). The greatest increase occurred in August, with mean temperatures between the first and second regimes increasing from 16.70 to 18.70C.