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.