Fig. 6: Time series of observed atmospheric conditions.

Annual averages of 2 m air temperature (TA), 10 m wind speed (WS), cloud cover (CC), and downward shortwave radiation anomaly (SWR) show a change in the mid to late 1990s to a period of increased air temperatures and wind speeds, and decreased cloud cover (increase in shortwave radiation). For TA, WS, and CC, colors represent values that are above (red) or below (blue) their long-term annual mean. For the shorter time series record for SWR anomaly, annual averages are plotted directly. Linear regressions over the period of water temperature observations (1990–2018, except for SWR, which starts in 1995) estimate trends in TA (0.52 ± 0.22 °C/decade), WS (0.23 ± 0.04 m s−1/decade), CC (−4.55 ± 1.17%/decade), and SWR (4.66 ± 1.79 W m−2/decade).