You are probably familiar with temperature anomalies over land. Meteorologists often report how much the thermometer deviates from normal climates. Soil temperature anomalies can reach 20°C above, such as this week in parts of coastal California. Of course, water has a very high heat capacity and is extremely capable of absorbing energy. It takes a lot more energy to heat water than air, so meteorologists start paying attention when an ocean temperature anomaly exceeds a few degrees Celsius. Here is the current water anomaly as of September 5, 2022, for Atlantic Canada: Some buoys just a few hundred kilometers off Newfoundland measure the water temperature at 23°C (Buoy 44139) What is the main reason we have seen this ocean temperature deviation from the mean? Here are the statistics from the meteorological summer, which runs from June to August. As expected, it was one of the hottest summers on record for parts of Newfoundland. See the average temperature for St. John’s at 17°C. This is 2.5°C warmer than the 1990-2020 average, a finding consistent with climate change. A persistent, gentle southwesterly flow dominated the summer months, with the main depression anchoring northwest over Hudson Bay.
Tropical impacts possible this weekend
The first test of this drop could be as early as this coming weekend. Hurricane Earl will pass southeast of Bermuda late Thursday and eventually stall south of Atlantic Canada by next weekend. Assume that tropical disturbances interact with warmer waters south of Atlantic Canada. In this case, it could potentially delay the transition to extratropical systems. Warmer ocean temperatures mean the surrounding air can carry more moisture, causing more moisture-laden storms. Systems tracking the warm water are also mixing surface waters, which will likely locally suppress some of the extreme water temperatures recorded in recent weeks.
