By Dr. Rob Moir, a nationally recognized and award-winning environmental activist.
Who hasn’t heard that the Gulf of Maine is heating 97% faster than the world’s oceans? But the real reason can get lost in the constant headlines about global warming and rising greenhouse gases. To explain this unusual phenomenon, let’s take a closer look at four factors: surface ocean temperature, heat intensity, air temperature, and precipitation every month for five years.
The National Oceanic and Atmospheric Administration (NOAA) produces monthly charts of sea surface temperatures. Below is the latest chart for June 2024.
The deep blue water was between 32 and 41 degrees Fahrenheit. The light blue was 54 degrees Fahrenheit. The green water in Massachusetts Bay was about 65 degrees and the yellow water south of Cape Cod was about 70 degrees Fahrenheit. There is no single temperature in the Gulf of Maine. Overall ocean surface temperatures drop from 65 degrees along the coast to 54 degrees in the Atlantic Ocean.
Monthly changes, long-term effects
These temperatures vary from month to month throughout the year. In the following images from NOAA, the top row shows sea surface temperatures for April, going back from 2024 to 2020. Map of the Northeast shows changes in precipitation in the Gulf of Maine watershed. The largest river is the St. Johns River, which flows through the northern tip of Maine. April 2024 was the driest month and April 2020 was the wettest month. Displays the monthly average daytime temperature. The bottom graph shows the past 30-year average of right whale density in April. In spring, sea surface temperature changes slightly, precipitation changes significantly, and air temperature changes little. Right whales are increasing, especially in Cape Cod Bay and Nantucket Reef.
In May, you will notice that the surface temperature starts to warm up.
The lighter blue shown below indicates warmer surface water (54 °F). The year 2024 will have the highest sea temperatures and the highest precipitation. Some might think that rising temperatures are warming the oceans. However, I would like to draw your attention to the map below of inland heat severity over the past five years. This image shows the combined air and geothermal averages. Heat appears bright red when the average annual temperature is higher than normal or approaching dangerous levels.
Since 2019, the severity of heat has increased dramatically, especially from 2022 to 2023, with high temperatures peaking in summer. As temperatures rise inland, the Gulf of Maine absorbs more heat.
Every June, surface temperatures along the coast of the Gulf of Maine become even warmer, reaching 65 degrees Fahrenheit. This is consistent with the heat severity map. No wonder the Boston area is so hot. Surface water temperatures have increased due to increased precipitation.
2020 was the driest month and had the coldest surface water temperatures.
In July, warm surface waters spread further across the Gulf of Maine. Black spots represent missing data, likely due to fog or low cloud cover. 2023 was the wettest year on record since 1955. It was also the first year it turned orange (81 degrees Fahrenheit).
Although temperatures are high in July, surface water temperatures do not increase. July 2019’s temperature was 78 degrees, colder than 2023’s temperature of 74 degrees.
Evidence of summer warming will show long-term effects on the Gulf of Maine in the later months of the year. In October 2021, there was a lot of precipitation and the sea surface temperature was warm, and in 2019, although there was a lot of precipitation, the rise in the water surface temperature was not so large. The heat intensity map shows that even though there was a lot of rain in 2019, the heat intensity in 2019 was significantly lower and therefore did not affect water temperatures. Land temperature around the Gulf was the determining factor for surface water temperature.
The warm waters of the Gulf Stream were mapped in the bottom right corner in some years, but not in other years. The Gulf Stream meanders northward to dissipate energy. How close you get to the Gulf of Maine varies from month to month.
This was more pronounced in July than in other months, when increased precipitation led to warmer surface waters. Soil temperature increases with air temperature. When precipitation increases, more water runs off the land. During the summer, the heating of the ground surface is a factor. There was a lot of rainfall in October 2019, and there was almost no change in surface water temperature. This was due to the low surface temperature.
There’s one surprising fix
Seasons in New England vary greatly in the amount of rainfall and severity of heat. Rising temperatures have led to higher temperatures on the ground. More precipitation, especially on hot, impermeable surfaces, spreads more fresh water over salty ocean surfaces, warming them 97% faster than the world’s oceans.
to cool the Gulf of Maine. All you have to do is reduce the amount of water that runs off the land. Slowing the flow allows more water to stagnate and infiltrate the land. Moist soil allows plants to grow and absorb more carbon. Increasing green vegetation and restoring healthy soil will reduce the burden of carbon dioxide in the atmosphere. The Gulf of Maine will no longer heat up faster than 97% of the world’s oceans.
About the author
Dr. Rob Moir is president and executive director of Ocean River Research Institute, based in Cambridge, Massachusetts. Ocean River Institute is a nonprofit organization that supports the efforts of environmental organizations by providing expertise, services, resources, and information not available at the local level. Please take a look www.oceanriver.org For more information.
