Local waters are experiencing noticeable cooler water temperatures this season due to subarctic water being pulled into the Gulf of Maine. GBH Meteorologist Dave Epstein recently spoke with Nick Record, a senior research scientist at Bigelow Lab for Ocean Sciences in Maine. What follows is a lightly edited transcript.
Dave Epstein: Today I want to talk about the fact that the National Weather Service recently had a cold water advisory for parts of Southern Maine. And I’ve been in the water this summer, and it does feel colder than the past couple of years. What is going on?
Nick Record: Yeah, that’s a great question. You’ve probably heard stories about how rapidly the Gulf of Maine is warming. That’s been a narrative that has been around for 10 or 15 years now. And indeed that has been happening. But one of the interesting things we’ve seen oceanographically is the last two or three years, there has been this pulse of subarctic water that has come into the Gulf of Maine and slowly worked its way toward the coast. And that’s the cold water that you and the National Weather Service are experiencing this summer.
Epstein: So Nick, you mentioned subarctic water. Where is that? And you said it’s coming down, we’ve noticed it. How do you know that that’s happening?
Record: Yes, I say subarctic, but of course the whole ocean is connected with this really complex network of currents that go from the Arctic to the Antarctic, from the surface ocean to the deep.
One of those currents, the Labrador Current, comes down from the Arctic and hugs the coast of Canada and comes into the Gulf of Maine, sometimes near the surface, but oftentimes through this deep Northeast Channel. And we here in the Gulf of Maine, and Canadians, and others further up that current have different oceanographic equipment that monitors it as it sort of moves down the coast. And because it comes in often, these waters come in through that deep channel — if we’re measuring deep offshore waters, we can see it before it gets in toward the coast where you and I might go for a swim and feel that it’s really cold.
And that’s through oceanographic buoys, shipboard measurements. We have a survey here at Bigelow called the Gulf of Maine North Atlantic Time Series. Satellite measurements are helpful in some cases, at least for the surface component of that. So there’s a lot of people making different measurements that can feed into this big picture.
Epstein: So a couple of more questions here. We hear about the oceans warming up, and you talked about that right at the beginning. And now we’re talking about slightly colder water in the Gulf of Maine. Help square away those two different things — colder over the past couple of years, but overall warming [waters].
Record: The overall warming is driven by the warming atmosphere because of fossil fuels and climate change and so on. And that overall trend, you can’t really reverse that on a long timescale unless you do something about the greenhouse gases. And the ocean absorbs a huge amount of that heat, by the way.
But on top of this long-term trend of warming, there are ups and downs. So you have warm years and you have cold years. And the other thing that we’re seeing is that those ups and downs are also increasing in magnitude. So the warm years might be like a little bit warmer than before, but some of those cold years could be colder as well. It’s these sort of extremes that we’re getting and it makes the year-to-year changes in the Gulf of Maine and many other places a little bit harder to predict, a little bit harder to expect what’s coming. And almost every year seems unusual now with some kind of new twist on it. And so that latest twist is this influx of cold, fresh Arctic water.
Epstein: So obviously bathers, we’ve still got plenty of summer left and even into the autumn might be going to the ocean. They might be saying, ‘Whoa, this is a little colder than the past couple of years.’ But that’s just our recreation. What about the things that actually live in the ocean? Have you seen any changes with any of the fish and other creatures that are in the ocean because of this cooling specifically?
Record: Yeah. And I will say, among some of the first people who noticed this was the lobster industry, because they’re interacting with a species that lives right on the bottom where that deep water first started coming in. So they were noticing it a couple of years ago around the same time we saw it in the buoys.
About other things that we’ve seen, there are historically some really great feeding habitats for the North Atlantic right whale in the Gulf of Maine. We’re one of the most productive oceans on the planet, and right whales feed on this cold water, sort of subarctic species of plankton called Calanus. And when the Gulf of Maine started warming rapidly, those feeding areas went away. And since we’ve seen this cold water come back in, we’ve seen some of those feeding areas start to light up again. So indeed, the ocean does respond. And the right whales picked up on it even sooner than people did in some cases. So all of these things are interconnected. And I think we sort of have to pay attention to all of them if we want to figure out what’s going on and how these changes are affecting one another.
Epstein: What else are you noticing this summer? I know you’re really intimately studying the ocean. So what else should folks be aware of that they might see on the beach that you’re seeing in terms of your research and other reports that you get?
Record: Well, we do have a community reporting program for jellyfish on the beach. So if you see a jellyfish, you can [email me] and I’ll probably email you back if I’m not getting too many emails. But we do see especially this time of year, a lot of lion’s mane jellyfish on beaches or just off of beaches that we advise people to try to avoid if they’re swimming.
But they’re also something really interesting to observe biologically and oceanographically. So if you see them, you could send sightings directly to me, and I have a many-year time series going of the sightings that people send me. And, you know, in general, there are a million things to watch in the ocean and to pay attention to. So find what it is that you’re interested in and start getting engaged.
