In this week's blog post, Chief Scientific Officer Andy Pershing drops by to explain El Niño and how it affects us in the Gulf of Maine.
Greetings from February 18! This week, we went from the coldest temperatures of the year on Valentine’s Day to windy, wet, and (relatively) warm conditions a few days later. After experiencing extremes that are wacky, even by New England standards, it requires a bit of courage to predict that water temperatures will be warm this spring — yet, that’s exactly what I’m about to do.
So far, this has been one of the mildest winters ever in New England. December was 11.4°F above normal, making it the warmest December in Maine by almost 5°. January was 6.1°F above normal — warm, but not quite record-setting. NOAA’s Climate Prediction Center is forecasting that mild conditions will prevail into the spring.
You can blame these unusually mild conditions on the Pacific Ocean. Normally, the trade winds that blow from east-to-west along the equator create a blob of very warm water in the western Pacific, near Indonesia. These same winds pull cold water to the surface in the east, leading to cold conditions off of Ecuador. If the trade winds get weaker, the warm water sloshes to the east. The appearance of warmer-than-normal water off of Ecuador is the hallmark of the phenomenon known as “El Niño.” When it happens, global weather patterns go haywire.
The impacts of El Niño are dramatic, but they aren’t random. Conditions in an El Niño year are incredibly predictable, and El Niño effects stretch far away from the warm waters of the Pacific. The warm water sloshing across the Pacific during El Niño changes the flow of heat and moisture across the globe. For us, it means that we get warm, moist air from the south — almost the exact opposite of the conditions we experienced last February. You can learn more about El Niño and what it means for the Northeast at http://www.nrcc.cornell.edu/services/special/special.html.
It is important to note that El Niño is not the only part of the story. Each year, the Earth gets a little bit warmer as our temperature adjusts to the extra carbon dioxide we’ve put in the atmosphere. This means that the conditions this winter are warm, even when compared to other El Niño years.
What does this mean for lobsters? Right now, the water temperatures at the three NERACOOS buoys along the coast of Maine are running about 2°F above average at both the surface and 165 feet below. This is quite warm, but it’s down from the record temperatures we were at before the Valentine’s Day cold snap.
Although we’re not quite at record levels, the warm temperatures and mild weather are reminiscent of 2012. That year, the Gulf of Maine was at the epicenter of a large scale “ocean heatwave.” The warm water caused the lobster fishery to shift into its summer, high-landings mode 3–4 weeks early. The sudden influx of soft-shell lobster created havoc in the lobster supply chain and made for a very challenging year for many lobstermen.
The experience in 2012 caused me and my colleagues to ask whether we could have predicted the early uptick in landings. We found that water temperatures in March and April are a good indicator of whether it will be an early or late lobster season. We started issuing forecasts in earnest last year. Because water temperatures were cold last spring, we predicted that the fishery would switch into summer mode about two weeks later than normal.
We are planning to release our forecast for the 2016 season during the first week of March at the Fishermen’s Forum and at www.gmri.org/lobster-forecast. Water temperatures are already warm. El Niño makes mild weather more likely and makes long-range predictions more reliable. Taking these together, I expect water temperatures will be warm this spring, but exactly how warm is hard to predict. If this plays out, the lobster season will look very different from last year.
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