If you follow science and climate news even a bit, you likely have heard that the sea ice in the Arctic region this year has been way below average.

It’s so low, that even without any sun right now in that region, the ice isn’t expanding.

This lower ice coverage isn’t new. Scientists have noticed for years that the extent and the depth of the ice in the Arctic has been shrinking.

The image below shows the current extent of Arctic ice. Note how low it is this year.

 Arctic sea ice has been hitting monthly lows nearly all of 2016


Arctic sea ice has been hitting monthly lows for nearly all of 2016.

Our reliable data for sea ice only goes back to 1979, which is a relatively short period. However, the trend is clear – the ice is shrinking.

Of course, nearly everyone cares about the planet’s health, but many of us might not understand how something like Arctic sea ice can affect the weather in Maine and the rest of New England.

Advertisement

A few years ago, a research paper about the diminishing sea ice was published in IOP Science by two authors, Jennifer A. Francis from the Institute of Marine and Coastal Sciences at Rutgers University and Stephen J. Vavrus with the Center for Climatic Research, University of Wisconsin-Madison.

As of late fall 2016 sea ice was not even close to average across the Arctic.

As of late fall 2016 sea ice was not even close to average across the Arctic.

What was interesting about this paper is how it equated the disappearing ice with changes to the jet stream over the mid-latitude part of the planet where we live. The research found that the jet stream has become wavier and parts of it become stuck in places for longer periods of time.

It is hypothesized that the reason for this change is that, as the Arctic warms and there is less of a gradient of temperature between the north and the south, the jet stream will weaken and move in a more erratic way.

Since the jet stream controls our weather, a more amplified jet stream would likely bring more extreme weather to the United States, including in New England.

While the mechanisms are complicated, the basic premise is this: As the ice disappears or thins, heat from the oceans that had been capped by the ice is allowed to escape into the atmosphere. This leads to warming, a weaker jet stream and a jet stream which becomes stuck for longer periods of time in one position. This leads to some areas being exceedingly cold, others warm, some dry and some wet – in other words, more extremes.

Below is one of the images from the research paper. The top panel shows how the thickness of the atmosphere has changed in winter, leading to warm temperatures. The middle panel indicates a more amplified jet stream, and the bottom panel uses an index, called the Meridional Circulation Index or MCI, to show how the waviness of the pattern is increasing. The more wavy the jet stream the more extreme the weather. The jet stream typically oscillates with some regularity between a flat state or zonal flow and a wavy one or meridional flow.

Advertisement

Research shows how the jet stream is responding to warmer temperatures in the Arctic region.

Research shows how the jet stream is responding to warmer temperatures in the Arctic region.

All of this can mean much stormier winters with wide swings in temperatures. This has real impact not only on what we experience, but how we live.

For example, extreme periods of snow and cold followed by dramatic warming can ruin a ski season. Warm weather followed by unusual cold, even a day or two, can damage entire fruit crops, like what happened this spring when the entire peach crop was destroyed.

Other flora and fauna can also be hurt when atypical weather occurs. Perhaps our recent drought is in part a result of this shifting jet stream.

With the polar night in full swing right now, the Arctic ice will hopefully begin to build back in the coming days and weeks.

However, the climate is clearly changing and with it will come more surprises and forecasting challenges ahead.


Only subscribers are eligible to post comments. Please subscribe or login first for digital access. Here’s why.

Use the form below to reset your password. When you've submitted your account email, we will send an email with a reset code.

filed under: