Does Arctic Warming Bring on Colder Winter for Japan?
Just as global warming continues to speed up, Japan’s winter is becoming colder than ever.
In 2016, Tokyo had the first snow of the season in November — the earliest snowfall recorded in 54 years. On Dec. 10 that year, 65 cm (2 ft) of snow fell in the northern city of Sapporo, followed by another 96 cm (3 ft) of snowfall in less than two weeks. The wicked weather that brought all traffic in Sapporo to a standstill remains fresh in our memory.
Anyone who gives a quick review of weather reports from around the world would realize this extraordinary wintry winter phenomenon is not unique to Japan. From North America to Europe, record-breaking temperature plunges and blizzards have been wreaking havoc across the mid-latitude area in recent years. This leads us to ask the question: Is this seasonal “cooling” interconnected with global warming that has brought on other extreme weather events such as major droughts and flooding?
Ask an Expert: Associate Prof. Jun Inoue (National Institute of Polar Research)
Dr. Inoue studies meteorology focusing on the Arctic and Antarctic atmosphere and oceans to understand how these elements come together to form polar climates. He is particularly interested in low-pressure systems that induce heat and moisture transport as well as the mid-latitude extreme weather that is driven by the decrease of Arctic sea ice. He takes advantage of observation data as well as cutting-edge techniques for data analysis for his research. For his profile, click here.
While Earth Warms Up, Japan Faces Deep Freeze in Winter
In February 2015, the East River running along the island of Manhattan in New York City froze over, shutting down the commuter ferry service through the usually ice-free tidal waterway. The mercury dipped to record lows of minus 18 degrees Celsius in New York City, minus 15 degrees Celsius in the Great Lakes region and 0 degree Celsius in Florida.
“Japan had a similarly harsh winter in 2005-2006 with heavy snowfalls hammering the regions along the Sea of Japan,” said Jun Inoue, associate professor at the National Institute of Polar Research. “The data shows powerful storm systems have repeatedly developed during winter across the mid-latitude areas of the globe since the late 2000s, often resulting in heavy damage from freezing temperatures and snow.”
Common sense would dictate winter gets milder everywhere as global warming escalates. Inoue said he looked at what’s happening in the Arctic as a clue to understand the puzzling reality.
“I noticed that the Arctic sea ice area was the smallest on record in the summer leading up to the winter of 2005-2006,” Inoue said. “I decided to look into the potential relationship between the shrinking sea ice area in the Arctic and the climate in Japan.”
Decoding the Teleconnection Mechanism
The ongoing shrinkage of the sea ice area is one of the major environmental changes happening in the Arctic. The region has lost sea ice in the size of the Hokkaido prefecture on average every year since 1979 when data gathering via satellite began. It dwindled to the smallest size on record in 2007 before it shrunk even more in 2012. The summer of 2016 is the second on record thus far, which preceded the major cold snaps that hit North America in December that year.
Environmentally speaking, what happens in the Arctic never stays in the Arctic. Climate around the world also changes in response to that of the Arctic, which is known as teleconnection. Now, Inoue and his team believe they have decoded the mechanism of teleconnection.
“The Gulf Stream is becoming warmer and shifting northward, and this is keeping the high-latitude areas in Europe warmer in winter. We found that this also allows the low-pressure system that develops above the North Atlantic to move farther north toward the North Pole. Southern winds from this low-pressure system also push sea ice farther north,” Inoue explained. (Click here for the press release.)
Heat pours into the Arctic, accelerating the warming of the Arctic Ocean. In the meantime, this leaves the continents cooler and the temperature gaps result in the development of high-pressure systems above them.
“Japan lies in between high-pressure systems to the west and low-pressure systems to the east during winter. These western high-pressure systems above the Asian continent that give us Old Man Winter” Inoue said.
Inoue continues to investigate this mechanism through the Arctic Challenge for Sustainability (ArCS).
Understanding of Global Climate Requires Global and Reliable Data
Comprehensive climate studies require different types of data from various points around the globe. Inoue said collecting atmospheric data, such as air temperatures and humidity levels at up to 30 km above the ground is as critical to climate studies as ground- and satellite-based observation data. Observation stations that can gather such data are mainly located in the northern hemisphere, however. There need to be more observation stations in the Arctic and Antarctic regions as well as other underpopulated parts of the world, Inoue said.
Collected data benefits not only climate researchers but also ordinary people as weather forecasters in Japan, the U.S., Europe and many other countries use it every day. The World Meteorological Organization (WMO) has a data exchange network that connects observation centers and weather prediction centers around the world. Observation stations first send raw data to the WMO, which log and distributes it to the network members. The centralized system ensures weather forecasters and climate researchers have real-time access to trustworthy data from a reliable source, Inoue said.
More Arctic Data, the Better Forecasting
The speed and accuracy of weather forecasting today has a lot to do with the use of the real-time observation data coming out of the WMO.
“Real-time data enables you to compare the accuracy of various forecasting models. You can also plug in different data to see how that affects scenarios. Using real-time data this way helps improve the accuracy of weather and marine forecasting greatly. It also helps you understand what other data should be gathered to make forecasting even better,” Inoue said. (Click here for the latest research report.)
“Climate researches in Japan have traditionally focused on the tropical climate, but more researchers are beginning to focus on the Arctic region these days,” Inoue said. “Both 2017 and 2018 are slated as the Year of Polar Prediction. I am sure such a heightened interest in the Arctic climate will help improve the quantity and quality of data we gather and push the advancement of weather forecasting techniques.”
Interviewer: Rue Ikeya
Photographs: Yuji Iijima unless noted otherwise
Released on: Jun 27, 2017 (The Japanese version released on Jan. 10. 2017)