Bering Science

Ocean updates for spring 2020

The Bering Sea is experiencing many changes. Loss of sea ice and record high ocean and air temperatures impact wildlife and all aspects of life for coastal communities. 2019 saw many notable events, such as unusual mortality of ice seals, whales and sea birds; and changes in movement patterns and abundance of sub-arctic fish species.

We are Bering Sea scientists, mostly federal, state and university. This report is facilitated by a partnership between the Alaska Ocean Observing System (AOOS) and the University of Alaska Fairbanks International Arctic Research Center (IARC) with funding given to AOOS from a national initiative to increase sharing of ocean data. Our team worked with scientists from across the region to compile current updates of Bering Sea science.

We created this publication to share recent findings about some of the most striking changes in the Bering Sea region. This report focuses primarily on what we saw in 2019 in the northern Bering Sea, with some information about the southern and eastern Bering and the southern Chukchi.

Many unknowns

It is challenging to cover every species for each region. Some of the data we hoped to include still needs to be analyzed. Scientists often must focus on species important to resource managers to protect, rebuild and sustain marine ecosystems. They also collect information that is important to communities. We’ve tried to include a bit of everything in this report.

Since this is our first effort, we appreciate questions from readers, suggestions for changes to future reports, and information you would like to receive or see included. Please contact us directly or share your comments in a brief survey. Thank you!

Potential future publications

  • Mid-summer—brief update on early spring/summer observations (electronic version only)
  • Fall—preliminary results of research collected during the 2020 field season
  • Winter—final report of the 2020 research field season – similar to this report

Thanks to these collaborators

  • Alaska Ocean Observing System
  • Bering Region Ocean Data Sharing Initiative
  • UAF International Arctic Research Center
  • University of Alaska Fairbanks
people working on the seashore
Scientists gather samples from seabirds on St. Lawrence Island. (Photo: Akinori Takahashi)
research ship
NOAA research vessel. (Photo: NOAA)

Thank you to reviewers

Thank you to our reviewers who provided valuable input into this publications. We are particularly grateful to Gay Sheffield, Lauren Divine, Maggie Mooney-Seus, Gabe Dunham, and Jennifer Hooper.

Suggested citation

McFarland, H. R., J. Prewitt, R. Thoman, M. McCammon. 2020. Bering Science: Spring 2020 Bering region ocean update, Issue I [newsletter]. Alaska Ocean Observing System, Anchorage, Alaska.

Get in touch

Water and air temperatures

Summer 2019 ocean temperatures

Ocean surface temperatures were very warm in the Bering and southern Chukchi seas during summer 2019. Except for a small area in the Bering Strait, the May–October sea surface temperatures were more than 5°F above the 1971–2000 average. In some areas, these were the warmest average ocean surface temperatures on record. No Alaska waters were colder than normal.

Sea ice vanished from Bering Sea very early during the summer. By August there was no sea ice within 100 miles of the entire Alaska coast.

map of ocean temperatures

May–October 2019’s warm (red color) ocean surface temperatures compared to the 1971–2000 average. (Figure: Rick Thoman. Data: NOAA/PSD/ESRL)

Summer 2019 cold pool

The Bering Sea “cold pool” is a large mass of frigid water that forms near the ocean floor in areas with sea ice. Water temperatures in the cold pool are usually less than 36°F.

The cold pool is an important feature of the Bering Sea. It acts as a barrier between southern species, like pollock and cod, and Arctic waters where northern species flourish. In 2019, the cold pool was the second smallest ever recorded. Only 2018 was smaller. For the first time ever, the temperature at the seafloor in the southern Bering Sea was over 46°F.

map of ocean temperatures off alaska

Water temperatures at the ocean floor in summer 2010 (left), when the cold pool was intact, compared to 2019 (right). (Figure: NOAA National Marine Fisheries Service courtesy L. Britt.)

Winter air temperatures

Fall 2019 was very mild, and in most parts of the state it was warmer than usual. These graphs show examples of winter air temperatures in Bering Sea communities. At times, November and December temperatures were 20°F warmer than normal.

All of Alaska became colder by mid-December. Late January 2020 to early March was the coldest period. While cold compared to recent years, no records were set. Conditions since mid-March were generally milder throughout the Bering region.

Nome temperatures Oct 2019–May 2020

nome temperatures

Nome temperatures October 2019–May 2020. Red=warmer than normal. Blue=colder than normal.

Gambell temperatures Oct 2019–May 2020

gambell air temperatures

Gambell temperatures October 2019–May 2020. Red=warmer than normal. Blue=colder than normal.

Dillingham temperatures Oct 2019–May 2020

Dillingham air temperatures

Dillingham temperatures October 2019–May 2020. Red=warmer than normal. Blue=colder than normal.

Information source

Rick Thoman, UAF International Arctic Research Center, Alaska Center for Climate Assessment & Policy

Winter sea ice
Ocean acidification
Harmful algal blooms
Spectacled eiders
Marine mammals
Future research