Photograph of Ira Flatow speaking at AGU

Ira Flatow, host of National Public Radio’s Talk of the Nation: Science Friday, spoke at the AGU Presidential Forum, reminding us why we need to communicate science clearly and effectively. Credit: Laura Naranjo

If NSIDC scientists are busy all year long conducting their own research, how do they keep up with what their colleagues elsewhere are doing? They exchange flurries of emails and phone calls, of course, and collaborate on journal articles and projects. But once a year, many of them are in the same place at the same time for the same reason: to attend the fall meeting of the American Geophysical Union (AGU). Whether you’re interested in glaciers or geoids, sea ice or plate tectonics, Earth or Mars, AGU is right up your alley. Each year, more than 20,000 scientists, students, and educators converge in San Francisco for the weeklong meeting. Many of NSIDC’s staff participate in the meeting as well, presenting talks and posters detailing their latest research, data, and success stories. Continue reading

Is Arctic sea ice back to normal?

Arctic sea ice was at record highs in the Bering Sea this spring, and near the long-term average for the Arctic as a whole. But much of that ice was spread thinly across the ocean, and is now melting quickly. This image, from the NASA Moderate Resolution Imaging Spectroradiometer (MODIS), shows sea ice in Bristol Bay off of Alaska, on April 24, 2012. |Credit: {a href=http://earthobservatory.nasa.gov/IOTD/view.php?id=77832}NASA Earth Observatory{/a} image by Jesse Allen|{a href=http://nsidc.org/icelights/files/2012/05/bristolbay_amo_2012115_lrg.png}High Resolution Image{/a}

In April, average ice extent in the Arctic Ocean was right near the long-term average for the month. Ice extent even reached a near-record high in the Bering Sea, and still remains above average for that region. Does this mean that the Arctic sea ice has stopped declining? Is it starting to recover?

Unfortunately, scientists say no—and they are not surprised to see such a short upward bump in ice extent. “This does not indicate that the Arctic sea ice is recovering,” said Marika Holland, a sea ice expert at the National Center for Atmospheric Research (NCAR). Instead, the higher ice extent this year compared to recent years likely just reflects different weather this winter compared to last winter.  “Sea ice exhibits large natural variability due to year-to-year variations in weather,” she said. Continue reading

What is causing Arctic sea ice decline?

The Arctic Ocean has lost more than 30 percent of its summer ice cover in the last thirty years. Scientists have long thought that climate change is to blame, but a new study provides more evidence for that idea. Credit: Patrick Kelley, U.S. Coast Guard. High Resolution Image

Readers sometimes ask us, “What are the reasons behind Arctic sea ice decline?” In summer months, ice extent has declined by more than 30 percent since the start of satellite observations in 1979. But is climate change really the culprit, or could other factors be contributing? Continue reading

Are icebreakers changing the climate?

On July 20, 2011, the U.S. Coast Guard Cutter Healy traveled through a break in the sea ice and melt ponds in the Arctic Ocean, during the NASA Impacts of Climate on Ecosystems and Chemistry of the Arctic Pacific Environment (ICESCAPE) mission, a field survey aimed at understanding the ecology of the Arctic Ocean. Credit: NASA/Kathryn Hansen

In summer months, icebreaking ships head north into the Arctic Ocean, tearing through the sea ice and leaving trails of open water in their wakes. Readers occasionally write in to ask us whether the trails left by these ships contribute to the melting of sea ice. Continue reading

Modeling the Arctic climate

In February, polar climate researchers gathered at the National Center for Atmospheric Research in Boulder, Colorado to discuss the newest updates to models of the Earth’s climate system. The researchers are working together to create better models of the Arctic and Antarctic climates, which will feed into larger models of the whole Earth that help scientists understand how climate will change in the future. What goes into a climate model, and what can scientists learn from models that they cannot learn from observations?

This image shows several aspects of climate, including sea ice, surface winds, and sea surface temperature. This image came from data simulated from NCAR’s Community Earth System Model. Credit: ©UCAR, image courtesy Gary Strand, NCAR

What’s in a model?
Computer climate models are based on scientists’ understanding of Earth’s climate. The models use mathematical relationships to try to quantify the relationships between parts of the climate system. If you tweak one factor in climate, how does the simulated climate system respond? Models that bring many factors together help scientists learn how the climate system works, and let them run simulations on Earth’s climate. They also allow scientists to assess how climate may be affected by present and future changes in greenhouse gases and solar forcing, and how much of a role natural variability plays. Continue reading