In just four days this summer, miles of snow melted from
Lowell Glacier in Canada. Mauri Pelto, a glaciologist at Nichols College,
called the area of water-saturated snow a “snow swamp.”
These false-color images
show the rapid snow melt in Kluane National Park in the Yukon Territory. The
first image was taken on July 22, 2018, by the European Space Agency’s Sentinel-2;
the next image was acquired on July 26, 2018, by the Landsat 8 satellite.
Ice is shown as light blue, while meltwater is dark blue. On
July 26, the slush covered more than 25 square miles (40 square km).
During those four days, daily temperatures 40 miles (60 km)
northeast of the glacier reached 84 degrees Fahrenheit (29 degrees Celsius) —
much higher than normal for the region in July.
In 1910, glaciers covered at least 4 square miles (10 square
km) of the mountainous region of northwestern Venezuela. Today, less than one
percent of that ice remains, and all of it is locked up in one glacier. The
ongoing retreat of Humboldt Glacier—Venezuela’s last patch of perennial
ice—means that the country could soon be glacier-free.
The glacier is in the highest part of the Andes Mountains,
on a slope at nearly 16,000 feet. A cold
and snowy climate at high elevations is key for glaciers to exist in the
tropics. Most of Earth’s tropical glaciers are found in the Andes, which runs
through Venezuela, Colombia, Ecuador, Peru and Bolivia. But warming air temperatures
have contributed to their decline, including Humboldt Glacier.
The relatively recent changes to Humboldt are evident in
these images, acquired on Jan. 20, 1988, by the
United States Geological Survey’s Landsat 5 and on Jan. 6, 2015,
by Landsat 8. The images are false-color to better differentiate between areas
of snow and ice (blue), land (brown) and vegetation (green).
Scientists are trying to understand how long Humboldt will remain.
One said: “Let’s call it no more than 10 to 20 years.”
This year, we will launch two satellite missions that will increase our understanding of Earth’s frozen reaches. Snow, ice sheets, glaciers, sea ice and permafrost, known as the cryosphere, act as Earth’s thermostat and deep freeze, regulating temperatures by reflecting heat from the Sun and storing most of our fresh water.
2. GRACE-FO: Building on a Legacy and Forging Ahead
The next Earth science satellites set to launch are twins! The identical satellites of the GRACE Follow-On mission will build on the legacy of their predecessor GRACE by also tracking the ever-changing movement of water around our planet, including Earth’s frozen regions. GRACE-FO, a partnership between us and the German Research Center for Geosciences (GFZ), will provide critical information about how the Greenland and Antarctic ice sheets are changing. GRACE-FO, working together, will measure the distance between the two satellites to within 1 micron (much less than the width of a human hair) to determine the mass below.
Greenland has been losing about 280 gigatons of ice per year on average, and Antarctica has lost almost 120 gigatons a year with indications that both melt rates are increasing. A single gigaton of water would fill about 400,000 Olympic-sized swimming pools; each gigaton represents a billion tons of water.
3. ICESat-2: 10,000 Laser Pulses a Second
In September, we will launch ICESat-2, which uses a laser instrument to precisely measure the changing elevation of ice around the world, allowing scientists to see whether ice sheets and glaciers are accumulating snow and ice or getting thinner over time. ICESat-2 will also make critical measurements of the thickness of sea ice from space. Its laser instrument sends 10,000 pulses per second to the surface and will measure the photons’ return trip to satellite. The trip from ICESat-2 to Earth and back takes about 3.3 milliseconds.
4. Seeing Less Sea Ice
Summertime sea ice in the Arctic Ocean now routinely covers about 40% less area than it did in the late 1970s, when continuous satellite observations began. This kind of significant change could increase the rate of warming already in progress and affect global weather patterns.
5. The Snow We Drink
In the western United States, 1 in 6 people rely on snowpack for water. Our field campaigns such as the Airborne Snow Observatory and SnowEx seek to better understand how much water is held in Earth’s snow cover, and how we could ultimately measure this comprehensively from space.
6. Hidden in the Ground
Permafrost – permanently frozen ground in the Arctic that contains stores of heat-trapping gases such as methane and carbon dioxide – is thawing at faster rates than previously observed. Recent studies suggest that within three to four decades, this thawing could be releasing enough greenhouse gases to make Arctic permafrost a net source of carbon dioxide rather than a sink. Through airborne and field research on missions such as CARVE and ABoVE – the latter of which will put scientists back in the field in Alaska and Canada this summer – our scientists are trying to improve measurements of this trend in order to better predict global impact.
7. Breaking Records Over Cracking Ice
Last year was a record-breaking one for Operation IceBridge, our aerial survey of polar ice. For the first time in its nine-year history, the mission carried out seven field campaigns in the Arctic and Antarctic in a single year. In total, the IceBridge scientists and instruments flew over 214,000 miles, the equivalent of orbiting the Earth 8.6 times at the equator.
On March 22, we completed the first IceBridge flight of its spring Arctic campaign with a survey of sea ice north of Greenland. This year marks the 10th Arctic spring campaign for IceBridge. The flights continue until April 27 extending the mission’s decade-long mapping of the fastest-changing areas of the Greenland Ice Sheet and measuring sea ice thickness across the western Arctic basin.
Researchers were back in the field this month in Greenland with our Oceans Melting Greenland survey. The airborne and ship-based mission studies the ocean’s role in melting Greenland’s ice. Researchers examine temperatures, salinity and other properties of North Atlantic waters along the more than 27,000 miles (44,000 km) of jagged coastline.
9. DIY Glacier Modeling
Computer models are critical tools for understanding the future of a changing planet, including melting ice and rising seas. Our new sea level simulator lets you bury Alaska’s Columbia glacier in snow, and, year by year, watch how it responds. Or you can melt the Greenland and Antarctic ice sheets and trace rising seas as they inundate the Florida coast.
10. Ice Beyond Earth
Ice is common in our solar system. From ice packed into comets that cruise the solar system to polar ice caps on Mars to Europa and Enceladus-the icy ocean moons of Jupiter and Saturn-water ice is a crucial ingredient in the search for life was we know it beyond Earth.
Read the full version of this week’s 10 Things to Know HERE.
This Winter Olympics, our researchers are hoping for what a lot of Olympic athletes want in PyeongChang: precipitation and perfection.
Our researchers are measuring the quantity and type of snow falling on the slopes, tracks and halfpipes at the 2018 PyeongChang Winter Olympics and Paralympic games.
We are using ground instruments, satellite data and weather models to deliver detailed reports of current snow conditions and are testing experimental forecast models at 16 different points near Olympic event venues (shown below). The information is relayed every six hours to Olympic officials to help them account for approaching weather.
We are performing this research in collaboration with the Korea Meteorological Administration, as one of 20 agencies from about a dozen countries and the World Meteorological Organization’s World Weather Research Programme in a project called the International Collaborative Experiments for PyeongChang 2018 Olympic and Paralympic Winter Games, or ICE-POP. The international team will make measurements from the start of the Olympics on Feb. 9 through the end of the Paralympics on March 18.
Image Credit: Republic of Korea
South Korea’s diverse terrain makes this project an exciting, albeit challenging, endeavor for scientists to study snow events. Ground instruments provide accurate snow observations in easily accessible surfaces, but not on uneven and in hard to reach mountainous terrain. A satellite in space has the ideal vantage point, but space measurements are difficult because snow varies in size, shape and water content. Those variables mean the snowflakes won’t fall at the same speed, making it hard to estimate the rates of snowfall. Snowflakes also have angles and planar “surfaces” that make it difficult for satellite radars to read.
The solution is to gather data from space and the ground and compare the measurements. We will track snowstorms and precipitation rates from space using the Global Precipitation Measurement mission, or GPM. The GPM Core Observatory is a joint mission between NASA and the Japan Aerospace Exploration Agency and coordinates with twelve other U.S. and international satellites to provide global maps of precipitation every 30 minutes (shown below).
We will complement the space data with 11 of our instruments observing weather from the ground in PyeongChang. These instruments are contributing to a larger international pool of measurements taken by instruments from the other ICE-POP participants: a total of 70 instruments deployed at the Olympics. We deployed the Dual-frequency, Dual-polarized, Doppler Radar system, usually housed at our Wallops Flight Facility in Virginia, to PyeongChang (shown below) that measures the quantity and types of falling snow.
The data will help inform Olympic officials about the current weather conditions, and will also be incorporated into the second leg of our research: improving weather forecast models. Our Marshall Space Flight Center’s Short-term Prediction Research and Transition Center (SPoRT) is teaming up with our Goddard Space Flight Center to use an advanced weather prediction model to provide weather forecasts in six-hour intervals over specific points on the Olympic grounds.
The above animation is our Unified Weather Research Forecast model (NU-WRF) based at Goddard. The model output shows a snow event on Jan. 14, 2018 in South Korea. The left animation labeled “precipitation type” shows where rain, snow, ice, and freezing rain are predicted to occur at each forecast time. The right labeled “surface visibility” is a measure of the distance that people can see ahead of them.
The SPoRT team will be providing four forecasts per day to the Korea Meteorological Administration, who will look at this model in conjunction with all the real-time forecast models in the ICE-POP campaign before relaying information to Olympic officials. The NU-WRF is one of five real-time forecast models running in the ICE-POP campaign.
For more information, watch the video below or read the entire story HERE.
They’ve packed extreme cold-weather gear and scientific instruments onto sleds pulled by two tank-like snow machines called PistenBullys, and after a stop at the South Pole Station (seen in this image), they began a two- to three-week traverse.
This traverse provides an extremely challenging way to assess the accuracy of the data. ICESat-2’s datasets are going to tell us incredible things about how Earth’s ice is changing, and what that means for things like sea level rise.