Some lakes in Minnesota are taking their time to thaw this spring, setting new “ice-out” records.
Attributed to unusually cool spring temperatures, this satellite image shows lingering ice and white lake landscapes.
The first photo was captured on May 12, 2013, when NASA’s Terra satellite passed over northern Minn.
“Ice-out” is defined in this context as a lake being free of ice, but the definition often varies.
Some define it based on ease of navigation, while others believe a lake has “iced-out” when it’s 90 percent free of ice, according to a report from the Minnesota Department of Natural Resources.
Mille Lacs, the second largest lake in the state, iced out on May 16, breaking the previous record of May 15.
Osakis Lake was free of ice on May 13, a day shy of breaking a 144-year record. The last time ice remained on the lake past May 13 was in 1950.
To see what the lakes look like on a more typical year, consult the second image from May 2009.
This photo was taken from the International Space Station by Canadian astronaut Chris Hadfield, commander of Expedition 35. He posted several photos on May 5 to his Twitter account showing how the springtime water flows in the Great Lakes. Lakes Huron, Erie and Ontario are featured in the photo above.
The heavy flooding that struck Michigan this month is evident in these photos from NASA’s Earth Observatory. The photos, taken from NASA’s Terra satellite, show the Saginaw River on the east side of the state and the Grand River as it flows west from the center of the state toward Lake Michigan on April 5 and April 21. A comparison of the photos shows a much-widened Grand River and major flooding conditions on the Saginaw River near the city of Saginaw, according to the NASA report. The National Weather Service continues to place Saginaw under a flood warning, stating that the river is not expected to fall below flood levels until May 1.
The photos combine infrared and visual light imagery to increase the contrast between the water and land, highlighting the expansion of the rivers, according to NASA. The agency’s report also mentions the more vibrant green hue of vegetation in the April 21 photo, stating that it is a consequence of both the heavy rainfall enlivening plant life and the onset of spring in the state.
The flood currents are driving a plume of sediment into Lake Michigan at the mouth of the Grand River, according to an MLive report from April 23.
The Great Lakes appear through the clouds in this photo taken from the International Space Station by Canadian astronaut Chris Hadfield. He posted it recently on his Twitter account as part of a social media campaign to promote his team’s mission. Hadfield is the commander of Expedition 35, marking the first time a Canadian astronaut has been in command of the station, according to the Canadian Space Agency.
The Gulf of St. Lawrence, the outlet of the Great Lakes into the Atlantic Ocean, is building toward its annual peak accumulation of sea ice, according to a recent photograph captured from NASA’s Aqua satellite.
According to NASA, each year, the amount of frozen seawater, known as sea ice, in the Arctic Ocean builds from September through February or March as surface air temperatures drop below freezing. As it reaches the peak of its expansion, it begins to form in the Gulf of St. Lawrence.
Sea ice typically forms in layers, with younger layers being particularly thin. Many of these young sheets drift their points of origin, propelled by ocean winds and currents. In the photograph, examples of this wayward ice can be seen in the wispy sheets around Île d’Anticosti and in the seas north of Newfoundland. According to NASA, the ice surrounding Prince Edward Island appears thicker and is therefore more likely to have formed there as a result of cold north winds.
NASA satellites have monitored the growth and retreat of sea ice since 1978. Since observation began, NASA has seen a decline in sea ice, a decline which accelerated with the dawn of the new century.
The drought plaguing the country continues to sap the groundwater and soil water of the Great Lakes region, according to new NASA satellite data.
The two maps, constructed using data from NASA’s Gravity Recovery and Climate Experiment satellites, show low near-surface and subterranean water levels across the region between January 8 and 14, 2013. These satellites have been used to examine surface soil and ground water levels since they were launched in 2002.
While not as low as some areas of the southeast or west, much of the region remains below the 1948-2009 average. Average levels are denoted by white space on the maps, while above-average is blue and below-average appears red.
Recent winter storms, according to NASA, have alleviated low surface water in some areas of the nation, including southeast Michigan and Ohio, but done little to raise groundwater stores. Michigan’s Upper Peninsula, northern Wisconsin and Minnesota, and areas along the Indiana-Illinois border show particularly low groundwater levels.
NASA reports that the surface soil map illustrates present conditions, while the groundwater storage map reveals a glimpse of the long-term issue.
The map, known as the Great Lakes Surface Environmental Analysis, is a composite of data taken from NOAA satellites orbiting the earth’s poles and radar scans of the lakes by the National Ice Center. The resulting image shows surface water temperature and ice coverage, important data for region scientists, fishermen and boaters. The map’s data is updated daily.
“Previously, the lowest ice coverage year was 2002,” CoastWatch manager George Leshkevich said. “2012 came very close to 2002, and this year is looking very similar to last year.”
Lack of ice cover leads to increased water evaporation, a serious concern in light of already-low lake levels.
The map is used by people in many different fields, Leshkevich said. It began as a tool to help hydrodynamic modelers who needed daily temperature readings across the entire Great Lakes region. It has since been used by fishermen and charter boat captains in order to find warmer areas of the lakes where fish gather, as well as by ecologists studying temperature-sensitive species like the zebra mussel.
“It’s a fairly accurate product,” Leshkevich said. “We’ve validated it against data buoys in the lakes and against visual data we’ve been able to get on clear days, and it’s always been very close.”
According to Leshkevich, inaccuracies can result from cloud cover and solar warming of the lakes during the day. Many of these issues have been reduced by the introduction of more satellites into NOAA’s system. Originally only two satellites were positioned to retrieve data. Now there are four, with a fifth expected to begin transmitting data within the next week.