Steve Zip's Climate Blog: Greenland Climate and Geological History

Greenland: Ice Sheet

http://www.dmi.dk/en/klima/klimaet-frem-til-i-dag/groenland/

Greenland is in Northern North America, and lies between the Arctic Ocean and the North Atlantic Ocean, northeast of Canada. At a little more than 3 times the size of Texas, Greenland is the world’s largest island of which about 81% is ice covered. Greenland consists of 2,166,086 sq km, and of this 1,755,637 sq km is ice-covered, while 410,449 sq km are free of ice. The coastline of Greenland is 44,087 km. The northern two thirds of Greenland are covered in permafrost.

Climate in Greenland

The climate of Greenland is considered to be Artic to sub-Arctic with very cold winters and cool summers. The mean temperature in June, July and August is 50 degrees F, however in the southern part of the country and the innermost parts of the long fjords, the temperature can rise to more than 20° C (68° F) in June, July or August. The remainder of the year is below freezing throughout the country. In the northern regions, average temperatures during February are -4 degrees F. Due to the size of the country and the fact that it is the world’s largest island there are wide ranges of temperature in Greenland. Due to low humidity and the country’s geographical position in the high north, the air quality and visibility in Greenland are excellent. Heavy rain in Greenland is infrequent with heavier rainfall in the south of the country (35 inches in the south and 8 inches in the north), the average annual rainfall across the country is 3.62 inches. Also common in Greenland are föhn winds, föhn winds are a type of dry, warm, down-slope wind that occurs on the downwind side of a mountain range. Snow during most of the winter months is common with and average snowfall across the country of 18 inches.

Here is a link to a brief You Tube video that shows Greenland in winter and adiabatic winds.

Following are some graphs of climate in Greenland obtained from http://en.climate-data.org/location/128775/

The driest month is January. There is 58 mm of precipitation in January. Most precipitation falls in May, with an average of 140 mm
http://en.climate-data.org/location/128775/

Temperature graph - July is the warmest month (average 25.7 °C) and January the coldest (average 1.7 °C)
http://en.climate-data.org/location/128775/

Climate table // Historical Weather data
http://en.climate-data.org/location/128775/

Winter in Greenland - photos by John Cappelen
https://www.dmi.dk/en/klima/klimaet-frem-til-i-dag/groenland/

Greenland: Billions of Years Ago

artist's illustration: meteor striking Greenland 3 billion years ago
http://www.sci-news.com/geology/article00439.html

Millions of years before the Pleistocene epoch, a team of northern scientists believe a meteor struck the earth over 3 billion years ago creating, what they believe is, the oldest known crater on Earth. Although awaiting final study and confirmation, the team of scientists from Wales, Denmark, Sweden and Russia theorized that the meteor formed the 62 mile wide crater near the Maniitsoq region of West Greenland leaving evidence over 15 miles deep in the earth’s crust. Three years of thorough study preceded the scientists’ announcement in 2012. According to one of the paper’s authors, Dr. Iain McDonald of the Cardiff University’s School of Earth and Ocean Sciences, they studied the erosion that had occurred over the past 3 billion years. Dr. McDonald noted that finding the evidence of a huge, impactful shock wave which they believe proves there was an impact and crater “was rather like a Sherlock Holmes story.”

There are no agricultural lands on Greenland, however natural resources include coal, iron ore, lead, zinc, molybdenum, diamonds, gold, platinum, niobium, tantalite, uranium, fish, seals, whales, hydropower, and possible oil and gas. Interestingly, the idea that a meteorite may have struck Greenland encouraged a Canadian exploration company to invest time and money into searching for nickel and platinum deposits in this region.

During the Pleistocene epoch, ice sheets expanded out of Greenland carving out chasms and ruts in the land, and leaving behind deposits of material to create much of the landscape in other countries that we see today. Incidentally, remains of these ice sheets, glaciers, or icebergs can be seen today in Greenland. The ice sheets and earth heated up due to change in seasons, the position of the sun, as well as the resulting increased light reflection (albedo) from the ice sheets themselves. The movement of the ice sheets created and diverted rivers and lakes, raised the sea level significantly, and caused the earth’s crust to rise and fall as a result of the ice sheets moving onto, through and off areas of land. In fact, Greenland’s center is depressed below sea level as a result of the weight of the ice sheets.

Mastadons as they may have existed in Greenland

While there is no evidence that mammoths or mastodons existed on Greenland, it is possible that they did live there. The Pleistocene epoch saw the elimination these and many other species of mammals and animals, although the ice sheets and their movements may not have been the cause of the extinction; some believe a massive meteorite was the cause of this extinction on earth and other theories point to human hunting or disease.

Today scientists find the history frozen in Greenland’s ice sheets one of the most valuable records of past climates in the world, more valuable that reading tree rings or layers of sediment. It is reported that the ice cores have provided information about the earth’s:

· temperature variations

· volume of the ocean

· existence of deserts

· rain, snow and sleet volume

· atmospheric composition

· volcanic and solar eruptions

· sun variability

· forest fires