Greenland Melting Trends

Changes in the climate around Greenland can have a world-wide effect. According to Dr. Konrad Steffen, professor of geography at the University of Colorado and director of the NOAA joint institute CIRES, "For every degree (F) increase in the mean annual temperature near Greenland, the rate of sea level rise increases by about 10 percent." As Greenland warms, the ice that covers it melts and flows into the oceans. In order to study melting trends on Greenland, researchers at NASA developed a "melt index" which is the number of days that melting occurred multiplied by the melting area. There is a steady increase in the melt index from 1988 through present. In fact, in 2006 Greenland experienced more days of melting snow and at higher altitudes than the average over the past 18 years that have been studied. See full story

Scientists are tracking these trends because it will help them understand how fast the ice is melting, the speed of glacier flow, how much melt water is entering the ocean, and how the Earth's energy budget is changing. Melting ice can have a large impact on the amount of radiation that is either absorbed or reflected back to space. Because ice and snow are white, they generally do a good job of reflecting sunlight and radiation back to space. However, there is a difference between dry snow and wet, melting snow. Dry snow reflects 85% of sunlight back to space, while wet snow and even refrozen snow only reflect 50-60% of sunlight back to space. This means that as the area of wet or refrozen snow increases, the amount of sunlight being absorbed is also increasing. The color scheme is this dataset represents the number of melting days. Blue is 10 melting days and red is 60 or more melting days. This visualization starts in 1989 and goes through 2006.