Happy Birthday Keith! - Day 15

Keith Heger

May 27, 2011
Happy Birthday Keith! This morning the team enjoyed breakfast in the group shelter to celebrate the birthday boy! They opened gifts packed by Annie Aggens of PolarExplorers.


It was a clear and cold start to the day. The team faced katabatic wind from the north to northwest at 24 mph. The wind was basically over their shoulders for the entire day of skiing.


Again, to lessen the burden for any one team member, they swapped leads throughout their trek. They were privileged to witness the changing snow as the day began with firm and flat snow which transformed into soft windblown peaks before them as they skied. The team was mesmerized by waves of snow, a beautiful sight that very few are allowed the opportunity to witness. 


Breaking trail was difficult again today, the snow was deep! Winds were about 20 mph all day again from the northwest.


Tonight the team relaxed in their tents recovering from the days work. They successfully skied 27 km today. They're working hard out there!


Greenland Fact: Katabatic wind defintion: (from the Greek: katabaino - to go down) is the generic term for downslope winds flowing from high elevations of mountains, plateaus, and hills down their slopes to the valleys or planes below. Katabatic winds exist in many parts of the World and there are many different names for katabatic winds depending where they are located and how they are formed. 

Warm, dry katabatic winds occur on the lee side of a mountain range situated in the path of a depression. Examples for these descending,adiabatically warmed katabatic winds are the Foehn winds. 


Cold and usually dry katabatic winds, like the Bora, result from the downslope gravity flow of cold, dense air. Katabatic flows slumping down from uplands or mountains may be funneled and strengthened by the landscape and are then known as mountain gap wind such as the Santa Ana, mountain breeze or drainage wind. The gentler katabatic flows of hill slopes produce frost hollows. Mountain breezes are part of a local wind system. When the mountainside is heated by the Sun the mountain breeze will break down, reverse and blowing upslope. These winds are known as valley wind or anabatic wind.

However, katabatic winds might also reach gale force as an outblowing wind over ice-covered surfaces in Antarctica and Greenland, where the wind may be extremely strong and gusty near the coasts and less severe in mountain regions. 

Most katabatic winds (except the Foehn) are more or less the result of air in contact with upper level ground is cooled by radiation, increases in density, and flows downhill and along the valley bottom. For example radiation cooling during nighttime can cause a katabatic flow in the early morning when a pool of cold, high elevation air begins to descend beneath warmer, less dense air. This effect is enhanced during winter over snow covered surfaces and after dry, clear nights. These types of winds can reach velocities of up to 4 meters per second. The rush of cold air down the slopes rapidly decreases the surrounding air temperature as it speeds down the topography to the valleys and planes below it. Courtesy of http://www.weatheronline.co.uk.