Intro

Numerous surface-based and satellite observations of polar sea ice offer substantial evidence of a recent reduction in the areal extent and thickness of the Arctic ice cover. Indeed the Arctic sea ice cover is viewed as a "canary in a coal mine," an indicator of global climate change. In an effort to analyze and quantify this change within the context of both an Arctic and a global climate system, the Healy-Oden Trans-Arctic Expedition 2005 (HOTRAX 2005) conducted a pan-Arctic survey of the stratigraphical, paleoclimatic, geological, and physical properties of the polar ice pack.The USCGC Healy and the Swedish icebreaker Oden departed from Dutch Harbor, Alaska on 5 August 2005, crossed the North Pole on 12 September 2005, and arrived in Tromsø, Norway on 30 September 2005. The icebreakers' 8200 km trans-Arctic course is denoted by the blue line. Ice stations are indicated by blue dots. The white area represents the total ice cover on 22 September 2005.

In light of the changing condition of the ice pack, a thorough understanding of the interrelationships between the ice cover and sunlight are of great significance. The Cold Regions Research and Engineering Laboratory (CRREL) of the U. S. Army Corps worked in conjunction with the University of Washington under the HOTRAX 2005 program to obtain a trans-Arctic dataset describing large-scale spatial variability of the morphological and optical properties of the summer ice pack. The field team consisted of Don Perovich, Tom Grenfell, Bruce Elder, and Jeremy Harbeck. Bonnie Light is leading the laboratory studies effort. Research consisted of four broad classes of snow and ice activities: measurements made at ice stations; ice and radiation observations made while the ship was in transit; helicopter photography flights; and the deployment of autonomous ice mass balance buoys (IMB).

Snow depth, ice thickness, and light transmission were measured at each of 30 ice stations along the cruise track, where ice cores and soot were also sampled. In-transit measurements included incident solar irradiance, spectral reflectance, surface temperature, and an ice watch, which described the ice cover at two-hour intervals. Aerial photographs were taken over the course of 11 helicopter flights. Autonomous IMB buoys were deployed at 3 locations.

Introduction


Numerous surface-based and satellite observations of polar sea ice offer substantial evidence of a recent reduction in the areal extent and thickness of the Arctic ice cover. Indeed the Arctic sea ice cover is viewed as a "canary in a coal mine," an indicator of global climate change. In an effort to analyze and quantify this change within the context of both an Arctic and a global climate system, the Healy-Oden Trans-Arctic Expedition 2005 (HOTRAX 2005) conducted a pan-Arctic survey of the stratigraphical, paleoclimatic, geological, and physical properties of the polar ice pack.The USCGC Healy and the Swedish icebreaker Oden departed from Dutch Harbor, Alaska on 5 August 2005, crossed the North Pole on 12 September 2005, and arrived in Tromsø, Norway on 30 September 2005. The icebreakers' 8200 km trans-Arctic course is denoted by the blue line. Ice stations are indicated by blue dots. The white area represents the total ice cover on 22 September 2005. In light of the changing condition of the ice pack, a thorough understanding of the interrelationships between the ice cover and sunlight are of great significance. The Cold Regions Research and Engineering Laboratory (CRREL) of the U. S. Army Corps worked in conjunction with the University of Washington under the HOTRAX 2005 program to obtain a trans-Arctic dataset describing large-scale spatial variability of the morphological and optical properties of the summer ice pack. The field team consisted of Don Perovich, Tom Grenfell, Bruce Elder, and Jeremy Harbeck. Bonnie Light is leading the laboratory studies effort. Research consisted of four broad classes of snow and ice activities: measurements made at ice stations; ice and radiation observations made while the ship was in transit; helicopter photography flights; and the deployment of autonomous ice mass balance buoys (IMB). Snow depth, ice thickness, and light transmission were measured at each of 30 ice stations along the cruise track, where ice cores and soot were also sampled. In-transit measurements included incident solar irradiance, spectral reflectance, surface temperature, and an ice watch, which described the ice cover at two-hour intervals. Aerial photographs were taken over the course of 11 helicopter flights. Autonomous IMB buoys were deployed at 3 locations.