The following photos were sent by Dr. Jenny Hutchings.

Ice observed from helicopter at 78N, 150W.

This photograph was taken from helicopter at 76 56N 139 25W. The ice we saw here was similar to ice observed further west at the same latitude. Note the heavily watered appearance of the ice. It is close to the end of summer and the ice is in an advanced stage of melt.

As we travelled east, the ice conditions have changed dramatically. The ship had to navigate through old, thick ice. Luckily for travel, the ice only covered about 60% of the ocean, so we could pick our way through patches of open water between hugh ice floes. In some cases these floes were miles wide. This photo taken at 2000 feet altitude shows some of the old ice we encountered.

The Louis is now at 78N 140W. All the way along the 140W line from 76N we have experienced poor satellite communication. So I expect that this message will reach Fairbanks a few days late. This black out on email communication is not unusual at these northerly latitudes. Due to the path of the satellites, which circumnavigate the earth in an orbit that is offset from the pole, there is often less satellites with a view of our northern location, and hence often satellite blackouts. When we reach these locations, it truly feels we are at a remote point on the earth.

Alice and I have had a busy week. There have been 4 ice stations, where we were able to get off the ship onto a multi-year ice floe and take a variety of measurements. I am mostly interested in the ice thickness. We find that ice thickness observations taken from the ship (by observing the upturning blocks of ice broken of floes as the ice breaker rides over these floes) tend to underestimate the thickness of the thickest ice floes. This is for two reasons. First the ship’s navigator is skilled at choosing a path of least resistance (aka thinner ice) through the ice pack. Second, when blocks are broken of the largest floes they tend not to fully overturn. Making it really difficult to estimate their thickness. So it is vital that we are able to measure the thickness of the thickest ice floes directly. With the combination of ship based observations and direct measurements on the ice, we are painting a portrait of the Beaufort Sea pack ice conditions towards the end of summer 2007.

For other dispatches from the cruise, see: http://www.whoi.edu/beaufortgyre/dispatch2007/index2007.html

dispatch excerpt from Beaufort Gyre Exploration Project - 2007:

In many ways, the ice is very inconvenient for our work. Most people here are interested in the water properties. Of course the ice is what makes this ocean so different than the others, but it makes it very difficult to sample the water column. First you need a big ice breaker to get here (comfortable but very expensive), even then you can’t always go where you want, and there often is the stubborn ice floe drifting towards the wire when your instrument is 3000 meters down…

Click here to read the full dispatch and view photos!

Alice and I have now been on the Louis S. St. Laurent for 2 weeks. During this time we have traversed much of the southern Beaufort Sea, and right now we are steaming due north hoping to achieve 150W 80N. We are at 77.5N now, and well on our way. The ice has been thin and the Louis is making steady progress at 12 to 13 knots. It is very impressive to watch how the ship cuts through the ice like butter at these speeds!

Martin, thank you very much for your question regarding our goals on this cruise. You may know that I attended the same cruise last summer. Last year our primary objective was to deploy 6 buoys in a cluster that will monitor ice deformation. These were deployed around a cluster of other buoys to make up an Ice Based Observatory, which automatically monitors thermodynamic and dynamic changes in the ice pack, ocean currents and the top 300m of ocean water masses. Our part of this collaborative effort is funded by the National Science Foundation, to investigate the effect of sub-diurnal ice motion on the sea ice mass balance. We believe that inertial motion of the ice-ocean surface layer and tides might have a significant impact on the thickness of sea ice by increasing lead and ridging activity. Bill Hibler and Andrew Roberts have developed a model of this phenomena, and the buoy data will be used to validate this model. This year I am deploying another cluster of buoys.

In support of the buoy experiment Alice and I are making hourly ice observations during the cruise. This provides a great deal of information that can not be obtained directly from satellite data during the summer. For example, we are recording the type of ice we travel through, how dense the ice pack is and what the mean thickness of the ice is. Last year this information proved very useful to identify why ice conditions were so unusual in the Beaufort Sea during late summer. I am repeating ice observations this year, as with two years of observations, buoy and satellite data, we can track the motion of particular ice regions. We are interested in how ice moves around the Beaufort Gyre, and how ice is entrained from the Chukchi Sea and high Arctic north of the Canadian Archipelago. The origin of ice influences the thickness and age characteristics of the ice in the Beaufort Sea. We hypothesis that recent low ice conditions can partially be explained by a younger ice pack in the Southern Beaufort that is more susceptible to summer melt than older ice prevalent in the region twenty years ago. Hence the variability in ice drift patterns might explain some of the variability in summer time minimum ice extent in the Beaufort. We are also interested in how the changes in storm patterns of the Beaufort affect the ice mass balance. Our buoys provide information about localized divergence of the ice pack, which results in ice growth, and convergence, resulting in ridging. With several years of data we hope to determine what the interannual variability of this phenomena is and whether it has a significant impact on the sea ice mass balance. In summary, we are investigating how changes in weather and storminess of the Beaufort are impacting the sea ice cover.

~Jenny Hutchings

August 3, 2007

Jenny Hutchings reporting from the Canadian Coast Guard ice breaker Louis St. Laurent.

Alice Orlich and myself embarked the Louis last Friday from Kugluktuk in Nunevat. We did not get to see this small community on the northern coast of Canada, as we were quickly whisked to the ship by helicopter.

Since then we have had a hectic time setting up our ice observation equipment before the ship entered the ice. We are taking hourly ice observations, and have a couple of web-cams to monitor ice conditions. The first ice occurred late on Saturday. Ice conditions in the eastern Beaufort Sea are remarkably light this year, allowing easy access to the data poor region along the north-western coast of Banks Island. The oceanographers on board took full advantage of this opportunity. Which gave us the chance to assess the ice conditions in the region. It was fascinating to revisit a region of ice that we had previous observed in 2006. Last year, this patch of ice was closer to 78N, having drifted southward over the winter to around 75-74N. We found that this ice was predominantly second year. The large concentration of first year ice we observed last year having survived last summer, to become the hummucky ice we see now.

Life is slowly getting to a routine. Alice and I are working 12 hour shifts, and it always takes several days to get used to the shifts and to get all our equipment tuned. We have also been enjoying some unusually beautiful weather, with clear skies and clear blue ice.

Until later,
Jenny

ps: You can track the location of the Louis S. St. Laurent at
http://www.sailwx.info/shiptrack/researchships.phtml