Imagine being chilled to the very bone; where every step brings pain and discomfort; where there is no way of getting respite from a permanently aching back; where hauling a sledge twice your body weight is like dragging a car with the handbrake on; and where, despite trekking for over eight hours in the type of biting winds that feel like being relentlessly pecked at by invisible crows, you are getting nowhere. Literally nowhere. 

Caught on a polar treadmill that will happily drive you backwards if you stop your herculean efforts to…. Just. Keep. Going. 

Some 50-odd days into the expedition, and Ann, Charlie and Martin find themselves once again suffering from the powerful negative drift that persecuted them at the start of their mission. 

Aside from pressure ridges, open leads of water and large patches of thin ice, negative drift is one of the biggest factors affecting Arctic crossings. Psychologically, it is the most damaging of all. 

But why does the phenomenon occur? On a micro scale, movement of relatively small pans of ice will be affected by that day’s weather conditions. Masses of sea ice also move across large regions, in circulation patterns driven primarily through wind. These have two primary components; the Beaufort Gyre and the Transpolar Drift System. 

Looking from above the North Pole, the Beaufort Gyre is a clockwise circulation in the Beaufort Sea, north of Alaska. This circulation results from an average high-pressure system that spawns winds over the region. Sea ice that forms or becomes trapped in the Beaufort Gyre may circulate around the Arctic for several years.

In the Transpolar Drift Stream, ice moves from the Siberian coast of Russia across the Arctic basin, exiting into the North Atlantic off the east coast of Greenland. Sea ice that forms or becomes trapped in the Transpolar Drift Stream generally leaves the Arctic more quickly, usually in one to two years.

Both of these patterns tend to be large-scale and observable over a long period of time, but there can be a great deal of variation. Both are capable of completely reversing direction in the event of differing pressure conditions, which could cause the dramatic changes in the day-to-day movement our team have experiencing. 

To see just how much the team’s progress north has been affected, just look at the image below. Using a combination of Google Earth and the Solara tracking beacons the team are carrying, you can see how their route has taken a few unwanted detours.  Fingers crossed that the drift releases its grip again today so that at least their morale is not affected, even if their mileage has been.  

Listen to Ann's audioblog describing their latest drift and how the team have even seen waves in open leads, so strong are the winds they're experiencing. 

Explorer Team position at 12:30 BST on 06.05.10: 89.06.44 N / 73.12.25 W