Degrees of Frost
When we last left the men of the Crozier party, they had just finished their first full day of sledging on the McMurdo Ice Shelf and they came to find it was a real drag. Temperatures hovered at or below -50°F (-45.6°C), creating a rough, sandy pulling surface for the men. A few of the men are already starting to suffer from frostbites, and sleep is hard to come by in the frigid tent at night. How were things on the morning of June 30th, 1911?
Position: Camp 3
Temperature: -54.5°F (-48.1°C)
Wind Direction/Speed: Calm
Sky Condition: Clear
Overnight Minimum Temperature: Not reportedBritish Antarctic Expedition 1910-1913, Meteorology, Vol. III Table 69
The party struck camp and started off to the east-northeast by late morning, using a sliver of daylight on the horizon to navigate. However, the men quickly ran into problems. The extreme cold and sandy snow surface prevented the men from pulling both sledges at once. As such, they were reduced to a grueling day of relay work, pulling one sledge forward and then returning to retrieve the other. In essence, the men had to cover 3 miles for every mile made good – talk about two steps forward and one step backward!
The cold only intensified as the day went on – Birdie Bowers recorded a temperature of -61.6°F (-52°) at lunch. Compounding the low temperature was the fact that the men were now entering an area known as the Windless Bight. This region along the southern fringe of Ross Island is known for it’s general lack of wind, owing to the complex terrain of the northwestern Ross Ice Shelf. The lack of wind allows loose snow crystals to gather in this area, and the deep, sandy snow is hell on sledge travelers. The manifold mesoscale and microscale wind patterns are outside the scope of this series, and probably deserve their own article in order to do them justice.
After lunch, the little natural light the men had earlier in the day had faded, and the men navigated by a combination of candlelight and celestial bodies, sparking one of my favorite quotes from the journey:
It was the weirdest kind of procession, three frozen men and a little pool of light. Generally, we steered by Jupiter, and I never see him now without recalling his friendship in those days.Apsley Cherry-Garrard, The Worst Journey in the World
It took the Crozier party 11 hours to cover just over 3 miles for the day, marching a total of 10 miles to do it. The men pitched camp in the late evening and took the last weather observation for the day:
Position: Camp 4
Miles Made Good: 3.25
Temperature: -65°F (-53.9°C)
Wind Direction/Speed: Calm
Sky Condition: ClearBritish Antarctic Expedition 1910-1913, Meteorology, Vol. III Table 69
I can only imagine the men had to feel nothing more than abject misery on this march. The temperature was -55°F (-48.1°C) at the start of the day, and only got colder, falling to -65°F (-53.9°C) by late evening. The lack of wind surely led to the decrease in temperatures, with outgoing longwave radiation continuing unimpeded under the light wind and clear skies. How do the 1911 conditions stack up against today’s obseration? Much colder….the most recent temperature reported by the Windless Bight automatic weather station is -23.8°C (-10.8°F). I also came across an interesting weather term that I love…degrees of frost. Essentially, a degree of frost is calculated by finding the difference between the freezing point, 32°F (0°C) and the observed temperature. At -65°F, the Crozier party experienced 97 degrees of frost!
Will the men of the Crozier party get a respite from the intense cold? Check in tomorrow to find out!