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AN EXCEPTIONAL SUMMER DURING THE SOUTH POLE RACE OF 1911/12 RYAN L. FOGT, MEGAN E. JONES, SUSAN SOLOMON, JULIE M. JONES, AND CHAD A. GOERGENS The race for the South Pole during the summer of 1911/12 was marked by exceptionally high temperature and pressure anomalies experienced by both Amundsen and Scott. he Norwegian and British Antarctic expedi- and his four companions, who primarily man-hauled tions to the South Pole are often regarded as their sledges and supplies, unfortunately perished on T the height of the heroic age of Antarctic explora- their return journey to their main base of Cape Evans tion. Using a team of five men and primarily relying on Ross Island. Figure 1 shows the routes of each polar on dog sledges, Roald Amundsen first reached the expedition, as well as the location of their main bases. geographic South Pole on 14 December 1911. Just The stories of these heroic journeys have been over a month later, a team of five men led by Captain documented in several books but are also recorded Robert Falcon Scott reached the South Pole on 17 in journals kept by many of the members of both January 1912, only to find a tent left by Amundsen. polar parties. Both teams kept meteorological logs While Amundsen and the remaining crew at the main of the weather conditions at their main bases and at Norwegian base at Framheim were able to safely leave least daily measurements made by various sledging the Antarctic continent in late February 1912, Scott parties, containing primarily pressure and tempera- ture data. In particular, the extensive analysis of the observations by British meteorologist George Simpson AFFILIATIONS: FOGT, M. E. JONES, AND GOERGENS—Department provides substantial insight into the conditions faced of Geography, and Scalia Laboratory for Atmospheric Analysis, by the teams. Using these data in comparison with Ohio University, Athens, Ohio; SOLOMON—Department of Earth, contemporary automatic weather station (AWS) Atmospheric, and Planetary Science, Massachusetts Institute of data on the Ross Ice Shelf (called the “Barrier” by Technology, Cambridge, Massachusetts; J. M. JONES—Department both polar parties), Solomon and Stearns (1999) and of Geography, University of Sheffield, Sheffield, United Kingdom Solomon (2001) concluded that the weather in March CORRESPONDING AUTHOR: Ryan L. Fogt, [email protected] 1912, when Scott and his two remaining companions The abstract for this article can be found in this issue, following the perished, was much colder and persistent than aver- table of contents. age and was a primary cause of their tragic end. Here DOI:10.1175/BAMS-D-17-0013.1 it is demonstrated that the atmospheric pressure and A supplement to this article is available online (10.1175/BAMS-D-17-0013.2) associated temperature conditions throughout much In final form 16 March 2017 of early December 1911 and late February and March ©2017 American Meteorological Society 1912 were also exceptional across the location of the For information regarding reuse of this content and general copyright information, consult the AMS Copyright Policy. South Pole race and likely across much of Antarctica. In the context of the colder-than-average conditions AMERICAN METEOROLOGICAL SOCIETY OCTOBER 2017 | 2189 Unauthenticated | Downloaded 10/11/21 01:45 AM UTC FIG. 1. Map showing the routes of Scott and Amundsen, along with key locations. The return journey for Scott is depicted only for when meteorological observations were collected up until 10 Mar 1912. in March 1912 experienced by Scott and his polar third book provides numerical tables of observations party, this places an even more dramatic change in at Cape Evans and all the field party observations. For the weather coming down from the south polar pla- the field party observations, latitude and longitude teau to the Ross Ice Shelf and therefore might have are given when they were determined by theodolite or also caused these cold spells to be perceived as more sextant. Observations at Cape Evans were generally intense by comparison. It is not our intent to contrast taken every hour, while up to three data points per day the leadership styles or other factors that led to the were typically taken by the field parties (often morn- vastly different outcomes between the Norwegian and ing, lunchtime, and evening). Rather than focusing British Antarctic South Pole expeditions as done by on daily minimum temperatures as done in Solomon Huntford (1985), but to demonstrate that the pres- and Stearns (1999), this study uses daily means for sure and temperature conditions during the journey both temperature and pressure, averaging all avail- to the pole in December for both polar parties and able well-exposed sling thermometer observations back in February and March for Scott were unique for each day that they were recorded. Exposure to the in many aspects. free airstream is critical for accurate measurements of atmospheric temperature, and both expeditions used DATA AND METHODS. The primary source sling thermometers that were twirled to ensure this of data for the British Antarctic expedition comes (Simpson 1919, 17–18; Mohn 1915, 49–50). Minimum from atmospheric temperature and pressure data thermometer data recorded underneath the sledges analyzed by Simpson, who first published the records reported by the Scott expedition are not used because and other aspects of the Antarctic meteorology in a they can display a cold bias as a result of pooling of cold three-volume set in 1919 (Simpson 1919, 1923). The air beneath the sledges, impeding the airflow needed 2190 | OCTOBER 2017 Unauthenticated | Downloaded 10/11/21 01:45 AM UTC for accurate temperature measurements (Simpson the early twentieth century. While pressures can be 1919, p. 19). Similar results for the sling thermometer considered fairly uniform, local temperatures are data along the sledging journeys are obtained using well known to be highly variable around Ross Island daily maximum and minimum temperatures or by and on parts of the Ross Ice Shelf, owing to, for ex- averaging the measured maximum and minimum ample, katabatic and foehn winds and variations in temperatures rather than all available observations sea ice cover (e.g., Bromwich 1989; Spiers et al. 2012; (Fig. ES1 of the online supplement; see http://dx.doi Costanza et al. 2016). .org/10.1175/BAMS-D-17-0013.2 for more informa- To estimate the long-term climatological context tion), despite some of the differences discussed be- of the meteorological conditions along the sledge tween these values in Simpson (1919). In addition to the journeys for both Amundsen and Scott, daily mean meteorological observations from the main polar party temperature and pressure from the European Centre led by Scott, we also make use of data from shorter- for Medium-Range Weather Forecasts (ECMWF) duration sledging parties in support of the main British interim reanalysis (ERA-Interim) are used. This re- polar party (such as the Dog Sledge party, the Motor analysis is available at 0.75° × 0.75° latitude–longitude Sledge party, and the First Relief party), available in resolution and compares well to surface observations Simpson (1923). of Antarctic climate (Bracegirdle and Marshall 2012). For the Norwegian expedition, meteorological The climatological aspects of near-surface temperature observations were published in 1915 that similarly on the Ross Ice Shelf and surrounding polar plateau include observations at their main base of Framheim in ERA-Interim (Fig. ES2) agree well with tempera- and observations during the dog sledging journey ture maps from interpolated AWS data discussed in to the South Pole and back (Mohn 1915). For the Costanza et al. (2016), including the relatively colder Framheim observations, the three-times-daily pres- temperatures extending westward from Roosevelt sure and temperature observations from April 1911 Island toward the Transantarctic Mountains and the to January 1912 are used. On the main polar journey, relatively warmer air on the Ross Ice Shelf near many there are often three observations per day from 19 of the major glacial valleys in the Transantarctic October 1911 through 26 January 1912; daily mean Mountains. However, in places of steep terrain, es- temperature and pressure are used, averaging over all pecially within the Transantarctic Mountains when available observations each day. the journeys ascended glaciers (the Axel Heiberg for To place the observations in a climatological con- Amundsen and the Beardmore for Scott; Fig. 1) to text, pressure and temperature measurements at Mc- reach the polar plateau, there are differences in the Murdo—the main U.S. Antarctic base situated on the surface elevation between ERA-Interim and the real southern tip of Ross Island in very close proximity to world reflected in the observations collected on both the British base of Cape Evans (Fig. 1)—are employed, sledge journeys. To account for this, the model eleva- although sea ice conditions at the two stations often tions in ERA-Interim (determined from the invariant differ, which can affect climate. Hourly observa- variable geopotential; Fig. ES3) were corrected to a best tions from 1957 to 2016 are analyzed, obtained from estimate taken along each sledging journey track in the British Antarctic Survey. During the summer, Fig. 1 from Google Earth. For temperature, a standard pressures at McMurdo are similar to those across atmospheric environmental lapse rate of 6.5°C km–1 the Ross Ice Shelf/Barrier (Costanza et al. 2016), and was used to adjust ERA-Interim temperatures to this single point with the longest continuous record the actual elevation; despite large differences in the therefore provides an estimate of pressure across the ERA-Interim elevations within the Transantarctic entire Ross Ice Shelf, as will be demonstrated later. Mountains, the corrected temperature climatology Further, the seasonal pressure reconstructions at from ERA-Interim agrees well with observations by McMurdo presented in Fogt et al.