The USCGC (Coast Guard Cutter) Bear moored to sea ice in 1918. The Bear was initially purchased by the Navy for the Greely Relief Expedition in 1884 (Schley 1887) and subsequently served with the Revenue Cutter Service/Coast Guard in Alaska until 1928, then on Admiral Byrd’s expeditions to Antarctica from 1933 to 1940, and finally with the Navy on the Greenland Patrol during World War II. It was decommissioned for the last time in 1944. (The photograph was provided by the Coast Guard Museum Northwest in Seattle, Washington.)
The meteorological station network developed by the U.S. Army Signal Service and the Weather Bureau in Alaska, 1867–1921. The IPY stations at Fort Conger, on Ellesmere Island, and at Fort Chimo (Kuujjuaq, Nunavit) are also included. The IPY period is marked by gray lines. The collapse of the Signal Service network in 1887 is apparent.
Ferrel’s map in Meteorological Researches for the Use of the Coast Pilot (Ferrel 1875) “showing by isobaric lines the mean pressure of the atmosphere for January in millimeters, reduced to the gravity of the parallel of 45°, and by arrows the prevailing directions of the wind, for the Northern Hemisphere.” Although the center of action in the Pacific (Aleutian low) is placed too far north, as his colleague Dall noted, the resemblance to modern maps is unmistakable (see, e.g., Hurrell et al. 2003, their Figs. 1 and 2).
(top) Dall’s (1879) regional map of barometric pressure in January showing a split Aleutian low (referred to by Dall as the Kadiak area in general, with the Kamchatka area appearing in the case of split development). Dall recognized that the lack of data from the western Aleutians left this question ambiguous, but today it is seen to be the correct interpretation (e.g., Rodionov et al. 2005). (bottom) Dall’s (1879) map of summer sea surface isotherms and main ocean currents. The average extent of sea ice in summer is also shown and is generally consistent with what is known about ice distribution in the early satellite era and before (e.g., Danske Meteorologiske Institut 1900–1939, 1946–1956; U.S. Hydrographic Office 1946).
(top) Map of the Bering Strait region showing surface isotherms and sea ice observed by the U.S. Coast Survey schooner Yukon in August/September 1880, and (bottom) the hydrographic section obtained on 5 September 1880 (Dall 1882).
Officers of the USRC Thetis on the Arctic cruise of 1903 (the photograph was provided by the Coast Guard Museum Northwest).
Time series of annual (October–September) air temperature anomaly averaged over 60°–90°N (blue curve) and the globe (red curve). Anomalies are relative to corresponding means for 1980–2010. Both the Arctic and the global time series are based on surface air temperature measurements from land stations archived in the CRUTEM4 dataset (https://crudata.uea.ac.uk/cru/data/temperature/). [Source: after Fig. 1 from Overland et al. (2017); see also
The network of radar stations established during the 1950s and known as the DEW line. (Source: http://military.wikia.com/wiki/Distant_Early_Warning_Line; photograph taken by Technical Sergeant Donald L. Wetterman, U.S. Air Force).
Locations of Antarctic stations operated during the IGY. The flag at each location denotes the nation that operates the station. [Source: Tom Woolley Illustration (https://www.tomwoolley.com/portfolio/map-infographics-for-the-polar-museum/)/Scott Polar Research Institute (https://www.spri.cam.ac.uk/museum/exhibitions/previous.html), University of Cambridge.]
Sequence of late-winter maps of ozone concentration (in Dobson units) illustrating the ozone holes (deep blue and purple) during each year of the 2006–13 period, taken from Newman et al. (2014, their Fig. 6.9). The occurrence of an ozone hole in each of these years contrasts with (top left) 1979, during which ozone concentrations were much higher.
Sample distribution (9 Jan 2011) of buoys operating as part of the IABP network. Gray lines show buoy tracks over the previous 60 days (source: IABP; from an earlier version of http://iabp.apl.washington.edu/maps.html).
AWSs operated in Antarctica during 2018. The symbols denote the institutions that operate each station (legend in lower right). [Source: the Antarctic Meteorological Research Center of the University of Wisconsin–Madison Space Science and Engineering Center (http://amrc.ssec.wisc.edu/aws/); created by Sam Batzli under NSF Grant ANT-1543305.]
Mean January and February 2016 spatial patterns of (a) near-surface (925 hPa) air temperature anomalies and (b) averaged geopotential height at 700 hPa. The data are from the NOAA–NCAR reanalysis using the NOAA/ESRL online plotting routines. [The data and image were provided by the NOAA/OAR/ESRL Physical Sciences Division (https://www.esrl.noaa.gov/psd/).]
Evolution of Arctic sea ice area in recent years (colored lines) relative to the historical range (gray shading: 1979–2006 average ± 1 std dev). Recent years (2015–18) have had the lowest winter ice areas of the post-1979 period of record. [Source: Nansen Environmental and Remote Sensing Center (http://web.nersc.no/WebData/arctic-roos.org/observation/ssmi1_ice_area.png); after a figure from the Arctic Regional Ocean Observing System (ArcticROOS; https://arctic-roos.org/).]
June 2018 nested grid configuration of AMPS. The outermost grid resolution is 24 km, Antarctica and the adjacent Southern Ocean are at 8 km, the 2.7-km grid spans from the South Pole to the Ross Sea, and the 0.9-km innermost grid is focused on McMurdo Station. A 2.7-km grid covers the Antarctic Peninsula. (The image is provided through the courtesy of NCAR.)
