Overview

Summary

This data set contains sea ice and snow measurements collected during aircraft landings associated with the Soviet Union's historical Sever airborne and North Pole drifting station programs. The High-Latitude Airborne Annual Expeditions Sever (Sever means North) took place in 1928, 1937, 1941, 1948-1952, and 1954-1993 (Konstantinov and Grachev 2000). In Spring 1993, the last (45th) Sever expedition finished long-term activity in the Arctic. Snow and sea ice data were collected, along with meteorological and hydrological measurements (the latter are not part of this data set). Up to 202 landings were accomplished each year.

The data set contains measurements of 23 parameters, including ice thickness and snow depth on the landing runway and surrounding area; ridge, hummock, and sastrugi dimensions and areal coverage; and snow density. The sea ice thickness data are of particular importance, as ice thickness measurements for the Arctic Basin are scarce. These data are a subset of those used to create the atlas Morphometric Characteristics of Ice and Snow in the Arctic Basin, self-published by Ilya P. Romanov in 1993, and republished by Backbone Publishing Company in 1995. Romanov personally provided these data to the National Snow and Ice Data Center (NSIDC) in 1994. Note: NSIDC only holds data through 1989.

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Background

In 1994, NSIDC received two data sets from Ilya Pavlovich Romanov, a scientist who spent his career with the Arctic and Antarctic Research Institute (AARI), St. Petersburg, Russia. One data set consists of files of gridded parameters that were used in the construction of the atlas Morphometric Characteristics of Ice and Snow in the Arctic Basin, self-published by Ilya P. Romanov in 1993, and republished in a revised version with accompanying data diskette and additional charts, as Atlas of Ice and Snow of the Arctic Basin and Siberian Shelf Seas, by Backbone Publishing Company in 1995. The second consists of files of raw (ungridded) data from aircraft landings on Arctic pack ice, beginning in 1928 and ending in 1989, with relatively few observations before the 1950s. NSIDC offers the raw observations, but not the gridded data, due to irregularities in the gridded data set. Unfortunately, Ilya Romanov died in 1995, before complete documentation on both data sets could be obtained. See Detailed Data Description for information on the contents of the new data set.

Romanov compiled and analyzed his database during his 45-year career with AARI. His field experience included 19 Sever expeditions and five North Pole drifting stations, as well as scientific leadership on the first voyage to the North Pole by icebreaker, in 1977 (Atlas of Ice and Snow of the Arctic Basin and Siberian Shelf Seas Editor's Preface, 1995). The AARI Sever and North Pole programs are described below. In 1959, Romanov initiated an extracurricular program of routine measurements of snow and ice that resulted in an extensive personal archive. This database grew to include previously collected snow and ice data as well (R. Colony, "Forward," Atlas of Ice and Snow of the Arctic Basin and Siberian Shelf Seas, 1995).

Data sources for the Romanov atlases are described as the AARI Sever expeditions (1940s to 1980s), the AARI North Pole drift stations (1937-1991), the US-USSR joint research Polar Experiment (POLEX) program (1972-1981), ice reconnaissance flight reports, and literature in the public domain ("Executive Summary," Atlas of Ice and Snow of the Arctic Basin and Siberian Shelf Seas, 1995). NSIDC has published the data from aircraft landings only and has not included extensive data from the North Pole program. The source of each year's observations is uncertain. The observations from 1928 may be connected with the rescue efforts of the airship Italia and the aircraft landings of Chukhnovsky and M.S. Babushkin during that period.

Romanov's atlases and observational data are a unique contribution to arctic science. Snow measurements were made in the spring and therefore represent annual snow accumulation prior to significant summer melt. Romanov's assessments of area, thickness and the spatial distribution of snow contribute information useful for evaluating arctic freshwater balance (Roger Barry, personal communication, 2003). Sea ice thickness data are valuable additions to the limited record provided by upward looking sonar. The Atlas of Ice and Snow of the Arctic Basin and Siberian Shelf Seas contains many additional parameters presented in climatological analyses, with background information on observational methods.

The Sever Program

The Sever (in English, "North") expeditions, more formally named the High-Latitude Airborne Expeditions, were an intensive data acquisition program conducted by AARI. Between 1948 and 1989, but primarily in the mid 1950s and again during 1973-1979, the Arctic Basin and shelf seas were annually sampled at up to 202 separate landing sites per season, where observers would stay for several days. The landings generally took place from mid March into early May, when there was enough light to operate, but before summer melt made safe landings impossible. The Sever program included the acquisition of oceanographic and meteorological data (notably, the program focused on the wintertime hydrography of the Kara, Laptev, East Siberian, and Chukchi Seas); however, Romanov's database includes only sea ice and snow data. For more information on Sever, see Environmental Working Group Joint U.S.-Russian Sea Ice Atlas, and Borodachev and Shilnikov, 2002 (in Russian only).

The North Pole Program

AARI's North Pole program consisted of drifting stations that generally were set up on multiyear ice floes. The first station began operations in 1937. Observations were interrupted during World War II and resumed in 1950. For 1954 through 1991, one to three stations were in operation each year, with varying 'lifetimes' before the ice floe broke up or drifted through Fram Strait. North Pole Drifting Station 1 lasted nine months and North Pole Drifting Station 22 lasted eight and a half years. Stations were set up by delivering personnel and equipment by air, and resupply was by air. They drifted until the floe was in danger of breaking up, at which time the men and equipment were retrieved. An average ice station lifetime was 31.5 months. The North Pole drifting station measurement program was extensive. This data set contains only a selection of sea ice and snow measurements that were acquired possibly during aircraft support for the North Pole program. A detailed history of the program, with a gallery of photographs, station meteorological data, and drift tracks, may be found in the Joint U.S.-Russian Arctic Meteorology and Climate Atlas (Arctic Climatology Project, 2000).