Russian Drifting Stations
Russian Version

Documentation provided by V. Radionov, with additions from a previous edition of these data (see "Related data products"); edited by F. Fetterer

The history of the "North Pole" (NP) drifting station program is described in "A Look Back," in the manuscript titled North Pole Drifting Stations. This document has detailed information on each station. NP drifting stations were established on multiyear ice floes less than 2 km2 in diameter and 3 m to 5 m thick. Usually, a starting location to the northeast of Wrangel Island (about 175 degrees West) was chosen for the station. Station personnel generally debarked on the ice in spring (March through May) after being transported by air, but sometimes personnel were delivered to the site by icebreaker in autumn.

Meteorological observations at drifting stations

Meteorological observations at drifting stations were performed by the methods described Gidrometeoizdat [1969] and Gidrometeoizdat [1985]. AARI instructions made some changes to these standard observation methods related to the peculiarities of making observations on drifting ice.

Usually, meteorological observations were performed eight times daily (at 0000, 0300, 0600, 0900, 1200, 1500, 1800 and 2100 Moscow Local Time (MLT). (MLT is three hours later than GMT). However sometimes observations were performed four times daily (at 0300, 0900, 1500 and 2100 MLT) during times of ice breakup when new personnel arrived, so that some stations have observations at both three- and six-hourly observation periods. The observation record was kept at the meteorological site in a log book. Data tables were developed every month after laboratory processing.

The meteorological site was selected on level ice at a distance of not less than 70 m to 100 m away from hummocks and living accommodations. Devices and equipment were situated according to the standard plan of a 26 m by 26 m meteorological site. On site there was a psychrometric box with thermometers, hygrometers, and a box for recorders with thermometer and self-recording hygrometer, masts with wind vanes, and masts with an anemorumbometer. The thermometers to measure the snow surface temperature were located near the psychrometric box. During the polar night the meteorological site was electrically lighted. Flashlights were used to read the instruments when power outages occurred.

This Atlas contains data for the meteorological parameters described below. Parameters are available in uniformat synoptic data and as monthly averages. (Monthly averages for wind speed and wind direction are not given). Note that observations of additional parameters were taken, and some of these data are available on the related data products described in the section "Related data products".

Air pressure

Air pressures were measured by barograph and by using two mercury barometers located in the main meteorological building: one as the main instrument, and the other as a control. Pressure measurements from the control (calibration) barometer were taken at regular intervals; readings from the main barometer are provided on this Atlas. Air pressure was recorded in hPa referred to a temperature of 0 °C and standard gravity force, that is, gravity at a latitude of 45 degrees and at sea level.

A station cistern mercury barometer (SP-A) and an inspector's mercury siphon-cistern barometer (IP) were used.

The main parameters of the SP-A are:

Range of the instrument:   810 to 1070 hPa
Maximum error:   < or = 0.5 hPa
Accuracy of reading:   0.1 hPa
Scale spacing of cosine:   0.1 hPa
Scale spacing:   1.0 hPa
Range of the barometric thermometer:   -5 °C to +45 °C
Error of the barometric thermometer:   0.5 °C

The main parameters of the IP are:

Range of the instrument:   570 to 1070 hPa
Maximum error:   0.3 hPa
Accuracy of reading:   0.05 hPa
Scale spacing of cosine:   0.05 hPa
Scale spacing:    1.0 hPa
Range of the barometer thermometer: -5 °C to +45 °C

If these barometers failed to operate, the atmospheric pressure was measured by aneroid-barometer with an accuracy of 1 mmHg and a maximum measurement error of not more than 0.8 mmHg. Aneroid-barometers were used exclusively on NP-5, NP-8, NP-9, and NP16.

Air temperature and relative humidity

Air temperature and relative humidity were measured using instruments in a psychrometric box (similar to a Stevenson's Screen) 2.0 m over ice surface. When the temperature was higher than -30° C, mercury meteorological thermometers (TM-4) were used, otherwise, alcohol meteorological thermometers (TM-9) were used.

The main parameters of the TM-4 are:

Range of the instrument:   -35 °C to +40 °C
Scale spacing:   0.2 °C
Measurement error over the range from
+0 °C to +50C:    < or = 0.2 °C
< 0 °C:    < or = 0.3 °C

The main parameters of the TM-9 are:

Range of the instrument:   -65 °C to +25 °C
Scale spacing:   0.5 °C
Measurement error over the range from
+20 °C to -20 °C:    0.5 °C
-30 °C to -40 °C:    0.8 °C
-40 °C to -50 °C:    1.0 °C
-50 °C to -60 °C:    1.5 °C

Starting with NP-21, copper wire resistance thermometers (MT-102) were used as the wet-bulb thermometer as well as to measure the air and snow-ice surface temperature.

At temperatures above -10 °C, relative humidity was determined by psychrometry, which is based on measuring the difference between air temperature and the temperature of a wet-bulb thermometer. Values of relative humidity were calculated using the psychrometric table, and the results obtained using psychrometry were compared with a hair hygrometer in order to check and correct the hygrometer reading at regular intervals.

At air temperatures below -10 °C, the model MV-1 meteorological hygrometer used to measure relative air humidity. The main parameters of the MV-1 are:

Range of the instrument:   30 percent to 100 percent
Measurement error:    up to 10 percent
Scale spacing:    1 percent
Operating temperature range:   -50 °C to +55 °C

Surface temperature

The temperature of snow cover was usually measured from September to the end of April, but sometimes as late as mid-May, depending on the length of the period with stable negative temperatures. To measure snow surface temperature when the air temperature was higher than -30 °C, the TM-3 mercury thermometer with a scale spacing of 0.5 °C was used. The accuracy of the TM-3 measurement is ± 0.5 °C when temperature is higher than -20 °C and is ± 0.7 °C when temperature is below -20 °C. If temperature is below -30°C, an alcohol thermometer with scale spacing of 0.5 °C was used. The accuracy of the alcohol thermometer is given in the following table:

Temperature range:   Error

Greater than -20 °C:  ± 0.5 °C
-30 °C to -20 °C:  ± 0.5 °C
-40 °C to -30 °C:  ± 0.8 °C
-50 °C to -40 °C:  ± 1.0 °C
-60 °C to -50 °C:  ± 2 °C

Cloud amount

Cloud amount is defined visually on a ten-point scale, and the quantity of clouds (both total and low cloud cover) was recorded in tenths of coverage. Coverage that was almost complete ("10" with gaps) was coded as "11". The following devices were used to measure cloud height: cloud searchlight (up to 1963), pilot balloons, and radio sounding data. IVO-1, a device to measure cloud height, was used from 1969 on. Cloud height was defined visually in a case when the instrumental measurements could not be performed.

Wind direction and speed

Until 1962 wind direction and speed were measured by Wild's wind vane with heavy and light boards and also by meteorological devices DMS-49 or DMS-53. From 1963 on M-47 and M-49 type anemorumbometers and M-12 and M-64 type anemorumbographs were used. Table 10 lists the instrument types and heights of installation of the wind velocity sensors. Table 11 provides the main parameters of the instruments.

Table 10. Instruments and installation heights used for the measurement of wind velocity and direction.

Station Instrument(s) Height (m) (Dates)
NP-1 MS-13 2  
NP-2 8I0001M 8  
NP-3 MS-13; 8I0001M 8  
NP-4 8I0001M; FVL 8  
NP-5 FVL 6  
NP-6 FVL; FVT 8  
NP-7 FVL; FVT 10  
NP-8 FVL; FVT 8  
NP-9 FVL; FVT 8  
NP-10 M-49 6  
NP-11 FVL; FVT; M-47 8  
NP-12 M-49 10  
NP-13 M-47; M12 6  
NP-14 M-47;M-63 8  
NP-15 M-63 6  
NP-16 M-49 10  
NP-17 M-63 10  
NP-18 M-49; M-12 6.4 (11/68 - 05/69)
    8.5 (05/69 - 10/71)
NP-19 M-64; M-63M 6.4 (12/69 - 10/70)
    7.5 (11/70 - 01/71)
    9.5 (02/71 - 11/72)
    12 (11/72 - 03/73)
NP-20 M-47 8 (05/70 - 04/71)
    6 (05/71 - 05/72)
NP-21 M-47 10  
NP-22 M-64; M-63M 10  
NP-23 M-63M 10  
NP-24 M-63M 10  
NP-25 M-63M 10  
NP-26 M-63M 11  
NP-27 M-63M 10  
NP-28 M-63M 10  
NP-29 M-63M 10  
NP-30 M-63M 10  
NP-31 M-63M 10  

Table 11. Main characteristics of the instruments used for the measurement of wind velocity and direction.

Instrument

Speed

range

(m/s)

Direction

range

(degrees)

Accuracy of measurement of speed

(m/s)

Accuracy of measurement of direction

(deg)

Threshold sensitivity for speed

direction (m/s)

MS-13 1.0 - 20 - (0.3+0.06V) - 0.8/----
810001M 1.0 - 15 0-360 1.0 10 1.0/1.0
FVL 1.0 - 20 0-360 (16 compass points)      
FVT 1.0 - 40 0-360      
M-49 1.5-59 0-360 (0.5+0.05V) 10 1.2/1.2
M-47 1.5-50 0-360 (0.5+0.05V) 10 1.2/1.2
M-64 1.0-40 0-360 (0.5+0.05V) 10 0.8/1.5
M-12 1.0-40 0-360 (16 compass points) (0.5+0.05V) 11.25 0.7/0.9
M-63 1.0-40 0 -360 (0.5+0.05V) 10 0.8/1.5
M-63M 1.0-40 0 -360 (0.5+0.05V) 10 0.6/1.0

Notes for Table 11:

  1. MS-13 measures only wind speed.

  2. The choice of a light (FVL, 200 g) board or a heavy (FVT, 800 g) board depended on the observer's experience. Measurement error is not less than +/- 1 meter per second for speed and +/- 0.5 point (11 degrees) for direction.

  3. M-12, M-47, M-64, M-63, M-63M records the wind velocity averaged over 10 minutes; MS-13 records velocity averaged over two-10 minutes.

  4. V in formulas for velocity measurement precision is the measured wind velocity in m/s.

Accuracy of meteorological observations

Typical ranges in accuracy for the measurement of most of the parameters listed above are given in Table 12.

Table 12. Accuracy of meteorological observations.

Parameter Devices (methods) and units of error Error
   

Single Observation

24 hours (daily)

    average max average max
Air pressure Mercury barometer, mbar (mm) 0.2 0.5 0.2 0.4
Wind speed Wind vane, m/s 1-2 4-6 1-2 2-4
Wind direction Wind vane, points (22.5 degrees) 1 2 0.5 1
Air temperature Psychrometric thermometer, ° C 0.3 - 0.4 1.0 0.3 -0.4 0.6 - 0.8
Air temperature max. over 3 or 6 hour period Thermometer for measuring maximum temperature,° C 0.4 - 0.6 2.0 0.4 0.8 - 1.0
Air temperature min. over 3 or 6 hour period Thermometer for measuring minimum temperature,° C 0.5 2.0 0.5 1.0
Relative humidity Psychrometer or
self-recording hygrometer, mbar
0.2 0.4 0.2 0.4

Station positions

Positions of drifting stations NP-1 to NP-24 were determined primarily by celestial navigation. Sun fixes and star observations were made daily as season and weather permitted. Positioning errors are estimated to have been 3 km to 5 km. Starting with NP-25, positions were determined using satellite technology. NP-31 used the Satellite Navigation system.

The position data files received from AARI contained only observations that were actually made. After quality control, these positions were linearly interpolated to provide an approximate position for each meteorological observation. J. Comeaux, NCAR Data Support Section, provided the quality-controlled, interpolated positions for this Atlas.

Quality control of NP data

Meteorological data were checked at AARI as described in the section "AARI Quality Control Methods," and following Drozdov [1989]. Data underwent further quality control by J. Comeaux, NCAR Data Support Section, as follows.

These checks were performed on the position files:

Meteorological data files were checked for dates out of order, missing observation times and out of range values on all data fields.

Related data products

The NP data set on this Atlas corrects previous data and position records, and adds additional data records to the data set on CD-ROM published by AARI, the University of Washington Polar Science Center, and NSIDC in 1996 titled Arctic Ocean Snow and Meteorological Observations from Drifting Stations 1937, 1950-1991. (The 1996 CD-ROM included snow and radiation data from the NP stations that are not included in this Atlas). Specifically, this new version of the NP meteorological observations contains corrected latitude and longitudes for NP-18 and NP-26, includes data from NP-4 that are missing from the 1996 CD-ROM, and contains more data records. For a complete inventory of differences with the earlier version, contact NSIDC User Services. AARI, NCAR's Data Support Section, the University of Washington Polar Science Center, and NSIDC have cooperated in publishing this new edition of the NP meteorological data. This version of the data set is also available from NCAR's DSS, where it has been prepared for inclusion in the update to the Comprehensive Ocean-Atmosphere Data Set (COADS), and in the NCEP/NCAR and ECMWF Reanalysis projects.

Earlier versions of NP drifting station data were used in the following data products available from NSIDC:

Arctic Water Vapor Characteristics from Rawinsondes
http://nsidc.org/NSIDC/CATALOG/ENTRIES/nsi-0033.html

Daily Arctic Ocean Rawinsonde Data from Soviet Drifting Ice Stations
http://nsidc.org/NSIDC/CATALOG/ENTRIES/nsi-0060.html

Comprehensive Ocean - Atmosphere Data Set LMRF Arctic Subset
http://nsidc.org/NSIDC/CATALOG/ENTRIES/nsi-0057.html