Introduction

The Russian sector of Arctic includes a significant part of the northern polar region. It covers territory from 30° E geographic longitude, on its Western frontier, to 190° E on its Eastern edge, which is equal to 10 hourly belts. The Arctic Ocean Route along the Siberian Coast - a very important sea-surface transport artery - is located well inside this region.

Ionospheric investigations in the Russian part of the Arctic, besides their purely scientific purposes, were motivated by some pragmatic values. The role of ionospheric polar research increased continuously with the complex industrial development of the Russian Far Northern territories.

This paper will briefly describe the major stages of the Russian ionospheric polar investigations - from their initial steps up to the present time, with special emphasis on contemporary problems.

History of the Russian ionosondes explorations of the polar ionosphere

The first sporadic ionospheric investigations in the Arctic were made by Russian scientists during the Second International Polar Year (1932 - 1933 ). Basically, quantitative instrumental measurements of the signals levels from remote HF radio transmitters were made (later this method became the A3 ionospheric absorption measurement). These measurements showed that auroral events create disturbance effects on HF radiocommunication in the polar regions. The irregular character of the occurrence and intensity of these auroral events, in its turn, helped people to understand the need for regular measurements of the ionisation in the polar ionosphere. Consequently, one of the first Russian vertical ionosondes was installed for the regular observations in the Arctic in 1938.

The milestones of the development of the Russian high-latitude ionosonde network can be named as follows:

1938 - start of the first regular vertical ionospheric sounding at Tikhaja Bay (Franz-Josef Land Archipelago). The observations were performed annually.

1944 - start of the similar observations at Tixie Bay in Eastern Siberia (mouth of Lena river).

1950 - 1955. Three other vertical ionosondes were installed in the Arctic (Murmansk, Dixon Island, Cape Schmidt).

1954 - 1955. The first regular annual observations by a vertical ionosonde were performed at the Ice Drifting Station "North Pole-3", which drifted close to the North Geographical Pole. Perhaps they were the very first regular ionospheric observations ever made deep inside the Arctic Circle.

1956 - routine vertical ionospheric sounding in Antarctica (Vostok and Mirny).

1961 - the first airborne soundings of the polar ionosphere (Antarctica).

1963 - 1964 - routine operation of the Russian high-latitude riometer network, both in Arctic and Antarctica, started.

1969 - the first Russian regular oblique incidence bistatic ionospheric soundings between Saint Petersburg and Murmansk (sweeping frequency range 3.5 - 27.5 MHz).

1969 - 1975 - establishment of the permanent oblique incidence ionospheric sounding network both in Arctic and Antarctica closely connected with network of vertical sounders.

The formation of the Russian vertical ionosonde network in the Arctic region was completed towards the end of International Geophysical Year (1957 - 1959 ). The network was equipped throughout with the same type of ionosonde - the automatic ionospheric station, (AIS), similar to the U.S. C-4 ionosonde. Consequently, all ionospheric information collected in the Arctic had a uniform quality that was a great advantage in its interpretation.

The centres of ionospheric service and forecasting were organised simultaneously, originally under the auspices of the Academy of Science and afterwards the Hydrometeorological Service. Effective methods for both short-term and long-term ionospheric and radio-propagation forecasting were developed. The main purpose of all these actions was to organise a reliable radio-communication service for the Arctic Ocean Route - a very important transport link between European and Far Eastern parts of the Russian Arctic. Some other tasks including scientific ones were also solved by means of ionospheric information collected from this network.

The strategic ideas in the placement of the ionospheric stations was to make it possible to monitor the key regions of the polar ionosphere where the corpuscular radiation fluxes intrude into it: a nighttime part of the auroral oval and the polar cusp / cleft region. Subsequently the chains of ionosondes were organised along both geomagnetic meridians and parallels in order to cover the entire polar region.

The full list of the Russian high-latitude ionosondes that are in operation now is given in TABLE 1. The term "high-latitude" includes regions located above 60° of invariant latitude as geographically speaking the region is inside the North Polar Arctic circle ( 66.7° N ).

 

TABLE 1.

Russian high-latitude ionosondes stations in the Arctic.

Back to INAG Homepage

Back to UAG-104 Contents page