Probing of medium-scale traveling ionospheric disturbances using HF-induced scatter targets

N. F. Blagoveshchenskaya (1) , T. D. Borisova (1) , V. A. Kornienko (1) , I. V. Moskvin (1) , M. T. Rietveld (2) , V. L. Frolov (3) , V. P. Uryadov (3) , L. M. Kagan (4) , Yu. M. Yampolski (5) , V. L. Galushko (5) , A. V. Koloskov (5) , S. B. Kasheev (5) , A. V. Zalizovski (5) , G. G. Vertogradov (6) , V. G. Vertogradov (6) , M. C. Kelley (7)

1 AARI - Arctic and Antarctic Research Institute
2 EISCAT Scientific Association
3 NIRFI - Radiophysical Research Institute
4 UWO - University of Western Ontario
5 IRA - Institute of Radio Astronomy of NAS of Ukraine
6 SFEDU - Southern Federal University [Rostov-on-Don]
7 Cornell University [New York]

Experimental results from the Tromsø and Sura heating experiments at high and mid-latitudes are examined. It is shown that the combination of HF-induced target and bi-static HF Doppler radio scatter observations is a profitable method for probing medium-scale traveling ionospheric disturbances (TIDs) at high and mid-latitudes. HF ionospheric modification experiments provide a way of producing the HF-induced scatter target in a controlled manner at altitudes where the sensitivity to TIDs is highest. Bi-static HF Doppler radio scatter observations were carried out on the London-Tromsø-St. Petersburg path in the course of a Tromsø heating experiment on 16 November 2004 when the pump wave was reflected from an auroral Es-layer. During Sura heating experiments on 19 and 20 August 2004, when the HF pump wave was reflected from the F2 ionospheric layer, multi-position bi-static HF Doppler radio scatter observations were simultaneously performed at three reception points including St. Petersburg, Kharkov, and Rostov-on-Don. Ray tracing and Doppler shift simulations were made for all experiments. A computational technique has been developed allowing the reconstruction of the TID phase velocities from multi-position bi-static HF Doppler scatters. Parameters of medium-scale TIDs were found. In all experiments they were observed in the evening and pre-midnight hours. TIDs in the auroral E-region with periods of about 23 min were traveling southward at speeds of 210 m/s. TIDs in the mid-latitudinal F-region with periods from 20 to 45 min travelled at speeds between 40 and 150 m/s. During quiet magnetic conditions the waves were traveling in the north-east direction. In disturbed conditions the waves were moving in the south-west direction with higher speeds as compared with quiet conditions. Possible sources for the atmospheric gravity waves at middle and high latitudes are discussed.

Domaines: Océan, Atmosphère; Sciences de la Terre

N. F. Blagoveshchenskaya, T. D. Borisova, V. A. Kornienko, I. V. Moskvin, M. T. Rietveld, et al.. Probing of medium-scale traveling ionospheric disturbances using HF-induced scatter targets. Annales Geophysicae, 2006, 24 (9), pp.2333-2345. ⟨hal-00318163⟩