Simultaneous optical and HF radar observations of the ionospheric cusp

1995 ◽  
Vol 22 (15) ◽  
pp. 2045-2048 ◽  
Author(s):  
A. S. Rodger ◽  
S. B. Mende ◽  
T. J. Rosenberg ◽  
K. B. Baker
Keyword(s):  
Hf Radar ◽  
2015 ◽  
Vol 32 (2) ◽  
pp. 256-281 ◽  
Author(s):  
E. V. Stanev ◽  
F. Ziemer ◽  
J. Schulz-Stellenfleth ◽  
J. Seemann ◽  
J. Staneva ◽  
...  

AbstractAn observation network operating three Wellen Radars (WERAs) in the German Bight, which are part of the Coastal Observing System for Northern and Arctic Seas (COSYNA), is presented in detail. Major consideration is given to expanding the patchy observations over the entire German Bight on a 1-km grid and producing state estimates at intratidal scales, and 6- and 12-h forecasts. This was achieved with the help of the proposed spatiotemporal optimal interpolation (STOI) method, which efficiently uses observations and simulations from a free model run within an analysis window of one or two tidal cycles. In this way the method maximizes the use of available observations and can be considered as a step toward the “best surface current estimate.” The performance of the analysis was investigated based on the achieved reduction of the misfit between model and observations. The complex dynamics of the study domain was illustrated based on the spatial and temporal changes of tidal ellipses for the M2 and M4 constituents from HF radar observations. It was demonstrated that blending observations and numerical modeling facilitates physical interpretation of processes such as the nonlinear distortion of the Kelvin wave in the coastal zone and in particular in front of the Elbe and Weser estuaries. Comparisons with in situ data acquired outside the area covered by the HF radar demonstrated that the analysis method is able to propagate the HF radar information to larger spatial scales.


2015 ◽  
Vol 38 (sup1) ◽  
pp. 260-276 ◽  
Author(s):  
Ananda Pascual ◽  
Arancha Lana ◽  
Charles Troupin ◽  
Simón Ruiz ◽  
Yannice Faugère ◽  
...  

1999 ◽  
Vol 17 (7) ◽  
pp. 855-867 ◽  
Author(s):  
G. Provan ◽  
T. K. Yeoman

Abstract. A study has been performed on the occurrence of pulsed ionospheric flows as detected by the CUTLASS Finland HF radar. These flows have been suggested as being created at the ionospheric footprint of newly-reconnected field lines, during episodes of magnetic flux transfer into the terrestrial magnetosphere (flux transfer events or FTEs). Two years of both high-time resolution and normal scan data from the CUTLASS Finland radar have been analysed in order to perform a statistical study of the extent and location of the pulsed ionospheric flows. We note a great similarity between the statistical pattern of the coherent radar observations of pulsed ionospheric flows and the traditional low-altitude satellite identification of the particle signature associated with the cusp/cleft region. However, the coherent scatter radar observations suggest that the merging gap is far wider than that proposed by the Newell and Meng model. The new model for cusp low-altitude particle signatures, proposed by Lockwood and Onsager and Lockwood provides a unified framework to explain the dayside precipitation regimes observed both by the low-altitude satellites and by coherent scatter radar detection.Key words. Magnetospheric physics (magnetosphere · ionosphere interactions; plasma convection; solar wind-magnetosphere interactions)


1996 ◽  
Vol 101 (A12) ◽  
pp. 26981-26993 ◽  
Author(s):  
D. L. Hysell ◽  
M. C. Kelley ◽  
Y. M. Yampolski ◽  
V. S. Beley ◽  
A. V. Koloskov ◽  
...  

Author(s):  
A. Chaudhary ◽  
N. Agarwal ◽  
R. Sharma

The present study explores the possibility of deriving the across track currents along the Indian coastal region from SARAL/AltiKa mission. The across track surface geostrophic currents obtained from along track SARAL altimeter data are directly compared (qualitatively) with high frequency (HF) radar observations of surface currents in the Bay of Bengal. The velocity component from HF radar which is perpendicular to the altimeter tracks is considered. Since the ageostrophic velocity contribution is ignored for the moment, the surface geostrophic currents SARAL compare well only under low wind conditions. Due to high along track resolution of SARAL there are large variations in velocity which are not captured by the HF radar observations. In general, the magnitude and variations in surface currents derived from SARAL altimeter are comparable with HF radar observations.


2020 ◽  
Vol 118 (11) ◽  
pp. 1739
Author(s):  
B. K. Jena ◽  
K. S. Arunraj ◽  
V. Suseentharan ◽  
M. V. Ramanamurthy

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