Statistical patterns of high-latitude convection obtained from Goose Bay HF radar observations

1996 ◽  
Vol 101 (A10) ◽  
pp. 21743-21763 ◽  
Author(s):  
J. M. Ruohoniemi ◽  
R. A. Greenwald
Keyword(s):  
High Latitude ◽  
Hf Radar ◽  
Radar Observations

scholarly journals Blending Surface Currents from HF Radar Observations and Numerical Modeling: Tidal Hindcasts and Forecasts

2015 ◽  
Vol 32 (2) ◽  
pp. 256-281 ◽  
Author(s):  
E. V. Stanev ◽  
F. Ziemer ◽  
J. Schulz-Stellenfleth ◽  
J. Seemann ◽  
J. Staneva ◽  
...  
Keyword(s):  
Numerical Modeling ◽  
German Bight ◽  
Spatial Scales ◽  
Surface Current ◽  
Hf Radar ◽  
Optimal Interpolation ◽  
Kelvin Wave ◽  
Arctic Seas ◽  
Current Estimate ◽  
Radar Observations

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.

scholarly journals A comparison of satellite scintillation measurements with HF radar backscatter characteristics

2005 ◽  
Vol 23 (11) ◽  
pp. 3451-3455 ◽  
Author(s):  
S. E. Milan ◽  
S. Basu ◽  
T. K. Yeoman ◽  
R. E. Sheehan
Keyword(s):  
Broad Spectrum ◽  
High Latitude ◽  
Auroral Zone ◽  
Intersection Point ◽  
Density Fluctuations ◽  
Hf Radar ◽  
Ionospheric Scintillation ◽  
Radar Backscatter ◽  
Density Perturbations ◽  
Coherent Radar

Abstract. We examine the correspondence between high latitude ionospheric scintillation measurements made at 250MHz with the occurrence of 10MHz HF coherent radar backscatter, on 13 and 14 December 2002. We demonstrate that when the ionospheric intersection point of the scintillation measurements is co-located with significant HF radar backscatter, the observed scintillation, quantified by the S4 index, is elevated. Conversely, when the radar indicates that backscatter is observed away from the intersection point due to movements of the auroral zone, the observed scintillation is low. This suggests that scintillation is highly location-dependent, being enhanced in the auroral zone and being lower at sub-auroral latitudes. The coexistence of scintillation and HF radar backscatter, produced by ionospheric density perturbations with scale sizes of 100s of metres and ~15 m, respectively, suggests that a broad spectrum of density fluctuations is found in the auroral zone.

Assessing SARAL/AltiKa Data in the Coastal Zone: Comparisons with HF Radar Observations

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

scholarly journals Statistical observations of the MLT, latitude and size of pulsed ionospheric flows with the CUTLASS Finland radar

1999 ◽  
Vol 17 (7) ◽  
pp. 855-867 ◽  
Author(s):  
G. Provan ◽  
T. K. Yeoman
Keyword(s):  
Hf Radar ◽  
High Time Resolution ◽  
Plasma Convection ◽  
Unified Framework ◽  
Coherent Scatter ◽  
Radar Observations ◽  
Scatter Radar ◽  
Precipitation Regimes ◽  
Low Altitude ◽  
Flux Transfer

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)

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