scholarly journals A comparison of northern hemisphere winds using SuperDARN meteor trail and MF radar wind measurements

2000 ◽  
Vol 105 (D14) ◽  
pp. 18053-18066 ◽  
Author(s):  
G. C. Hussey ◽  
C. E. Meek ◽  
D. André ◽  
A. H. Manson ◽  
G. J. Sofko ◽  
...  
Keyword(s):  
Northern Hemisphere ◽  
Meteor Trail ◽  
Wind Measurements ◽  
Mf Radar

MF radar interferometer measurements of meteor trail motions

Radio Science ◽  
1990 ◽  
Vol 25 (4) ◽  
pp. 649-655 ◽  
Author(s):  
C. E. Meek ◽  
A. H. Manson
Keyword(s):  
Meteor Trail ◽  
Mf Radar

scholarly journals A comparison of 11-year mesospheric and lower thermospheric winds determined by meteor and MF radar at 69 ° N

2017 ◽  
Vol 35 (4) ◽  
pp. 893-906 ◽  
Author(s):  
Sven Wilhelm ◽  
Gunter Stober ◽  
Jorge L. Chau
Keyword(s):  
Lower Thermosphere ◽  
Meridional Wind ◽  
Correction Factors ◽  
Data Set ◽  
Wind Measurements ◽  
Mesosphere And Lower Thermosphere ◽  
Thermospheric Winds ◽  
Good Agreement ◽  
Mlt Region ◽  
Mf Radar

Abstract. The Andenes Meteor Radar (MR) and the Saura Medium Frequency (MF) Radar are located in northern Norway (69° N, 16° E) and operate continuously to provide wind measurements of the mesosphere and lower thermosphere (MLT) region. We compare the two systems to find potential biases between the radars and combine the data from both systems to enhance altitudinal coverage between 60 and 110 km. The systems have altitudinal overlap between 78 and 100 km at which we compare winds and tides on the basis of hourly winds with 2 km altitude bins. Our results indicate reasonable agreement for the zonal and meridional wind components between 78 and 92 km. An exception to this is the altitude range below 84 km during the summer, at which the correlation decreases. We also compare semidiurnal and diurnal tides according to their amplitudes and phases with good agreement below 90 km for the diurnal and below 96 km for the semidiurnal tides. Based on these findings we have taken the MR data as a reference. By comparing the MF and MR winds within the overlapping region, we have empirically estimated correction factors to be applied to the MF winds. Existing gaps in that data set will be filled with weighted MF data. This weighting is done due to underestimated wind values of the MF compared to the MR, and the resulting correction factors fit to a polynomial function of second degree within the overlapping area. We are therefore able to construct a consistent and homogenous wind from approximately 60 to 110 km.

scholarly journals Influence of gravity waves and tides on mesospheric temperature inversion layers: simultaneous Rayleigh lidar and MF radar observations

2008 ◽  
Vol 26 (12) ◽  
pp. 3731-3739 ◽  
Author(s):  
S. Sridharan ◽  
S. Sathishkumar ◽  
S. Gurubaran
Keyword(s):  
Gravity Wave ◽  
Wave Interaction ◽  
Temperature Inversion ◽  
Lapse Rate ◽  
Wave Interactions ◽  
Tidal Gravity ◽  
Mesospheric Temperature ◽  
Wind Measurements ◽  
Rayleigh Lidar ◽  
Mf Radar

Abstract. Three nights of simultaneous Rayleigh lidar temperature measurements over Gadanki (13.5° N, 79.2° E) and medium frequency (MF) radar wind measurements over Tirunelveli (8.7° N, 77.8° E) have been analyzed to illustrate the possible effects due to tidal-gravity wave interactions on upper mesospheric inversion layers. The occurrence of tidal gravity wave interaction is investigated using MF radar wind measurements in the altitude region 86–90 km. Of the three nights, it is found that tidal gravity wave interaction occurred in two nights. In the third night, diurnal tidal amplitude is found to be significantly larger. As suggested in Sica et al. (2007), mesospheric temperature inversion seems to be a signature of wave saturation in the mesosphere, since the temperature inversion occurs at heights, when the lapse rate is less than half the dry adiabatic lapse rate.

scholarly journals MF radar observations of mean winds and tides over Poker Flat, Alaska (65.1° N, 147.5° W)

2002 ◽  
Vol 20 (5) ◽  
pp. 679-690 ◽  
Author(s):  
P. Kishore ◽  
S. P. Namboothiri ◽  
K. Igarashi ◽  
Y. Murayama ◽  
B. J. Watkins
Keyword(s):  
Middle Atmosphere ◽  
Lower Thermosphere ◽  
Winter Season ◽  
Wave Model ◽  
Global Scale ◽  
Meridional Winds ◽  
Wind Measurements ◽  
The Mean ◽  
Tidal Characteristics ◽  
Mf Radar

Abstract. MF radar wind measurements in the mesosphere and lower thermosphere over Poker Flat, Alaska (65.1° N, 147.5° W) are used to study the features of mean winds and solar tides. Continuous observation with the newly installed radar is in progress and in the present study we have analyzed a database of the first 27 months (October 1998–December 2000) of observation. The observed mean wind climatology has been compared with previous measurements and the latest empirical model values (HWM93 model). Similarly, the tidal characteristics are described and compared with the Global Scale Wave Model (GSWM00). The mean wind characteristics observed are fairly consistent with previous wind measurements by the Poker Flat MST radar. The main feature of the zonal circulation is the annual variation with summer westward flow and winter eastward flow. The annual mean zonal wind has a west-ward motion at altitudes below 90 km. The annual mean meridional circulation has mainly southward motion at 70–100 km. There is very good agreement between the radar zonal winds and the HWM93 model winds. Comparison of the meridional winds shows some discrepancy. Analysis of two years of data indicated that the year-to-year consistency is preserved in the mean circulation in the mesosphere. Tidal characteristics observed are also consistent with previous measurements. Semidiurnal tides have the largest amplitudes in summer while the weakest amplitude is observed during the winter months. The vertical wavelength is longer during the summer season compared to the winter season. Comparison with the GSWM00 produces mixed results. There is reasonable agreement between the observed and modeled phases. Diurnal tide amplitudes are comparable in magnitude with that of the semidiurnal tide. Seasonal variation is less evident in the amplitudes. Comparison of the observed tidal parameters with the GSWM00 reveals some agreement and discrepancies.Key words. Meteorology and atmospheric dynamics (climatology; middle atmosphere dynamics; waves and tides)

Comparison of wind measurements between Yamagawa MF Radar and the MU Radar

1996 ◽  
Vol 23 (23) ◽  
pp. 3341-3344 ◽  
Author(s):  
K. Igarashi ◽  
I. Nishimuta ◽  
Y. Murayama ◽  
T. Tsuda ◽  
T. Nakamura ◽  
...  
Keyword(s):  
Mu Radar ◽  
Wind Measurements ◽  
Mf Radar

scholarly journals Comparisons of full correlation analysis (FCA) and imaging Doppler interferometry (IDI) winds using the Buckland Park MF radar

2004 ◽  
Vol 22 (11) ◽  
pp. 3829-3842 ◽  
Author(s):  
D. A. Holdsworth ◽  
I. M. Reid
Keyword(s):  
Statistical Analysis ◽  
Correlation Analysis ◽  
Radial Velocity ◽  
Wind Velocity ◽  
Data Set ◽  
Analysis Technique ◽  
Wind Measurements ◽  
Statistical Analysis Technique ◽  
Full Correlation Analysis ◽  
Mf Radar

Abstract. We present results from three years of mesospheric and thermospheric wind measurements obtained using full correlation analysis (FCA) and imaging Doppler interferometry (IDI) for the Buckland Park MF radar. The IDI winds show excellent agreement with the FCA winds, both for short (2-min) and longer term (hourly, fortnightly) comparisons. An extension to a commonly used statistical analysis technique is introduced to show that the IDI winds are approximately 10% larger than the FCA winds, which we attribute to an underestimation of the FCA winds rather than an indication that IDI overestimates the wind velocity. Although the distribution of IDI effective scattering positions are shown to be consistent with volume scatter predictions, the velocity comparisons contradict volume scatter predictions that the IDI velocity will be overestimated. However, reanalysis of a 14-day data set suggests the lack of overestimation is due to the radial velocity threshold used in the analysis, and that removal of this threshold produces the volume scatter predicted overestimation of the IDI velocities. The merits of using hourly IDI estimates versus hourly averaged 2-min IDI estimates are presented, suggesting that hourly estimated turbulent velocities are overestimated.

scholarly journals Comparison of wind measurements in the troposphere and mesosphere by VHF/MF radars and in-situ techniques

2008 ◽  
Vol 26 (12) ◽  
pp. 3693-3705 ◽  
Author(s):  
N. Engler ◽  
W. Singer ◽  
R. Latteck ◽  
B. Strelnikov
Keyword(s):  
Radiosonde Data ◽  
Narrow Beam ◽  
Vhf Radar ◽  
Wide Beam ◽  
In Situ Techniques ◽  
Falling Sphere ◽  
Wind Measurements ◽  
Highly Correlated ◽  
Mf Radar

Abstract. Radar wind observations at frequencies between 1.98 and 53.5 MHz obtained at polar latitudes were compared to in-situ wind measurements by radiosondes at tropospheric altitudes and to winds from falling spheres at mesospheric altitudes. Comparisons are shown for several campaigns of radiosonde and falling sphere observations. The radar wind directions agree well to the radiosonde and falling sphere observations and are highly correlated. The winds estimated from radar measurements are less than the radiosonde data by about 15% for spaced antenna observations and by about 10% for the Doppler beam swinging experiment. At mesospheric altitudes the spaced antenna winds obtained from the wide-beam Andenes MF radar are underestimated in the order of 35% and winds from the narrow-beam Saura MF radar are underestimated by about 20% compared to falling sphere winds at altitudes between 70 and 80 km. Furthermore, the relation between wind measurements using narrow-beam and wide-beam antenna arrangements for the MF radars is discussed and VHF radar observations are compared to the wide-beam MF radar.

scholarly journals Semidiurnal solar tide differences between fall and spring transition times in the Northern Hemisphere

2018 ◽  
Author(s):  
J. Federico Conte ◽  
Jorge L. Chau ◽  
Fazlul I. Laskar ◽  
Gunter Stober ◽  
Hauke Schmidt ◽  
...  
Keyword(s):  
Northern Hemisphere ◽  
Gravity Waves ◽  
Wave Activity ◽  
Wave Number ◽  
Meteor Radar ◽  
Strong Shift ◽  
Spring Transition ◽  
Solar Tide ◽  
Wind Measurements ◽  
Transition Times

Abstract. We present a study of the semidiurnal solar tide (S2) during the fall and spring transition times in the Northern Hemisphere. The tides have been obtained from wind measurements provided by three meteor radars located at: Andenes (69° N, 16° E), Juliusruh (54° N, 13° E) and Tavistock (42° N, 81° W). During the autumn, S2 is characterized by a sudden and pronounced decrease occurring every year and at all height levels. The spring transition also shows a decrease of S2, but not sudden and that ascends from lower to higher altitudes during an interval of ~ 15 to 40 days. To assess contributions of different semidiurnal tidal components, we have examined a 20-year free run simulation by the Hamburg Model of the Neutral and Ionized Atmosphere (HAMMONIA). We found that the differences exhibited by the S2 tide between equinox times are mainly due to distinct behaviors of the migrating semidiurnal and the non-migrating westward propagating wave number 1 tidal components (SW2 and SW1, respectively). Specifically, during the fall both, SW2 and SW1 decrease, while during the spring time SW2 decreases but SW1 remains approximately constant or decreases only slightly. The decrease shown by SW1 during the fall occurs later than that of SW2 and S2, which indicates that the behavior of S2 is mainly driven by the migrating component. Nonetheless, the influence of SW1 is necessary to explain the behavior of S2 during the spring. In addition, a strong shift in the phase of S2 (of SW2 in the simulations) is also observed during the fall. Our meteor radar wind measurements show more gravity wave activity in the autumn than during the spring, which might be indicating that the fall decrease is partly due to interactions between SW2 and gravity waves.

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