MF and HF radar techniques for investigating the dynamics and structure of the 50 to 110 km height region: a review

Reid, Iain Murray

doi:10.1186/s40645-015-0060-7

Cited by 35 publications

(45 citation statements)

References 159 publications

(266 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The former is thought to be mostly responsible for MST radar echoes and the latter for wide-beam MF radar echoes. However, the mechanisms are still not fully understood, and both scatters are thought to coexist in reality (Hocking and Röttger 2001;Reid 2015). We found that the AOAs of the MF echoes were more widely distributed in winter than in summer, implying more isotropic (less specular) echoes in winter.…”

Section: Discussionmentioning

confidence: 70%

“…The ratio for the meridional component is from approximately 0.85 to 1 above 70 km, but gradually decreases with decreasing height and reaches 0.7 at 60 km. It is known that wide beam MF radars such as the Syowa system tend to underestimate wind velocities (e.g., Manson et al 2004;Tsutsumi and Aso 2005) and that such radar data should be carefully treated (e.g., Reid 2015). The somewhat reduced Syowa MF meridional winds seem to be at least partly due to the low signal-to-noise ratio of one of the four antennas, at the northernmost corner of the triangle-shaped receiving array, located close to the radar hut.…”

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Characteristics of Mesosphere Echoes over Antarctica Obtained Using PANSY and MF Radars

Tsutsumi

Sato

et al. 2017

SOLA

View full text Add to dashboard Cite

We investigated characteristics of mesosphere echoes over Syowa Station (69S) in the Antarctic, which were detected by the Program of the Antarctic Syowa Mesosphere, Stratosphere and Troposphere/Incoherent Scatter (PANSY) radar (47 MHz) and Medium Frequency (MF) radar (2.4 MHz). Winter echoes from the PANSY radar and low altitude MF echoes below approximately 70−75 km mostly coexisted, appearing during the daytime as well as for a few hours post sunset. Summer echoes in the lower height region were absent in both radar observations, suggesting a close relationship in the generation mechanisms of these two radar echoes. High correlation between local K-index and the occurrence of winter echoes suggested that electron density enhancement due to ionized particle precipitation was one of the triggers of echo generation. Angles of arrival of the MF echoes were more isotropic in winter. Because gravity wave activity is much higher in winter over Syowa, higher turbulence energy caused by gravity wave breaking may also be responsible for the generation of the winter echoes and their isotropic behavior. The horizontal wind velocities of the two systems were further compared and agreed well throughout the height region of 60−90 km.

show abstract

Section: Discussionmentioning

confidence: 70%

Section: Resultsmentioning

confidence: 99%

Characteristics of Mesosphere Echoes over Antarctica Obtained Using PANSY and MF Radars

Tsutsumi

Sato

et al. 2017

SOLA

View full text Add to dashboard Cite

show abstract

“…The systems are the Andenes Meteor Radar, which measures radial velocities from meteor trails, and the Saura MF radar, which obtains measurements from refraction index variations due to dynamic processes (e.g., gravity waves) and D-layer ionization and associated irregularities (Reid, 2015). The technical details for both systems are summarized in Table 1.…”

Section: Methodsmentioning

confidence: 99%

“…A crucial aspect of the measured winds is the reliability of each technique. This requires a proper understanding of the underlying scattering processes and possible instrumental effects, analysis related simplifications, and assumptions that could introduce biases or systematic errors in the derived winds (Reid, 2015).…”

Section: Introductionmentioning

confidence: 99%

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

2017

View full text Add to dashboard Cite

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.

show abstract

“…The reliability has also been demonstrated in recent comparisons to other remote sensing techniques and the Navy Global Environmental Model (NAVGEM) (Reid, 2015;McCormack et al, 2017;Wilhelm et al, 2017).…”

Section: Meteor Radarmentioning

confidence: 85%

Validation of middle-atmospheric wind in observations and models

Rüfenacht

Baumgarten

Hildebrand

et al. 2017

Preprint

View full text Add to dashboard Cite

Abstract. Wind profile information throughout the upper stratosphere and lower mesosphere (USLM) is important for the understanding of atmospheric dynamics but became available only recently, thanks to developments in remote sensing techniques and modelling approaches. However, as wind measurements from these altitudes are still very rare, such products havegenerally not yet been validated with (other) observations. This paper presents the first long-term intercomparison of wind observations in the USLM by opposing co-located microwave radiometer and lidar instruments at Andenes (69.3 • N, 16.0 • E). 5Good correspondence has been found at all altitudes for both horizontal wind components for nighttime as well as daylight conditions. Biases are mostly within the random errors and do not exceed 5-10 m/s which is less than 10% of the typically encountered wind speeds. Moreover, comparisons of the observations with the major re-analyses and models covering this altitude range are shown, especially also with the freshly released ERA5, ECMWF's first re-analysis to cover the whole USLM region. The agreement between models and observations is very good in general, but temporally limited occurrences of pro-10 nounced discrepancies (up to 40 m/s) exist. In the article's appendix the possibility of obtaining nighttime wind information about the mesopause region by means of microwave radiometry is investigated.

show abstract

MF and HF radar techniques for investigating the dynamics and structure of the 50 to 110 km height region: a review

Cited by 35 publications

References 159 publications

Characteristics of Mesosphere Echoes over Antarctica Obtained Using PANSY and MF Radars

Characteristics of Mesosphere Echoes over Antarctica Obtained Using PANSY and MF Radars

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

Validation of middle-atmospheric wind in observations and models

Contact Info

Product

Resources

About

MF and HF radar techniques for investigating the dynamics and structure of the 50 to 110 km height region: a review

Cited by 35 publications

References 159 publications

Characteristics of Mesosphere Echoes over Antarctica Obtained Using PANSY and MF Radars

Characteristics of Mesosphere Echoes over Antarctica Obtained Using PANSY and MF Radars

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

Validation of middle-atmospheric wind in observations and models

Contact Info

Product

Resources

About

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