ORCID Profile
0000-0003-2340-9047
Current Organisations
University of Adelaide
,
ATRAD Pty. Ltd.
Does something not look right? The information on this page has been harvested from data sources that may not be up to date. We continue to work with information providers to improve coverage and quality. To report an issue, use the Feedback Form.
Publisher: Elsevier BV
Date: 1997
Publisher: American Geophysical Union (AGU)
Date: 20-04-1989
Publisher: MDPI AG
Date: 21-01-2020
Abstract: The Calbuco volcano in southern Chile (41.3° S, 72.6° W) underwent three separate eruptions on 22–23 April 2015. Following the eruptions, distinct layers of enhanced lidar backscatter at 532 nm were observed in the lower stratosphere above Buckland Park, South Australia (34.6° S, 138.5° E), and Kingston, Tasmania (43.0° S, 147.3° E), during a small set of observations in April–May 2015. Using atmospheric trajectory modelling and measurements from the Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) space-borne lidar and the Ozone Mapping Profiler Suite (OMPS) instrument on the Suomi National Polar-orbiting Partnership (NPP) satellite, we show that these layers were associated with the Calbuco eruptions. Buckland Park measurements on 30 April and 3 May detected discrete aerosol layers at and slightly above the tropopause, where the relative humidity was well below saturation. Stratospheric aerosol layers likely associated with the eruptions were observed at Kingston on 17 and 22 May in narrow discrete layers accompanied by weaker and more vertically extended backscatter. The measurements on 22 May provided a mean value of the particle linear depolarisation ratio within the main observed volcanic aerosol layer of 18.0 ± 3.0%, which was consistent with contemporaneous CALIOP measurements. The depolarisation measurements indicated that this layer consisted of a filament dominated by ash backscatter residing above a main region having likely more sulfate backscatter. Layer-average optical depths were estimated from the measurements. The mean lidar ratio for the volcanic aerosols on 22 May of 86 ± 37 sr is consistent with but generally higher than the mean for ground-based measurements for other volcanic events. The inferred optical depth for the main volcanic layer on 17 May was consistent with a value obtained from OMPS measurements, but a large difference on 22 May likely reflected the spatial inhomogeneity of the volcanic plume. Short-lived enhancements of backscatter near the tropopause of 17 May likely represented the formation cirrus that was aided by the presence of associated volcanic aerosols. We also provide evidence that gravity waves potentially influenced the layers, particularly in regard to the vertical motion observed in the strong layer on 22 May. Overall, these observations provide additional information on the dispersal and characteristics of the Calbuco aerosol plumes at higher southern latitudes than previously reported for ground-based lidar measurements.
Publisher: Elsevier BV
Date: 10-2014
Publisher: American Geophysical Union (AGU)
Date: 07-2000
DOI: 10.1029/1999RS002233
Publisher: Wiley
Date: 04-2018
DOI: 10.1002/2017JA025059
Publisher: Copernicus GmbH
Date: 21-07-2021
Abstract: Abstract. A 31 MHz meteor radar located in Svalbard was used to observe polar mesospheric echoes (PMSEs) during summer 2020. Data from 19 July were selected for detailed analysis, with a focus on extracting additional information to characterize the atmosphere in the PMSE region. The use of an all-sky meteor radar adds an additional use to data collected for meteor observations and enables the detection of PMSE layers across a wide field of view. Comparison with data from a 53.5 MHz narrow-beam mesosphere–stratosphere–troposphere (MST) radar shows good agreement in the morphology of the layer as detected between the two systems. Doppler spectra of PMSE layers reveal fine structure, including regions of enhanced return that move across the radar's field of view. Examination of the relationship between range and Doppler shift of off-zenith portions of the layer enables the estimation of wind speeds with high temporal resolution during PMSE conditions. Trials demonstrate good agreement between wind speeds obtained from PMSE Doppler spectra and those calculated from specular meteor trail radial velocities. Combined with the antenna polar diagram of the radar, this same relationship was used to infer the aspect sensitivity of observed PMSE backscatter, yielding a mean backscatter angular width of 6.8±3.3∘. A comparison of underdense meteor radar echo decay times during and outside of PMSE conditions did not demonstrate a strong correlation between the presence of PMSEs and shortened underdense meteor radar echo durations.
Publisher: American Geophysical Union (AGU)
Date: 11-1996
DOI: 10.1029/96RS02028
Publisher: American Geophysical Union (AGU)
Date: 07-1995
DOI: 10.1029/95RS00644
Publisher: American Geophysical Union (AGU)
Date: 03-1996
DOI: 10.1029/95JD03826
Publisher: IEEE
Date: 2003
Publisher: IEEE
Date: 2003
Publisher: American Geophysical Union (AGU)
Date: 11-1997
DOI: 10.1029/96JD03145
Publisher: Elsevier BV
Date: 10-2014
Publisher: Elsevier BV
Date: 02-2006
Publisher: American Geophysical Union (AGU)
Date: 25-08-2010
DOI: 10.1029/2009JD013772
Publisher: American Geophysical Union (AGU)
Date: 23-09-2015
DOI: 10.1002/2015JD023197
Publisher: American Geophysical Union (AGU)
Date: 11-1985
Publisher: American Geophysical Union (AGU)
Date: 02-1989
Publisher: Copernicus GmbH
Date: 04-02-2021
DOI: 10.5194/ACP-2021-33
Abstract: Abstract. We present a study of migrating and non-migrating tidal winds observed simultaneously by three meteor radars situated in the southern equatorial region. The radars are located at Cariri (7.4° S, 36.5° W), Brazil, Kototabang (0.2° S, 100.3° E), Indonesia and Darwin (12.3° S, 130.8° E), Australia. Harmonic analysis was used to obtain litudes and phases for diurnal and semidiurnal solar migrating and non-migrating tides between 80 and 100 km altitude during the period 2005 to 2008. They include the important tidal components of diurnal westward-propagating zonal wavenumber 1 (DW1), diurnal eastward-propagating zonal wavenumber 3 (DE3), semidiurnal westward-propagating zonal wavenumber 2 (SW2), and semidiurnal eastward-propagating zonal wavenumber 2 (SE2). In addition, we also present a climatology of these wind tides and analyze the reliability of the fitting through the reference to Whole Atmosphere Community Climate Model (WACCM) winds. The analysis suggests that the migrating tides could be well fitted by the three different radars, but the non-migrating tides might be overestimated. The results based on observations were also compared with the Climatological Tidal Model of the Thermosphere (CTMT). In general, climatic features between observations and model migrating tides were satisfactory in both wind components. However, the features of the DW1, DE3 and SW2 litudes in both wind components were slightly different from the results of the CTMT models. This result is probably because tides could be enhanced by the 2006 northern hemisphere stratospheric sudden warming (NH-SSW) event.
Publisher: Elsevier BV
Date: 05-2002
Publisher: American Geophysical Union (AGU)
Date: 09-2004
DOI: 10.1029/2003GL019200
Publisher: American Geophysical Union (AGU)
Date: 07-08-2022
DOI: 10.1029/2022JD036558
Abstract: Twenty six years of medium frequency (MF) radar wind measurements made from 1994 to 2019 at Davis Station (68.6°S, 77.9°E) are used to study the mean response of the mesosphere‐lower thermosphere to stratospheric warmings in the Southern Hemisphere. Warming events were detected using Modern‐Era Retrospective Analysis for Research and Applications (MERRA2) data with a systematic search for reductions in the zonal‐mean circulation at 60°S and corresponding increases in polar temperatures. Some 37 events were identified, including the 2002 major warming and the large event of 2019, with an average of 1–2 warmings per year. At the 10 hPa level, the polar cap temperature increases ranged from 3 to 28 K, with a mean value of 12 K, while the zonal wind speed reductions varied between −6 and −43 ms −1 , with a mean value of −15 ms −1 . Peak values occurred near 40 km. Warmings occurred mainly between August and October, with a small peak in occurrence in April/May. The MF radar data showed an average reduction in the mesospheric eastward winds of about 5–7 ms −1 at heights near 75 km that occurred 3–4 days prior to the changes in the stratosphere. Warming events were driven by episodic intensifications in planetary wave litudes, with quasi‐stationary planetary scale waves (PW) 1 being especially important. PW Eliassen‐Palm flux ergences show a systematic behavior with time and height that is consistent with a poleward residual circulation and downwelling over the pole prior to the warming events and an equatorward flow and upwelling after the peak of the events.
Publisher: American Geophysical Union (AGU)
Date: 09-11-2005
DOI: 10.1029/2004JD005427
Publisher: Elsevier BV
Date: 1996
Publisher: American Geophysical Union (AGU)
Date: 25-06-2013
DOI: 10.1002/JGRD.50372
Publisher: American Geophysical Union (AGU)
Date: 07-1995
DOI: 10.1029/95RS00994
Publisher: Oxford University Press (OUP)
Date: 30-07-2012
Publisher: American Geophysical Union (AGU)
Date: 05-2000
DOI: 10.1029/1999RS002226
Publisher: Copernicus GmbH
Date: 12-06-2017
DOI: 10.5194/ANGEO-35-733-2017
Abstract: Abstract. Mesospheric gravity wave (GW) momentum flux estimates using data from multibeam Buckland Park MF radar (34.6° S, 138.5° E) experiments (conducted from July 1997 to June 1998) are presented. On transmission, five Doppler beams were symmetrically steered about the zenith (one zenith beam and four off-zenith beams in the cardinal directions). The received beams were analysed with hybrid Doppler interferometry (HDI) (Holdsworth and Reid, 1998), principally to determine the radial velocities of the effective scattering centres illuminated by the radar. The methodology of Thorsen et al. (1997), later re-introduced by Hocking (2005) and since extensively applied to meteor radar returns, was used to estimate components of Reynolds stress due to propagating GWs and/or turbulence in the radar resolution volume. Physically reasonable momentum flux estimates are derived from the Reynolds stress components, which are also verified using a simple radar model incorporating GW-induced wind perturbations. On the basis of these results, we recommend the intercomparison of momentum flux estimates between co-located meteor radars and vertical-beam interferometric MF radars. It is envisaged that such intercomparisons will assist with the clarification of recent concerns (e.g. Vincent et al., 2010) of the accuracy of the meteor radar technique.
Publisher: Elsevier BV
Date: 11-2002
Publisher: Elsevier BV
Date: 1997
Publisher: IEEE
Date: 10-2014
Publisher: Springer Science and Business Media LLC
Date: 05-1987
DOI: 10.1038/327043A0
Publisher: Elsevier BV
Date: 12-2002
Publisher: American Geophysical Union (AGU)
Date: 10-2005
DOI: 10.1029/2004RS003055
Publisher: Elsevier BV
Date: 12-2002
Publisher: Copernicus GmbH
Date: 25-01-2021
DOI: 10.5194/AMT-2021-14
Abstract: Abstract. A 31 MHz meteor radar located in Svalbard has been used to observe polar mesospheric echoes (PMSE) during summer 2020. Data from 19 July was selected for detailed analysis, with a focus on extracting additional information to characterize the atmosphere in the PMSE region. The use of an all-sky meteor radar adds an additional use to data collected for meteor observations and enables the detection of PMSE layers across a wide field of view. Comparison with data from a 53.5 MHz narrow-beam MST radar shows good agreement in the morphology of the layer as detected between the two systems. Doppler spectra of PMSE layers reveal fine structure, including regions of enhanced return that move across the radar's field of view. The relationship between range and Doppler shift of off-zenith portions of the layer enable the estimation of wind speeds with high temporal resolution during PMSE conditions. Trials demonstrate good agreement between wind speeds obtained from PMSE Doppler spectra and those calculated from specular meteor trail radial velocities. Combined with the antenna polar diagram of the radar, this same relationship was used to infer the aspect sensitivity of observed PMSE backscatter, yielding a mean backscatter angular width of 6.6 ± 2.8°. A comparison of underdense meteor radar echo decay times during and outside of PMSE conditions did not demonstrate a strong correlation between the presence of PMSE and shortened underdense meteor radar echo durations.
Publisher: American Geophysical Union (AGU)
Date: 03-1997
DOI: 10.1029/97GL00128
Publisher: American Geophysical Union (AGU)
Date: 03-2013
DOI: 10.1002/RDS.20026
Publisher: Copernicus GmbH
Date: 07-12-2022
DOI: 10.5194/AMT-2022-254
Abstract: Abstract. All-sky meteor radars have become a reliable and widely used tool to observe horizontal winds in the mesosphere and lower thermosphere (MLT) region. The horizontal winds estimated by conventional single-station radars are obtained after averaging all meteor detections based on the assumption of the homogeneity of the horizontal wind in the meteor detection area (approximately 200–300 km radius). In this study, to improve the horizontal winds, we apply a multistatic meteor radar system consisting of a monostatic meteor radar in Mengcheng (33.36° N, 116.49° E) and a bistatic remote receiver in Changfeng (31.98° N, 117.22° E), separated by approximately 167 km to increase the number of meteors by at least 70 % and provide two different viewing angles of the meteor echoes. The accuracy of the horizontal wind measurement depends on the meteor number in time and altitude intervals. Compared to typical monostatic meteor radar, our approach shows the feasibility of estimating the two-dimensional horizontal wind field. The technique allows us to estimate the mean horizontal wind and the gradient terms of the horizontal wind, moreover, the horizontal ergence, relative vorticity, stretching and shearing deformation of the wind field. We are confident that the improved horizontal wind parameters will contribute to improving the understanding of the dynamics in the MLT region.
Publisher: American Geophysical Union (AGU)
Date: 09-2018
DOI: 10.1029/2018RS006613
Publisher: American Geophysical Union (AGU)
Date: 11-03-2015
DOI: 10.1002/2014JD022016
Publisher: American Geophysical Union (AGU)
Date: 22-02-2021
DOI: 10.1029/2020GL089957
Abstract: We report an analysis of the response of tides in neutral atmospheric mesospheric winds to recurrent geomagnetic activity in 2005 over Antarctica. The mesospheric winds were observed by the Davis meteor and medium frequency radars (68.5°S, 77.9°E magnetic latitude, 74.6°S). The zonal component of the daily prevailing winds showed a westward increase as the geomagnetic activity increased, while the meridional prevailing winds did not show a clear response. The semidiurnal tides responded greatly to geomagnetic activity, with significant increases in litude. The zonal and meridional semidiurnal tides both showed a clear upward propagating phase but responded differently to geomagnetic activity. The litude of the meridional component of the diurnal tides increased significantly, while the zonal diurnal tidal litude showed no apparent change. These results indicate that geomagnetic activity can significantly influence mesospheric dynamics.
Publisher: American Geophysical Union (AGU)
Date: 09-2001
DOI: 10.1029/2000RS002360
Publisher: American Geophysical Union (AGU)
Date: 07-2010
DOI: 10.1029/2010GL044086
Publisher: Copernicus GmbH
Date: 15-11-2018
Abstract: Abstract. The existing distribution of meteor radars located from high- to low-latitude regions provides a favourable temporal and spatial coverage for investigating the climatology of the global mesopause density. In this study, we report the climatology of the mesopause density estimated using multiyear observations from nine meteor radars, namely, the Davis Station (68.6° S, 77.9° E), Svalbard (78.3° N, 16° E) and Tromsø (69.6° N, 19.2° E) meteor radars located at high latitudes, the Mohe (53.5° N, 122.3° E), Beijing (40.3° N, 116.2° E), Mengcheng (33.4° N, 116.6° E) and Wuhan (30.5° N, 114.6° E) meteor radars located in the mid-latitudes, and the Kunming (25.6° N, 103.8° E) and Darwin (12.3° S, 130.8° E) meteor radars located at low latitudes. The daily mean density was estimated using ambipolar diffusion coefficients derived from the meteor radars and temperatures from the Microwave Limb Sounder (MLS) on board the Aura satellite. The seasonal variations in the Davis Station meteor radar densities in the southern polar mesopause are mainly dominated by an annual oscillation (AO). The mesopause densities observed by the Svalbard and Tromsø meteor radars at high latitudes and the Mohe and Beijing meteor radars at high mid-latitudes in the Northern Hemisphere show mainly an AO and a relatively weak semiannual oscillation (SAO). The mesopause densities observed by the Mengcheng and Wuhan meteor radars at lower mid-latitudes and the Kunming and Darwin meteor radars at low latitudes show mainly an AO. The SAO is evident in the Northern Hemisphere, especially at high latitudes, and its largest litude, which is detected at the Tromsø meteor radar, is comparable to the AO litudes. These observations indicate that the mesopause densities over the southern and northern high latitudes exhibit a clear seasonal asymmetry. The maxima of the yearly variations in the mesopause densities display a clear temporal variation across the spring equinox as the latitude decreases these latitudinal variation characteristics may be related to latitudinal changes influenced by gravity wave forcing. In addition to an AO, the mesopause densities over low latitudes also clearly show a variation with a periodicity of 30–60 days related to the Madden-Julian oscillation in the subtropical troposphere.
Publisher: Elsevier BV
Date: 1999
Publisher: American Geophysical Union (AGU)
Date: 11-2004
DOI: 10.1029/2004JA010450
Publisher: American Geophysical Union (AGU)
Date: 20-06-1990
Publisher: American Geophysical Union (AGU)
Date: 20-09-1989
Publisher: Elsevier BV
Date: 02-1988
Publisher: American Geophysical Union (AGU)
Date: 06-11-2004
DOI: 10.1029/2003JD003378
Publisher: American Geophysical Union (AGU)
Date: 07-1998
DOI: 10.1029/98RS00828
Publisher: Oxford University Press (OUP)
Date: 09-2009
Publisher: American Geophysical Union (AGU)
Date: 11-1985
Publisher: American Meteorological Society
Date: 05-1983
Publisher: MDPI AG
Date: 13-05-2022
DOI: 10.3390/RS14102354
Abstract: This study compares the hourly mesospheric horizontal winds observed by two collocated and independent low-latitude meteor radars operating at 37.5 MHz and 53.1 MHz in Kunming, China (25.6°N, 103.8°E). Upon analyzing simultaneously detected meteor echoes, we find a fixed angular deviation between the baselines of the two meteor radar antenna arrays within the east–north–up coordinate system. Then, we correct the deviation in the antenna azimuth direction using a novel method and recalculate the horizontal zonal and meridional winds. A comparison of the results before and after the correction shows strong consistency between the winds observed by both meteor radars within the entire detection altitude range. Furthermore, we summarize the performance of different techniques for measuring mesospheric winds. Ultimately, our statistical analysis approach allows the uncertainties associated with meteor radar wind observations to be more precisely estimated.
Publisher: Elsevier BV
Date: 2005
Publisher: Elsevier BV
Date: 2005
Publisher: American Geophysical Union (AGU)
Date: 08-2008
DOI: 10.1029/2008GL033763
Publisher: American Geophysical Union (AGU)
Date: 11-08-2004
DOI: 10.1029/2004JD004714
Publisher: Elsevier BV
Date: 1990
Publisher: American Geophysical Union (AGU)
Date: 04-1996
DOI: 10.1029/95JD03578
Publisher: American Geophysical Union (AGU)
Date: 30-11-2022
DOI: 10.1029/2022JA030678
Abstract: We present the migrating tidal winds decomposed jointly from multiple meteor radars in four longitudinal sectors situated in the equatorial mesosphere and lower thermosphere. The radars are located in Cariri, Brazil (7.4°S, 36.5°W), Kototabang, Indonesia (0.2°S, 100.3°E), Ascension Island, United Kingdom (7.9° S, 14.4° W), and Darwin, Australia (12.3°S, 130.8°E). Harmonic analysis was used to obtain litudes and phases for diurnal and semidiurnal solar migrating tides between 82 and 98 km altitude during the period 2005–2008. To verify the reliability of the tidal components calculated by the four meteor radar wind measurements, we also present a similar analysis for the Whole Atmosphere Community Climate Model winds, which suggests that the migrating tides are well observed by the four different radars. The tides include the important tidal components of diurnal westward‐propagating zonal wavenumber 1 and semidiurnal westward‐propagating zonal wavenumber 2. In addition, the results based on observations were compared with the Climatological Tidal Model of the Thermosphere (CTMT). In general, in terms of climatic features, our results for the major components of migrating tides are qualitatively consistent with the CTMT models derived from satellite data. In addition, the tidal litudes are unusually stronger in January–February 2006. This result is probably because tides were enhanced by the 2006 Northern Hemisphere stratospheric sudden warming event.
Publisher: American Geophysical Union (AGU)
Date: 07-1995
DOI: 10.1029/95RS00731
Publisher: American Geophysical Union (AGU)
Date: 07-1995
DOI: 10.1029/95RS00732
Publisher: American Geophysical Union (AGU)
Date: 09-1995
DOI: 10.1029/95RS01888
Publisher: American Geophysical Union (AGU)
Date: 15-03-2006
DOI: 10.1029/2005JD006589
Publisher: American Geophysical Union (AGU)
Date: 04-2022
DOI: 10.1029/2022JA030380
Abstract: The Meteor and ionospheric Irregularity Observation System (MIOS), which consists of multi‐station optical subsystem at Ledong (18.4°N, 109°E) and Sanya (18.3°N, 109.6°E), and radar subsystem including a 38.9 MHz all‐sky interferometric radar and a 47.5 MHz coherent phased array radar at Ledong, has been in full operational since December 2021. This paper describes the system design and first results of meteor plasma density irregularities and corresponding meteoroids. The MIOS optical subsystem consists of a few tens of video cameras for observing optical meteor trail and spectrum. The MIOS phased array is composed of 135 Yagi antennas, arranged in sword‐like grid and grouped into 15 identical subarrays, with distances separated by 2–19.5 times the wavelength for unambiguous interferometry measurements. The phased array can form narrow and wide beams, with half power width of 8° and 24° in azimuth, respectively, allowing narrow‐beam pulse‐to‐pulse steering and wide‐beam multi‐baseline imaging observations in the east‐west direction. Observational results show that the MIOS is capable of unambiguously locating various meteor echoes, that is, head, specular and non‐specular echoes, revealing the structural evolution of field‐aligned and non‐field‐aligned irregularity, and of determining the properties of meteoroids producing/not producing irregularities. Cases of bright meteors producing non‐field‐aligned irregularities and not producing field‐aligned irregularities respectively are presented, and possible factors affecting the generation of meteor trail irregularities are discussed based on current understanding. It is expected that the MIOS will provide an important tool to study the generation and evolution of various meteor trail irregularities and the properties of the corresponding meteoroids.
Publisher: American Geophysical Union (AGU)
Date: 10-2019
DOI: 10.1029/2019JA026538
Publisher: American Geophysical Union (AGU)
Date: 12-2008
DOI: 10.1029/2008JA013668
Publisher: American Geophysical Union (AGU)
Date: 12-01-2018
DOI: 10.1002/2017GL076282
Publisher: American Geophysical Union (AGU)
Date: 13-06-2014
DOI: 10.1002/2013JD020906
Publisher: American Geophysical Union (AGU)
Date: 10-2004
DOI: 10.1029/2003RS003014
Publisher: Elsevier BV
Date: 2007
Publisher: Copernicus GmbH
Date: 10-04-2019
DOI: 10.5194/AMT-2019-138
Abstract: Abstract. This paper assesses the ability of a recently-installed 55 MHz multistatic meteor radar to measure gravity wave-driven momentum fluxes around the mesopause, and applies it in a case study of measuring gravity wave forcing on the diurnal tide during a period following the autumnal equinox of 2018. The radar considered is in the vicinity of Adelaide, South Australia (34.9° S, 138.6° E) and consists of a monostatic radar and bistatic receiver separated by approximately 55 km. The assessment shows that the inclusion of the bistatic receiver reduces the relative uncertainty of the momentum flux estimate from about 75 % to 65 % (for a flux magnitude of ~ 20 m2 s−2, one day's worth of integration, and for a gravity wave field synthesized from a realistic spectral model). This increase in precision appears to be entirely attributable to the increased number of meteor detections associated with the combined monostatic and bistatic receivers, rather than changes in the meteors' spatial distribution. The case study reveals large modulations in the diurnal tidal litudes, with a maximum tidal litude of ~ 50 ms−1 and an associated maximum zonal wind velocity of around 140 ms−1. While the observed gravity wave forcing exhibits a complex relationship with the tidal winds during this period, the components of the forcing are seen to be approximately out of phase with the tidal winds above 88 km. No clear phase relationship has been observed below 88 km.
Publisher: Copernicus GmbH
Date: 18-04-2017
DOI: 10.5194/ANGEO-35-567-2017
Abstract: Abstract. We consider 5 years of spectrometer measurements of OH(6–2) and O2(0–1) airglow emission intensities and temperatures made near Adelaide, Australia (35° S, 138° E), between September 2001 and August 2006 and compare them with measurements of the same parameters from at the same site using an airglow imager, with the intensities of the OH(8–3) and O(1S) emissions made with a filter photometer, and with 2 years of Aura MLS (Microwave Limb Sounder) v3.3 temperatures and 4.5 years of TIMED SABER (Thermosphere Ionosphere Mesosphere Energetics and Dynamics Sounding of the Atmosphere using Broadband Emission Radiometry) v2.0 temperatures for the same site. We also consider whether we can recover the actual emission heights from the intercomparison of the ground-based and satellite observations. We find a significant improvement in the correlation between the spectrometer OH and SABER temperatures by interpolating the latter to constant density surfaces determined using a meteor radar.
Publisher: Elsevier BV
Date: 05-2002
Publisher: Copernicus GmbH
Date: 06-09-2019
Abstract: Abstract. This paper assesses the ability of a recently installed 55 MHz multistatic meteor radar to measure gravity-wave-driven momentum fluxes around the mesopause and applies it in a case study of measuring gravity wave forcing on the diurnal tide during a period following the autumnal equinox of 2018. The radar considered is in the vicinity of Adelaide, South Australia (34.9∘ S, 138.6∘ E), and consists of a monostatic radar and bistatic receiver separated by approximately 55 km. The assessment shows that the inclusion of the bistatic receiver reduces the relative uncertainty of the momentum flux estimate from about 75 % to 65 % (for a flux magnitude of ∼20 m2 s−2, 1 d's worth of integration, and for a gravity wave field synthesized from a realistic spectral model). This increase in precision appears to be entirely attributable to the increased number of meteor detections associated with the combined monostatic and bistatic receivers rather than changes in the meteors' spatial distribution. The case study reveals large modulations in the diurnal tidal litudes, with a maximum tidal litude of ∼50 m s−1 and an associated maximum zonal wind velocity of around 140 m s−1. While the observed gravity wave forcing exhibits a complex relationship with the tidal winds during this period, the components of the forcing are seen to be approximately out of phase with the tidal winds above 88 km. No clear phase relationship has been observed below 88 km.
Publisher: American Geophysical Union (AGU)
Date: 03-2012
DOI: 10.1029/2011JA016847
Publisher: American Geophysical Union (AGU)
Date: 08-2004
DOI: 10.1029/2004GL020352
Publisher: American Geophysical Union (AGU)
Date: 08-2017
DOI: 10.1002/2017JA024446
Publisher: American Geophysical Union (AGU)
Date: 24-07-2015
DOI: 10.1002/2015GL065066
Publisher: Elsevier BV
Date: 06-2015
Publisher: Elsevier BV
Date: 07-2008
Publisher: American Geophysical Union (AGU)
Date: 19-03-2021
DOI: 10.1029/2020JD034301
Abstract: We present the climatology of mesopause temperatures using high‐latitude and middle‐latitude meteor radars. The daily mesopause temperatures are estimated using ambipolar diffusion coefficient data from the meteor radars at Davis Station (68.6°S, 77.9°E), in Antarctica, Svalbard (78.3°N, 16°E), Tromsø (69.6°N, 19.2°E) in the Arctic, and Mohe (53.5°N, 122.3°E) and Beijing (40.3°N, 116.2°E) in the northern middle latitudes. The seasonal variations in the meteor radar‐derived temperatures are in good agreement with the temperatures from the Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) instrument onboard the TIMED satellite. Interhemispheric observations indicate that the mesopause temperatures over the southern and northern polar regions show a clear seasonal asymmetry. The seasonal variations in the Davis Station meteor radar temperatures in the southern polar mesopause are dominated by an annual oscillation (AO) with a relatively weak semiannual oscillation (SAO), which show a clear minimum during summer and a maximum during winter. The mesopause temperatures in the northern high and middle latitudes observed by the Svalbard, Tromsø, Mohe, and Beijing meteor radars mainly show an AO, with a maximum during winter and a minimum during summer. The AO in the northern polar regions is stronger than that in the southern polar regions, while the SAO in the southern polar regions is relatively strong compared to that in the northern polar regions.
Publisher: Springer Science and Business Media LLC
Date: 10-08-2018
Publisher: Elsevier BV
Date: 11-1986
Publisher: American Geophysical Union (AGU)
Date: 07-11-2019
DOI: 10.1029/2019JD030735
Publisher: Springer Science and Business Media LLC
Date: 21-05-2018
Publisher: American Geophysical Union (AGU)
Date: 09-2017
DOI: 10.1002/2017RS006284
Publisher: Elsevier BV
Date: 10-1987
Publisher: American Geophysical Union (AGU)
Date: 26-08-2017
DOI: 10.1002/2017GL074813
Publisher: American Geophysical Union (AGU)
Date: 10-2012
DOI: 10.1029/2012JA017850
Publisher: American Meteorological Society
Date: 06-2003
Publisher: American Geophysical Union (AGU)
Date: 17-11-2012
DOI: 10.1029/2012JD017847
Publisher: American Geophysical Union (AGU)
Date: 12-2014
DOI: 10.1002/2014JA020116
Publisher: American Geophysical Union (AGU)
Date: 17-09-2018
DOI: 10.1029/2017JD028250
Publisher: Copernicus GmbH
Date: 06-06-2019
Abstract: Abstract. The existing distribution of meteor radars located from high- to low-latitude regions provides a favorable temporal and spatial coverage for investigating the climatology of the global mesopause density. In this study, we report the climatology of the mesopause relative density estimated using multiyear observations from nine meteor radars, namely, the Davis Station (68.6∘ S, 77.9∘ E), Svalbard (78.3∘ N, 16∘ E) and Tromsø (69.6∘ N, 19.2∘ E) meteor radars located at high latitudes the Mohe (53.5∘ N, 122.3∘ E), Beijing (40.3∘ N, 116.2∘ E), Mengcheng (33.4∘ N, 116.6∘ E) and Wuhan (30.5∘ N, 114.6∘ E) meteor radars located in the midlatitudes and the Kunming (25.6∘ N, 103.8∘ E) and Darwin (12.3∘ S, 130.8∘ E) meteor radars located at low latitudes. The daily mean relative density was estimated using ambipolar diffusion coefficients derived from the meteor radars and temperatures from the Microwave Limb Sounder (MLS) on board the Aura satellite. The seasonal variations in the Davis Station meteor radar relative densities in the southern polar mesopause are mainly dominated by an annual oscillation (AO). The mesopause relative densities observed by the Svalbard and Tromsø meteor radars at high latitudes and the Mohe and Beijing meteor radars at high midlatitudes in the Northern Hemisphere show mainly an AO and a relatively weak semiannual oscillation (SAO). The mesopause relative densities observed by the Mengcheng and Wuhan meteor radars at lower midlatitudes and the Kunming and Darwin meteor radars at low latitudes show mainly an AO. The SAO is evident in the Northern Hemisphere, especially at high latitudes, and its largest litude, which is detected at the Tromsø meteor radar, is comparable to the AO litudes. These observations indicate that the mesopause relative densities over the southern and northern high latitudes exhibit a clear seasonal asymmetry. The maxima of the yearly variations in the mesopause relative densities display a clear latitudinal variation across the spring equinox as the latitude decreases these latitudinal variation characteristics may be related to latitudinal changes influenced by gravity wave forcing. In addition to an AO, the mesopause relative densities over low latitudes also clearly show an intraseasonal variation with a periodicity of 30–60 d.
Publisher: Elsevier BV
Date: 05-2002
Publisher: IEEE
Date: 09-2013
Publisher: American Geophysical Union (AGU)
Date: 18-06-2019
DOI: 10.1029/2018JD029728
Publisher: Elsevier BV
Date: 08-1996
Publisher: Elsevier BV
Date: 10-1990
Publisher: American Geophysical Union (AGU)
Date: 05-2006
DOI: 10.1029/2005JA011443
Publisher: Elsevier BV
Date: 04-1999
Publisher: American Geophysical Union (AGU)
Date: 11-1997
DOI: 10.1029/96JD03966
Publisher: American Geophysical Union (AGU)
Date: 1998
DOI: 10.1029/97GL03399
Publisher: American Geophysical Union (AGU)
Date: 07-1995
DOI: 10.1029/95RS00645
Publisher: American Geophysical Union (AGU)
Date: 26-08-2008
DOI: 10.1029/2008JD009907
Publisher: American Geophysical Union (AGU)
Date: 21-07-2004
DOI: 10.1029/2003JD004096
Publisher: American Geophysical Union (AGU)
Date: 10-1988
Publisher: Springer Science and Business Media LLC
Date: 19-10-2015
Publisher: American Geophysical Union (AGU)
Date: 10-2004
DOI: 10.1029/2003RS003026
Publisher: Elsevier BV
Date: 05-1987
Publisher: American Geophysical Union (AGU)
Date: 11-04-2013
DOI: 10.1002/JGRD.50315
Publisher: SPIE
Date: 30-09-1994
DOI: 10.1117/12.187600
Publisher: American Geophysical Union (AGU)
Date: 24-10-2003
DOI: 10.1029/2002JD003349
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 11-2021
Publisher: American Geophysical Union (AGU)
Date: 07-10-2014
DOI: 10.1002/2014GL061478
Publisher: American Geophysical Union (AGU)
Date: 10-1988
No related grants have been discovered for Iain Reid.