A5086695806- Ionosphere and magnetosphere dynamics
- Atmospheric Ozone and Climate
- Solar and Space Plasma Dynamics
- Geophysics and Gravity Measurements
- Astro and Planetary Science
- Earthquake Detection and Analysis
- Geomagnetism and Paleomagnetism Studies
- Planetary Science and Exploration
- Seismic Waves and Analysis
- Meteorological Phenomena and Simulations
- Climate variability and models
- Oceanographic and Atmospheric Processes
- Atmospheric and Environmental Gas Dynamics
- Cryospheric studies and observations
- Methane Hydrates and Related Phenomena
- Atmospheric aerosols and clouds
- GNSS positioning and interference
- Geophysics and Sensor Technology
- Arctic and Antarctic ice dynamics
- Ocean Waves and Remote Sensing
- Atmospheric chemistry and aerosols
- Seismic Imaging and Inversion Techniques
- Geology and Paleoclimatology Research
- Inertial Sensor and Navigation
- Tropical and Extratropical Cyclones Research
Australian Antarctic Division
2015-2024
University of Tasmania
1994-2022
EnergyAustralia (Australia)
2018
Antarctic Climate and Ecosystems Cooperative Research Centre
2017
Japan Agency for Marine-Earth Science and Technology
2015
Australian Government
2006-2007
The University of Adelaide
1994
Abstract The current standard version of the Whole Atmosphere Community Climate Model (WACCM) simulates Southern Hemisphere winter and spring temperatures that are too cold compared with observations. This “cold-pole bias” leads to unrealistically low ozone column amounts in Antarctic spring. Here, cold-pole problem is addressed by introducing additional mechanical forcing circulation via parameterized gravity waves. Insofar as observational guidance ambiguous regarding waves might be...
Abstract The Deep Propagating Gravity Wave Experiment (DEEPWAVE) was designed to quantify gravity wave (GW) dynamics and effects from orographic other sources regions of dissipation at high altitudes. core DEEPWAVE field phase took place May through July 2014 using a comprehensive suite airborne ground-based instruments providing measurements Earth’s surface ∼100 km. Austral winter chosen observe deep GW propagation based on South Island, New Zealand, provide access the Zealand Tasmanian...
Abstract A data assimilation system (DAS) is described for global atmospheric reanalysis from 0- to 100-km altitude. We apply it the 2014 austral winter of Deep Propagating Gravity Wave Experiment (DEEPWAVE), an international field campaign focused on gravity wave dynamics 0 100 km, where absence above 60 km inhibits research. Four experiments were performed April September and assessed skill 50 km. four-dimensional variational (4DVAR) run specified initial background error covariances...
Abstract. Long-term and continuous observations of mesospheric–lower thermospheric winds are rare, but they important to investigate climatological changes at these altitudes on timescales several years, covering a solar cycle longer. Such long time series natural heritage the mesosphere–lower thermosphere climate, valuable compare climate models or long-term runs general circulation (GCMs). Here we present comparison wind from six meteor radars two conjugate latitudes validate corresponding...
Abstract The mesosphere/lower thermosphere (MLT, 80–100 km) region is an important boundary between Earth's atmosphere below and space above may act as a sensitive indicator for anthropogenic climate change. Existing observational modeling studies have shown the middle MLT cooling contracting because of increasing greenhouse gas emissions. However, trend analyses are highly to time periods covered, their length, measurement type methodology used. We present first linear 11‐year solar cycle...
Abstract A sudden stratospheric warming (SSW) is an extremely rare event in the Southern Hemisphere (SH), but occurred early September 2019. From Antarctic meteor radar (MR) stations, Davis (68.6˚S, 77.9˚E) and King Sejong Station (62.2˚S, 58.8˚W), quasi 10‐day oscillations were clearly observed zonal mesospheric winds before central date (DOY 253) of SSW. northern low‐latitude Tirupati (13.6˚N, 79.4˚E) MR, a strong wave activity with period ∼6 days was detected right after date. This...
Abstract. The Hunga Tonga–Hunga Ha′apai volcano erupted on 15 January 2022, launching Lamb waves and gravity into the atmosphere. In this study, we present results using 13 globally distributed meteor radars identify volcanogenic in mesospheric/lower thermospheric winds. Leveraging High-Altitude Mechanistic general Circulation Model (HIAMCM), compare global propagation of these waves. We observed an eastward-propagating wave packet with phase speed 240 ± 5.7 m s−1 a westward-propagating...
A function that approximates atmospheric tidal behavior in the polar regions is described. This fitted to multistation radar measurements of wind mesosphere and lower thermosphere with aim obtaining a latitude‐longitude‐height description variation tides over whole Antarctic continent. Archival data sets are combined present‐day ones fill spatial distribution observations reduce potential effects aliasing. Multiple years through compilation monthly station composite days, yielding results...
[1] Gravity wave activity in the upper stratosphere and lower mesosphere (USLM) is investigated using temperature data retrieved from a Rayleigh lidar at Davis, Antarctica (69°S, 78°E) during 2007 2008 winters. The temporal height variabilities of waves with ground-based periods greater than 2 h vertical wavelengths between 4 km 20 are analyzed. Stratospheric gravity potential energy per unit mass shows weaker correlation stratospheric winds Davis that reported Arctic. dissipate above 40...
Abstract Observations performed with a Rayleigh lidar and an Advanced Mesosphere Temperature Mapper aboard the National Science Foundation/National Center for Atmospheric Research Gulfstream V research aircraft on 13 July 2014 during Deep Propagating Gravity Wave Experiment (DEEPWAVE) measurement program revealed large‐amplitude, multiscale gravity wave (GW) environment extending from ~20 to 90 km flight tracks over Mount Cook, New Zealand. Data four successive are employed here assess...
Abstract Radiosonde observations made from Davis station, Antarctica, (68.6°S, 78.0°E) between 2001 and 2012 are used to compile a climatology of lower stratosphere inertial gravity wave characteristics. Wavelet analysis extracts single packets the wind temperature perturbations. parameters, combined with linear theory, allow for derivation wide range Observational filtering associated this preferentially selects waves vertical wavelengths less than 2–3 km. The propagation statistics show...
Abstract Southern Hemisphere extratropical gravity wave activity is examined using simulations from a free-running middle-atmosphere general circulation model called Kanto that contains no parameterizations. The total absolute momentum flux (MF) and its intermittency, diagnosed by the Gini coefficient, are during January July. MF intermittency results calculated agree well with satellite limb superpressure balloon observations. analysis of indicates following results. Nonorographic waves...
Abstract. The Antarctic marginal ice zone (MIZ) is a highly dynamic region where sea interacts with ocean surface waves generated in ice-free areas of the Southern Ocean. Improved large-scale (satellite-based) estimates MIZ extent and variability are crucial for understanding atmosphere–ice–ocean interactions biological processes detection change therein. Legacy methods defining typically based on concentration thresholds do not directly relate to fundamental physical driving variability. To...
An unprecedented major stratospheric warming occurred in the Antarctic winter of 2002. We present measurements winds mesosphere‐lower thermosphere (MLT) made with MF radars located at Davis (69°S, 78°E), Syowa 40°E) and Rothera (68°S, 68°W). The mesospheric wind field 2002 was found to be considerably different other years due increased planetary wave activity throughout winter. Zonal were weaker than usual during also transition summer circulation. MLT zonal showed a reversal about one week...
Mean wind and gravity wave climatologies are presented for the polar mesosphere lower thermosphere (MLT). The data were derived using MF radars at Davis (69°S, 78°E) Syowa 40°E) in Antarctic Poker Flat (65°N, 147°W) Andenes (69°N, 16°E) Arctic. dynamics of MLT found to be significantly different from Arctic MLT. Summer maxima both westward equatorward winds occur closer solstice than greater symmetry around suggests radiative effects may play a role controlling state Arctic, where dynamical...
Abstract The semidiurnal lunar and solar tides obtained from meteor radar measurements spanning 2009 to 2013 observed at Davis (69°S) Rio Grande (54°S) are presented compared the Northern Hemisphere ones Andenes (69°N) Juliusruh (54°N). Mean tidal differences for both intrahemispheric interhemispheric scenarios analyzed. Tidal behavior is also against numerical simulations during sudden stratospheric warming (SSW) time periods. Possible influences in Southern local stratosphere investigated...
Abstract A new technique for determining the height of a constant density surface at altitudes 78–85 km is presented. The first results are derived from decade observations by meteor radar located Davis Station in Antarctica and compared with Microwave Limb Sounder instrument aboard Aura satellite. neutral atmosphere mesosphere/lower thermosphere region around 70–110 an essential parameter interpreting airglow‐derived atmospheric temperatures, planning entry maneuvers returning spacecraft,...
Abstract Mountain wave (MW) propagation and dynamics extending into the upper mesosphere accompanying weak forcing are examined using in situ remote‐sensing measurements aboard National Science Foundation/National Center for Atmospheric Research Gulfstream V (GV) research aircraft German Aerospace Falcon. The were obtained during Falcon flights FF9 FF10 GV Flight RF22 of Deep Propagating Gravity Wave Experiment (DEEPWAVE) performed over Mount Cook, New Zealand, on 12 13 July 2014. In...
Abstract We report the first observations of a high‐ and middle‐latitude neutral mesospheric density response to geomagnetic storms. Interhemisphere densities are estimated using data from meteor radars at Davis Station (68.6°S, 77.9°E), Svalbard (78.3°N, 16°E) Tromsø (69.6°N, 19.2°E), which located under auroral zone; Mohe (53.5°N, 122.3°E), Beijing (40.3°N, 116.2°E) radars, in northern midlatitudes, Microwave Limb Sounder (MLS) on Aura satellite. Both case studies superposed epoch analysis...
We compare hourly averaged neutral winds derived from two meteor radars operating at 33.2 and 55 MHz to estimate the errors in these measurements. then radar with those a medium-frequency partial reflection 1.94 MHz. These three are located Davis Station, Antarctica. consider middle-latitude wind comparison 1.98 determine how representative results are. At both sites, clearly underestimated, underestimation increases 80 km maximum height of 98 km. Correction factors suggested for results.
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 global mesopause density. In this study, we report relative density estimated using multiyear observations nine radars, namely, Davis Station (68.6∘ S, 77.9∘ E), Svalbard (78.3∘ N, 16∘ E) Tromsø (69.6∘ 19.2∘ at high latitudes; Mohe (53.5∘ 122.3∘ Beijing (40.3∘ 116.2∘ Mengcheng (33.4∘ 116.6∘ Wuhan (30.5∘ 114.6∘ in...
Abstract Direct measurement of mean vertical velocities in the mesosphere‐lower thermosphere (60–110 km) is not possible due to their small values. Here we derive using divergence meridional wind over Antarctic summer pole MF radar measurements made at Davis Station (69°S, 78°E) between 1994 and 2018. Estimates velocity are restricted a 21‐day period centered just after solstice when equatorward reaches its maximum value about 15 m s −1 heights near 90 km. The Medium Frequency (MF) winds...