Articles | Volume 35, issue 3
https://doi.org/10.5194/angeo-35-567-2017
© Author(s) 2017. This work is distributed under
the Creative Commons Attribution 3.0 License.
the Creative Commons Attribution 3.0 License.
https://doi.org/10.5194/angeo-35-567-2017
© Author(s) 2017. This work is distributed under
the Creative Commons Attribution 3.0 License.
the Creative Commons Attribution 3.0 License.
Seasonal MLT-region nightglow intensities, temperatures, and emission heights at a Southern Hemisphere midlatitude site
ATRAD Pty Ltd, 20 Phillips St., Thebarton, 5031, Australia
School of Physical Sciences, University of Adelaide, Adelaide 5000,
Australia
Andrew J. Spargo
School of Physical Sciences, University of Adelaide, Adelaide 5000,
Australia
Jonathan M. Woithe
ATRAD Pty Ltd, 20 Phillips St., Thebarton, 5031, Australia
Andrew R. Klekociuk
School of Physical Sciences, University of Adelaide, Adelaide 5000,
Australia
Antarctica and the Global System, Australian Antarctic
Division, Department of the Environment and Energy, Kingston, Tasmania,
Australia
Joel P. Younger
ATRAD Pty Ltd, 20 Phillips St., Thebarton, 5031, Australia
School of Physical Sciences, University of Adelaide, Adelaide 5000,
Australia
Gulamabas G. Sivjee
Embry Riddle Aeronautical University, Department
Physical Sciences, Daytona Beach, FL 32114, USA
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Atmos. Chem. Phys., 24, 13299–13315, https://doi.org/10.5194/acp-24-13299-2024, https://doi.org/10.5194/acp-24-13299-2024, 2024
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We present the impact of quasi-biennial oscillation (QBO) disruption events on diurnal tides over the low- and mid-latitude MLT region observed by a meteor radar chain. By using a global atmospheric model and reanalysis data, it is found that the stratospheric QBO winds can affect the mesospheric diurnal tides by modulating the subtropical ozone variability in the upper stratosphere and the interaction between tides and gravity waves in the mesosphere.
Zishun Qiao, Alan Z. Liu, Gunter Stober, Javier Fuentes, Fabio Vargas, Christian L. Adami, and Iain M. Reid
Atmos. Meas. Tech. Discuss., https://doi.org/10.5194/amt-2024-126, https://doi.org/10.5194/amt-2024-126, 2024
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This paper describes the installation of the Chilean Observation Network De MeteOr Radars (CONDOR) and its initial results. The routine winds are point-to-point comparable to the co-located lidar winds. The retrievals of spatially resolved horizontal wind fields, vertical winds, and temperatures are also facilitated benefiting from the extensive meteor detections. The successful deployment and maintenance of CONDOR provide 24/7 and state-of-the-art wind measurements to the research community.
Thomas Edward Chambers, Iain Murray Reid, and Murray Hamilton
Atmos. Meas. Tech., 17, 3237–3253, https://doi.org/10.5194/amt-17-3237-2024, https://doi.org/10.5194/amt-17-3237-2024, 2024
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Clouds have been identified as the largest source of uncertainty in climate modelling. We report an untethered balloon launch of a holographic imager through clouds. This is the first time a holographic imager has been deployed in this way, enabled by the light weight and low cost of the imager. This work creates the potential to significantly increase the availability of cloud microphysical measurements required for the calibration and validation of climate models and remote sensing methods.
Qingchen Xu, Iain Murray Reid, Bing Cai, Christian Adami, Zengmao Zhang, Mingliang Zhao, and Wen Li
Atmos. Meas. Tech., 17, 2957–2975, https://doi.org/10.5194/amt-17-2957-2024, https://doi.org/10.5194/amt-17-2957-2024, 2024
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To have better understanding of the dynamics of the lower and middle atmosphere, we installed a newly designed dual-frequency radar system that uses 53.8 MHz for near-ground to 20 km wind measurements and 35.0 MHz for 70 to 100 km wind measurements. The initial results show its good performance, along with the analysis of typical winter gravity wave activities.
Wen Yi, Jie Zeng, Xianghui Xue, Iain Reid, Wei Zhong, Jianfei Wu, Tingdi Chen, and Xiankang Dou
Atmos. Meas. Tech. Discuss., https://doi.org/10.5194/amt-2022-254, https://doi.org/10.5194/amt-2022-254, 2022
Revised manuscript not accepted
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In recent years, the concept of multistatic meteor radar systems has attracted the attention of the atmospheric radar community, focusing on the MLT region. In this study, we apply a multistatic meteor radar system consisting of a monostatic meteor radar in Mengcheng (33.36° N, 116.49° E) and a remote receiver in Changfeng (31.98° N, 117.22° E) to estimate the two-dimensional horizontal wind field, and the horizontal divergence and relative vorticity of the wind field.
Joel P. Younger, Iain M. Reid, Chris L. Adami, Chris M. Hall, and Masaki Tsutsumi
Atmos. Meas. Tech., 14, 5015–5027, https://doi.org/10.5194/amt-14-5015-2021, https://doi.org/10.5194/amt-14-5015-2021, 2021
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A radar in Svalbard usually used to study meteor trails was used to observe a thin icy layer in the upper atmosphere. New methods used the layer to measure wind speed over short periods of time and found that the layer is most reflective within 6.8 ± 3.3° of vertical. Analysis of meteor trail radar echo durations found that the layer may shorten meteor trail echoes, but more data are needed. This study shows new uses for data collected by meteor radars for other purposes.
Wei Zhong, Xianghui Xue, Wen Yi, Iain M. Reid, Tingdi Chen, and Xiankang Dou
Atmos. Meas. Tech., 14, 3973–3988, https://doi.org/10.5194/amt-14-3973-2021, https://doi.org/10.5194/amt-14-3973-2021, 2021
Jianyuan Wang, Wen Yi, Jianfei Wu, Tingdi Chen, Xianghui Xue, Robert A. Vincent, Iain M. Reid, Paulo P. Batista, Ricardo A. Buriti, Toshitaka Tsuda, and Xiankang Dou
Atmos. Chem. Phys. Discuss., https://doi.org/10.5194/acp-2021-33, https://doi.org/10.5194/acp-2021-33, 2021
Revised manuscript not accepted
Short summary
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In this study, we report the climatology of migrating and non-migrating tides in mesopause winds estimated using multiyear observations from three meteor radars in the southern equatorial region. The results reveal that the climatological patterns of tidal amplitudes by meteor radars is similar to the Climatological Tidal Model of the Thermosphere (CTMT) results and the differences are mainly due to the effect of the stratospheric sudden warming (SSW) event.
Andrew John Spargo, Iain Murray Reid, and Andrew David MacKinnon
Atmos. Meas. Tech., 12, 4791–4812, https://doi.org/10.5194/amt-12-4791-2019, https://doi.org/10.5194/amt-12-4791-2019, 2019
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We simulate the ability of a recently installed multistation meteor detection radar to measure characteristics of turbulence in the Earth's lower ionosphere. After verifying that it performs reasonably well, we use the radar's data to study an interaction between turbulence and tidal effects. We performed the study because no one has yet applied a multistation radar to this problem before and because multistation radars like this are becoming increasingly common worldwide.
Wen Yi, Xianghui Xue, Iain M. Reid, Damian J. Murphy, Chris M. Hall, Masaki Tsutsumi, Baiqi Ning, Guozhu Li, Robert A. Vincent, Jinsong Chen, Jianfei Wu, Tingdi Chen, and Xiankang Dou
Atmos. Chem. Phys., 19, 7567–7581, https://doi.org/10.5194/acp-19-7567-2019, https://doi.org/10.5194/acp-19-7567-2019, 2019
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The seasonal variations in the mesopause densities, especially with regard to its global structure, are still unclear. In this study, we report the climatology of the mesopause density estimated using multiyear observations from nine meteor radars from Arctic to Antarctic latitudes. The results reveal a significant AO and SAO in mesopause density, an asymmetry between the two polar regions and evidence of intraseasonal oscillations (ISOs), perhaps associated with the ISOs of the troposphere.
Andrew J. Spargo, Iain M. Reid, Andrew D. MacKinnon, and David A. Holdsworth
Ann. Geophys., 35, 733–750, https://doi.org/10.5194/angeo-35-733-2017, https://doi.org/10.5194/angeo-35-733-2017, 2017
Short summary
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Measuring the momentum transport due to gravity waves in the 80–100 km region is important for improving our understanding of the middle atmosphere, but it is still difficult to do at useful spatial scales. Here, we measure it using a method that has not been applied to the problem before, involving Doppler analysis of radar beams from multiple directions. The results are pleasing, and we conclude that the measurements may also be able to be made using cheaper, single-beam radar systems.
Jianyuan Wang, Na Li, Wen Yi, Xianghui Xue, Iain M. Reid, Jianfei Wu, Hailun Ye, Jian Li, Zonghua Ding, Jinsong Chen, Guozhu Li, Yaoyu Tian, Boyuan Chang, Jiajing Wu, and Lei Zhao
Atmos. Chem. Phys., 24, 13299–13315, https://doi.org/10.5194/acp-24-13299-2024, https://doi.org/10.5194/acp-24-13299-2024, 2024
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We present the impact of quasi-biennial oscillation (QBO) disruption events on diurnal tides over the low- and mid-latitude MLT region observed by a meteor radar chain. By using a global atmospheric model and reanalysis data, it is found that the stratospheric QBO winds can affect the mesospheric diurnal tides by modulating the subtropical ozone variability in the upper stratosphere and the interaction between tides and gravity waves in the mesosphere.
Zishun Qiao, Alan Z. Liu, Gunter Stober, Javier Fuentes, Fabio Vargas, Christian L. Adami, and Iain M. Reid
Atmos. Meas. Tech. Discuss., https://doi.org/10.5194/amt-2024-126, https://doi.org/10.5194/amt-2024-126, 2024
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This paper describes the installation of the Chilean Observation Network De MeteOr Radars (CONDOR) and its initial results. The routine winds are point-to-point comparable to the co-located lidar winds. The retrievals of spatially resolved horizontal wind fields, vertical winds, and temperatures are also facilitated benefiting from the extensive meteor detections. The successful deployment and maintenance of CONDOR provide 24/7 and state-of-the-art wind measurements to the research community.
Thomas Edward Chambers, Iain Murray Reid, and Murray Hamilton
Atmos. Meas. Tech., 17, 3237–3253, https://doi.org/10.5194/amt-17-3237-2024, https://doi.org/10.5194/amt-17-3237-2024, 2024
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Clouds have been identified as the largest source of uncertainty in climate modelling. We report an untethered balloon launch of a holographic imager through clouds. This is the first time a holographic imager has been deployed in this way, enabled by the light weight and low cost of the imager. This work creates the potential to significantly increase the availability of cloud microphysical measurements required for the calibration and validation of climate models and remote sensing methods.
Qingchen Xu, Iain Murray Reid, Bing Cai, Christian Adami, Zengmao Zhang, Mingliang Zhao, and Wen Li
Atmos. Meas. Tech., 17, 2957–2975, https://doi.org/10.5194/amt-17-2957-2024, https://doi.org/10.5194/amt-17-2957-2024, 2024
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To have better understanding of the dynamics of the lower and middle atmosphere, we installed a newly designed dual-frequency radar system that uses 53.8 MHz for near-ground to 20 km wind measurements and 35.0 MHz for 70 to 100 km wind measurements. The initial results show its good performance, along with the analysis of typical winter gravity wave activities.
Ruhi S. Humphries, Melita D. Keywood, Jason P. Ward, James Harnwell, Simon P. Alexander, Andrew R. Klekociuk, Keiichiro Hara, Ian M. McRobert, Alain Protat, Joel Alroe, Luke T. Cravigan, Branka Miljevic, Zoran D. Ristovski, Robyn Schofield, Stephen R. Wilson, Connor J. Flynn, Gourihar R. Kulkarni, Gerald G. Mace, Greg M. McFarquhar, Scott D. Chambers, Alastair G. Williams, and Alan D. Griffiths
Atmos. Chem. Phys., 23, 3749–3777, https://doi.org/10.5194/acp-23-3749-2023, https://doi.org/10.5194/acp-23-3749-2023, 2023
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Observations of aerosols in pristine regions are rare but are vital to constraining the natural baseline from which climate simulations are calculated. Here we present recent seasonal observations of aerosols from the Southern Ocean and contrast them with measurements from Antarctica, Australia and regionally relevant voyages. Strong seasonal cycles persist, but striking differences occur at different latitudes. This study highlights the need for more long-term observations in remote regions.
Wen Yi, Jie Zeng, Xianghui Xue, Iain Reid, Wei Zhong, Jianfei Wu, Tingdi Chen, and Xiankang Dou
Atmos. Meas. Tech. Discuss., https://doi.org/10.5194/amt-2022-254, https://doi.org/10.5194/amt-2022-254, 2022
Revised manuscript not accepted
Short summary
Short summary
In recent years, the concept of multistatic meteor radar systems has attracted the attention of the atmospheric radar community, focusing on the MLT region. In this study, we apply a multistatic meteor radar system consisting of a monostatic meteor radar in Mengcheng (33.36° N, 116.49° E) and a remote receiver in Changfeng (31.98° N, 117.22° E) to estimate the two-dimensional horizontal wind field, and the horizontal divergence and relative vorticity of the wind field.
Adrien Guyot, Alain Protat, Simon P. Alexander, Andrew R. Klekociuk, Peter Kuma, and Adrian McDonald
Atmos. Meas. Tech., 15, 3663–3681, https://doi.org/10.5194/amt-15-3663-2022, https://doi.org/10.5194/amt-15-3663-2022, 2022
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Ceilometers are instruments that are widely deployed as part of operational networks. They are usually not able to detect cloud phase. Here, we propose an evaluation of various methods to detect supercooled liquid water with ceilometer observations, using an extensive dataset from Davis, Antarctica. Our results highlight the possibility for ceilometers to detect supercooled liquid water in clouds.
Alexander D. Fraser, Robert A. Massom, Mark S. Handcock, Phillip Reid, Kay I. Ohshima, Marilyn N. Raphael, Jessica Cartwright, Andrew R. Klekociuk, Zhaohui Wang, and Richard Porter-Smith
The Cryosphere, 15, 5061–5077, https://doi.org/10.5194/tc-15-5061-2021, https://doi.org/10.5194/tc-15-5061-2021, 2021
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Landfast ice is sea ice that remains stationary by attaching to Antarctica's coastline and grounded icebergs. Although a variable feature, landfast ice exerts influence on key coastal processes involving pack ice, the ice sheet, ocean, and atmosphere and is of ecological importance. We present a first analysis of change in landfast ice over an 18-year period and quantify trends (−0.19 ± 0.18 % yr−1). This analysis forms a reference of landfast-ice extent and variability for use in other studies.
Camilla K. Crockart, Tessa R. Vance, Alexander D. Fraser, Nerilie J. Abram, Alison S. Criscitiello, Mark A. J. Curran, Vincent Favier, Ailie J. E. Gallant, Christoph Kittel, Helle A. Kjær, Andrew R. Klekociuk, Lenneke M. Jong, Andrew D. Moy, Christopher T. Plummer, Paul T. Vallelonga, Jonathan Wille, and Lingwei Zhang
Clim. Past, 17, 1795–1818, https://doi.org/10.5194/cp-17-1795-2021, https://doi.org/10.5194/cp-17-1795-2021, 2021
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We present preliminary analyses of the annual sea salt concentrations and snowfall accumulation in a new East Antarctic ice core, Mount Brown South. We compare this record with an updated Law Dome (Dome Summit South site) ice core record over the period 1975–2016. The Mount Brown South record preserves a stronger and inverse signal for the El Niño–Southern Oscillation (in austral winter and spring) compared to the Law Dome record (in summer).
Joel P. Younger, Iain M. Reid, Chris L. Adami, Chris M. Hall, and Masaki Tsutsumi
Atmos. Meas. Tech., 14, 5015–5027, https://doi.org/10.5194/amt-14-5015-2021, https://doi.org/10.5194/amt-14-5015-2021, 2021
Short summary
Short summary
A radar in Svalbard usually used to study meteor trails was used to observe a thin icy layer in the upper atmosphere. New methods used the layer to measure wind speed over short periods of time and found that the layer is most reflective within 6.8 ± 3.3° of vertical. Analysis of meteor trail radar echo durations found that the layer may shorten meteor trail echoes, but more data are needed. This study shows new uses for data collected by meteor radars for other purposes.
Wei Zhong, Xianghui Xue, Wen Yi, Iain M. Reid, Tingdi Chen, and Xiankang Dou
Atmos. Meas. Tech., 14, 3973–3988, https://doi.org/10.5194/amt-14-3973-2021, https://doi.org/10.5194/amt-14-3973-2021, 2021
Jianyuan Wang, Wen Yi, Jianfei Wu, Tingdi Chen, Xianghui Xue, Robert A. Vincent, Iain M. Reid, Paulo P. Batista, Ricardo A. Buriti, Toshitaka Tsuda, and Xiankang Dou
Atmos. Chem. Phys. Discuss., https://doi.org/10.5194/acp-2021-33, https://doi.org/10.5194/acp-2021-33, 2021
Revised manuscript not accepted
Short summary
Short summary
In this study, we report the climatology of migrating and non-migrating tides in mesopause winds estimated using multiyear observations from three meteor radars in the southern equatorial region. The results reveal that the climatological patterns of tidal amplitudes by meteor radars is similar to the Climatological Tidal Model of the Thermosphere (CTMT) results and the differences are mainly due to the effect of the stratospheric sudden warming (SSW) event.
William R. Hobbs, Andrew R. Klekociuk, and Yuhang Pan
Atmos. Chem. Phys., 20, 14757–14768, https://doi.org/10.5194/acp-20-14757-2020, https://doi.org/10.5194/acp-20-14757-2020, 2020
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Reanalysis products are an invaluable tool for representing variability and long-term trends in regions with limited in situ data. However, validation of these products is difficult because of that lack of station data. Here we present a novel assessment of eight reanalyses over the polar Southern Ocean, leveraging the close relationship between trends in sea ice cover and surface air temperature, that provides clear guidance on the most reliable product for Antarctic research.
W. John R. French, Andrew R. Klekociuk, and Frank J. Mulligan
Atmos. Chem. Phys., 20, 8691–8708, https://doi.org/10.5194/acp-20-8691-2020, https://doi.org/10.5194/acp-20-8691-2020, 2020
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We explore a quasi-quadrennial oscillation (QQO; 3–4 K amplitude, ~ 4-year period) in mesopause region temperatures observed in 24 years of hydroxyl airglow measurements over Davis, Antarctica (68° S, 78° E). Correlation and composite analysis using meteorological reanalysis and satellite data reveals complex patterns on the QQO timescale in both hemispheres. Modulation of the meridional circulation, linked to the propagation of gravity waves, plays a significant role in producing the QQO response.
W. John R. French, Frank J. Mulligan, and Andrew R. Klekociuk
Atmos. Chem. Phys., 20, 6379–6394, https://doi.org/10.5194/acp-20-6379-2020, https://doi.org/10.5194/acp-20-6379-2020, 2020
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In this study, we analyse 24 years of atmospheric temperatures from the mesopause region (~87 km altitude) derived from ground-based spectrometer observations of hydroxyl airglow at Davis station, Antarctica (68° S, 78° E). These data are used to quantify the effect of the solar cycle and the long-term trend due to increasing greenhouse gas emissions on the atmosphere at this level. A record-low winter-average temperature is reported for 2018 and comparisons are made with satellite observations.
Julie M. Nicely, Bryan N. Duncan, Thomas F. Hanisco, Glenn M. Wolfe, Ross J. Salawitch, Makoto Deushi, Amund S. Haslerud, Patrick Jöckel, Béatrice Josse, Douglas E. Kinnison, Andrew Klekociuk, Michael E. Manyin, Virginie Marécal, Olaf Morgenstern, Lee T. Murray, Gunnar Myhre, Luke D. Oman, Giovanni Pitari, Andrea Pozzer, Ilaria Quaglia, Laura E. Revell, Eugene Rozanov, Andrea Stenke, Kane Stone, Susan Strahan, Simone Tilmes, Holger Tost, Daniel M. Westervelt, and Guang Zeng
Atmos. Chem. Phys., 20, 1341–1361, https://doi.org/10.5194/acp-20-1341-2020, https://doi.org/10.5194/acp-20-1341-2020, 2020
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Differences in methane lifetime among global models are large and poorly understood. We use a neural network method and simulations from the Chemistry Climate Model Initiative to quantify the factors influencing methane lifetime spread among models and variations over time. UV photolysis, tropospheric ozone, and nitrogen oxides drive large model differences, while the same factors plus specific humidity contribute to a decreasing trend in methane lifetime between 1980 and 2015.
Andrew John Spargo, Iain Murray Reid, and Andrew David MacKinnon
Atmos. Meas. Tech., 12, 4791–4812, https://doi.org/10.5194/amt-12-4791-2019, https://doi.org/10.5194/amt-12-4791-2019, 2019
Short summary
Short summary
We simulate the ability of a recently installed multistation meteor detection radar to measure characteristics of turbulence in the Earth's lower ionosphere. After verifying that it performs reasonably well, we use the radar's data to study an interaction between turbulence and tidal effects. We performed the study because no one has yet applied a multistation radar to this problem before and because multistation radars like this are becoming increasingly common worldwide.
Yuke Wang, Valerii Shulga, Gennadi Milinevsky, Aleksey Patoka, Oleksandr Evtushevsky, Andrew Klekociuk, Wei Han, Asen Grytsai, Dmitry Shulga, Valery Myshenko, and Oleksandr Antyufeyev
Atmos. Chem. Phys., 19, 10303–10317, https://doi.org/10.5194/acp-19-10303-2019, https://doi.org/10.5194/acp-19-10303-2019, 2019
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The major sudden stratospheric warming (SSW) dramatically changed atmospheric conditions. This event is accompanied by a sharp increase in the polar stratosphere temperature, zonal wind reverse, and strong changes in the polar mesosphere. These changes affect even the midlatitude mesosphere, which is not widely covered by observations. Our newly installed microwave radiometer allowed for studying mesospheric zonal wind and CO variations to understand the SSW 2018 effects at midlatitudes.
Wen Yi, Xianghui Xue, Iain M. Reid, Damian J. Murphy, Chris M. Hall, Masaki Tsutsumi, Baiqi Ning, Guozhu Li, Robert A. Vincent, Jinsong Chen, Jianfei Wu, Tingdi Chen, and Xiankang Dou
Atmos. Chem. Phys., 19, 7567–7581, https://doi.org/10.5194/acp-19-7567-2019, https://doi.org/10.5194/acp-19-7567-2019, 2019
Short summary
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The seasonal variations in the mesopause densities, especially with regard to its global structure, are still unclear. In this study, we report the climatology of the mesopause density estimated using multiyear observations from nine meteor radars from Arctic to Antarctic latitudes. The results reveal a significant AO and SAO in mesopause density, an asymmetry between the two polar regions and evidence of intraseasonal oscillations (ISOs), perhaps associated with the ISOs of the troposphere.
Blanca Ayarzagüena, Lorenzo M. Polvani, Ulrike Langematz, Hideharu Akiyoshi, Slimane Bekki, Neal Butchart, Martin Dameris, Makoto Deushi, Steven C. Hardiman, Patrick Jöckel, Andrew Klekociuk, Marion Marchand, Martine Michou, Olaf Morgenstern, Fiona M. O'Connor, Luke D. Oman, David A. Plummer, Laura Revell, Eugene Rozanov, David Saint-Martin, John Scinocca, Andrea Stenke, Kane Stone, Yousuke Yamashita, Kohei Yoshida, and Guang Zeng
Atmos. Chem. Phys., 18, 11277–11287, https://doi.org/10.5194/acp-18-11277-2018, https://doi.org/10.5194/acp-18-11277-2018, 2018
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Stratospheric sudden warmings (SSWs) are natural major disruptions of the polar stratospheric circulation that also affect surface weather. In the literature there are conflicting claims as to whether SSWs will change in the future. The confusion comes from studies using different models and methods. Here we settle the question by analysing 12 models with a consistent methodology, to show that no robust changes in frequency and other features are expected over the 21st century.
Jesse W. Greenslade, Simon P. Alexander, Robyn Schofield, Jenny A. Fisher, and Andrew K. Klekociuk
Atmos. Chem. Phys., 17, 10269–10290, https://doi.org/10.5194/acp-17-10269-2017, https://doi.org/10.5194/acp-17-10269-2017, 2017
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An analysis of data from ozonesondes released at three southern oceanic sites shows the impact of stratospheric ozone in this region. Using a novel method of transport classification, this work estimates the seasonality and quantity of stratospherically sourced ozone. We find that ozone is transported most frequently in summer due to regional-scale low-pressure weather systems. We also estimate a stratospheric ozone source of 2.0–3.3 Tg/year over three Southern Ocean regions.
Andrew J. Spargo, Iain M. Reid, Andrew D. MacKinnon, and David A. Holdsworth
Ann. Geophys., 35, 733–750, https://doi.org/10.5194/angeo-35-733-2017, https://doi.org/10.5194/angeo-35-733-2017, 2017
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Measuring the momentum transport due to gravity waves in the 80–100 km region is important for improving our understanding of the middle atmosphere, but it is still difficult to do at useful spatial scales. Here, we measure it using a method that has not been applied to the problem before, involving Doppler analysis of radar beams from multiple directions. The results are pleasing, and we conclude that the measurements may also be able to be made using cheaper, single-beam radar systems.
Chris S.~M. Turney, Andrew Klekociuk, Christopher J. Fogwill, Violette Zunz, Hugues Goosse, Claire L. Parkinson, Gilbert Compo, Matthew Lazzara, Linda Keller, Rob Allan, Jonathan G. Palmer, Graeme Clark, and Ezequiel Marzinelli
The Cryosphere Discuss., https://doi.org/10.5194/tc-2017-51, https://doi.org/10.5194/tc-2017-51, 2017
Revised manuscript not accepted
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We demonstrate that a mid-twentieth century decrease in geopotential height in the southwest Pacific marks a Rossby wave response to equatorial Pacific warming, leading to enhanced easterly airflow off George V Land. Our results suggest that in contrast to ozone hole-driven changes in the Amundsen Sea, the 1979–2015 increase in sea ice extent off George V Land may be in response to reduced northward Ekman drift and enhanced (near-coast) production as a consequence of low latitude forcing.
Asen Grytsai, Andrew Klekociuk, Gennadi Milinevsky, Oleksandr Evtushevsky, and Kane Stone
Atmos. Chem. Phys., 17, 1741–1758, https://doi.org/10.5194/acp-17-1741-2017, https://doi.org/10.5194/acp-17-1741-2017, 2017
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Twenty years ago we discovered that the ozone hole shape is asymmetric. This asymmetry is minimum over the Weddell Sea region and maximum over the Ross Sea area. Later we detected that the position of the ozone minimum is shifting east. We have continued to follow this event, and a couple years ago we revealed that the shift is slowing down and starting to move back. We connect all this movement with ozone hole increase; since 2000 the ozone layer has been stabilizing and recently recovering.
Kane A. Stone, Olaf Morgenstern, David J. Karoly, Andrew R. Klekociuk, W. John French, N. Luke Abraham, and Robyn Schofield
Atmos. Chem. Phys., 16, 2401–2415, https://doi.org/10.5194/acp-16-2401-2016, https://doi.org/10.5194/acp-16-2401-2016, 2016
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This paper describes the set-up and evaluation of the Australian Community Climate and Earth System Simulator – chemistry-climate model.
Emphasis is placed on the Antarctic ozone hole, which is very important considering its role modulating Southern Hemisphere surface climate. While the model simulates the global distribution of ozone well, there is a disparity in the vertical location of springtime ozone depletion over Antarctica, highlighting important areas for future development.
Emphasis is placed on the Antarctic ozone hole, which is very important considering its role modulating Southern Hemisphere surface climate. While the model simulates the global distribution of ozone well, there is a disparity in the vertical location of springtime ozone depletion over Antarctica, highlighting important areas for future development.
R. S. Humphries, A. R. Klekociuk, R. Schofield, M. Keywood, J. Ward, and S. R. Wilson
Atmos. Chem. Phys., 16, 2185–2206, https://doi.org/10.5194/acp-16-2185-2016, https://doi.org/10.5194/acp-16-2185-2016, 2016
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This work represents the first observational study of atmospheric sub-micron aerosols in the East Antarctic pack ice region and found springtime aerosol concentrations were higher than any observed elsewhere in the Antarctic and Southern Ocean region. Further analysis suggested these aerosols formed in the Antarctic free troposphere. Their subsequent transport to the Southern Ocean, as suggest by trajectory analyses, could help to reduce the discrepancy in the radiative budget in the region.
C. S. M. Turney, C. J. Fogwill, A. R. Klekociuk, T. D. van Ommen, M. A. J. Curran, A. D. Moy, and J. G. Palmer
The Cryosphere, 9, 2405–2415, https://doi.org/10.5194/tc-9-2405-2015, https://doi.org/10.5194/tc-9-2405-2015, 2015
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Recent trends in ocean circulation, sea ice and climate over the Southern Ocean and Antarctica are highly complex. Here we report a new snow core from the South Pole alongside reanalysis of 20th century global atmospheric circulation. We demonstrate for the first time that atmospheric pressure anomalies in the mid-latitudes act as "gatekeepers" to meridional exchange over continental Antarctica, modulated by the tropical Pacific, with potentially significant impacts on surface mass balance.
R. S. Humphries, R. Schofield, M. D. Keywood, J. Ward, J. R. Pierce, C. M. Gionfriddo, M. T. Tate, D. P. Krabbenhoft, I. E. Galbally, S. B. Molloy, A. R. Klekociuk, P. V. Johnston, K. Kreher, A. J. Thomas, A. D. Robinson, N. R. P. Harris, R. Johnson, and S. R. Wilson
Atmos. Chem. Phys., 15, 13339–13364, https://doi.org/10.5194/acp-15-13339-2015, https://doi.org/10.5194/acp-15-13339-2015, 2015
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An atmospheric new particle formation event that was observed in the pristine East Antarctic pack ice during a springtime voyage in 2012 is characterised in terms of formation and growth rates. Known nucleation mechanisms (e.g. those involving sulfate, iodine and organics) were unable to explain observations; however, correlations with total gaseous mercury were found, leading to the suggestion of a possible mercury-driven nucleation mechanism not previously described.
J. M. Siddaway, S. V. Petelina, D. J. Karoly, A. R. Klekociuk, and R. J. Dargaville
Atmos. Chem. Phys., 13, 4413–4427, https://doi.org/10.5194/acp-13-4413-2013, https://doi.org/10.5194/acp-13-4413-2013, 2013
S. P. Alexander, D. J. Murphy, and A. R. Klekociuk
Atmos. Chem. Phys., 13, 3121–3132, https://doi.org/10.5194/acp-13-3121-2013, https://doi.org/10.5194/acp-13-3121-2013, 2013
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We measured temperatures in the atmosphere at heights near 90 km using nightglow emissions and compared them with satellite measurements and with measurements made with a meteor radar. We found good agreement between the techniques, which improved when we used the meteor radar and satellite data to measure densities at two heights separated by about 10 km to estimate the nightglow emission height.
We measured temperatures in the atmosphere at heights near 90 km using nightglow emissions and...