Ground-based Ku-band microwave observations of ozone in the polar middle atmosphere

Abstract. Ground based observations of 11.072 GHz atmospheric ozone (O3) emission have been made using the Ny Ålesund Ozone in the Mesosphere Instrument (NAOMI) at the UK Arctic Research Station (latitude 78°55’0” N, longitude 11°55’59” E), Spitsbergen. Seasonally averaged O3 vertical profiles in the Arctic polar mesosphere lower thermosphere region for night-time and twilight conditions in the period 15 August 2017 to 15 March 2020 have been retrieved over the altitude range 62–98 km. NAOMI measurements are compared with corresponding, overlapping observations by the Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) satellite instrument. The NAOMI and SABER data are binned according to the SABER instrument 60 day yaw cycles into 3 month ‘winter’ (15 December–15 March), ‘autumn’ (15 August–15 November), and ‘summer’ (15 April–15 July) periods. The NAOMI observations show the same year-to-year and seasonal variabilities as the SABER 9.6 μm O3 data. The winter night-time (solar zenith angle, SZA ≥ 110°) and twilight (75° ≤ SZA ≤ 110°) NAOMI and SABER 9.6 μm O3 volume mixing ratio (VMR) profiles agree to within the measurement uncertainties. However, for autumn twilight conditions the SABER 9.6 μm O3 secondary maximum VMR values are higher than NAOMI over altitudes 88–97 km by 47 % and 59 % respectively in 2017 and 2018. Comparing the two SABER channels which measure O3 at different wavelengths and use different processing schemes, the 9.6 μm O3 autumn twilight VMR data for the three years 2017–19 are higher than the corresponding 1.27 μm measurements with the largest difference (58 %) in the 65–95 km altitude range similar to the NAOMI observation. The SABER 9.6 μm O3 summer daytime (SZA < 75°) mesospheric O3 VMR is also consistently higher than the 1.27 μm measurement, confirming previously reported differences between the SABER 9.6 μm channel and measurements of mesospheric O3 by other satellite instruments.

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Large-Scale Waves in the Mesosphere and Lower Thermosphere Observed by SABER

Journal of the Atmospheric Sciences ◽

10.1175/jas3612.1 ◽

2005 ◽

Vol 62 (12) ◽

pp. 4384-4399 ◽

Cited By ~ 104

Author(s):

Rolando R. Garcia ◽

Ruth Lieberman ◽

James M. Russell ◽

Martin G. Mlynczak

Keyword(s):

Large Scale ◽

Middle Atmosphere ◽

Lower Thermosphere ◽

Normal Modes ◽

Zonal Winds ◽

Broadband Emission ◽

Summer Hemisphere ◽

Mean Structure ◽

Mesosphere And Lower Thermosphere ◽

The Tropics

Abstract Observations made by the Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) instrument on board NASA’s Thermosphere–Ionosphere–Mesosphere Energetics and Dynamics (TIMED) satellite have been processed using Salby’s fast Fourier synoptic mapping (FFSM) algorithm. The mapped data provide a first synoptic look at the mean structure and traveling waves of the mesosphere and lower thermosphere (MLT) since the launch of the TIMED satellite in December 2001. The results show the presence of various wave modes in the MLT, which reach largest amplitude above the mesopause and include Kelvin and Rossby–gravity waves, eastward-propagating diurnal oscillations (“non-sun-synchronous tides”), and a set of quasi-normal modes associated with the so-called 2-day wave. The latter exhibits marked seasonal variability, attaining large amplitudes during the solstices and all but disappearing at the equinoxes. SABER data also show a strong quasi-stationary Rossby wave signal throughout the middle atmosphere of the winter hemisphere; the signal extends into the Tropics and even into the summer hemisphere in the MLT, suggesting ducting by westerly background zonal winds. At certain times of the year, the 5-day Rossby normal mode and the 4-day wave associated with instability of the polar night jet are also prominent in SABER data.

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Horizontally resolved structures of radar backscatter from polar mesospheric layers

Advances in Radio Science ◽

10.5194/ars-10-285-2012 ◽

2012 ◽

Vol 10 ◽

pp. 285-290 ◽

Cited By ~ 5

Author(s):

R. Latteck ◽

W. Singer ◽

M. Rapp ◽

T. Renkwitz ◽

G. Stober

Keyword(s):

Middle Atmosphere ◽

Beam Steering ◽

Lower Thermosphere ◽

The Arctic ◽

Phased Array Antenna ◽

Vhf Radar ◽

The North ◽

Expansion Stage ◽

Arctic Atmosphere ◽

High Flexibility

Abstract. The Leibniz-Institute of Atmospheric Physics in Kühlungsborn, Germany (IAP) installed a new powerful VHF radar on the North-Norwegian island Andøya (69.30° N, 16.04° E) from 2009 to 2011. The new Middle Atmosphere Alomar Radar System (MAARSY) replaces the existing ALWIN radar which has been in continuous operation on Andøya for more than 10 yr. MAARSY is a monostatic radar operated at 53.5 MHz with an active phased array antenna consisting of 433 Yagi antennas each connected to its own transceiver with independent control of frequency, phase and power of the transmitted signal. This arrangement provides a very high flexibility of beam forming and beam steering. It allows classical beam swinging operation as well as experiments with simultaneous multiple beams and the use of modern interferometric applications for improved studies of the Arctic atmosphere from the troposphere up to the lower thermosphere with high spatial-temporal resolution. The installation of the antenna was completed in August 2009. An initial expansion stage of 196 transceiver modules was installed in spring 2010, upgraded to 343 transceiver modules in December 2010 and the installation of the radar was completed in spring 2011. Beside standard observations of tropospheric winds and Polar Mesosphere Summer Echoes, multi-beam experiments using up to 91 beams quasi-simultaneously in the mesosphere have been carried out using the different expansion stages of the system during campaigns in 2010 and 2011. These results provided a first insight into the horizontal variability of Polar Mesosphere Summer and Winter Echoes in an area of about 80 km by 80 km with time resolutions between 3 and 9 min.

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Sea surface temperature as a proxy for convective gravity wave excitation: a study based on global gravity wave observations in the middle atmosphere

Annales Geophysicae ◽

10.5194/angeo-32-1373-2014 ◽

2014 ◽

Vol 32 (11) ◽

pp. 1373-1394 ◽

Cited By ~ 10

Author(s):

J. Y. Jia ◽

P. Preusse ◽

M. Ern ◽

H.-Y. Chun ◽

J. C. Gille ◽

...

Keyword(s):

Surface Temperature ◽

Sea Surface Temperature ◽

Gravity Wave ◽

Middle Atmosphere ◽

Lower Thermosphere ◽

Correlation Coefficients ◽

Sea Surface ◽

Broadband Emission ◽

Global Gravity ◽

Ray Tracing Simulation

Abstract. Absolute values of gravity wave momentum flux (GWMF) deduced from satellite measurements by the Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) instrument and the High Resolution Dynamics Limb Sounder (HIRDLS) are correlated with sea surface temperature (SST) with the aim of identifying those oceanic regions for which convection is a major source of gravity waves (GWs). Our study identifies those latitude bands where high correlation coefficients indicate convective excitation with confidence. This is based on a global ray-tracing simulation, which is used to delineate the source and wind-filtering effects. Convective GWs are identified at the eastern coasts of the continents and over the warm water regions formed by the warm ocean currents, in particular the Gulf Stream and the Kuroshio. Potential contributions of tropical cyclones to the excitation of the GWs are discussed. Convective excitation can be identified well into the mid-mesosphere. In propagating upward, the centers of GWMF formed by convection shift poleward. Some indications of the main forcing regions are even shown for the upper mesosphere/lower thermosphere (MLT).

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Intra-annual variations of spectrally resolved gravity wave activity in the upper mesosphere/lower thermosphere (UMLT) region

Atmospheric Measurement Techniques ◽

10.5194/amt-13-5117-2020 ◽

2020 ◽

Vol 13 (9) ◽

pp. 5117-5128

Author(s):

René Sedlak ◽

Alexandra Zuhr ◽

Carsten Schmidt ◽

Sabine Wüst ◽

Michael Bittner ◽

...

Keyword(s):

Gravity Wave ◽

Annual Cycle ◽

Large Scale ◽

Middle Atmosphere ◽

Wave Spectrum ◽

Lower Thermosphere ◽

Wave Activity ◽

Environmental Research ◽

Research Station ◽

Period Range

Abstract. The period range between 6 and 480 min is known to represent the major part of the gravity wave spectrum driving mesospheric dynamics. We present a method using wavelet analysis to calculate gravity wave activity with a high period resolution and apply it to temperature data acquired with the OH* airglow spectrometers called GRIPS (GRound-based Infrared P-branch Spectrometer) within the framework of the NDMC (Network for the Detection of Mesospheric Change; https://ndmc.dlr.de, last access: 22 September 2020). We analyse data measured at the NDMC sites Abastumani in Georgia (ABA; 41.75∘ N, 42.82∘ E), ALOMAR (Arctic Lidar Observatory for Middle Atmosphere Research) in Norway (ALR; 69.28∘ N, 16.01∘ E), Neumayer Station III in the Antarctic (NEU; 70.67∘ S, 8.27∘ W), Observatoire de Haute-Provence in France (OHP; 43.93∘ N, 5.71∘ E), Oberpfaffenhofen in Germany (OPN; 48.09∘ N, 11.28∘ E), Sonnblick in Austria (SBO; 47.05∘ N, 12.95∘ E), Tel Aviv in Israel (TAV; 32.11∘ N, 34.80∘ E), and the Environmental Research Station Schneefernerhaus on top of Zugspitze mountain in Germany (UFS; 47.42∘ N, 10.98∘ E). All eight instruments are identical in construction and deliver consistent and comparable data sets. For periods shorter than 60 min, gravity wave activity is found to be relatively low and hardly shows any seasonal variability on the timescale of months. We find a semi-annual cycle with maxima during winter and summer for gravity waves with periods longer than 60 min, which gradually develops into an annual cycle with a winter maximum for longer periods. The transition from a semi-annual pattern to a primarily annual pattern starts around a gravity wave period of 200 min. Although there are indications of enhanced gravity wave sources above mountainous terrain, the overall pattern of gravity wave activity does not differ significantly for the abovementioned observation sites. Thus, large-scale mechanisms such as stratospheric wind filtering seem to dominate the evolution of mesospheric gravity wave activity.

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Unusually strong nitric oxide descent in the Arctic middle atmosphere in early 2013 as observed by Odin/SMR

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-14-3563-2014 ◽

2014 ◽

Vol 14 (3) ◽

pp. 3563-3581

Author(s):

K. Pérot ◽

J. Urban ◽

D. P. Murtagh

Keyword(s):

Nitric Oxide ◽

Middle Atmosphere ◽

Lower Thermosphere ◽

Polar Vortex ◽

Meteorological Conditions ◽

Atmospheric Composition ◽

The Arctic ◽

The Reformation ◽

Polar Stratosphere ◽

Energetic Particle Precipitation

Abstract. The middle atmosphere has been affected by an exceptionally strong midwinter stratospheric sudden warming (SSW) during the Arctic winter 2012/2013. These unusual meteorological conditions led to a breakdown of the polar vortex, followed by the reformation of a strong upper stratospheric vortex associated with particularly efficient descent of air. Measurements by the Sub-Millimetre Radiometer (SMR), on board the Odin satellite, show that very large amounts of nitric oxide (NO), produced by Energetic Particle Precipitation (EPP) in the mesosphere/lower thermosphere (MLT), could thus enter the polar stratosphere in early 2013. The mechanism referring to the downward transport of EPP generated-NOx during winter is generally called the EPP indirect effect. SMR observed up to 20 times more NO in the upper stratosphere than the average NO measured at the same latitude, pressure and time during three previous winters where no mixing between mesospheric and stratospheric air was noticeable. This event turned out to be an unprecedently strong case of this effect. Our study is based on a comparison with the Arctic winter 2008/2009, when a similar situation was observed and which was so far considered as a record-breaking winter for this kind of events. This outstanding situation is the result of the combination between a relatively high geomagnetic activity and an unusually high dynamical activity, which makes this case a prime example to study the EPP impacts on the atmospheric composition.

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Optical and geometrical properties of Arctic clouds over northern Finland during PaCE campaign in 2019

10.5194/egusphere-egu2020-17951 ◽

2020 ◽

Author(s):

Xiaoxia Shang ◽

Mika Komppula ◽

Elina Giannakaki ◽

Stephanie Bohlmann ◽

Maria Filioglou ◽

...

Keyword(s):

Optical Properties ◽

Hydrological Cycle ◽

Signal To Noise Ratio ◽

Ground Level ◽

The Arctic ◽

Vertical Profiles ◽

Backscatter Coefficient ◽

Night Time ◽

Geometrical Properties ◽

532 Nm

In the Arctic areas the influence of climate change is being felt at a higher degree than elsewhere. Enabling a better understanding of the environment in region is of high importance. Clouds play a significant role in the energy budget and the hydrological cycle of the Earth&#8217;s atmosphere system. In order to provide insights into Arctic cloud processes for Arctic cloud-climate studies, the field campaign PaCE (Pallas Cloud Experiment) was organized during autumn and winter 2019; the campaign was focusing on aerosol and cloud vertical profiling using in-situ and remote sensing techniques.During the campaign, a ground-based multi-wavelength Raman polarization lidar PollyXT performed continuous measurements from September to December 2019, at the Kentt&#228;rova station (N 67&#176;59&#8217;14&#8221;, E 24&#176;14&#8217;35&#8221;, 347 m above sea level) at Pallas, in the northern Finland. This is a background station surrounded by the forest, where the atmosphere is quite clean. Cloud vertical structures and optical properties have been determined from lidar analysis. During day-time, the Klett method is applied to retrieve the vertical profiles of cloud extinction and backscatter coefficient at three wavelengths (355 nm, 532 nm and 1064 nm). During night-time, the standard Raman method is used to provide additional lidar ratio profiles at 355 nm and 532 nm. The actual linear depolarization ratio at two wavelengths (355 nm and 532 nm) are also retrieved. With water vapor channel at 407 nm, the relative humidity profile are also available for received signal with good signal-to-noise ratio. The combined use of near and far field telescopes provides reliable vertical profiles of optical properties from 0.25 km to 10 km above ground level. The temperature and thickness dependencies on optical properties have also been studied in detail. Geometrical properties of cloud are retrieved using both lidar and ceilometer, statistic values of cloud height, and thickness are shown.

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Resonant scattering as a cause for the registration of scattering layers in the thermosphere and imaginary aerosol formations in the middle atmosphere

E3S Web of Conferences ◽

10.1051/e3sconf/201912701009 ◽

2019 ◽

Vol 127 ◽

pp. 01009

Author(s):

Vasily Bychkov ◽

Andrey Perezhogin ◽

Ilya Seredkin

Keyword(s):

Middle Atmosphere ◽

Lower Thermosphere ◽

Resonant Scattering ◽

Resonance Scattering ◽

Altitude Range ◽

Entire Region ◽

Scattering Signal ◽

Additional Channel

The results of lidar and ionospheric observations from August to November 2017 are discussed. Resonance scattering was detected at wavelengths of 532.08 and 561.106 nm in the altitude range of 200-400 km and in the middle atmosphere. A possible mechanism for the formation of a resonant scattering signal on excited ions of the main gas components of the atmosphere is presented. The possibility of estimating the spectra of precipitated electrons is shown. It is shown that the complete profile of the backscattering signal can be restored in the region of 10–25 km using an additional channel for recording the attenuated signal separated from the main signal. Thus, it becomes possible to estimate the energies of electron flows in the entire region from the lower thermosphere to the stratosphere.

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MAARSY – the new MST radar on Andøya/Norway

Advances in Radio Science ◽

10.5194/ars-8-219-2010 ◽

2010 ◽

Vol 8 ◽

pp. 219-224 ◽

Cited By ~ 14

Author(s):

R. Latteck ◽

W. Singer ◽

M. Rapp ◽

T. Renkwitz

Keyword(s):

Middle Atmosphere ◽

Beam Steering ◽

Lower Thermosphere ◽

The Arctic ◽

Circular Aperture ◽

Phased Array Antenna ◽

Spatiotemporal Resolution ◽

Vhf Radar ◽

High Flexibility ◽

New System

Abstract. The Leibniz-Institute of Atmospheric Physics in Kühlungsborn, Germany (IAP) is installing a new powerful VHF radar on the North-Norwegian island Andøya (69.30° N, 16.04° E) in 2009/2010. The new Middle Atmosphere Alomar Radar System (MAARSY) replaces the existing ALWIN radar which has been operated continuously on Andøya for more than 10 years. The new system is a monostatic radar operated at 53.5 MHz with an active phased array antenna consisting of 433 Yagi antennas. The 3-element Yagi antennas are arranged in an equilateral triangle grid forming a circular aperture of approximately 6300 m2. Each individual antenna is connected to its own transceiver with independent phase control and a scalable output up to 2 kW. This arrangement allows very high flexibility of beam forming and beam steering with a symmetric radar beam of a minimum half power beam width of 3.6°, a maximum directive gain of 33.5 dB and a total transmitted peak power of approximately 800 kW. The IF signals of each 7 transceivers connected to each 7 antennas arranged in a hexagon are combined to 61 receiving channels. Selected channels or combinations of IF signals are sent to a 16-channel data acquisition system with 25 m sampling resolution and 16-bit digitization specified which will be upgraded to 64 channels in the final stage. The high flexibility of the new system allows classical Doppler beam swinging as well as experiments with simultaneously formed multiple beams and the use of modern interferometric applications for improved studies of the Arctic atmosphere from the troposphere up to the lower thermosphere with high spatiotemporal resolution.

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Self-sustained Oscillations in the Atmosphere (0–110 km) at Long Periods

10.5194/acp-2020-89 ◽

2020 ◽

Author(s):

Dirk Offermann ◽

Christoph Kalicinsky ◽

Ralf Koppmann ◽

Johannes Wintel

Keyword(s):

General Circulation ◽

Middle Atmosphere ◽

Lower Thermosphere ◽

Vertical Displacement ◽

General Circulation Models ◽

Dynamical Structure ◽

Vertical Profiles ◽

Atmospheric Measurements ◽

Model Calculations ◽

Sustained Oscillations

Abstract. Self-generated (self-sustained) oscillations have been observed in measured atmospheric data at multi-annual periods. These oscillations are also present in General Circulation Models even if their boundary conditions with respect to solar cycle, sea surface temperature, and trace gas variability are kept constant. The present analysis contains temperature oscillations with periods from below 5 yr up to 341 yr in an altitude range from the Earth’s surface to the lower thermosphere (110 km). The periods are quite robust as they are found to be the same in different model calculations and in atmospheric measurements. The oscillations show vertical profiles with special structures of amplitudes and phases. They form layers of high/low amplitudes that are a few dozen km wide. Within the layers the data are correlated. Adjacent layers are anticorrelated. A vertical displacement mechanism is indicated with displacement heights of a few 100 metres. Vertical profiles of amplitudes and phases of the various oscillation periods as well as their displacement heights are surprisingly similar. The oscillations are related to the thermal and dynamical structure of the middle atmosphere. These results are from latitudes/longitudes in Central Europe.

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Vertical Atmospheric Coupling during the September 2019 Antarctic Sudden Stratospheric Warming

10.5194/egusphere-egu2020-11224 ◽

2020 ◽

Author(s):

Yosuke Yamazaki ◽

Vivien Matthias ◽

Yasunobu Miyoshi ◽

Claudia Stolle ◽

Tarique Siddiqui ◽

...

Keyword(s):

Large Scale ◽

Middle Atmosphere ◽

Lower Thermosphere ◽

Upper Atmosphere ◽

The Arctic ◽

Electron Content ◽

Stratospheric Warming ◽

Sudden Stratospheric Warming ◽

Total Electron ◽

Zonal Wavenumber

A sudden stratospheric warming (SSW) is an extreme wintertime meteorological phenomenon occurring mostly over the Arctic region. Studies have shown that an Arctic SSW can influence the whole atmosphere including the ionosphere. In September 2019, a rare SSW event occurred in the Antarctic region, following strong wave-1 planetary wave activity. The event provides an opportunity to investigate its broader impact on the upper atmosphere, which has been largely unexplored in previous studies. Ionospheric data from ESA's Swarm satellite constellation mission show prominent 6-day variations in the dayside low-latitude region during the SSW, including 20-70% variations in the equatorial zonal electric field, 20-40% variations in the electron density, and 5-10% variations in the top-side total electron content. These ionospheric variations have characteristics of a westward-propagating wave with zonal wavenumber 1, and can be attributed to forcing from the middle atmosphere by the Rossby normal mode &#8220;quasi-6-day wave&#8221; (Q6DW). Geopotential height measurements by the Microwave Limb Sounder aboard NASA's Aura satellite reveal a burst of global Q6DW activity in the mesosphere and lower thermosphere at this time, which is one of the strongest in the record. These results suggest that an Antarctic SSW can lead to ionospheric variability by altering middle atmosphere dynamics and propagation characteristics of large-scale waves from the middle atmosphere to the upper atmosphere.

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