scholarly journals Mesospheric ozone in artificial modification of lower ionosphere.

2020 ◽  
Author(s):  
N.V. Bakhmetieva ◽  
◽  
V.L. Frolov ◽  
Y.Y. Kulikov ◽  
◽  
...  
Keyword(s):  
Radio Emission ◽  
Middle Atmosphere ◽  
Lower Ionosphere ◽  
Physical Nature ◽  
Microwave Emission ◽  
Heating Facility ◽  
Mesospheric Ozone

We present some results of microwave observations of the middle atmosphere ozone under perturbation of the ionosphere by a power HF radio emission by the mid-latitude SURA heating facility (56N, 46E). New experiment was a continuation of studies to clarify the physical nature of the new phenomenon a decrease of the intensity of the microwave emission of the mesosphere in the ozone line when artificially impact on the lower ionosphere [1].

Response of mesospheric ozone to the heating of the lower ionosphere by high-power HF radio emission

2013 ◽  
Vol 53 (1) ◽  
pp. 96-103 ◽  
Author(s):  
Yu. Yu. Kulilov ◽  
V. L. Frolov ◽  
G. I. Grigor’ev ◽  
V. M. Demkin ◽  
G. P. Komrakov ◽  
...  
Keyword(s):  
Radio Emission ◽  
High Power ◽  
Lower Ionosphere ◽  
Mesospheric Ozone

scholarly journals Coronal Magnetic Fields of Algol Binaries from Microwave Spectra

1991 ◽  
Vol 130 ◽  
pp. 498-500
Author(s):  
G. Umana ◽  
C. Trigilio ◽  
R. M. Hjellming ◽  
S. Catalano ◽  
M. Rodonò
Keyword(s):  
Magnetic Fields ◽  
Radio Emission ◽  
Mass Exchange ◽  
Thermal Emission ◽  
Magnetic Activity ◽  
Microwave Emission ◽  
X Ray ◽  
Coronal Magnetic Fields ◽  
Hydrodynamic Processes ◽  
Hot Corona

Algol-type binaries are basically known to undergo hydrodynamic processes related to mass exchange between components. Recent observations on radio, X-ray emission and flare-like events have raised the question of possible magnetic activity in the secondary component of these systems (Hall, 1989).From a microwave emission survey we have shown that the radio emission from Algol systems cannot be accounted for by thermal emission from an hot corona (T ≥ 107K) and that their radio luminosities compare very well with those of the magnetically active RS CVn systems (Umana et al., 1990).

scholarly journals Nighttime Mesospheric Ozone During the 2002 Southern Hemispheric Major Stratospheric Warming

2016 ◽  
Author(s):  
Christine Smith-Johnsen ◽  
Yvan Orsolini ◽  
Frode Stordal ◽  
Varavut Limpasuvan ◽  
Kristell Pérot
Keyword(s):  
Atomic Oxygen ◽  
Lower Stratosphere ◽  
Climate Model ◽  
Middle Atmosphere ◽  
Ozone Layer ◽  
Stratospheric Warming ◽  
Mesospheric Ozone ◽  
Northern Hemispheric ◽  
Second Year ◽  
The Antarctic

Abstract. A Sudden Stratospheric Warming (SSW) affects the chemistry and dynamics of the middle atmosphere. The major warmings occur roughly every second year in the Northern Hemispheric (NH) winter, but has only been observed once in the Southern Hemisphere (SH), during the Antarctic winter of 2002. Using the National Center for Atmospheric Research's (NCAR) Whole Atmosphere Community Climate Model with specified dynamics (WACCM-SD), this study investigates the effects of this rare warming event on the ozone layer located around the SH mesopause. This secondary ozone layer changes with respect to hydrogen, oxygen, temperature, and the altered SH polar circulation during the major SSW. The 2002 SH winter was characterized by three zonal-mean zonal wind reductions in the upper stratosphere before a fourth wind reversal reaches the lower stratosphere, marking the onset of the major SSW. At the time of these four wind reversals, a corresponding episodic increase can be seen in the modeled nighttime ozone concentration in the secondary ozone layer. Observations by the Global Ozone Monitoring by Occultation of Stars (GOMOS, an instrument on board the satellite Envisat) demonstrate similar ozone enhancement as in the model. This ozone increase is attributable largely to enhanced upwelling and the associated cooling of the altitude region in conjunction with the wind reversal. Unlike its NH counterpart, the secondary ozone layer during the SH major SSW appeared to be impacted more by the effects of atomic oxygen than hydrogen.

scholarly journals Results of microwave monitoring of middle atmosphereozone in polar latitudes for two winter seasons 2017-2018 and 2018-2019.

2020 ◽  
Author(s):  
Y.Y. Kulikov ◽  
◽  
A.F. Andriyanov ◽  
V.G. Ryskin ◽  
V.M. Demkin ◽  
...  
Keyword(s):  
Middle Atmosphere ◽  
Continuous Series ◽  
Vertical Profiles ◽  
Stratospheric Warming ◽  
Geophysical Institute ◽  
Sudden Stratospheric Warming ◽  
Polar Geophysical Institute ◽  
Mesospheric Ozone ◽  
Dynamic Components ◽  
Microwave Data

We present data continuous series of microwave observations of the middle atmosphere in winters 2017-2018, 2018-2019 and 2019-2020. In each of these winters sudden stratospheric warming were marked.Measurements were carried out with the help of mobile ozonemeter (observation frequency 110836.04 MHz), which was established at Polar Geophysical Institute in Apatity (67N, 33E). The parameters of the device allow to measure a spectrum of the ozone emission line for time about 15 min a precision of 2%. On the measured spectra were appreciated of ozone vertical profiles in the layer of 22 60 km which were compared to satellite data MLS/Aura and with the data of ozonesonde at station Sodankyla (67N, 27E). The microwave data on the behavior of mesospheric ozone (altitude 60 km) indicate the presence of bothphotochemical and dynamic components in its changes.

scholarly journals Cosmology with gravitationally lensed repeating fast radio bursts

2021 ◽  
Vol 645 ◽  
pp. A44
Author(s):  
O. Wucknitz ◽  
L. G. Spitler ◽  
U.-L. Pen
Keyword(s):  
High Resolution ◽  
Radio Emission ◽  
Mass Distribution ◽  
High Precision ◽  
Time Delays ◽  
Cosmological Parameters ◽  
Physical Nature ◽  
Radio Bursts ◽  
Gravitational Lenses ◽  
Proper Motions

High-precision cosmological probes have revealed a small but significant tension between the parameters measured with different techniques, among which there is one based on time delays in gravitational lenses. We discuss a new way of using time delays for cosmology, taking advantage of the extreme precision expected for lensed fast radio bursts, which are short flashes of radio emission originating at cosmological distances. With coherent methods, the achievable precision is sufficient for measuring how time delays change over the months and years, which can also be interpreted as differential redshifts between the images. It turns out that uncertainties arising from the unknown mass distribution of gravitational lenses can be eliminated by combining time delays with their time derivatives. Other effects, most importantly relative proper motions, can be measured accurately and disentangled from the cosmological effects. With a mock sample of simulated lenses, we show that it may be possible to attain strong constraints on cosmological parameters. Finally, the lensed images can be used as galactic interferometer to resolve structures and motions of the burst sources with incredibly high resolution and help reveal their physical nature, which is currently unknown.

scholarly journals Observation of eruptive events with the Siberian Radioheliograph

2018 ◽  
Vol 4 (3) ◽  
pp. 17-27
Author(s):  
Анастасия Федотова ◽  
Anastasiya Fedotova ◽  
Александр Алтынцев ◽  
Alexander Altyntsev ◽  
Алексей Кочанов ◽  
...  
Keyword(s):  
Radio Emission ◽  
Magnetic Structure ◽  
Microwave Emission ◽  
Radio Brightness ◽  
Microwave Source ◽  
Local Sources ◽  
Cold Matter ◽  
Radio Map

We describe methods for monitoring eruption activity with the first phase of the multiwave Siberian Radioheliograph (SRH-48). We give examples of the recorded eruptive events: 1) rise of a prominence above the limb observed in the radio map sequence of April 24, 2017; 2) a jet recorded on August 2, 2017, whose cold matter screened a compact microwave source for several tens of minutes. The shading due to the jet appearance was observed on SRH-48 correlation curves as the so-called “negative” burst. Using the “negative” burst on the correlation curves of February 9, 2017 as an example, we show that the intervals with depression of the microwave emission of local sources are not always caused by shading of their emission. In this event, the radio brightness decreased within ten hour period of the increased quasi-stationary emission during the development of AR 12635 magnetic structure. Similar behavior was observed in EUV, SXR, and radio emission at 17 GHz.

Observational evidence of polar mesospheric ozone loss following substorm events

2021 ◽  
Author(s):  
Keeta Chapman-Smith ◽  
Annika Seppälä ◽  
Craig Rodger ◽  
Aaron Hendry
Keyword(s):  
Middle Atmosphere ◽  
Energetic Particles ◽  
Observational Evidence ◽  
Electron Precipitation ◽  
Data Sets ◽  
Ozone Loss ◽  
Mesospheric Ozone ◽  
Ozone Monitoring ◽  
The Impact

<p>Ozone in the polar middle atmosphere is known to be affected by charged energetic particles precipitating into the atmosphere from the magnetosphere. In recent years there has been increased interest in the sources and consequences of electron precipitation into the atmosphere. Substorms are an important source of electron precipitation. They occur hundreds of times a year and drive processes which cause electrons to be lost into our atmosphere. The electrons ionise neutrals in the atmosphere resulting in the production of HO<sub>x</sub> and NO<sub>x</sub>, which catalytically destroy ozone. Simulations have examined substorm driven ozone loss and shown it is likely to be significant. However, this has not previously been verified from observations. Here we use polar mesospheric ozone observations from the Global Ozone Monitoring by Occultation of Stars (GOMOS) and Microwave Limb Sounder (MLS) instruments to investigate the impact of substorms. Using the superposed epoch technique we find consistent 10-20% reduction in mesospheric ozone in both data sets. This provides the first observational evidence that substorms are important to the ozone balance within the atmosphere.<span> </span></p>

scholarly journals Ionospheric measurements during the CRISTA/MAHRSI campaign: their implications and comparison with previous campaigns

1999 ◽  
Vol 17 (8) ◽  
pp. 1040-1052
Author(s):  
J. Laštovicka ◽  
D. Pancheva ◽  
D. Altadill ◽  
E. A. Benediktov ◽  
J. Boška ◽  
...  
Keyword(s):  
Middle Atmosphere ◽  
Space Shuttle ◽  
Lower Ionosphere ◽  
Data Series ◽  
Short Term ◽  
Climatological Data ◽  
Middle Latitudes ◽  
Solar Influence ◽  
The Given

Abstract. The CRISTA/MAHRSI experiment on board a space shuttle was accompanied by a broad campaign of rocket, balloon and ground-based measurements. Supporting lower ionospheric ground-based measurements were run in Europe and Eastern Asia between 1 October-30 November, 1994. Results of comparisons with long ionospheric data series together with short-term comparisons inside the interval October-November, 1994, showed that the upper middle atmosphere  (h = 80-100 km) at middle latitudes of the Northern Hemisphere in the interval of the CRISTA/MAHRSI experiment (4-12 November, 1994) was very close to its expected climatological state. In other words, the average results of the experiment can be used as climatological data, at least for the given area/altitudes. The role of solar/geomagnetic and "meteorological" control of the lower ionosphere is investigated and compared with the results of MAP/WINE, MAC/SINE and DYANA campaigns. The effects of both solar/geomagnetic and global meteorological factors on the lower ionosphere are found to be weak during autumn 1994 compared to those in MAP/WINE and DYANA winters, and they are even slightly weaker than those in MAP/SINE summer. The comparison of the four campaigns suggests the following overall pattern: in winter the lower ionosphere at northern middle latitudes appears to be fairly well "meteorologically" controlled with a very weak solar influence. In summer, solar influence is somewhat stronger and dominates the weak "meteorological" influence, but the overall solar/meteorological control is weaker than in winter. In autumn we find the weakest overall solar/meteorological control, local effects evidently dominate.Key words. Ionosphere (ionosphere · atmosphere interactions; mid-latitude ionosphere)

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