We retrieve ionization rates in the atmosphere caused by energetic electron precipitation from balloon observations in the polar atmosphere and compare them against ionization rates recommended for ...the Phase 6 of the Coupled Model Intercomparison Project. In our retrieval procedure, we consider the precipitating electrons with energies from about tens of keV to 5 MeV. Our simulations with 1‐D radiative‐convective model with interactive neutral and ion chemistry show that the difference of the Phase 6 of the Coupled Model Intercomparison Project and balloon‐based ionization rate can lead to underestimation of the NOx enhancement by more than 100% and ozone loss up to 25% in the mesosphere. The atmospheric response is different below 50 km due to considering highly energetic electrons, but it is not important because the absolute values of atmospheric impact is tiny. Ionization rates obtained from the balloon observations reveal a high variability.
Plain Language Summary
The main idea of our manuscript is to demonstrate that the atmospheric ionization rates (IR) can be successfully retrieved from the long‐term balloon observations of the energetic electron precipitation (EEP) events and used to evaluate the uncertainties of the other IR data sets, for example, IR recommended for the Phase 6 of the Coupled Model Intercomparison Project (CMIP6). IR obtained from the balloon observations reveal a high variability. This means that the time resolution used in CMIP6 probably is not enough to consider high frequency variability of the precipitating electron fluxes. Using 1‐D radiative‐convective model with neutral and ion chemistry, we compared the atmospheric response to the one particular EEP observed by balloons and presented in CMIP6 data. We show that the difference of the CMIP6 and balloon‐based IRs can lead to underestimation of the NOx enhancement by more than 100% and ozone loss by up to 25% in the mesosphere. Our results are new and needed for the understanding of the potential uncertainties in CMIP6 EEP forcing. Our paper will give inspiration for the continuation of the balloon measurements of EEP‐related processes using improved instruments.
Key Points
Ionization rates (IR) from energetic electron precipitation (EEP) are calculated using balloon observations and compared to the CMIP6 data set
The difference in the atmospheric response calculated with these two data sets can exceed 100% for NOx and reach 25% for O3
IR obtained from balloon measurements reveal a high temporal variability, which is absent in CMIP6 data
Numerous energetic electron precipitation events were recorded since 1963 in the atmosphere at polar latitudes in the course of regular measurements of charged particle fluxes in the Earth's ...atmosphere being performed by the Lebedev Physical Institute. The experimental data obtained represent the only uniform database in the world on electron precipitation events recorded directly in the atmosphere well below satellite orbits. The precipitating electrons are absorbed in the upper atmosphere. However, they generate X‐rays that can penetrate deep into the atmosphere sometimes down to altitudes of 20–35 km accessible to balloon measurements. These experimental data allow studying energy, temporal and spatial characteristics of electron precipitation events. In particular, based on PLANETOCOSMICS/GEANT4 we developed a method for evaluating the energy spectra of the primary flux of precipitating electrons. This method was used for evaluation of primary spectra of precipitating electrons assuming exponential energy distribution of incident electrons. Now, for the development of the method, we present the possibility of determining the energy spectra of electrons in the power‐law form, using new software RUSCOSMICS code. This new method, based on the GEANT4 software, makes it possible to describe the transport of precipitating electrons in the atmosphere taking into account the evolution of the energy and pitch‐angle distributions of electrons and X‐ray photons.
Key Points
We developed a new method of evaluation of energy spectra of primary flux of precipitating electrons
Knowledge of the spectrum is important for understanding the processes of acceleration and loss of electrons in the outer radiation belt
The method describes evolution of the energy and pitch‐angle distributions of electrons and X‐ray photons in the atmosphere
An overview is presented of basic results and recent developments in the field of cosmic ray induced ionisation in the atmosphere, including a general introduction to the mechanism of cosmic ray ...induced ion production. We summarize the results of direct and indirect measurements of the atmospheric ionisation with special emphasis to long-term variations. Models describing the ion production in the atmosphere are also overviewed together with detailed results of the full Monte-Carlo simulation of a cosmic ray induced atmospheric cascade. Finally, conclusions are drawn on the present state and further perspectives of measuring and modeling cosmic ray induced ionisation in the terrestrial atmosphere.
Since the International Geophysical Year (1957), the Lebedev Physical Institute performs the regular measurements of charged particle fluxes in the Earth's atmosphere (from the ground level up to ...30–35km) at several latitudes. The unique experimental data base obtained during 58 years of cosmic rays observations in the atmosphere allows to investigate temporal, spatial and energetic characteristics of galactic and solar cosmic rays as well as the role of charged particles in the atmospheric processes. Analysis of this data base also revealed a special class of numerous events caused by energetic electron precipitation recorded in the atmosphere at polar latitudes. In this paper we present Catalogue of electron precipitation events observed in the polar atmosphere during 1961–2014 and briefly outline the previous results of this data set analysis.
•Regular measurements of cosmic rays in the Earth's atmosphere (0–35km) since 1957.•A special class of events caused by energetic electron precipitation at polar latitudes is defined.•More than 550 events of precipitating electron events are recorded during 58 years of observations.•Characteristics of precipitating electron spectra are determined.•We present the Catalogue of electron precipitation events observed during 1961–2014.
About Cosmic Ray Sources in Galaxy Stozhkov, Y. I.; Filippov, M. V.; Logachev, V. I. ...
Physics of atomic nuclei,
11/2021, Letnik:
84, Številka:
6
Journal Article
Recenzirano
In the last two decades the new experimental data on cosmic rays concerning energy spectra in a wide energy range up to 10
eV, isotropy, ratio of positron flux to electron one, and others were ...obtained. These data came mainly from satellites. It is difficult to explain these experimental data within a generally accepted model of cosmic ray sources, namely, that supernova explosions are the main sources of cosmic rays in Galaxy. We consider the question that with high probability the active red dwarf stars could be cosmic ray sources up to energy of 10
–10
eV.
We compare the quasi-biennial variations and Rieger-type variations (on a timescale of less than 1 year) in solar activity, interplanetary magnetic field, and galactic cosmic-ray flux modulation. We ...show that, in comparison with the 11-year cycle, the quasi-biennial variations are less suppressed in the interplanetary medium than on the Sun. Although the Rieger-type variations are adjacent in frequency to the quasi-biennial variations, they differ noticeably from them in the degree of reproduction in the interplanetary medium and the influence on the cosmic-ray modulation.
The paper summarizes the properties of precipitation of magnetospheric electrons with energy above several hundred keV recorded by observing X‐ray bremsstrahlung in the polar stratosphere above the ...Murmansk region, Russia, in 1961–2019. Precipitation occurrence rate demonstrates a clear dependence on the solar activity with a maximum at the decay phase of the 11‐year solar cycle, similarly to the variability in occurrences of the high‐speed solar wind streams (HSSWS). The energetic electron precipitation (EEP) event series is often initiated by a moderate geomagnetic storm caused by a HSSWS and continues during geomagnetic storm recovery. EEP demonstrates the seasonal rate variation with the maxima in occurrence rate around the spring and the autumn solstices and correlates with fluences of relativistic electrons in the outer radiation belt. For 59 years, 589 events of precipitation were observed. Analysis of the long‐term time series revealed a growing trend in the rate of precipitation occurrence, especially in the 1990s to 2000s that is not properly explained yet.
Plain Language Summary
Since the beginning of the 1960s, the group from Lebedev Physical Institute watches the precipitation of energetic electrons from the outer radiation belt to the atmosphere. The precipitation reflects the condition in the interplanetary space and in the magnetosphere, that is, it is governed by solar activity. In the 1990s, solar activity started weakening: the maximum annual mean of sunspot number decreased from 233 in Solar Cycle 21 to 116 in Cycle 24. But the occurrence rate of precipitation increased, which has not found an explanation yet.
Key Points
Balloon observations allow recording precipitation of magnetospheric electrons via bremsstrahlung in the atmosphere
Since 1961 till 2019, 589 electron precipitation events were observed in the Murmansk region
An unexpected increase of precipitation occurrence rate was found in the 1990s to 2000s
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The Galactic Cosmic Rays (GCR) portable scientific instrument was developed in 2022 by the Dolgoprudny Scientific Station of the Lebedev Physical Institute for detecting the charged component of ...cosmic rays. Its description and performance characteristics are presented. STS-6 gas-discharge counters arranged in two layers with five counters in each are used as detecting elements. The layers of the upper and lower counters are separated by a 7-mm-thick aluminum filter. This instrument is intended for the TI3GER international experiment (Technological Innovation Into Iodine and GV Environmental Research), which is aimed at studying the effect of iodine oxides on the reduction of the ozone layer.
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•NiMoSx/Al-MCM-41 and NiMoSx/Al-HMS catalysts were synthesized.•Ni-Mo sulfide catalysts are active in WGSR providing in situ hydrogen generation.•Ni-Mo sulfide catalysts are active in ...HDS and HYD in H2O/CO system.•Al-MCM-41 supported catalyst provide better DBT conversion.•Al-HMS-based catalysts are more active in HYD of aromatics.
The mesoporous aluminosilicates Al-HMS (Si/Al = 10) and Al-MCM-41 (Si/Al = 20) types were synthesized via the neutral templating pathway and used as supports for Ni-Mo sulfide catalysts, prepared by standard incipient wetness co-impregnation technique followed by sulfidation procedure. Ni and Mo content were 7 and 24 wt.% respectively. Both mesoporous aluminosilicates and supported oxide Ni-Mo catalyst precursors were characterized by TEM, solid-state 29Si and 27Al MAS NMR, N2 adsorption/desorption, TPD-NH3, TPR-H2, ICP-AES techniques. The chemical state and surface composition of freshly sulfided catalysts were revealed by XPS and TEM. The performance of mesoporous Al-HMS and Al-MCM-41 supported Ni-Mo sulfide catalysts in hydroconversion of 1-methylnaphtalene (1 MN), 2- methylnaphthalene (2 MN) and dibenzothiophene (DBT) was studied in high-pressure batch reactor at T = 320-400 °C, P(CO) = 3–5 MPa in the presence of water (20 wt.%) providing in situ hydrogen generation through a water gas shift reaction (WGSR). The results obtained showed that Al-HMS-based catalysts are more active in hydrogenation of aromatics while the higher DBT conversions were obtained over Al-MCM-41 supported catalyst. Mo-containing supported catalysts promoted by Ni were found the most active at T = 380 °C, P(CO) = 3 MPa and CO/H2O molar ratio 1.5–2.0.
Regular measurements of fluxes of charged particles in the Earth’s atmosphere conducted by the Lebedev Physical Institute (LPI) made it possible to register since 1963 more than 500 cases of ...precipitation of energetic electrons in the northern polar latitudes. The obtained experimental data represent the world’s only database on the precipitation of electrons registered directly in the Earth’s atmosphere. Primary precipitating electrons are absorbed in the upper layers of the atmosphere. However, the fluxes of secondary photons generated by them can penetrate deep into the atmosphere, sometimes to heights of ~20 km, which are accessible for balloon measurements by the Lebedev Physical Institute. This paper presents a new technique for reconstructing the energy spectrum of precipitating electrons developed on the basis of the Monte Carlo simulation of the processes of electron propagation in the atmosphere. The applicability of the technique to the accumulated experimental data is shown, and new results are presented for individual events recorded in the atmosphere.
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