scholarly journals HEPPA III intercomparison experiment on electron precipitation impacts, part I: Estimated ionization rates during a geomagnetic active period in April 2010

2021 ◽  
Author(s):  
H. Nesse Tyssøy ◽  
M. Sinnhuber ◽  
T. Asikainen ◽  
S. Bender ◽  
M. A. Clilverd ◽  
...  
Keyword(s):  
Electron Precipitation ◽  
Active Period ◽  
Ionization Rates

scholarly journals Contribution of proton and electron precipitation to the observed electron concentration in October–November 2003 and September 2005

2015 ◽  
Vol 33 (3) ◽  
pp. 381-394 ◽  
Author(s):  
P. T. Verronen ◽  
M. E. Andersson ◽  
A. Kero ◽  
C.-F. Enell ◽  
J. M. Wissing ◽  
...  
Keyword(s):  
Electron Concentration ◽  
Solar Proton ◽  
Electron Ionization ◽  
Climate Impacts ◽  
Electron Precipitation ◽  
Incoherent Scatter ◽  
Solar Proton Events ◽  
Spatio Temporal ◽  
The Difference ◽  
Ionization Rates

Abstract. Understanding the altitude distribution of particle precipitation forcing is vital for the assessment of its atmospheric and climate impacts. However, the proportion of electron and proton forcing around the mesopause region during solar proton events is not always clear due to uncertainties in satellite-based flux observations. Here we use electron concentration observations of the European Incoherent Scatter Scientific Association (EISCAT) incoherent scatter radars located at Tromsø (69.58° N, 19.23° E) to investigate the contribution of proton and electron precipitation to the changes taking place during two solar proton events. The EISCAT measurements are compared to the results from the Sodankylä Ion and Neutral Chemistry Model (SIC). The proton ionization rates are calculated by two different methods – a simple energy deposition calculation and the Atmospheric Ionization Model Osnabrück (AIMOS v1.2), the latter providing also the electron ionization rates. Our results show that in general the combination of AIMOS and SIC is able to reproduce the observed electron concentration within ± 50% when both electron and proton forcing is included. Electron contribution is dominant above 90 km, and can contribute significantly also in the upper mesosphere especially during low or moderate proton forcing. In the case of strong proton forcing, the AIMOS electron ionization rates seem to suffer from proton contamination of satellite-based flux data. This leads to overestimation of modelled electron concentrations by up to 90% between 75–90 km and up to 100–150% at 70–75 km. Above 90 km, the model bias varies significantly between the events. Although we cannot completely rule out EISCAT data issues, the difference is most likely a result of the spatio-temporal fine structure of electron precipitation during individual events that cannot be fully captured by sparse in situ flux (point) measurements, nor by the statistical AIMOS model which is based upon these observations.

scholarly journals HEPPA III intercomparison experiment on electron precipitation impacts:  Estimated ionization rates during a geomagnetic active period in April 2010

2021 ◽  
Author(s):  
Hilde Nesse Tyssøy ◽  
Miriam Sinnhuber ◽  
Timo Asikainen ◽  
Stefan Bender ◽  
Mark A. Clilverd ◽  
...  
Keyword(s):  
Climate Models ◽  
Climate Model ◽  
Ionization Rate ◽  
Data Sets ◽  
Active Period ◽  
Medium Energy ◽  
Model Driven ◽  
Wide Range ◽  
Order Of Magnitude ◽  
Ionization Rates

<p>Precipitating auroral and radiation belt electrons are considered an important part of the natural forcing of the climate system.  Recent studies suggest that this forcing is underestimated in current chemistry-climate models. The HEPPA III intercomparison experiment is a collective effort to address this point. Here, eight different estimates of medium energy electron (MEE) (>30 keV) ionization rates are assessed during a geomagnetic active period in April 2010.  The objective is to understand the potential uncertainty related to the MEE energy input. The ionization rates are all based on the Medium Energy Proton and Electron Detector (MEPED) on board the NOAA/POES and EUMETSAT/MetOp spacecraft series. However, different data handling, ionization rate calculations, and background atmospheres result in a wide range of mesospheric electron ionization rates. Although the eight data sets agree well in terms of the temporal variability, they differ by about an order of magnitude in ionization rate strength both during geomagnetic quiet and disturbed periods. The largest spread is found in the aftermath of the geomagnetic activity.  Furthermore, governed by different energy limits, the atmospheric penetration depth varies, and some differences related to latitudinal coverage are also evident. The mesospheric NO densities simulated with the Whole Atmospheric Community Climate Model driven by highest and lowest ionization rates differ by more than a factor of eight. In a follow-up study, the atmospheric responses are simulated in four chemistry-climate models and compared to satellite observations, considering both the model structure and the ionization forcing.</p>

scholarly journals Energetic electron precipitation and their atmospheric effect

2020 ◽  
Vol 196 ◽  
pp. 01005
Author(s):  
Irina Mironova ◽  
Miriam Sinnhuber ◽  
Eugene Rozanov
Keyword(s):  
Climate Models ◽  
Energetic Electron ◽  
Electron Precipitation ◽  
Atmospheric Composition ◽  
Energy Spectra ◽  
Atmospheric Effect ◽  
Entire Energy Range ◽  
A Chain ◽  
Reaction Cycles ◽  
Ionization Rates

Energetic particle precipitation induces ionization of the atmosphere which initiates a chain of reaction cycles affecting atmospheric composition and dynamics potentially down to surface weather systems. Ionization rates are retrieved based on yield functions or pre-calculated monoenergetic electron flux and energy spectra of precipitated energetic particles. Usually, information about energy spectra is obtained from satellites, balloons, and various ground-based observations. In all cases, some assumptions about spectral distribution for the entire energy range have to be made. As ionization rates are widely used in chemistry-climate models to estimate the atmospheric response to particle forcing, evaluation of the energy spectra is a key task in the solar-terrestrial studies. In this paper, it is shown that possible uncertainties of the ionization rates retrieval based on different spectral functions can lead to large disagreements in the ionization rates, with implications for the modelled response of atmospheric composition and dynamics to electron precipitation.

scholarly journals Spectra of high energy electron precipitation and atmospheric ionization rates retrieval from balloon measurements

2019 ◽  
Vol 693 ◽  
pp. 133242 ◽  
Author(s):  
Irina Mironova ◽  
Galina Bazilevskaya ◽  
Gennady Kovaltsov ◽  
Anton Artamonov ◽  
Eugene Rozanov ◽  
...  
Keyword(s):  
High Energy ◽  
Energy Electron ◽  
Electron Precipitation ◽  
High Energy Electron ◽  
Atmospheric Ionization ◽  
Balloon Measurements ◽  
Ionization Rates

Energy Saving Scheme with an Extra Active Period for LAN Switches

2010 ◽  
Vol E93-B (12) ◽  
pp. 3542-3554 ◽  
Author(s):  
Hitomi TAMURA ◽  
Ritsuko TOMIHARA ◽  
Yutaka FUKUDA ◽  
Kenji KAWAHARA ◽  
Yuji OIE
Keyword(s):  
Energy Saving ◽  
Active Period

scholarly journals The quality of life in Chinese juvenile idiopathic arthritis patients: psychometric properties of the pediatric quality of life inventor generic core scales and rheumatology module

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Hua-hong Wu ◽  
Feng-qi Wu ◽  
Yang Li ◽  
Jian-ming Lai ◽  
Gai-xiu Su ◽  
...  
Keyword(s):  
Quality Of Life ◽  
Juvenile Idiopathic Arthritis ◽  
Reliability And Validity ◽  
Correlation Coefficients ◽  
Active Period ◽  
Generic Core Scale ◽  
Remission Period ◽  
Pedsql 4.0 ◽  
The Mean

Abstract Background Juvenile idiopathic arthritis (JIA) may seriously affects patients’ quality of life (QoL), but it was rarely focused and studied in China, so we explore JIA children’s QoL using Chinese version of the PedsQL4.0 Generic Core and PedsQL3.0 Rheumatology Module scale, and analyzed the psychometric properties of these two Scales among Chinese JIA children. Methods We recruited 180 JIA patients from Children's Hospital Affiliated to Capital Institute of Pediatrics and Hebei Yanda Hospital from July 2018 to August 2019. The questionnaires include information related on JIA, PedsQL4.0 generic core and PedsQL3.0 Rheumatology Module scales. According to the disease type, onset age of and course of JIA, we divided them into different groups, then compared the QoL status among different groups. Moreover, we analyzed the reliability and validity of these two scales in these 180 JIA children. Results The mean score of PedsQL4.0 generic core scale on these 180 patients was 82.85 ± 14.82, for these in active period was 72.05 ± 15.29, in remission period was 89.77 ± 9.23; the QoL score of systemic, polyarticular and oligoarticular JIA patients were 77.05 ± 19.11, 84.33 ± 12.46 and 87.12 ± 10.23. The mean score of PedsQL3.0 Rheumatology Module scale on 180 patients was 91.22 ± 9.45, for these in active period was 84.70 ± 11.37, in remission period was 95.43 ± 4.48; the QoL score of systemic, polyarticular and oligoarticular JIA patients were 89.41 ± 11.54, 89.38 ± 10.08 and 93.71 ± 6.92. In the PedsQL 4.0 Generic Core scale, the α coefficients of total scale and almost every dimension are all greater than 0.8 except for the school activity dimension of 0.589; the correlation coefficients of 22 items’ scores (total 23 items) with the scores of dimensions they belong to are greater than 0.5 (maximum value is 0.864), and the other one is 0.406. In PedsQL3.0 Rheumatology Module scale, except for the treatment and worry dimensions of 0.652 and 0.635, the α coefficients of other dimensions and the total scale are all greater than 0.7; the correlation coefficients of all items’ score were greater than 0.5 (the maximum is 0.933, the minimum is 0.515). Conclusions The QoL of Chinese JIA children is worse than their healthy peers, these in active period and diagnosed as systemic type were undergoing worst quality of life. The reliability and validity of PedsQL 4.0 Generic Core and PedsQL3.0 Rheumatology Module scale in Chinese JIA children are satisfactory, and can be used in clinical and scientific researches.

scholarly journals Time-restricted feeding regulates circadian rhythm of murine uterine clock

2021 ◽  
Author(s):  
Takashi Hosono ◽  
Masanori Ono ◽  
Takiko Daikoku ◽  
Michihiro Mieda ◽  
Satoshi Nomura ◽  
...  
Keyword(s):  
Circadian Rhythm ◽  
Circadian Rhythms ◽  
Protein Expression ◽  
Western Blot ◽  
Active Phase ◽  
Active Period ◽  
Restricted Feeding ◽  
Group Iii ◽  
Breakfast Skipping ◽  
Group I

Abstract Background Skipping breakfast is associated with dysmenorrhea in young women. This suggests that the delay of food intake in the active phase impairs uterine functions by interfering with circadian rhythms. Objective To examine the relationship between the delay of feeding and uterine circadian rhythms, we investigated the effects of the first meal occasion in the active phase on the uterine clock. Methods Zeitgeber time (ZT) was defined as ZT 0 (8:45) with lights on and ZT 12 (20:45) with lights off. Young female mice (8 weeks of age) were divided into 3 groups: group I (ad-libitum feeding), group II (time-restricted feeding during ZT12–16, initial 4 hours of the active period), and group III (time-restricted feeding during ZT20–24, last 4 hours of the active period, a breakfast-skipping model). After two weeks of dietary restriction, mice in each group were sacrificed at 4-hour intervals and the expression profiles of uterine clock genes, Bmal1, Per1, Per2, and Cry1, were examined. Results qPCR and Western blot analyses demonstrated synchronized circadian clock gene expression within the uterus. Immunohistochemical analysis confirmed that Bmal1 protein expression was synchronized among the endometrium and myometrium. In groups I and II, mRNA expression of Bmal1 was elevated after ZT12 at the start of the active phase. In contrast, Bmal1 expression was elevated just after ZT20 in group III, showing that the uterine clock rhythm had shifted 8 hours backward. The changes in Bmal1 protein expression were confirmed by Western blot analysis. Conclusion This study is the first to indicate that time-restricted feeding regulates a circadian rhythm of the uterine clock that is synchronized throughout the uterine body. These findings suggest that the uterine clock system is a new candidate to explain the etiology of breakfast skipping-induced uterine dysfunction.

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