scholarly journals Short-Term Lightning Response to Ground Level Enhancements

2020 ◽  
Vol 8 ◽  
Author(s):  
Qiong Wu ◽  
Hui Li ◽  
Chi Wang
Keyword(s):  
Ground Level ◽  
Short Term ◽  
Ground Level Enhancements

scholarly journals Retrospective analysis of GLEs and estimates of radiation risks

2018 ◽  
Vol 8 ◽  
pp. A52 ◽  
Author(s):  
Leonty I. Miroshnichenko
Keyword(s):  
Solar Activity ◽  
Ground Level ◽  
Radiation Hazard ◽  
Occurrence Rate ◽  
Solar Cosmic Rays ◽  
Dose Rates ◽  
Recent Debate ◽  
Unique Distribution ◽  
Different Levels ◽  
Ground Level Enhancements

28 February 2017 marked 75 years since the first confident registration of solar cosmic rays (SCRs), i.e., accelerated solar particles with energies from about 106 to ~1010 ÷ 1011 eV. Modern state of the problems related to the studies of Ground Level Enhancements (GLEs) of relativistic SCRs is critically analyzed based on available direct and proxy data. We are also taking into account extremely large fluxes of non-relativistic solar energetic particles (SEPs). Both kinds of SCR events are of great astrophysical and geo-scientific (geophysical) interests. A number of the GLE properties (total statistics, occurrence rate, longitude distribution, ranking of GLEs, a number of specific GLEs – so-called “rogue” SEP events etc.) are discussed in some detail. We note also the problems of GLE identification (definition) by ground-based observations, the difficulties in the studies of weak (“hidden”, or sub-) GLEs etc. One of serious challenges to the problem of radiation hazard in space is a lack of a clear, unambiguous relation between the fluxes (fluences) of relativistic SCR and non-relativistic SEPs. Special attention is paid to the recent debate on the validity, origin and properties of the “ancient” events AD775, AD994, AD1859 (Carrington event) and BC3372. We demonstrate that, in spite of existing uncertainties in proton fluences above 30 MeV, all of them are fitted well by a unique distribution function, at least, with the present level of solar activity. Extremely large SEP events are shown to obey a probabilistic distribution on their fluences with a sharp break in the range of large fluences (or low probabilities). The studies of this kind may be extended for periods with different levels of solar activity in the past and/or in the future. Dose rates at aircraft altitudes are also demonstrated during some GLEs. Several examples of using the SCR data and GLE properties in radiation prediction schemes are considered.

scholarly journals Inversion Methodology of Ground Level Enhancements

2017 ◽  
pp. 179-199 ◽  
Author(s):  
B. Heber ◽  
N. Agueda ◽  
R. Bütikofer ◽  
D. Galsdorf ◽  
K. Herbst ◽  
...  
Keyword(s):  
Ground Level ◽  
Ground Level Enhancements

scholarly journals Birds and bats captured in a managed forest in Southwestern Brazilian Amazonia: Results and recommendations from a short-term study

2019 ◽  
Vol 6 (12) ◽  
pp. 283-295
Author(s):  
Diego Pedroza ◽  
Rair de Sousa Verde ◽  
Edson Guilherme
Keyword(s):  
Activity Pattern ◽  
Ground Level ◽  
Trophic Guilds ◽  
Clear Pattern ◽  
Managed Forest ◽  
Short Term ◽  
Term Study ◽  
Short Term Study ◽  
Pattern Of Variation ◽  
Capture Rates

Understanding the activity pattern and the height of capture of birds and bats can help to optimize the sampling of both groups. Our aimed was to determine the rates of capture at different times of day/night, and the overlap in the height of capture; classify the trophic guilds, and check variation in the capture rates of the birds and bats. We conducted the study in the Antimary State Forest, in March, 2017. We set mist-nets at the same location during five consecutive days, and were open between 06:00 h and 00:00 h. The birds presented a bimodal activity pattern, as well as bats. Bats were captured at higher levels than birds. Most of the birds captured were insectivores, where as most of the bats were frugivores. Neither group presented a clear pattern of variation in capture rates. Therefore, the first hours of the morning are fundamental for the capture of birds. For bats, we would recommend the captures only after 17:00 h. Mist-nets should be set at ground level for birds, whereas for bats, they should be set above a height of 0.5 m. Thus, the captures should be optimized.

scholarly journals Detecting Ground Level Enhancements using Soil Moisture Sensor Networks

Space Weather ◽  
2021 ◽  
Author(s):  
A. D. P. Hands ◽  
F. Baird ◽  
K. A. Ryden ◽  
C. S. Dyer ◽  
F. Lei ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Sensor Networks ◽  
Ground Level ◽  
Moisture Sensor ◽  
Soil Moisture Sensor ◽  
Ground Level Enhancements

Prediction of Ground Level Enhancements

2017 ◽  
Vol 13 (S335) ◽  
pp. 301-303
Author(s):  
Marlon Núñez ◽  
Pedro J. Reyes-Santiago ◽  
Olga E. Malandraki
Keyword(s):  
Neutron Monitor ◽  
Ground Level ◽  
Prediction Performance ◽  
Probability Of Detection ◽  
Satellite Network ◽  
Prediction Tool ◽  
X Ray ◽  
Horizon 2020 ◽  
Research And Innovation ◽  
Ground Level Enhancements

AbstractThis paper summarizes the first tool that is able to predict Ground Level Enhancements (GLE). It makes real-time predictions of the occurrence of GLE events from the analysis of soft X-ray and differential proton flux measured by the GOES satellite network. Before the development of this tool, space weather systems have been warning users about evolving GLE events by processing neutron measurements recorded on ground level. This tool, called HESPERIA UMASEP-500, can predict GLE events before the detection by any neutron monitor (NM) station. The prediction performance measured for the period from 1986 to 2016 is presented for two consecutive periods, because of their notable difference in performance. For the 2000-2016 period, this prediction tool obtained a probability of detection (POD) of 53.8% (7 of 13 GLE events), a false alarm ratio (FAR) of 30.0%, and average warning times (AWT) of 8 min and 15 min with respect to the first NM station’s alert and the GLE Alert Plus warning, respectively. This project has received funding from the European Union’s Horizon 2020 research and innovation programme under agreement No 637324.

Seasonal patterns of age-composition of sylvan mosquito populations in Uganda (Diptera, Culicidae)

1963 ◽  
Vol 54 (2) ◽  
pp. 213-227 ◽  
Author(s):  
Philip S. Corbet
Keyword(s):  
Virus Isolation ◽  
Ground Level ◽  
Total Sample ◽  
Main Peak ◽  
Seasonal Patterns ◽  
Short Term ◽  
Age Composition ◽  
Tree Hole ◽  
Small Container ◽  
Age Grading

Fifty-two standardised weekly collections of female mosquitos were made by human catchers at ground-level in lake-side forest near Entebbe, Uganda. The numbers of nullipars and pars in each sample were recorded, in order to determine whether the capacity of these mosquito populations to transmit virus varied seasonally. Methods are described for handling large catches for the purpose of identifying and age-grading. The total sample comprised 31,978 mosquitos belonging to 37 or more species. Results for 15 species are presented in detail.The nulliparous rate (i.e., the number of nullipars as a percentage of total females) differs markedly between species, but relatively little within species. Certain species of Mansonia (Coquillettidia), mainly swamp breeders, have the highest nulliparous rate, and species of Aedes and Eretmapodites, which breed in small containers, have the lowest. In some species, biting females show a lower nulliparous rate than those caught resting.Culex annulioris Theo. and species of Mansonia, which are swamp breeders, have a main peak of abundance between May and July, during the main rains and when lake-level is highest. Species of Aedes (Stegomyia), which are tree-hole or small-container breeders, show small, irregular, short-term fluctuations in numbers.The number of pars, an epidemiologically important parameter, is absolutely highest at or soon after the time of greatest abundance. For certain bird-biting mosquitos, namely, Culex annulioris and species of Mansonia (Coquillettidia), most pars are found during the main rains, when susceptible hosts are also most numerous. Implications of these findings on virus-isolation programmes are briefly discussed.

Small Size Ground Level Enhancements During Solar Cycle 24

Solar Physics ◽  
2020 ◽  
Vol 295 (7) ◽  
Author(s):  
Leonty I. Miroshnichenko ◽  
Chuan Li ◽  
Victor G. Yanke
Keyword(s):  
Solar Cycle ◽  
Ground Level ◽  
Solar Cycle 24 ◽  
Cycle 24 ◽  
Ground Level Enhancements

Short-term effects of herbage allowance on milk production, milk composition and grazing time of cows grazing nitrogen-fertilized tropical grass pasture

1977 ◽  
Vol 17 (89) ◽  
pp. 892 ◽  
Author(s):  
TH Stobbs
Keyword(s):  
Milk Production ◽  
Milk Fat ◽  
Latin Square ◽  
Ground Level ◽  
Short Chain Fatty Acids ◽  
Lower Percentage ◽  
Panicum Maximum ◽  
Fat Percentage ◽  
Short Term ◽  
Short Term Effects

The short-term effects of varying the quantities of herbage allocated (15, 25, 35, 55 kg DM cow-1, day-1) to lactating Jersey cows strip grazing 3-week regrowths of nitrogen-fertilized Panicum maximum cv. Gatton panic pastures, upon the diet selected, milk production, milk and milk fat composition and grazing time, were measured. Sixteen cows were used in a latin-square design with experimental periods of 1 4 days. With increasing herbage allowance milk yields rose, averaging 8.9, 9.9, 10.4 and 10.6 kg milk cow-1, day-1 respectively. A lower solids-not-fat percentage in milk from cows receiving 15 kg DM cow-1, day-1 and a lower percentage protein from cows receiving 15 and 25 kg DM cow-1 day-1 indicated a lower intake of digestible energy by cows at these lower herbage allowances. Molar percentages of short-chain fatty acids in milkfat (C6, C8, C10, C14) increased linearly and oleic acid (C18:1) decreased linearly as herbage allowance increased, showing that a higher proportion of the milk fat was coming from energy in the feed and a smaller proportion from body reserves. Cows selectively grazed leaf from the uppermost layers of the swards. As herbage allowance was restricted, a higher proportion of pasture was eaten and this came mainly from pasture growing 10 cm or more above ground level. Total time spent grazing was similar for all herbage allowances but the proportion of night grazing was consistently lower at the higher intensities of grazing.

The Ground-level Enhancements of 1989 September 29 and October 22

1993 ◽  
Vol 10 (3) ◽  
pp. 211-217 ◽  
Author(s):  
M.L. Duldig ◽  
J.L. Cramp ◽  
J.E. Humble ◽  
J.W. Bieber ◽  
P. Evenson ◽  
...  
Keyword(s):  
Particle Flux ◽  
Temporal Structure ◽  
Cosmic Ray ◽  
Ground Level ◽  
Reverse Direction ◽  
Particle Injection ◽  
The Earth ◽  
Particle Propagation ◽  
Multiple Particle ◽  
Ground Level Enhancements

Abstract During the solar maximum of 1989–91 an unprecedented sequence of 13 cosmic ray ground-level enhancements (GLEs) was observed by the world-wide neutron monitor network. Of particular interest were two GLEs observed by the Australian network. The 1989 September 29 event was the largest GLE in the space era while the October 22 GLE included an highly anisotropic precursor peak.Analysis of both these GLEs, taking into account disturbed geomagnetic conditions, shows that the particle arrivals at the earth were unusual. The September 29 GLE had significant particle propagation in the reverse direction and as the particle flux decreased following the peak the spectrum also softened. In contrast, the 1989 October 22 precursor exhibited extreme anisotropy while the particles involved in the main GLE showed a complex temporal structure possibly indicating multiple particle injection at the solar acceleration region.

Sign in / Sign up

Export Citation Format

Share Document