Major update of the International GLE database: detrended GLE profiles
I. Usoskin, S. Koldobskiy, A. Gil, G. Kovaltsov, I. Usoskina, A. Ibragimov, T. Willamo
High-energy and high-intensity events of solar energetic particles, called ground-level enhancements (GLEs), form a special class of solar eruptive events with the highly efficient acceleration of charged particles. These events are studied using continuous measurements performed by the global network of ground-based neutron monitors (NMs). All available NM data related to GLE events since 1956 are collected in the International GLE Database (IGLED, http://gle.oulu.fi). The data are presented in the form of relative NM count-rate increases with respect to the constant pre-increase background count-rate level due to galactic cosmic rays (GCR). However, the implicit assumption of the constancy of the GCR background level throughout GLE events is often not valid, since the GCR background may vary essentially even during relatively short GLE events. Here we revisited all the GLE NM records and de-trended GLE count-rate increases considering the actual variable GCR background. The detrended count-rates have been added to the IGLED database for all GLE events since 1956. This forms a basis for more precise studies of parameters of SEP events and, thus, for solar and space physics.
Status of the NMDB
Christian T. Steigies Universität Kiel, Germany
Since 2008 the EU FP7 funded Neutron Monitor database (NMDB) is providing access to 1-minute neutron monitor data in real-time as well as different neutron monitor data products for the public. Several space weather services routinely rely on the availability of the neutron monitor data from the worldwide network, and NMDB is continuing to provide real-time data even ten years after the official end of the project. To ensure the availability of this data in the future, a major upgrade to the database infrastructure of NMDB was performed in the fall of 2019. An overview of the new setup, usage statistics, the status of the data quality, software tools and the (new) website will be given.
Cutoff rigidity and particle trajectories online Calculator
Belov S. M., Zobnin G. I., Yanke V. G. Pushkov Institute of terrestrial magnetism, ionosphere and radio wave propagation (IZMIRAN), Moscow, Russia
Over the years, many authors have developed unique software packages for calculating of geomagnetic cut off rigidities and the asymptotic directions of particle arrival. The accuracy of the results and the capabilities of the programs expanded with increasing capabilities of computing tools, with the development of models of the magnetic field and models of the Earth's magnetosphere. Such programs are used for mass settlements and require some qualifications. However, it is often necessary to carry out single calculations with the same accuracy. For this purpose, on the basis of the programs developed by us, a calculator program has been created. The Cutoff-2050 calculator (http://22.214.171.124/cutoff2050) calculates the rigidity of geomagnetic cut off and the particle path for a given date (1900-2015 with extrapolation to 2050) and at a given geographical point for magnetosphere models: dipole, IGRF, models Tsyganenko: IGRF +T89 and higher order models IGRF + T96 and IGRF + T02, but the latter requires a long time for calculation. The visualization of all the data obtained: penumbra, time of motion and particle trajectories.
For regular users there is the possibility of organizing personal accounts on the server to store the results. A comparison is made with other models of geomagnetic cut off rigidity calculators.
Global neutron monitor network data for the period of 1953-2019: Survey for quality control
Pauli Väisänen, Ilya Usoskin, Kalevi Mursula
Galactic cosmic rays (GCRs) produce secondary particles in the Earth’s atmosphere. The flux of these secondary nucleons is continuously measured since the 1950s using neutron monitors (NMs) which are located all around the globe. The datasets provided by NMs form an important source of information for different studies, including, e.g., solar activity, heliospheric conditions, solar eruptive events and other solar and space phenomena. The datasets of NMs are usually publicly distributed through either the stations’ own web services or through centralized data services offering data from several stations. The most common and extensive data services include 1. the World Data Center for Cosmic Rays (WDC-CR) in Nagoya, Japan, 2. the Pushkov Institute of Terrestrial Magnetism, Ionosphere and Radiowave Propagation (IZMIRAN) in Moscow, Russia, 3. and the European FP7-collaboration Neutron Monitor Database (NMDB).
A careful inspection reveals that the different datasets of the same station available from different data services are not always consistent with each other. The different datasets may have different coverages, normalizations, scaling, corrections or versions of the same data. This can lead to erroneous results and difficulties in interpreting or reproducing the results produced from different datasets.
We report here an extensive data survey, which makes an inter-comparison and analysis of most publicly available NM datasets since 1953. The analysis includes data with 1-hour resolution from more than 150 NMs obtained from over 300 data tables at the three major data services mentioned above, as well as from homepages of 23 individual NM stations. We compare the different datasets of all NM stations obtained from different data services, and study consistency of the data sets between the different services. We identify specific prime stations and use them to define the best data service for each NM station. We give this information in the form of a tabulated list. This data survey will help scientists and other NM data users to select the best possible data sources for their studies.
The Database of Directivity Functions of Neutron Monitors
Grigori Karapetyan, Tigran Karapetyan and Zaruhi Asaturyan
We present the database of directivity functions of Neutron Monitors (NM) located worldwide. The concept of directivity function of particle detector and the database of directivity functions of NMs have been developed in Cosmic Ray Division of Yerevan Physics Institute during 2014-2017. Directivity function describes directional sensitivity of the detector to primary protons. It enables to calculate the acceptance cone - the key characteristics of the detector for space research, determining the solid angle, inside which coming protons contribute significantly to count rate. Based on this database, each NM station can estimate the shape of their acceptance cone.
PHA Analysis - Telemetry and Data Acquisition