Объявляется программа поддержки научной мобильности ученых
Илья Едемский представит статью:
Jun Tang et al., Tomographic reconstruction of ionospheric electron density during the storm of 5-6 August 2011 using multi-source data
Место: Институт солнечно-земной физики Л413
Время: 2016.02.05 в 10:00
Abstract
The insufficiency of data is the essential reason for ill-posed problem existed in computerized ionospheric tomography (CIT) technique. Therefore, the method of integrating multi-source data is proposed. Currently, the multiple satellite navigation systems and various ionospheric observing instruments provide abundant data which can be employed to reconstruct ionospheric electron density (IED). In order to improve the vertical resolution of IED, we do research on IED reconstruction by integration of ground-based GPS data, occultation data from the LEO satellite, satellite altimetry data from Jason-1 and Jason-2 and ionosonde data. We used the CIT results to compare with incoherent scatter radar (ISR) observations, and found that the multi-source data fusion was effective and reliable to reconstruct electron density, showing its superiority than CIT with GPS data alone.
Параллельное программирование с MPI (Виктор Ташлыков)
Анна Полякова представит статью:
Место: Институт солнечно-земной физики Л413
Время: 2016.01.29 в 10:00
Abstract
Global Positioning System (GPS) L1-frequency (1.575 GHz) amplitude scintillations at São José dos Campos (23.1°S, 45.8°W, dip latitude 17.3°S), located under the southern crest of the equatorial ionization anomaly, are analyzed during the Northern Hemisphere winter sudden stratospheric warming (SSW) events of 2001/2002, 2002/2003, and 2012/2013. The events occurred during a period when moderate to strong scintillations are normally observed in the Brazilian longitude sector. The selected SSW events were of moderate and major categories and under low Kp conditions. The most important result of the current study is the long-lasting (many weeks) weakening of scintillation amplitudes at this low-latitude station, compared to their pre-SSW periods. Ionosonde-derived evening vertical plasma drifts and meridional neutral wind effects inferred from total electron content measurements are consistent with the observed weakening of GPS scintillations during these SSW events. This work provides strong evidence of SSW effects on ionospheric scintillations and the potential consequences of such SSW events on Global Navigation Satellite System-based applications.
Совет научной молодежи запускает конкурс на поддержку командировок молодых сотрудников.
Конкурс проводится 2 раза в год.
Для участия в конкурсе до 11-00 12 февраля 2016 г. необходимо отправить заявку по форме на адрес совета научной молодежи (snm@iszf.irk.ru).
Правила конкурса смотри далее и в прикрепленном файле: Правила конкурса и форма заявки
V Международная конференция «Atmosphere, Ionosphere, Safety» и
I Балтийская международная Школа молодых ученых “Магнитосферно-Ионосферно-Атмосферных Связей” (I Балтийская Школа “МИАС”)
19-25 июня 2016 г.
место проведения: г. Калининград (берег Балтийского моря)
Важные даты:
Крайний срок регистрации и подачи трудов конференции — 15 марта 2016 г.
Публикация предварительной программы — 1 мая 2016 г.
Прибытие участников, заселение, Welcome Party — 19 июня 2016 г.
Открытие конференции — 20 июня 2016 г.
Закрытие конференции, отъезд участников — 25 июня 2016 г.
Подробнее о конференции: http://ais2016.ru
Сайт школы молодых ученых: http://cepri.kantiana.ru/miac
28 января (четверг) Научно-популярная лекция о Солнце астрофизика Николя Ораса Биана Место: Библиотека им. И.И. Молчанова-Сибирского Язык - французский. Перевод на русский язык - Екатерина Коржова Информация на сайте библиотеки: http://www.irklib.ru/afisha/612/
В этот четверг (24.12.2015) в 10:00 Виктор Ташлыков представит статью:
D. Perez et al. ORBIT-CENTERED ATMOSPHERIC DENSITY PREDICTION USING ARTIFICIAL NEURAL NETWORKS
Место: Институт солнечно-земной физики, Л413
Время: 2015.12.24 в 10:00
Abstract
At low Earth orbits, drag force is a significant source of error for propagating the motion of a spacecraft. The main factor driving the changes on the drag force is neutral density. Global atmospheric models provide estimates for the density which are significantly affected by bias due to misrepresentations of the underlying physics and limitations on the statistical models. In this work a localized predictor based on artificial neural networks is presented. Localized refers to the focus being on a specific orbit, rather than a global prediction. The predictor uses density measurements or estimates on a given orbit and a set of proxies for solar and geomagnetic activities to predict the value of the density along the future orbit of the spacecraft. The performance of the localized predictor is studied for different neural network structures, testing periods of high and low solar and geomagnetic activities and different prediction windows. Comparison with previously developed methods show substantial benefits in using artificial neural networks, both in prediction accuracy and in the potential for spacecraft onboard implementation. In fact, the proposed neural networks are computationally efficient and would be straightforward to integrate into onboard software.
The study of the ionospheric dynamics during strong sudden stratospheric warmings in Russia’s Arctic region
Иван Ткачев представит статью:
Место: Институт солнечно-земной физики, Л413
Время: 2015.12.17 в 10:00
Abstract
We present experimental results from multiinstrument observations in the high-latitude ionospheric F2 layer at the EISCAT (European Incoherent Scatter Scientific Association) heating facility. The results come from a set of experiments, when an X-polarized HF pump wave at high heater frequencies (fH > 6.0 MHz) was injected into the F region of the ionosphere toward the magnetic zenith. Experiments were carried out under quiet magnetic conditions with an effective radiated power of 458–548 MW. HF pumping was produced at different heater frequencies, away from electron gyroharmonic frequencies, and different durations of heater pulses. We show the first experimental evidence of the excitation of artificial optical emissions at red (630 nm) and green (557.7 nm) lines in the high-latitude ionospheric F2 layer induced by an X-polarized HF pump wave. Intensities at red and green lines varied in the range 110–950 R and 50–350 R, respectively, with a ratio of green to red line of 0.35–0.5. The results of optical observations are compared with behaviors of the HF-enhanced ion and plasma lines from EISCAT UHF incoherent scatter radar data and small-scale field-aligned artificial irregularities from Cooperative UK Twin Located Auroral Sounding System observations. It was found that the X-mode radio-induced optical emissions coexisted with HF-enhanced ion and plasma lines and strong artificial field-aligned irregularities throughout the whole heater pulse. It is indicative that parametric decay or oscillating two-stream instabilities were not quenched by fully established small-scale field-aligned artificial irregularities excited by an X-mode HF pump wave.