Monitoring the ionospheric storm effect with multiple instruments in North China: July 15–16, 2012 magnetic storm event

The technique of using instantaneous maps for ionospheric storm studies is further developed. Integral parameters are introduced characterizing the main features of each map. These parameters are the net volumes of ?f0F2, ?M(3000)F2and their gradients. The magnetic storm 1-2 March, 1982 was considered and it was found that before the storm commencement and in recovery phase the Net Gradient (NG) is directed steadily to the East, while in the main phase it turns southward. NG shows where the changes of the F-layer come from. The net volume of ?f0F2 (NF) correlates well with Dst and AE indices.

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The structure of mid- and high-latitude ionosphere during September 1999 storm event obtained from GPS observations

Annales Geophysicae ◽

10.5194/angeo-20-655-2002 ◽

2002 ◽

Vol 20 (5) ◽

pp. 655-660 ◽

Cited By ~ 20

Author(s):

I. I. Shagimuratov ◽

L. Baran ◽

P. Wielgosz ◽

G. A. Yakimova

Keyword(s):

Magnetic Storm ◽

High Latitude ◽

Sampling Rate ◽

Negative Phase ◽

Storm Event ◽

Ionospheric Disturbances ◽

Auroral Ionosphere ◽

Data Set ◽

High Latitude Ionosphere ◽

Gps Observations

Abstract. TEC data, obtained from over 60 GPS stations, were used to study the ionospheric effects of the 12–16 September 1999 magnetic storm over Europe. The spatial and temporal changes of the ionosphere were analysed as a time series of TEC maps, which present 15 min averages of TEC. The data set consisting of GPS observations, collected by a dense network of European stations, with sampling rate of 30 s, enable the creation of TEC maps with high spatial and temporal resolution. The storm included the positive as well as the negative phase. The positive phase took place during the first storm day of 12 September 1999. The short-lived daytime TEC enhancement was observed at all latitudes. The maximal enhancement reached a factor of 1.3–1.5. On the second and third days, the negative phase of the storm developed. The TEC decrease was registered regardless of time of the day. The TEC depression exceeded 70% relative to quiet days. On the following days (15 and 16 September), a significant daytime enhancement of TEC was observed once again. The complex occurrence of the ionospheric storm was probably related to the features of development of the magnetic storm. We found out that during the storm the large and medium-scale irregularities developed in the high-latitude ionosphere. The multi-stations technique, employed to create TEC maps, was particularly successful while studying the mid-latitude ionospheric trough. We found out that the essential changes of TEC during the storm, which were registered at the auroral and sub-auroral ionosphere, were connected with the effect of the trough and its dynamics, which depends on geomagnetic activity.Key words. Ionosphere (ionospheric disturbances; auroral ionosphere; mid-latitude ionosphere)

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Comparing ground magnetic field perturbations from global MHD simulations with magnetometer data for the 10 January 1997 magnetic storm event

Journal of Geophysical Research Atmospheres ◽

10.1029/2000ja000445 ◽

2002 ◽

Vol 107 (A8) ◽

pp. SMP 11-1-SMP 11-10 ◽

Cited By ~ 11

Author(s):

X. Shao ◽

P. N. Guzdar ◽

G. M. Milikh ◽

K. Papadopoulos ◽

C. C. Goodrich ◽

...

Keyword(s):

Magnetic Field ◽

Magnetic Storm ◽

Storm Event ◽

Mhd Simulations ◽

Magnetometer Data ◽

Ground Magnetic

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Application of the Fengyun 3 C GNSS occultation sounder for assessing the global ionospheric response to a magnetic storm event

Atmospheric Measurement Techniques ◽

10.5194/amt-12-1483-2019 ◽

2019 ◽

Vol 12 (3) ◽

pp. 1483-1493 ◽

Cited By ~ 2

Author(s):

Weihua Bai ◽

Guojun Wang ◽

Yueqiang Sun ◽

Jiankui Shi ◽

Guanglin Yang ◽

...

Keyword(s):

Magnetic Storm ◽

Radio Occultation ◽

Correlation Coefficients ◽

Satellite System ◽

Storm Event ◽

Calibration Data ◽

Long Term Stability ◽

Negative Effect ◽

Occultation Data ◽

Global Navigation Satellite

Abstract. The rapid advancement of global navigation satellite system (GNSS) occultation technology in recent years has made it one of the most advanced space-based remote sensing technologies of the 21st century. GNSS radio occultation has many advantages, including all-weather operation, global coverage, high vertical resolution, high precision, long-term stability, and self-calibration. Data products from GNSS occultation sounding can greatly enhance ionospheric observations and contribute to space weather monitoring, forecasting, modeling, and research. In this study, GNSS occultation sounder (GNOS) results from a radio occultation sounding payload aboard the Fengyun 3 C (FY3-C) satellite were compared with ground-based ionosonde observations. Correlation coefficients for peak electron density (NmF2) derived from GNOS Global Position System (GPS) and Beidou navigation system (BDS) products with ionosonde data were higher than 0.9, and standard deviations were less than 20 %. Global ionospheric effects of the strong magnetic storm event in March 2015 were analyzed using GNOS results supported by ionosonde observations. The magnetic storm caused a significant disturbance in NmF2 level. Suppressed daytime and nighttime NmF2 levels indicated mainly negative storm conditions. In two longitude section zones of geomagnetic inclination between 40 and 80∘, the results of average NmF2 observed by GNOS and ground-based ionosondes showed the same basic trends during the geomagnetic storm and confirmed the negative effect of this storm event on the ionosphere. The analysis demonstrates the reliability of the GNSS radio occultation sounding instrument GNOS aboard the FY3-C satellite and confirms the utility of ionosphere products from GNOS for statistical and event-specific ionospheric physical analyses. Future FY3 series satellites and increasing numbers of Beidou navigation satellites will provide increasing GNOS occultation data on the ionosphere, which will contribute to ionosphere research and forecasting applications.

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The role of vibrationally excited nitrogen in the formation of the mid-latitude negative ionospheric storms

Annales Geophysicae ◽

10.1007/s00585-994-0554-x ◽

1994 ◽

Vol 12 (6) ◽

pp. 554-564 ◽

Cited By ~ 40

Author(s):

A. V. Pavlov

Keyword(s):

Magnetic Storm ◽

Electron Density ◽

Electron Gas ◽

Energy Balance Equation ◽

Ion Temperature ◽

Ionospheric Storm ◽

Vibrationally Excited ◽

Electron Density And Temperature ◽

Excited Nitrogen

Abstract. Millstone Hill ionospheric storm time measurements of the electron density and temperature during the ionospheric storms (15-16 June 1965; 29-30 September 1969 and 17-18 August 1970) are compared with model results. The model of the Earth's ionosphere and plasmasphere includes interhemispheric coupling, the H+, O+(4S), O+(2D), O+(2P), NO+, O+2 and N+2 ions, electrons, photoelectrons, the electron and ion temperature, vibrationally excited N2 and the components of thermospheric wind. In order to model the electron temperature at the time of the 16 June 1965 negative storm, the heating rate of the electron gas by photoelectrons in the energy balance equation was multiplied by the factors 5-30 at he altitude above 700 km for the period 4.50-12.00 LT, 16 June 1965. The [O]/[N2] MSIS-86 decrease and vibrationally excited N2 effects are enough to account for the electron density depressions at Millstone Hill during the three storms. The factor of 2 (for 27-30 September 1969 magnetic storm) and the & actor 2.7 (for 16-18 August 1970 magnetic storm) reduction in the daytime peak density due to enhanced vibrationally excited N2 is brought about by the increase in the O++N2 rate factor.

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Effect of ecological restoration programs on dust pollution in North China Plain: a case study

10.5194/acp-2017-855 ◽

2017 ◽

Author(s):

Xin Long ◽

Xuexi Tie ◽

Guohui Li ◽

Junji Cao ◽

Tian Feng ◽

...

Keyword(s):

Air Pollution ◽

Land Cover ◽

Ecological Restoration ◽

Dust Storm ◽

North China Plain ◽

North China ◽

Eastern China ◽

Storm Event ◽

Air Pollutions ◽

Dust Storm Event

Abstract. In recent years, Chinese government has taken great efforts in initiating large-scale ecological restoration programs (ERPs) to reduce the dust pollutions in China. Using a satellite measurement product of Moderate Resolution Imaging Spectroradiometer (MODIS), the changes in land cover are quantitatively evaluated in this study. We find that grass and forest are increased in berried lands and deserts in northwestern China, which locate in the upwind regions of the populated areas of the North China Plain (NCP) in eastern China. As a result, the changes in land cover could produce important impacts on the dust pollutions in eastern of China. To assess the effect of ERPs on dust pollutions, a regional transport/dust model (WRF-DUST, Weather Research and Forecast model with dust) is applied to investigate the evolution of dust pollutions during a strong dust episode (from 2 to 8 March 2016). The calculations are intensively evaluated by comparing with the measured data. Despite some model biases, the WRF-DUST model reasonably reproduced the temporal variations and spatial distributions during the dust storm event. The correlation coefficient (R) between the calculated and measured dust concentrations is 0.77. The indices of agreement (IOAs) are 0.96 and 0.83, and the normalized mean bias (NMBs) are 2 % and −15 % in the dust source region (DSR) and the downwind populated area of NCP, respectively, suggesting that the WRF-DUST model well captures the spatial variations and temporal evolutions of the dust storm event. The impacts of EPRs induced land cover changes on the dust pollutions in NCP are quantitatively assessed using the WRF-DUST model. We find that the ERPs significantly reduce the dust pollutions in NCP, especially in the heart area of NCP (BTH, Beijing-Tianjin-Hebei). During the episode when the dust storm was transported from the DSR to NCP, the reduction of dust pollutions induced by ERPs ranges from −5 % to −15 % in NCP, with the maximum reduction of −15.3 % (−21.0 μg m−3) in BTH, and −6.2 % (−9.3 μg m−3) in NCP. Because the air pollution is severe in eastern China, especially in NCP, the reduction of dust pollutions has important effects on the severe air pollutions. This study shows that ERPs help to reduce air pollutions in the region, especially in springtime, suggesting the important contributions of ERPs to the air pollution control in China.

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