A5020231098- Ionosphere and magnetosphere dynamics
- GNSS positioning and interference
- Earthquake Detection and Analysis
- Geomagnetism and Paleomagnetism Studies
- Solar and Space Plasma Dynamics
- Geophysics and Gravity Measurements
- Methane Hydrates and Related Phenomena
- Astro and Planetary Science
- Atomic and Subatomic Physics Research
- Atmospheric Ozone and Climate
- Advanced Frequency and Time Standards
- Computational Physics and Python Applications
- earthquake and tectonic studies
- Planetary Science and Exploration
- Radio Astronomy Observations and Technology
- Geophysics and Sensor Technology
- Geological and Geophysical Studies
- Astrophysics and Cosmic Phenomena
- Astronomical Observations and Instrumentation
- Inertial Sensor and Navigation
- Non-Invasive Vital Sign Monitoring
- Seismic Waves and Analysis
- Plasma Diagnostics and Applications
- Aerospace Engineering and Energy Systems
- Radioactive contamination and transfer
University of New Brunswick
2016-2025
Shandong University
2021
Institute of Space Sciences
2017
Institute of Space Science - INFLPR Subsidiary
2017
Western University
1998-2007
Andhra University
1996-1999
Abstract In this study, we use measurements from over 4,735 globally distributed Global Navigation Satellite System receivers to track the progression of traveling ionospheric disturbances (TIDs) associated with 15 January 2022 Hunga Tonga‐Hunga Ha'apai submarine volcanic eruption. We identify two distinct Large Scale (LSTIDs) and several subsequent Medium (MSTIDs) that propagate radially outward eruption site. Within 3,000 km epicenter, LSTIDs >1,600 wavelengths are initially observed...
Abstract The high latitude ionospheric evolution of the May 10‐11, 2024, geomagnetic storm is investigated in terms Total Electron Content and contextualized with Incoherent Scatter Radar ionosonde observations. Substantial plasma lifting observed within initial Storm Enhanced Density plume peak heights increasing by 150–300 km, reaching levels up to 630 km. Scintillation cusp during expansion phase storm, spreading across auroral oval thereafter. Patch transport into polar cap produces...
Polar cap ionospheric measurements are important for the complete understanding of various processes in solar wind‐magnetosphere‐ionosphere system as well space weather applications. Currently, polar region is lacking high temporal and spatial resolution because orbit limitations space‐based sparse network providing ground‐based measurements. Canada has a unique advantage remedying this shortcoming it most accessible landmass Arctic regions, Canadian High Ionospheric Network (CHAIN) designed...
Abstract. High-latitude irregularities can impair the operation of GPS-based devices by causing fluctuations GPS signal amplitude and phase, also known as scintillation. Severe scintillation events lead to losses phase lock, which result in cycle slips. We have used data from Canadian High Arctic Ionospheric Network (CHAIN) measure L1 signals total electron content (TEC) L2 study relative role that various high-latitude irregularity generation mechanisms producing In first year during...
Abstract We present here the Empirical Canadian High Arctic Ionospheric Model (E‐CHAIM) quiet N m F 2 , perturbation and h models. These models provide peak ionospheric characteristics for a domain above 50°N geomagnetic latitude. fitting is undertaken using all available ionosonde radio occultation electron density data, constituting data set of over 28 million observations. A comprehensive validation model undertaken, performance compared to that International Reference Ionosphere (IRI)....
Abstract As L‐band radio waves travel through the ionosphere, such as those transmitted by Global Positioning System (GPS) satellites, changes in electron density along ray path may induce refractive and/or diffractive variations signal's phase; where are deterministic and stochastic. Typically, component of these is thought to be slow varying, associated with frequencies less than 0.1 Hz. Therefore, if contribution assumed Hz, greater Hz then treated diffractive. These usually referred...
Abstract. Maps of GPS phase scintillation at high latitudes have been constructed after the first two years operation Canadian High Arctic Ionospheric Network (CHAIN) during 2008–2009 solar minimum. CHAIN consists ten dual-frequency receivers, configured to measure amplitude and from L1 signals ionospheric total electron content (TEC) L2 signals. Those data mapped as a function magnetic local time geomagnetic latitude assuming pierce points (IPPs) 350 km. The mean TEC depletions are...
Abstract. Global positioning system scintillation and total electron content (TEC) data have been collected by ten specialized GPS Ionospheric Scintillation TEC Monitors (GISTMs) of the Canadian High Arctic Network (CHAIN). The phase index σΦ is obtained from L1 signal sampled at 50 Hz. Maps occurrence as a function altitude-adjusted corrected geomagnetic (AACGM) latitude magnetic local time (MLT) are computed for period 2008 to 2013. Enhanced collocated with regions that known ionospheric...
Abstract The geomagnetic storm of 17–18 March 2015 was caused by the impacts a coronal mass ejection and high‐speed plasma stream from hole. high‐latitude ionosphere dynamics is studied using arrays ground‐based instruments including GPS receivers, HF radars, ionosondes, riometers, magnetometers. phase scintillation index computed for signals sampled at rate up to 100 Hz specialized receivers supplemented proxy obtained geodetic‐quality data 1 Hz. In context solar wind coupling...
An investigation of the evening prereversal enhancement in equatorial zonal electric field (PRE) based on ionosonde data show that PRE development process is coupled with sporadic E layer formation over Fortaleza. Larger amplitudes are associated disruption Es layer, whereas for smaller such does not occur, general. The occur also when amplitude decreases or inhibited under a disturbance dynamo field. these layers followed by their reconstitution after break ∼3 hours. examination relative...
Abstract Monthly median values of ionospheric peak height (hmF 2 ) and density (NmF ), derived from ionosonde measurements at four Canadian High Arctic Ionospheric Network (CHAIN) stations situated within the polar cap Auroral Oval, are used to evaluate performance International Reference Ionosphere (IRI) 2007 empirical model during recent solar minimum between 2008 2010. This analysis demonstrates notable differences IRI NmF diurnal seasonal behavior over entire period studied, where good...
Abstract. The amplitude and phase scintillation indices are customarily obtained by specialised GPS Ionospheric Scintillation TEC Monitors (GISTMs) from L1 signal recorded at the rate of 50 Hz. S4 σΦ stored in real time an array high-rate receivers Canadian High Arctic Network (CHAIN). was observed high latitudes during a moderate geomagnetic storm (Dst = −61 nT) that caused solar wind plasma stream compounded with impact two coronal mass ejections. most intense (σΦ ~ 1 rad) occurred cusp...
Abstract In this study, we present a topside model representation to be used by the Empirical Canadian High Arctic Ionospheric Model (E‐CHAIM). process of this, also comprehensive evaluation NeQuick's, and extension International Reference Ionosphere's, electron density for middle high latitudes in Northern Hemisphere. Using data gathered from all available incoherent scatter radars, sounders, Global Navigation Satellite System Radio Occultation satellites, show that current NeQuick...
Abstract First experimental proof of a clear and strong dependence the standard phase scintillation index (σ φ ) derived using Global Positioning System measurements on ionospheric plasma flow around noon sector polar ionosphere is presented. σ shows linear drift speed measured by Super Dual Auroral Radar Network radars, whereas amplitude (S 4 does not. This observed can be explained as consequence Fresnel frequency relative used constant cutoff (0.1 Hz) to detrend data for obtaining . The...
Abstract The Assimilative Canadian High Arctic Ionospheric Model (A‐CHAIM) is an operational ionospheric data assimilation model that provides a 3D representation of the high latitude ionosphere in Near‐Real‐Time (NRT). A‐CHAIM uses low‐latency observations slant Total Electron Content (sTEC) from ground‐based Global Navigation Satellite System (GNSS) receivers, ionosondes, and vertical TEC JASON‐3 altimeter satellite to produce updated electron density above 45 ° geomagnetic latitude. first...
Abstract. Arrays of GPS Ionospheric Scintillation and TEC Monitors (GISTMs) are used in a comparative scintillation study focusing on quasi-conjugate pairs receivers the Arctic Antarctic. Intense phase rapid variations ionospheric total electron content (TEC) that can result cycle slips were observed at high latitudes with dual-frequency during first significant geomagnetic storm solar 24 5–7 April 2010. The impact bipolar magnetic cloud north-south (NS) type embedded speed wind from coronal...
Abstract While modern GPS receiver differential code bias estimation techniques have become highly refined, they still demonstrate unphysical behavior, namely, notable solar cycle variability. This study investigates the nature of these seasonal and variabilities in polar cap region using single‐station methods. It is shown that minimization standard deviation technique linearly dependent on user's choice shell height, where sensitivity this dependence varies significantly from 1 total...
Results of a superposed epoch (SPE) analysis occurrence phase scintillation and cycle slips at high latitudes keyed by arrival times high-speed solar wind streams (HSS) interplanetary coronal mass ejections (ICME) for years 2008 to 2012 are presented. Phase index σ Φ is obtained in real time from L1 signal recorded the rate 50 Hz specialized global positioning system (GPS) ionospheric total electron content (TEC) monitors (GISTMs) deployed as part Canadian High Arctic Ionospheric Network...
Abstract A comparison tool has been developed by mapping the global GPS total electron content (TEC) and large coverage of ionospheric scintillations together on geomagnetic latitude/magnetic local time coordinates. Using this tool, a between large‐scale irregularities is pursued during storm. Irregularities, such as storm enhanced density, middle‐latitude trough, polar cap patches, are clearly identified from TEC maps. At edges these irregularities, clear appeared but their behaviors were...
Abstract Total electron content (TEC) measurements from 10 dual‐frequency GPS receivers in the Canadian High Arctic Ionospheric Network (CHAIN) are used to evaluate performance of International Reference Ionosphere (IRI)‐2007 within sector. Throughout region, we see systematic underestimation daytime TEC, particularly at solar maximum, where summer and equinox root‐mean‐square errors reach as high 14 total units, 1 TECU = 16 el m −2 (TECU). It is also shown that use a monthly IG index, place...
Abstract Based on in situ and ground‐based observations, a new type of “polar cap hot patch” has been identified that is different from the classical polar enhanced density structure (cold patches). Comparing with patches, which are transported dayside sunlit region dense cold plasma, patches associated particle precipitations (therefore field‐aligned currents), ion upflows, flow shears. The may have same order enhancement as topside ionosphere, suggesting be produced by photoionization...
Abstract In this study, we present a bottomside model representation to be used by the Empirical Canadian High Arctic Ionospheric Model (E‐CHAIM). This features new approach modeling electron density; namely, instead of modelling density directly, E‐CHAIM models altitude profile scale thickness single layer. approach, curvature in associated with E region and F 1 layer is represented domain as peak function centered at altitude. The use ensures production explicitly doubly differentiable...
We look at patches observed by digital ionosondes in the northern polar cap. These observations show that have following properties. (1) Patches are relatively large, typically ∼500 km sunward‐antisunward direction and ∼1000 dawn‐dusk direction. (2) When IMF Bz has abnormally large positive‐negative swings correlation with swings. (3) For typical days no average By only weak negative Bz. (4) slightly weaker summer. The patch max‐to‐min Ne variation winter is ∼2 × 10 11 el/m 3 summer it ∼1.5...