A5084133551- Geomagnetism and Paleomagnetism Studies
- Earthquake Detection and Analysis
- Geophysical and Geoelectrical Methods
- Geophysics and Gravity Measurements
- Ionosphere and magnetosphere dynamics
- Geological and Geophysical Studies
- Underwater Acoustics Research
- Oceanographic and Atmospheric Processes
- earthquake and tectonic studies
- Neural Networks and Applications
- Geological Modeling and Analysis
- Underwater Vehicles and Communication Systems
- Human Mobility and Location-Based Analysis
- Advanced Computational Techniques and Applications
- Geochemistry and Geologic Mapping
- Solar and Space Plasma Dynamics
- Inertial Sensor and Navigation
- Offshore Engineering and Technologies
- Geology and Paleoclimatology Research
- Image Processing and 3D Reconstruction
- Distributed and Parallel Computing Systems
- Opportunistic and Delay-Tolerant Networks
- Astro and Planetary Science
- Mobile Learning in Education
- GNSS positioning and interference
Cooperative Institute for Research in Environmental Sciences
2018-2024
University of Colorado Boulder
2017-2024
NOAA National Centers for Environmental Information
2018-2024
National Oceanic and Atmospheric Administration
2018-2024
University of Colorado System
2014-2023
Czech Academy of Sciences, Institute of Geophysics
2022
Abstract In December 2019, the International Association of Geomagnetism and Aeronomy (IAGA) Division V Working Group (V-MOD) adopted thirteenth generation Geomagnetic Reference Field (IGRF). This IGRF updates previous with a definitive main field model for epoch 2015.0, 2020.0, predictive linear secular variation 2020.0 to 2025.0. letter provides equations defining IGRF, spherical harmonic coefficients this model, maps magnetic declination, inclination total intensity their predicted rate...
Abstract On 15 January 2022, at around 04:00 UTC, the submarine volcano Hunga Tonga‐Hunga Ha'apai explosively erupted. We examine data from 10 Pacific Ocean geomagnetic observatories and process using both high pass filters cross‐wavelet analyses to enable evaluating time‐frequency characteristics of magnetic signals across region. At Western Samoa observatory (API), 3–8 min period, visible in vertical horizontal fields, arrived ∼04:44 UTC. The Chichijima Island (CBI) Easter (IPM) had local...
In the United States, hundreds of thousands undocumented orphan wells have been abandoned, leaving burden managing environmental hazards to governmental agencies or public. These wells, a result over century fossil fuel extraction without adequate regulation, lack basic information like location and depth, emit greenhouse gases, leak toxic substances into groundwater. For most these such as well depth is unknown unverified. Addressing this issue necessitates innovative interdisciplinary...
The updated World Magnetic Model (WMM) 2025 was released in December 2024, alongside a new WMM – High Resolution version for the first time. is spherical harmonic model of internal magnetic field, designed to provide values field navigation, heading and direction over 5-years as part Geodetic System 1984 standard coordinate reference frame. produced jointly by British Geological Survey US NOAA National Centers Environmental Information, funded Defence Geographic Centre Geospatial...
Abstract In December 2019, the 13th revision of International Geomagnetic Reference Field (IGRF) was released by Association Geomagnetism and Aeronomy (IAGA) Division V Working Group V-MOD. This comprises two new spherical harmonic main field models for epochs 2015.0 (DGRF-2015) 2020.0 (IGRF-2020) a model predicted secular variation interval to 2025.0 (SV-2020-2025). The were produced from candidates submitted fifteen international teams. These teams led British Geological Survey (UK), China...
Abstract Enhanced interaction between solar‐wind and Earth's magnetosphere can cause space weather geomagnetic storms that have the potential to damage critical technologies, such as magnetic navigation, radio communications, power grids. The severity of a storm is measured using disturbance‐storm‐time ( Dst ) index. index calculated by averaging horizontal component field observed at four near‐equatorial observatories used drive disturbance models. As key specification magnetospheric...
Abstract Observed tidal geomagnetic field variations are due to a combination of electric currents in the ionosphere, ocean, and their induced counterparts. Using these constrain subsurface electrical conductivity oceanic regions is promising frontier; however, properly separating ionospheric contributions magnetic critical for this. We compare semidiurnal lunar signals (i.e., M 2 mode) estimated from 64 global observatories physics‐based forward models field. At ground level, predicted...
Abstract The Equatorial Electrojet (EEJ) is one of the important near‐earth space weather phenomena which exhibits significant diurnal, seasonal and solar activity variations. This paper investigates EEJ variations at cycle time scales from Indian sector portrays a new empirical field model developed using observations spanning over nearly two cycles. Method Naturally Orthogonal Components (MNOC), also known as Principal Component Analysis (PCA), was employed to extract dominant patterns...
Abstract The International Geomagnetic Reference Field (IGRF) is a set of parameters representing the large-scale internal part Earth’s magnetic field. 13th generation IGRF requested candidate models for definitive main field 2015.0, provisional 2020.0, and predictive secular variation covering period 2020.0–2025.0. University Colorado (CU) National Centers Environmental Information (NCEI), Oceanic Atmospheric Administration (NOAA), have produced these three consideration in IGRF-13. In this...
Abstract Directional drilling in the oil fields relies particularly on “on‐fly” measurements of natural magnetic field (measurements while drilling; MWD); MWD are eventually used to construct well path. These superposition signals from internal, core and crustal, external, ionospheric magnetospheric sources noise elements borehole assembly. The internal mostly constant time accounted for through Earth's models. external origin give rise diurnal irregular spatio‐temporal variations observable...
Abstract Earth’s gravity and magnetic fields are used as natural reference frames in directional drilling. The azimuth of the bottomhole assembly is inferred by comparing field measured-while-drilling (MWD) with a geomagnetic model. To provide sufficient quality for accurate well placement, US National Geophysical Data Center (NGDC), partnership industry, has developed high-definition models (HDGM), updated regularly using latest satellite, airborne marine measurements field. Standard...
Abstract. Marine electromagnetic (EM) signals largely depend on three factors: flow velocity, Earth's main magnetic field, and seawater's electrical conductivity (which depends the local temperature salinity). Because of this, there has been recent interest in using marine EM to monitor study ocean circulation. Our utilizes voltage data from retired seafloor telecommunication cables Pacific Ocean examine whether such could be used circulation velocity or transport large oceanic scales. We...
Abstract Magnetic wellbore positioning depends on an accurate representation of the Earth's magnetic field,where borehole azimuth is inferred by comparing field measured-whiledrilling (MWD) with a geomagnetic reference model. Therefore, model accuracy improvements reduce position uncertainties. An improved high-resolution describing core, crustal and external components presented, it validated anindependent set measurements. Additionally, we benchmark against other models. The part...
Abstract The Geomagnetism Group at the National Centers for Environmental Information (NCEI), in collaboration with Cooperative Institute Research Sciences (CIRES), along various government and industry partners, specializes developing providing access to Earth's internal magnetic field models. These models are crucial applications such as compass navigation wellbore positioning, offering reference values geomagnetic (total field, dip or inclination, declination) any location across Earth....
Earth and Space Science Open Archive This preprint has been submitted to is under consideration at Geophysical Research Letters. ESSOAr a venue for early communication or feedback before peer review. Data may be preliminary.Learn more about preprints preprintOpen AccessYou are viewing the latest version by default [v1]Magnetic Signatures of January 15 2022 Hunga Tonga–Hunga Ha`apai Volcanic EruptionAuthorsNeeshaSchnepfiDTakutoMinamiiDHiroakiTohiDManojNairSee all authors Neesha...
Directional drilling in the oil fields relies particularly on “on-fly” measurements of natural magnetic field (measurements while drilling; MWD); MWD are eventually used to construct well path. These superposition signals from internal, core and crustal, external, ionospheric magnetospheric sources noise elements borehole assembly. The internal mostly constant time accounted for through Earth’s models. external origin give rise diurnal irregular spatio-temporal variations observable MWD. One...