A5064075393- Ionosphere and magnetosphere dynamics
- Solar and Space Plasma Dynamics
- Earthquake Detection and Analysis
- Geomagnetism and Paleomagnetism Studies
- Astro and Planetary Science
- GNSS positioning and interference
- Geophysics and Gravity Measurements
- Lightning and Electromagnetic Phenomena
- Atmospheric Ozone and Climate
- Spacecraft Design and Technology
- Laser-induced spectroscopy and plasma
- Planetary Science and Exploration
- Magnetic confinement fusion research
- Atomic and Subatomic Physics Research
- Spacecraft and Cryogenic Technologies
- Space Satellite Systems and Control
- Spacecraft Dynamics and Control
- Nuclear Physics and Applications
- Space Exploration and Technology
- Space exploration and regulation
- Scientific Research and Discoveries
- Maritime Transport Emissions and Efficiency
- Radiation Effects in Electronics
- Plasma Diagnostics and Applications
- Meteorological Phenomena and Simulations
Goddard Space Flight Center
2015-2025
Heliophysics
2011-2024
Deleted Institution
2023
Heliophysics Science Division
2013
University of Wollongong
2012
Seattle University
2010
Oregon Health & Science University
2010
Twin Cities Orthopedics
2005
University of Minnesota
2005
Boston University
1995
The Electric and Magnetic Field Instrument Integrated Science (EMFISIS) investigation on the NASA Radiation Belt Storm Probes (now named Van Allen Probes) mission provides key wave very low frequency magnetic field measurements to understand radiation belt acceleration, loss, transport. science objectives contribution that EMFISIS makes providing as well theory modeling are described. components of instruments suite, both electronics sensors, including functional parameters, calibration,...
This paper presents the first simultaneous in situ measurements of large‐scale convection electric field and ring current induced magnetic perturbations equatorial plane inner magnetosphere compares them to evolution major geomagnetic storms as characterized by Dst . The were obtained from University California, Berkeley double‐probe experiment Air Force Geophysics Laboratory fluxgate magnetometer on CRRES spacecraft. spacecraft had an apogee near geosynchronous orbit a perigee 300 km...
Abstract We investigate the spatiotemporal and altitude variations in ionospheric F‐region electron density response to 10 May 2024 superstorm, most significant geomagnetic disturbance two decades. The unprecedented sampling by ∼12,000 profiles each day from COSMIC‐2, Spire FengYun‐3 radio occultation observations provided a nearly global full local time coverage of this event. During main phase storm, (200–500 km altitude) decreased globally, with peak height increasing during daytime...
Measurements made with the University of California, Berkeley/Air Force Geophysics Laboratory electric field instrument on CRRES spacecraft are examined to determine average structure inner magnetospheric for different geomagnetic activity levels. Data were gathered between L =2.5 and =8.5 over period from January October 1991 in local time sector 1200 0400 magnetic time. The dawn‐dusk component was nearly always duskward, scaling magnitude 0.05 mV/m 1.5 as Kp increased 0 9‐. data indicate...
Combined Release and Radiation Effects Satellite (CRRES) Electric Field Instrument (EFI) data are used to determine the electric field power spectral density as a function of L Kp over frequency range 0.2 15.9 mHz. The at each is fit P(L, Kp) = b exp(cKp). Assuming purely electrostatic making several other assumptions regarding azimuthal dependence fluctuations, Kp‐dependent radial diffusion coefficient D LL E computed from spectra. model average for high activity (Kp 6) between 1 2 orders...
DC electric fields and associated E × B plasma drifts detected with the double‐probe experiment on C/NOFS satellite during extreme solar minimum conditions near June 2008 solstice are shown to be highly variable, weak moderate ambient amplitudes of ∼1–2 mV/m (∼25–50 m/s). Average field or drift patterns show similarities those reported for more active conditions, i.e., eastward outward day westward inward at night. However, these vary significantly longitude not always present. Daytime...
The JOULE‐II sounding rocket salvo was launched from Poker Flat Rocket Range into weak pulsating aurora following a moderate substorm at 0345 LT on 19 January 2007. We present in situ measurements of ion flow velocity and electric magnetic fields combined with neutral wind observations derived ground chemical tracers. Measured drifts the 150–198 km 92–105 altitude ranges are consistent × motion to within 16 m s −1 rms 20 , respectively. From these we have calculated ratio κ cyclotron...
During the recent solar minimum, activity reached lowest levels observed during space age. This extremely low has accompanied a number of unexpected observations in Earth s ionosphere-thermosphere system when compared to previous minima. Among these are fact that ionosphere is significantly contracted beyond expectations based on empirical models. Altitude profiles ion density and composition measurements near magnetic dip equator constructed from Communication/Navigation Outage Forecast...
Abstract We use 4 years of Time History Events and Macroscale Interactions during Substorms (THEMIS) double‐probe measurements to offer, for the first time, a complete picture dawn‐dusk electric field covering all local times radial distances in inner magnetosphere based on situ equatorial observations. This study is motivated by results from CRRES mission, which revealed maximum developing near Earth storm times, rather than expected enhancement at higher L shells that shielded as suggested...
Abstract We present for the first time dramatic variations in atmospheric composition and density at high altitudes from 170 to 220 km Mars' neutral thermosphere response dust increases lower atmosphere, observed by situ Neutral Gas Ion Mass Spectrometer onboard Mars Atmosphere Volatile EvolutioN satellite. The observations reveal that CO 2 , Ar, N CO, O densities all increase up ~200% compared longer‐term running median densities. are seen throughout this altitude region, relative be...
Abstract The plasmasphere is a key component of Earth's magnetosphere, regulating numerous energy transfer processes. also cold multi‐species plasma. Tracing differences in dynamics between low and high mass ions important for identifying the processes that drive plasmaspheric evolution. At same time, measurements ion fractional composition within are sparse challenging to obtain. Seeking overcome this challenge, work presents novel concept combining extreme ultraviolet (EUV) photon imaging...
Abstract. Small scale dynamic auroras are generally related with dispersive Alfvén waves. Due to the short spatial and time scales involved, investigating effects of this type auroral precipitation on ionosphere is challenging. In study, we address challenge by introducing a recently developed improved time-dependent electron transport code entitled AURORA. We use high-resolution data from Visualizing Ion Outflow via Neutral Atom Sensing-2 (VISIONS-2) sounding rocket campaign as input for...
We report for the first time day-to-day variation of longitudinal structure in height F2 layer (hmF2) equatorial ionosphere using multi-satellite observations electron density profiles by Constellation Observing System Meteorology, Ionosphere and Climate-2 (COSMIC-2). These reveal a ~3-day modulation hmF2 wavenumber-4 viewed fixed local frame during January 30-February 14, 2021. Simultaneously, planetary wave activity is discerned from zonal wind at ~100 km Ionospheric Connection Explorer...
[1] Plasma density structures are frequently encountered in the nighttime low-latitude ionosphere by probes on Communication/Navigation Outage Forecasting System (C/NOFS) satellite. Of particular interest to us here plasma enhancements, which typically observed ±15° away from magnetic equator. The low inclination of C/NOFS satellite offers an unprecedented opportunity examine these and their associated electric fields velocities, including field-aligned components, along east-west...
We investigate the forces and atmosphere-ionosphere coupling that create atmospheric dynamo currents using two rockets launched nearly simultaneously on 4 July 2013 from Wallops Island (USA), during daytime Sq conditions with ΔH of -30 nT. One rocket released a vapor trail observed an airplane which showed peak velocities >160 m/s near 108 km turbulence coincident strong unstable shear. Electric magnetic fields plasma density were measured second rocket. The current peaked 110 exhibiting...
[1] Direct evidence is presented for a causal relationship between lightning and strong electric field transients inside equatorial ionospheric density depletions. In fact, these whistler mode plasma waves may be the dominant signal within such Optical data from Communication/Navigation Outage Forecast System (C/NOFS) satellite global location information World Wide Lightning Location Network are as independent verification that caused by lightning. The instrument on C/NOFS routinely...
The ACES‐High rocket, part of the Auroral Current and Electrodynamics Structure (ACES) mission launched from Poker Flat Research Range on 29 January 2009, obtained first in situ measurements indicative both observational characteristics associated with ionospheric feedback instability as it flew through an auroral arc its return current region. observed Alfvénic wave structures localized areas roughly 10 km near boundaries region discrete increased electron density a temperature...
The ionosphere response resulting from minimum solar activity during cycle 23/24 was unusual and offered unique opportunities for investigating space weather in the near‐Earth environment. We report ultra low frequency electric field signatures related to ionospheric Alfvén resonator detected by Communications/Navigation Outage Forecasting System (C/NOFS) satellite equatorial region. These are used constrain empirical models offer a new approach monitoring dynamics phenomena, namely aeronomy...
The 1970s and 1980s were heydays for using active electron beam experiments to probe some of the fundamental physical processes that occur throughout heliosphere in astrophysical contexts. Electron used study spacecraft charging spacecraft-plasma coupling; beam-plasma interaction physics; magnetic bounce drift auroral wave generation; military applications. While these enormously successful, they also limited by technologies available at time. New advances space instrumentation, data...
Abstract The ultraviolet‐imaging spectrograph that comprises Global‐scale Observations of the Limb and Disk (GOLD) mission in geostationary orbit at 47.5°W longitude has taken full disk images high cadence throughout deep solar minimum period 2019–2020. Synoptic (i.e., concurrent spatially unified resolved) observations thermospheric temperature composition ∼150 km altitude are made for first time, allowing GOLD to disambiguate temporal spatial variations. Here we analyze daytime effective...
We present in situ and ground‐based measurements of the ratio κ ion cyclotron angular frequency to ion‐neutral momentum transfer collision investigate ionosphere‐thermosphere (IT) coupling auroral E region. In observations were obtained by NASA sounding rocket 36.234, which was launched into nightside region ionosphere at 1229 UT on 19 January 2007 from Poker Flat, AK. The payload carried instrumentation determine drift angle electric field vectors. Neutral winds measured triangulating a...