A5080012671- Ionosphere and magnetosphere dynamics
- Solar and Space Plasma Dynamics
- Astro and Planetary Science
- Planetary Science and Exploration
- Space Exploration and Technology
- Geomagnetism and Paleomagnetism Studies
- Atmospheric Ozone and Climate
- Gamma-ray bursts and supernovae
- Scientific Research and Discoveries
- Earthquake Detection and Analysis
- Geophysics and Gravity Measurements
- Atmospheric and Environmental Gas Dynamics
- Dust and Plasma Wave Phenomena
- Astronomical Observations and Instrumentation
- Plasma Diagnostics and Applications
- Laser-induced spectroscopy and plasma
- Nuclear Physics and Applications
- Atomic and Molecular Physics
- Scientific Computing and Data Management
- Vacuum and Plasma Arcs
- Advanced Mathematical Physics Problems
- Astrophysics and Cosmic Phenomena
- Spaceflight effects on biology
- Spectroscopy and Laser Applications
- Software-Defined Networks and 5G
Southwest Research Institute
2014-2025
Jadavpur University
1976-1998
What's Happening in the Heliosphere The influence of Sun is felt well beyond orbits planets. solar wind a stream charged particles emanating from that carves bubble interstellar space known as heliosphere and shrouds entire system. edge heliosphere, region where interacts with space, largely unexplored. Voyager 1 2 crossed this boundary 2004 2007, respectively, providing detailed but only localized information. In issue (see cover), McComas et al. (p. 959 , published online 15 October),...
On 9 October 2009, the Lunar Crater Observation and Sensing Satellite (LCROSS) sent a kinetic impactor to strike Cabeus crater, on mission search for water ice other volatiles expected be trapped in lunar polar soils. The Lyman Alpha Mapping Project (LAMP) ultraviolet spectrograph onboard Reconnaissance Orbiter (LRO) observed plume generated by LCROSS impact as far-ultraviolet emissions from fluorescence of sunlight molecular hydrogen carbon monoxide, plus resonantly scattered atomic...
Although of great interest for science and resource utilization, the Moon's permanently shadowed regions (PSRs) near each pole present difficult targets remote sensing. The Lyman Alpha Mapping Project (LAMP) instrument on Lunar Reconnaissance Orbiter (LRO) mission is able to map PSRs at far‐ultraviolet (FUV) wavelengths using two faint sources illumination from night sky: all‐sky Ly α glow produced as interplanetary medium (IPM) H atoms scatter Sun's emissions, much fainter source UV‐bright...
We present an analysis of Lunar Reconnaissance Orbiter (LRO) Lyman Alpha Mapping Project (LAMP) measurements the dayside lunar surface at far‐ultraviolet wavelengths. use strong 165 nm H 2 O absorption edge to look for diurnal variations in hydration. find that spectral slope are indeed present; they superimposed on latitudinal and spatial related composition weathering. two different regions (164–173 175–190 nm) separate out these effects. Highlands mare have distinct reflectance spectra,...
Abstract The Magnetospheric Multiscale (MMS) mission was designed to make observations in the very small electron diffusion region (EDR), where magnetic reconnection takes place. From a data set of over 4500 magnetopause crossings obtained first phase mission, MMS had encounters near or within 12 EDRs. These events and associated are considered as group determine if they span widest possible range external internal conditions (i.e., solar wind magnetosphere). In addition, from used there...
Abstract Data from the Cassini Electron Spectrometer are used to investigate location of magnetic reconnection at Saturn's magnetopause. Heated, streaming electron distributions in boundary layer on magnetosheath side magnetopause evidence and an open A model for is compare modeled observed direction heated distributions. Magnetic predicted occur locations similar those Earth's Although not conclusive, results here consistent with expected importance X‐line drifts suppressing low‐shear...
Abstract Magnetospheric ions from the ring current, warm plasma cloak, and plasmaspheric drainage plume all interact with dusk flank magnetopause. During periods of strong magnetospheric convection, these may contribute significantly to mass density at Observations Multiscale mission Hot Plasma Composition Analyzer duskside magnetopause near reconnection X lines show that current cloak have high densities. However, densities are not as large in magnetosheath. The results suggest except for...
Abstract Magnetospheric ions have the potential to affect magnetic reconnection at magnetopause. The results of a survey magnetospheric near magnetopause are reported here. Composition measurements from Multiscale (MMS) mission used determine total mass density all and distinguish two populations ions: warm plasma cloak plasmaspheric drainage plume. can contain substantial O + , plume He . show that, for nominal activity, will reduce normalized rate by greater than 20% only few percent time.
Abstract Magnetic flux ropes of various scale sizes have been observed at the Earth's magnetopause for four decades. These multiple structures resulting from reconnection complex internal field and plasma signatures, evolve as they propagate along dayside magnetopause. Here magnetic observations Magnetospheric Multiscale (MMS) mission are used to describe a different type large‐scale reconnection, rope‐like structure show least two X lines separated by many Earth radii. Unlike smaller‐scale...
Abstract The warm plasma cloak is a source of magnetospheric that contain significant O + . When the density in magnetosphere near magnetopause >0.2 cm ‐3 and H <1.5 , then dominates ion mass by more than factor 2. A survey conducted such ‐rich intervals their effect on reconnection at Earth's magnetopause. uses data from Magnetospheric Multiscale mission (MMS) results are compared combined with previous cloak. Overall, reduce rate >20% due to mass‐loading only about 2% 4% time....
Abstract The Miniaturized Electron pRoton Telescope, MERiT, is a low‐mass, low‐power, compact instrument using an innovative combination of particle detectors, sensor electronics, and onboard processing. MERiT flying on the Compact Radiation belt Explorer, CeREs, 3U CubeSat launched into low earth orbit 500‐km altitude inclination 85° 16 December 2018. primary secondary science goals CeREs are to investigate electron microbursts study solar particles. comprises stack solid state detectors...
Abstract Data are analyzed from a Magnetospheric Multiscale encounter with dayside magnetopause reconnection region on 29 December 2016. The uniqueness of the event stems small (~7 km) average spacecraft separation and sequential sampling an electron diffusion crescent distributions. We quantitatively investigate earthward acceleration magnetosheath electrons through in‐plane null by polarization electric field E N that points radially outward magnetopause. results compare favorably previous...
Abstract Here we present some unique observations of reconnection at a quasi‐perpendicular bow shock as an interplanetary directional discontinuity (DD) is crossing it simultaneously with the Magnetospheric Multiscale (MMS) mission. There are no burst data, but available data show indications ongoing southward MMS: bifurcated current sheet signatures Hall magnetic and electric fields, normal fields indicating connection between two reconnecting regions, field‐aligned currents E · J >0...
Abstract At Saturn, solar wind driving of the magnetosphere is predicted to be reduced due extreme rotationally driven interior. As a result, plasma corotates with planet, possibly out magnetopause. Modeling suggests that this corotation should set up conditions are unfavorable for onset magnetic reconnection on dawnside magnetopause generation significant flow shear. The shear model being tested makes use idealized steady state models and dominant east‐west interplanetary field orientation...
Abstract Observations from the Cassini Plasma Spectrometer/Electron Spectrometer (CAPS/ELS) are used in an in‐depth investigation of occurrence and location reconnection at Saturn's magnetopause. Heated, streaming electrons parallel and/or antiparallel to magnetic field magnetosheath adjacent magnetopause indicate that is occurring somewhere on boundary. In these instances, spacecraft connected open lines thread A survey 99 crossings with sufficient pitch angle coverage CAPS/ELS indicates...
In this study, the ion composition of flux transfer events (FTEs) observed within magnetosheath proper is examined. These FTEs were just upstream Earth's postnoon magnetopause by National Aeronautics and Space Administration (NASA) Magnetospheric Multiscale (MMS) spacecraft constellation. The minor characteristics are described using energy spectrograms, distributions, moments as constellation encountered each FTE. conjunction with electron data magnetic field observations, such observations...
Abstract Under northward interplanetary magnetic field conditions, reconnection at the Earth's magnetopause is usually thought to operate through merging of magnetosheath lines and open from magnetospheric lobe. However, also occurs between closed in magnetosphere. certain this nonlobe line has distinct plasma signatures that distinguish it lobe lines. A survey these conditions suggests may be common even for relatively strong IMF.
Abstract The dusk flank magnetopause was surveyed with instruments on board the Magnetospheric Multiscale (MMS) spacecraft 28 August 2015 between 13:55 UT and 14:15 during a period of persistent southward interplanetary magnetic field (IMF) varying dawn‐dusk component. Plasma measurements (500 eV electrons, > 2 keV ions) revealed existence at least one active reconnection region that persisted throughout interval. convected equatorward despite poleward tailward magnetosheath flow, which...
Abstract Warm (several eV to 100 eV) ions are an important, and still poorly understood, component of the magnetospheric plasma environment. We present first comprehensive statistical analysis several distinct populations warm in dayside middle outer magnetosphere. analyze 7 months (1 September 2015–31 March 2016) Magnetospheric Multiscale Hot Plasma Composition Analyzer data comprising 734,200 moments (density, temperature) energy‐dependent pitch angle distributions (PADs) three major ion...
Abstract Observations within the solar wind (SW) environment outside of Earth's magnetosphere were conducted on 6 December 2016, by Hot Plasma Composition Analyzer Magnetospheric Multiscale mission. At time measurement, SW was in a compressed state with southbound interplanetary magnetic field 9 nT and corresponding increases proton density dynamic pressure. High resolution measurements pickup ions this region made during when Earth is situated gravitational focusing cone for interstellar...
Abstract On 05 December 2015 the Magnetospheric MultiScale constellation observed interstellar pickup ion distributions during an inbound crossing of Earth's perpendicular bow shock near subsolar point, which provides new insights into acceleration ions throughout heliosphere. In this study we analyze upstream and downstream velocity H + He using data from Hot Plasma Composition Analyzer on MultiScale. We derive average two‐dimensional pitch angle in field‐aligned bulk plasma frame, as well...
Abstract Near‐Earth plasma surges sunward during enhanced magnetospheric convection (driven by dayside magnetic reconnection) to form a pathway feature called plasmaspheric plume. This study uses Magnetospheric Multiscale (MMS) observations investigate the heating of warm ions (H + and He ) inside plumes. We identify 287 plume events using targeted in‐situ‐observational criteria plasmapause test particle simulations. One plume‐crossing event MMS shows that scalar temperatures increase from...