A5062628135- Solar and Space Plasma Dynamics
- Ionosphere and magnetosphere dynamics
- Geomagnetism and Paleomagnetism Studies
- Earthquake Detection and Analysis
- Astro and Planetary Science
- Geophysics and Gravity Measurements
- Atmospheric Ozone and Climate
- GNSS positioning and interference
- Solar Radiation and Photovoltaics
- Stellar, planetary, and galactic studies
- Climate variability and models
- Planetary Science and Exploration
- Lightning and Electromagnetic Phenomena
- Astrophysics and Cosmic Phenomena
- Geology and Paleoclimatology Research
- Global Energy and Sustainability Research
- Atmospheric and Environmental Gas Dynamics
- Plasma Diagnostics and Applications
- Atomic and Subatomic Physics Research
- Particle physics theoretical and experimental studies
- Atmospheric chemistry and aerosols
- Gas Dynamics and Kinetic Theory
- Gamma-ray bursts and supernovae
- Atmospheric aerosols and clouds
- Inertial Sensor and Navigation
University of Reading
2016-2025
University of Maryland, College Park
2025
University Hospitals Birmingham NHS Foundation Trust
2023
Queen Elizabeth Hospital
2023
University of Liverpool
2008-2022
National Institute of Meteorology
2022
Health Affairs
2022
Liberty University
2022
Rutherford Appleton Laboratory
2006-2017
Imperial College London
1988-2017
[1] Understanding the influence of solar variability on Earth's climate requires knowledge variability, solar-terrestrial interactions, and mechanisms determining response system. We provide a summary our current understanding in each these three areas. Observations for Sun's are described, including irradiance variations both decadal centennial time scales their relation to galactic cosmic rays. Corresponding observations associated ozone, temperatures, winds, clouds, precipitation,...
The magnetometer instrument on the Solar Orbiter mission is designed to measure magnetic field local spacecraft continuously for entire duration. need characterise not only background but also its variations scales from far above well below proton gyroscale result in challenging requirements stability, precision, and noise, as operational limitations both other instruments. vibration thermal environment has led significant development of mechanical sensor design. overall design, performance,...
We report progress on the ongoing recalibration of Wolf sunspot number (SN) and Group (GN) following release version 2.0 SN in 2015. This constitutes both an update efforts reported 2016 Topical Issue Solar Physics a summary work by International Space Science Institute (ISSI) Team formed 2017 to develop optimal GN re-construction methods while continuing expand historical database. Significant has been made database side more is needed bring various proposed (primarily) reconstruction...
Low‐energy (below approximately 50 eV) ionospheric ions, injected into the magnetosphere at dayside cleft, are studied using data from retarding ion mass spectrometer (RIMS) experiment on Dynamics Explorer 1 satellite. It is concluded that upwelling ions cleft form an fountain and blown polar cap by antisunward convection. At high K p (>4), convection generally strong enough to fill entire with low‐energy O + whereas low k (<2) they largely restricted half of cap. Using a...
A new dayside source of O + ions for the polar magnetosphere is described, and a statistical survey presented upward flows using 2 years data from retarding ion mass spectrometer (RIMS) experiment on board DE 1, at geocentric distances below 3 R E invariant latitudes above 40°. The are classified according to their spin angle distributions. It believed that spacecraft potential near perigee generally less than +2 V, in which case entire population energies about 60 eV sampled. Examples given...
Some implications are considered of recent theoretical work concerning the excitation dayside ionospheric convection by magnetic reconnection at magnetopause. In particular, transient bursts such (‘flux transfer events’) as a cause polar cap ‘patches’ enhanced plasma density. Examples patches, observed European longitudes EISCAT radar, presented and used to discuss proposed mechanism.
Combined observations by meridian‐scanning photometers, all‐sky auroral TV camera and the EISCAT radar permitted a detailed analysis of temporal spatial development midday breakup phenomenon related ionospheric ion flow pattern within 71°–75° invariant latitude field view. The data revealed dominating northward westward drifts, magnitudes close to corresponding velocities discrete, transient forms, during two different events reported here, characterized IMF |B Y /B Z | < 1 > 2,...
A method is presented which allows estimation of the variation rate magnetic reconnection at day side magnetopause. This achieved using observations cusp particle precipitation made by low‐altitude polar‐orbiting spacecraft. In this paper we apply technique to a previously published example intersection DMSP F7 satellite. It shown that signature in case was produced three separate bursts were order 10 min apart, each lasting roughly 1 min. similar required explain typical flux transfer event...
Recent observations of ionospheric flows by ground‐based radars, in particular the European Incoherent Scatter (EISCAT) facility using “Polar” experiment, together with previous analyses response geomagnetic disturbance to variations interplanetary magnetic field (IMF), suggest that convection high‐latitude ionosphere should be considered sum two intrinsically time‐dependent patterns, one driven solar wind‐magnetosphere coupling at dayside magnetopause, other release energy tail (mainly and...
Abstract There is considerable evidence for solar influence on the Earth's pre-industrial climate and Sun may well have been a factor in post-industrial change first half of last century. Here we show that over past 20 years, all trends could had an opposite direction to required explain observed rise global mean temperatures.
Solar activity during the current sunspot minimum has fallen to levels unknown since start of 20th century. The Maunder (about 1650–1700) was a prolonged episode low solar which coincided with more severe winters in United Kingdom and continental Europe. Motivated by recent relatively cold UK, we investigate possible connection activity. We identify regionally anomalous detrending Central England temperature (CET) record using reconstructions northern hemisphere mean temperature. show that...
Earth's cusps are magnetic field features in the magnetosphere associated with regions through which plasma from Sun can have direct access to upper atmosphere. Recently, new ground‐based observations, combined situ satellite measurements, led way reinterpreting cusp signatures. These theoretical advances, stimulated interest solar wind‐magnetosphere‐ionosphere coupling chain. This process is important because it causes both momentum and energy wind enter into near‐Earth region. Here we...
Plasma parcels are observed propagating from the Sun out to large coronal heights monitored by Heliospheric Imagers (HI) instruments onboard NASA STEREO spacecraft during September 2007. The source region of these out‐flowing is found corotate with and be rooted near western boundary an equatorial hole. These plasma enhancements evolve their propagation through HI cameras' fields view only becoming fully developed in outer camera field view. We provide evidence that observing formation a...
Solar outputs during the current solar minimum are setting record low values for space age. Evidence is here reviewed that this part of a decline in activity from grand maximum and Sun has returned to state last prevailed 1924. Recent research into what means, does not mean, climate change reviewed.
The literature relevant to how solar variability influences climate is vast—but much has been based on inadequate statistics and non-robust procedures. common pitfalls are outlined in this review. best estimates of the influence global mean air surface temperature show relatively small effects, compared with response anthropogenic changes (and broadly line their respective radiative forcings). However, situation more interesting when one looks at regional season variations around means. In...
We use geomagnetic activity data to study the rise and fall over past century of solar wind flow speed VSW, interplanetary magnetic field strength B, open flux FS. Our estimates include allowance for kinematic effect longitudinal structure in speed. As well as cycle variations, all three parameters show a long-term during first half 20th followed by peaks around 1955 1986 then recent decline. Cosmogenic isotope reveal that this constitutes grand maximum which began 1920, using definition...
Historic geomagnetic activity observations have been used to reveal centennial variations in the open solar flux and near-Earth heliospheric conditions (the interplanetary magnetic field wind speed). The various methods are very good agreement for past 135 years when there were sufficient reliable observatories operation eliminate problems due site-specific errors calibration drifts. This review underlines physical principles that allow these reconstructions be made, as well details of...
Patchy Polar Cap Patches of enhanced density plasma in the polar ionosphere (or cap patches) disturb radio communications and satellite positioning at high latitudes during magnetospheric storms. Using data from Global Positioning System satellites a high-frequency radar network, Q.-H. Zhang et al. (p. 1597 ) analyzed storm driven by strong coronal mass ejection Sun followed evolution motion patch ionization throughout cap. The localized dayside flow response to solar disturbance allowed be...