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Journal articleToledo-Redondo S, Lee JH, Vines SK, et al., 2024,
Statistical Observations of Proton-Band Electromagnetic Ion Cyclotron Waves in the Outer Magnetosphere: Full Wavevector Determination
, JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS, Vol: 129, ISSN: 2169-9380 -
Journal articleLewis ZM, Beth A, Galand M, et al., 2024,
Constraining ion transport in the diamagnetic cavity of comet 67P
, Monthly Notices of the Royal Astronomical Society, Vol: 530, Pages: 66-81, ISSN: 0035-8711The European Space Agency Rosetta mission escorted comet 67P for a 2-yr section of its six and a half-year orbit around theSun. By perihelion in 2015 August, the neutral and plasma data obtained by the spacecraft instruments showed the comet hadtransitioned to a dynamic object with large-scale plasma structures and a rich ion environment. One such plasma structure isthe diamagnetic cavity: a magnetic field-free region formed by interaction between the unmagnetized cometary plasma andthe impinging solar wind. Within this region, unexpectedly high ion bulk velocities have been observed, thought to have beenaccelerated by an ambipolar electric field. We have developed a 1D numerical model of the cometary ionosphere to constrainthe impact of various electric field profiles on the ionospheric density profile and ion composition. In the model, we includethree ion species: H2O+, H3O+, and NH+4 . The latter, not previously considered in ionospheric models including acceleration, isproduced through the protonation of NH3 and only lost through ion–electron dissociative recombination, and thus particularlysensitive to the time-scale of plasma loss through transport. We also assess the importance of including momentum transferwhen assessing ion composition and densities in the presence of an electric field. By comparing simulated electron densities toRosetta Plasma Consortium data sets, we find that to recreate the plasma densities measured inside the diamagnetic cavity nearperihelion, the model requires an electric field proportional to r−1 of around 0.5–2 mV m−1 surface strength, leading to bulk ionspeeds at Rosetta of 1.2–3.0 km s−1.
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Journal articleZhou Y, He F, Archer MO, et al., 2024,
Spatial evolution characteristics of plasmapause surface wave during a geomagnetic storm on 16 July 2017
, Geophysical Research Letters, Vol: 51, ISSN: 0094-8276Boundary dynamics are crucial for the transport of energy, mass, and momentum in geospace. The recently discovered plasmapause surface wave (PSW) plays a key role in the inner magnetosphere dynamics. However, a comprehensive investigation of spatial variations of the PSW remains absent. In this study, we elucidate the spatial characteristics of a PSW through observations from multiple spacecrafts in the magnetosphere. Following the initiation of the PSW, quasi-periodic injections of energetic ions, rather than electrons, are suggested to serve as energy source of the PSW. Based on the distinct wave and particle signatures, we categorize the PSW into four regions: seed region, growth region, stabilization region and decay region, spanning from nightside to afternoon plasmapause. These findings advance our understanding of universal boundary dynamics and contribute to a deeper comprehension of the pivotal roles of surface waves in the energy couplings within the magnetosphere-plasmasphere-ionosphere system.
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ReportZachariah M, Kimutai J, Barnes C, et al., 2024,
Heavy precipitation hitting vulnerable communities in the UAE and Oman becoming an increasing threat as the climate warms
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Journal articleSparks N, Toumi R, 2024,
The Imperial College Storm model (IRIS) dataset
, Scientific Data, Vol: 11, ISSN: 2052-4463Assessing tropical cyclone risk on a global scale given the infrequency of landfalling tropical cyclones (TC) and the short period of reliable observations remains a challenge. Synthetic tropical cyclone datasets can help overcome these problems. Here we present a new global dataset created by IRIS, the ImpeRIal college Storm model. IRIS is novel because, unlike other synthetic TC models, it only simulates the decay from the point of lifetime maximum intensity. This minimises the bias in the dataset. It takes input from 42 years of observed tropical cyclones and creates a 10,000 year synthetic dataset of wind speed which is then validated against the observations. IRIS captures important statistical characteristics of the observed data. The return periods of the landfall maximum wind speed are realistic globally.
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Journal articleBlackford K, Kasoar M, Burton C, et al., 2024,
INFERNO-peat v1.0.0: a representation of northern high latitude peat fires in the JULES-INFERNO global fire model
, Geoscientific Model Development, Vol: 17, Pages: 3063-3079, ISSN: 1991-959XPeat fires in the northern high latitudes have the potential to burn vast amounts of carbon-rich organic soil, releasing large quantities of long-term stored carbon to the atmosphere. Due to anthropogenic activities and climate change, peat fires are increasing in frequency and intensity across the high latitudes. However, at present they are not explicitly included in most fire models. Here we detail the development of INFERNO-peat, the first parameterization of peat fires in the JULES-INFERNO (Joint UK Land Environment Simulator INteractive Fire and Emission algoRithm for Natural envirOnments) fire model. INFERNO-peat utilizes knowledge from lab and field-based studies on peat fire ignition and spread to be able to model peat burnt area, burn depth, and carbon emissions, based on data of the moisture content, inorganic content, bulk density, soil temperature, and water table depth of peat. INFERNO-peat improves the representation of burnt area in the high latitudes, with peat fires simulating on average an additional 0.305×106 km2 of burn area each year, emitting 224.10 Tg of carbon. Compared to Global Fire Emissions Database version 5 (GFED5), INFERNO-peat captures ∼ 20 % more burnt area, whereas INFERNO underestimated burning by 50 %. Additionally, INFERNO-peat substantially improves the representation of interannual variability in burnt area and subsequent carbon emissions across the high latitudes. The coefficient of variation in carbon emissions is increased from 0.071 in INFERNO to 0.127 in INFERNO-peat, an almost 80 % increase. Therefore, explicitly modelling peat fires shows a substantial improvement in the fire modelling capabilities of JULES-INFERNO, highlighting the importance of representing peatland systems in fire models.
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Journal articleDing M, Ryabtsev AN, Kononov EY, et al., 2024,
Spectrum and energy levels of the low-lying configurations of Nd III
, ASTRONOMY & ASTROPHYSICS, Vol: 684, ISSN: 0004-6361 -
Journal articleColomban L, Kretzschmar M, Krasnoselkikh V, et al., 2024,
Quantifying the diffusion of suprathermal electrons by whistler waves between 0.2 and 1 AU with Solar Orbiter and Parker Solar Probe
, ASTRONOMY & ASTROPHYSICS, Vol: 684, ISSN: 0004-6361 -
Journal articleMathews J, Czaja A, 2024,
Oceanic maintenance of atmospheric blocking in wintertime in the North Atlantic
, CLIMATE DYNAMICS, ISSN: 0930-7575 -
Journal articleHellinger P, Verdini A, Montagud-Camps V, et al., 2024,
Anisotropy of plasma turbulence at ion scales: Hall and pressure-strain effects
, ASTRONOMY & ASTROPHYSICS, Vol: 684, ISSN: 0004-6361 -
Journal articleChawner H, Saboya E, Adcock KE, et al., 2024,
Atmospheric oxygen as a tracer for fossil fuel carbon dioxide: a sensitivity study in the UK
, Atmospheric Chemistry and Physics, Vol: 24, Pages: 4231-4252, ISSN: 1680-7316We investigate the use of atmospheric oxygen (O2) and carbon dioxide (CO2) measurements for the estimation of the fossil fuel component of atmospheric CO2 in the UK. Atmospheric potential oxygen (APO) – a tracer that combines O2 and CO2, minimizing the influence of terrestrial biosphere fluxes – is simulated at three sites in the UK, two of which make APO measurements. We present a set of model experiments that estimate the sensitivity of APO simulations to key inputs: fluxes from the ocean, fossil fuel flux magnitude and distribution, the APO baseline, and the exchange ratio of O2 to CO2 fluxes from fossil fuel combustion and the terrestrial biosphere. To estimate the influence of uncertainties in ocean fluxes, we compare three ocean O2 flux estimates from the NEMO–ERSEM, the ECCO–Darwin ocean model, and the Jena CarboScope (JC) APO inversion. The sensitivity of APO to fossil fuel emission magnitudes and to terrestrial biosphere and fossil fuel exchange ratios is investigated through Monte Carlo sampling within literature uncertainty ranges and by comparing different inventory estimates. We focus our model–data analysis on the year 2015 as ocean fluxes are not available for later years. As APO measurements are only available for one UK site at this time, our analysis focuses on the Weybourne station. Model–data comparisons for two additional UK sites (Heathfield and Ridge Hill) in 2021, using ocean flux climatologies, are presented in the Supplement. Of the factors that could potentially compromise simulated APO-derived fossil fuel CO2 (ffCO2) estimates, we find that the ocean O2 flux estimate has the largest overall influence at the three sites in the UK. At times, this influence is comparable in magnitude to the contribution of simulated fossil fuel CO2 to simulated APO. We find that simulations using different ocean fluxes differ from each other substantially. No single model estimate, or a model estimate that assumed zero oce
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Journal articleHuang J, Kasper JC, Larson DE, et al., 2024,
Parker Solar Probe Observations of High Plasma β Solar Wind from the Streamer Belt (vol 265, 47, 2023)
, ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES, Vol: 271, ISSN: 0067-0049 -
Journal articleMitchell DG, Hill ME, Mccomas DJ, et al., 2024,
Likely Common Coronal Source of Solar Wind and <SUP>3</SUP>He-enriched Energetic Particles: Uncoupled Transport from the Low Corona to 0.2 au
, ASTROPHYSICAL JOURNAL, Vol: 965, ISSN: 0004-637X -
Journal articleEriksson S, Swisdak M, Mallet A, et al., 2024,
Parker Solar Probe Observations of Magnetic Reconnection Exhausts in Quiescent Plasmas near the Sun
, ASTROPHYSICAL JOURNAL, Vol: 965, ISSN: 0004-637X -
Journal articleBowen TA, Bale SD, Chandran BDG, et al., 2024,
Mediation of collisionless turbulent dissipation through cyclotron resonance
, NATURE ASTRONOMY, Vol: 8, Pages: 482-490, ISSN: 2397-3366 -
Journal articleFiedler S, Naik V, O'Connor FM, et al., 2024,
Interactions between atmospheric composition and climate change - progress in understanding and future opportunities from AerChemMIP, PDRMIP, and RFMIP
, GEOSCIENTIFIC MODEL DEVELOPMENT, Vol: 17, Pages: 2387-2417, ISSN: 1991-959X -
Journal articleStephenson P, Galand M, Deca J, et al., 2024,
Cold electrons at a weakly outgassing comet
, MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, Vol: 529, Pages: 2854-2865, ISSN: 0035-8711 -
Journal articleSishtla CP, Pomoell J, Magyar N, et al., 2024,
Validity of using Elsasser variables to study the interaction of compressible solar wind fluctuations with a coronal mass ejection
, ASTRONOMY & ASTROPHYSICS, Vol: 683, ISSN: 0004-6361 -
Journal articleRojo M, Persson M, Sauvaud J-A, et al., 2024,
Electron moments derived from the Mercury Electron Analyzer during the cruise phase of BepiColombo
, ASTRONOMY & ASTROPHYSICS, Vol: 683, ISSN: 0004-6361 -
Conference paperLewis Z, Beth A, Galand M, et al., 2024,
Constraining ion transport in the diamagnetic cavity of comet 67P
<jats:p>Comets are small icy bodies originating from the outer solar system that produce an increasingly dense gas coma through sublimation as they approach perihelion. Photoionisation of this gas results in a cometary ionosphere, which interacts with the impinging solar wind, leading to large scale plasma structures. One such structure is the diamagnetic cavity: the magnetic field-free inner region that the solar wind cannot penetrate. This region was encountered many times by the ESA Rosetta mission, which escorted comet 67P/Churyumov-Gerasimenko for a two-year section of its orbit.Within the diamagnetic cavity, high ion bulk velocities have been observed by the Rosetta Plasma Consortium (RPC) instruments. The fast ions are thought to have been accelerated by an ambipolar electric field, but the nature and strength of this field are difficult to determine analytically. Our study therefore aims to model the impact of various electric field profiles on the ionospheric density profile and ion composition. The 1D numerical model we have developed includes three key ion species (H2O+, H3O+, and NH4+) in order to assess the sensitivity of each to the timescale of plasma loss through transport. NH4+ is of particular interest, as it has been previously shown to be the dominant ion species at low cometocentric distances near perihelion. It is only produced through the protonation of NH3, a minor component of the neutral gas, and we show that this makes it particularly sensitive to the electric field.We also compare the simulated electron density to RPC datasets, to find the electric field strength and profile which best recreate the plasma densities measured inside the diamagnetic cavity near perihelion. From this, we also constrain the radial bulk ion speed that is required to explain the observations with the model.</jats:p>
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Conference paperBeth A, Galand M, Modolo R, et al., 2024,
Ionospheric environment of Ganymede during the Galileo flybys
<jats:p>The Galileo spacecraft flew by Ganymede, down to 0.1 RG from the surface for the closest, six times giving us insight into its plasma environment. Its ionosphere, made of ions born from the ionisation of neutrals present in Ganymede&#8217;s exosphere, represents the bulk of the plasma near the moon around closest approach. As it has been revealed by Galileo and Juno, near closest approach the ion population is dominated by low-energy ions from the water ion group (O+, HO+, H2O+) and O2+. However, little is known about their density, spatial distribution, and effect on the surface weathering of the moon itself. Galileo G2 flyby has been extensively studied. Based on a comparison between observations and 3D test-particle simulations, Carnielli et al. (2020a and 2020b) confirmed the ion composition (debated at the time), highlighted the inconsistency between the assumed exospheric densities and the observed ionospheric densities, and derived the contribution of ionospheric ions as an exospheric source. However, other flybys of Ganymede are also available (e.g. G1, G7, G8, G28, and G29) providing in-situ measurements at different phases of Ganymede around Jupiter or jovian magnetospheric conditions at the moon. We extend the original study by Carnielli et al. to other flybys, and compare our modelled ion moments (ion number density, velocity, and energy distribution) with Galileo in-situ data. We discuss our results and contrast them with those obtained for the G2 flyby.&#160;&#160;</jats:p>
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Journal articleHeinemann SG, Sishtla C, Good S, et al., 2024,
Classification of Enhanced Geoeffectiveness Resulting from High-speed Solar Wind Streams Compressing Slower Interplanetary Coronal Mass Ejections
, ASTROPHYSICAL JOURNAL LETTERS, Vol: 963, ISSN: 2041-8205 -
Journal articleKuhlbrodt T, Swaminathan R, Ceppi P, et al., 2024,
A glimpse into the future: the 2023 ocean temperature and sea ice extremes in the context of longer-term climate change
, Bulletin of the American Meteorological Society, Vol: 105, Pages: E474-E485, ISSN: 0003-0007In the year 2023, we have seen extraordinary extrema in high sea surface temperature (SST) in the North Atlantic and in low sea ice extent in the Southern Ocean, outside the 4σ envelope of the 1982–2011 daily time series. Earth’s net global energy imbalance (12 months up to September 2023) amounts to +1.9 W m−2 as part of a remarkably large upward trend, ensuring further heating of the ocean. However, the regional radiation budget over the North Atlantic does not show signs of a suggested significant step increase from less negative aerosol forcing since 2020. While the temperature in the top 100 m of the global ocean has been rising in all basins since about 1980, specifically the Atlantic basin has continued to further heat up since 2016, potentially contributing to the extreme SST. Similarly, salinity in the top 100 m of the ocean has increased in recent years specifically in the Atlantic basin, and in addition in about 2015 a substantial negative trend for sea ice extent in the Southern Ocean began. Analyzing climate and Earth system model simulations of the future, we find that the extreme SST in the North Atlantic and the extreme in Southern Ocean sea ice extent in 2023 lie at the fringe of the expected mean climate change for a global surface-air temperature warming level (GWL) of 1.5°C, and closer to the average at a 3.0°C GWL. Understanding the regional and global drivers of these extremes is indispensable for assessing frequency and impacts of similar events in the coming years.
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Journal articleKellogg PJ, Mozer FS, Moncuquet M, et al., 2024,
Heating and Acceleration of the Solar Wind by Ion Acoustic Waves-Parker Solar Probe
, ASTROPHYSICAL JOURNAL, Vol: 964, ISSN: 0004-637X -
Journal articleJohnson M, Rivera YJ, Niembro T, et al., 2024,
Helium Abundance Periods Observed by the Solar Probe Cup on Parker Solar Probe: Encounters 1-14
, ASTROPHYSICAL JOURNAL, Vol: 964, ISSN: 0004-637X -
Journal articleCoburn JT, Verscharen D, Owen CJ, et al., 2024,
The Regulation of the Solar Wind Electron Heat Flux by Wave-Particle Interactions
, ASTROPHYSICAL JOURNAL, Vol: 964, ISSN: 0004-637X -
Journal articleLiu YD, Zhu B, Ran H, et al., 2024,
Direct In Situ Measurements of a Fast Coronal Mass Ejection and Associated Structures in the Corona
, ASTROPHYSICAL JOURNAL, Vol: 963, ISSN: 0004-637X -
Journal articleGrimmich N, Prencipe F, Turner DL, et al., 2024,
Multi Satellite Observation of a Foreshock Bubble Causing an Extreme Magnetopause Expansion
, JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS, Vol: 129, ISSN: 2169-9380 -
Journal articleMatteini L, Tenerani A, Landi S, et al., 2024,
Alfvénic fluctuations in the expanding solar wind: Formation and radial evolution of spherical polarization
, PHYSICS OF PLASMAS, Vol: 31, ISSN: 1070-664X -
Journal articleFeingold G, Ghate VP, Russell LM, et al., 2024,
Physical science research needed to evaluate the viability and risks of marine cloud brightening
, Science Advances, Vol: 10, ISSN: 2375-2548Marine cloud brightening (MCB) is the deliberate injection of aerosol particles into shallow marine clouds to increase their reflection of solar radiation and reduce the amount of energy absorbed by the climate system. From the physical science perspective, the consensus of a broad international group of scientists is that the viability of MCB will ultimately depend on whether observations and models can robustly assess the scale-up of local-to-global brightening in today’s climate and identify strategies that will ensure an equitable geographical distribution of the benefits and risks associated with projected regional changes in temperature and precipitation. To address the physical science knowledge gaps required to assess the societal implications of MCB, we propose a substantial and targeted program of research—field and laboratory experiments, monitoring, and numerical modeling across a range of scales.
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