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  • Journal article
    Hall RJ, Mitchell DM, Seviour WJM, Wright CJet al., 2021,

    Tracking the Stratosphere-to-Surface Impact of Sudden Stratospheric Warmings

    , JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES, Vol: 126, ISSN: 2169-897X
  • Journal article
    Liou K, Paranicas C, Vines S, Kollmann P, Allen R, Clark G, Mitchell D, Jackman C, Masters A, Achilleos N, Roussos E, Krupp Net al., 2021,

    Dawn-dusk asymmetry in energetic (>20 keV) particles adjacent to Saturn's magnetopause

    , Journal of Geophysical Research: Space Physics, Vol: 126, ISSN: 2169-9380

    Energetic particles (>∼25 keV) have been observed routinely in the terrestrial magnetosheath, but have not been well studied at the magnetosheaths of the outer planets. Here we analyze energetic electrons and ions (mostly protons) in the vicinity (±1 RS) of Saturn's magnetopause, using particle data acquired with the low‐energy magnetosphere measurements system, one of the three sensors of the magnetosphere imaging instrument on board the Cassini spacecraft, during a period of ∼14 years (2004–2017). It is found that energetic particles, especially ions, are also common in Saturn's magnetosheath. A clear inward (toward Saturn) gradient in the electron differential flux is identified, suggestive of magnetospheric sources. Such an inward gradient does not appear in some of the ion channels. We conclude that Saturn's magnetopause acts as a porous barrier for energetic electrons and, to a lesser extent, for energetic ions. A dawn‐dusk asymmetry in the gradient of particle flux across the magnetopause is also identified, with a gradual decrease at the dawn and a sharp decrease at the dusk magnetopause. It is also found that magnetic reconnection enhanced flux levels just outside of the magnetopause, with evidence suggesting that these particles are from magnetospheric sources. These findings strongly suggest that Saturn's magnetosphere is most likely the main source of energetic particles in Saturn's magnetosheath and magnetosphere leakage is an important process responsible for the presence of the energetic particles in Saturn's magnetosheath.
  • Journal article
    Kilpua EKJ, Good SW, Ala-Lahti M, Osmane A, Fontaine D, Hadid L, Janvier M, Yordanova Eet al., 2021,

    Statistical Analysis of Magnetic Field Fluctuations in Coronal Mass Ejection-Driven Sheath Regions

    , FRONTIERS IN ASTRONOMY AND SPACE SCIENCES, Vol: 7, ISSN: 2296-987X
  • Journal article
    Zappa G, Ceppi P, Shepherd TG, 2021,

    Eurasian cooling in response to Arctic sea-ice loss is not proved by maximum covariance analysis

    , Nature Climate Change, Vol: 11, Pages: 106-108, ISSN: 1758-678X
  • Journal article
    Southwood DJ, Cao H, Shebanits O, Elsden T, Hunt GJ, Dougherty MKet al., 2021,

    Discovery of Alfven waves planetward of Saturn's rings

    , Journal of Geophysical Research: Space Physics, Vol: 126, Pages: 1-18, ISSN: 2169-9380

    Between April and September 2017 in the final stages of the Cassini Saturn Orbiter mission the spacecraft executed 22 orbits passing planetward of the innermost ring, the D-ring. During all periapsis passes oscillations were detected in the azimuthal magnetic field components on typical time scales of a few minutes. We argue that these time-varying magnetic signals detected on the spacecraft are also primarily time-varying in the plasma frame. Furthermore, we show that nearly all signals exhibit a spatial feature, namely a magnetic node near the effective field line equator. We propose that the oscillations are associated with Alfvén waves excited in local field line resonances, most likely driven from global sources.
  • Journal article
    Sparks N, Toumi R, 2021,

    On the seasonal and sub-seasonal factors influencing East China tropical cyclone landfall

    , Atmospheric Science Letters, Vol: 22, Pages: 1-8, ISSN: 1530-261X

    To date it has proved difficult to make seasonal forecasts of tropical cyclones, particularly for landfall and in East China specifically. This study examines sources of predictability for the number of landfalling typhoons in East China on seasonal (June–October) and sub‐seasonal time scales. East China landfall count is shown to be independent of basin‐scale properties of TC tracks, such the genesis location, duration, basin track direction and length, and basin total count. Large‐scale environmental climate indices which are potential basin scale drivers are also shown to be largely uncorrelated with landfall prior to and throughout the season. The most important factor is the steering in the final stages to landfall. The seasonal landfall is strongly anti‐correlated with the more local zonal mid‐tropospheric wind field over the East China sea (r = −.61, p < .001). It is proposed that geopotential height anomalies over Korea/Japan cause anomalous easterly winds in the East China Sea and enhance landfall rates by steering typhoons onto the coast. Early, peak, and late sub‐seasonal landfall counts are shown to be independent of each other yet share this predictor. This local feature may be dynamically predictable allowing a potential hybrid dynamical‐statistical seasonal forecast of landfall.
  • Journal article
    Madanian H, Desai M, Schwartz SJ, Wilson LB, Fuselier SA, Burch JL, Le Contel O, Turner DL, Ogasawara K, Brosius AL, Russell CT, Ergun RE, Ahmadi N, Gershman DJ, Lindqvist P-Aet al., 2021,

    The Dynamics of a High Mach Number Quasi-perpendicular Shock: MMS Observations

    , ASTROPHYSICAL JOURNAL, Vol: 908, ISSN: 0004-637X
  • Journal article
    Agiwal O, Cao H, Cowley SWH, Dougherty MK, Hunt GJ, Muller-Wodarg I, Achilleos Net al., 2021,

    Constraining the Temporal Variability of Neutral Winds in Saturn's Low-Latitude Ionosphere Using Magnetic Field Measurements

    , JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS, Vol: 126, ISSN: 2169-9097
  • Journal article
    Chandler MO, Schwartz SJ, Avanov LA, Coffey VN, Giles BL, Moore TE, Pollock CJ, Burch JL, Russell CT, Torbert RBet al., 2021,

    Observations of Mirror Mode Structures in the Dawn-Side Magnetosphere

    , JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS, Vol: 126, ISSN: 2169-9380
  • Journal article
    Lai T-K, Hendricks EA, Menelaou K, Yau MKet al., 2021,

    Roles of Barotropic Instability across the Moat in Inner Eyewall Decay and Outer Eyewall Intensification: Three-Dimensional Numerical Experiments

    , JOURNAL OF THE ATMOSPHERIC SCIENCES, Vol: 78, Pages: 473-496, ISSN: 0022-4928
  • Journal article
    Shi C, Zhao J, Huang J, Wang T, Wu D, Chen Y, Hu Q, Kasper JC, Bale SDet al., 2021,

    Parker Solar Probe Observations of Alfvenic Waves and Ion-cyclotron Waves in a Small-scale Flux Rope

    , ASTROPHYSICAL JOURNAL LETTERS, Vol: 908, ISSN: 2041-8205
  • Journal article
    Jannet G, de Wit TD, Krasnoselskikh V, Kretzschmar M, Fergeau P, Bergerard-Timofeeva M, Agrapart C, Brochot J-Y, Chalumeau G, Martin P, Revillet C, Bale SD, Maksimovic M, Bowen TA, Brysbaert C, Goetz K, Guilhem E, Harvey PR, Leray V, Lorfevre Eet al., 2021,

    Measurement of Magnetic Field Fluctuations in the Parker Solar Probe and Solar Orbiter Missions

    , JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS, Vol: 126, ISSN: 2169-9380
  • Journal article
    Liggins FS, Pickering JC, Nave G, Kramida A, Gamrath S, Quinet Pet al., 2021,

    New Ritz Wavelengths and Transition Probabilities of Parity-forbidden [Mn II] Lines of Astrophysical Interest

    , ASTROPHYSICAL JOURNAL, Vol: 907, ISSN: 0004-637X
  • Journal article
    Toumi R, Wang S, 2021,

    Recent migration of tropical cyclones toward coasts

    , Science, Vol: 371, Pages: 514-517, ISSN: 0036-8075

    Poleward migrations of tropical cyclones have been observed globally, but their impact on coastal areas remains unclear. We investigated the change in global tropical cyclone activity in coastal regions over the period 1982–2018. We found that the distance of tropical cyclone maximum intensity to land has decreased by about 30 kilometers per decade, and that the annual frequency of global tropical cyclones increases with proximity to land by about two additional cyclones per decade. Trend analysis reveals a robust migration of tropical cyclone activity toward coasts, concurrent with poleward migration of cyclone locations as well as a statistically significant westward shift. This zonal shift of tropical cyclone tracks may be mainly driven by global zonal changes in environmental steering flow.
  • Journal article
    Choi KTH, Brindley H, 2021,

    COVID-19 lockdown air quality change implications for solar energy generation over China

    , Environmental Research Letters, Vol: 16, Pages: 1-10, ISSN: 1748-9326

    We exploit changes in air quality seen during the COVID-19 lockdown over China to show how a cleaner atmosphere has notable co-benefits for solar concentrator photovoltaic energy generation. We use satellite observations and analyses of the atmospheric state to simulate surface broadband and spectrally resolved direct normal irradiance (DNI). Over Wuhan, the first city placed under lockdown, we show how the atmospheric changes not only lead to a 19.8% increase in broadband DNI but also induce a significant blue-shift in the DNI spectrum. Feeding these changes into a solar cell simulator results in a 29.7% increase in the power output for a typical triple-junction photovoltaic cell, with around one-third of the increase arising from enhanced cell efficiency due to improved spectral matching. Our estimates imply that these increases in power and cell efficiency would have been realised over many parts of China during the lockdown period. This study thus demonstrates how a cleaner atmosphere may enable more efficient large scale solar energy generation. We conclude by setting our results in the context of future climate change mitigation and air pollution policies.
  • Journal article
    Bowen TA, Bale SD, Bandyopadhyay R, Bonnell JW, Case A, Chasapis A, Chen CHK, Curry S, de Wit TD, Goetz K, Goodrich K, Gruesbeck J, Halekas J, Harvey PR, Howes GG, Kasper JC, Korreck K, Larson D, Livi R, MacDowall RJ, Malaspina DM, Mallet A, McManus MD, Page B, Pulupa M, Raouafi N, Stevens ML, Whittlesey Pet al., 2021,

    Kinetic-Scale Turbulence in the Venusian Magnetosheath

    , GEOPHYSICAL RESEARCH LETTERS, Vol: 48, ISSN: 0094-8276
  • Journal article
    Heiter U, Lind K, Bergemann M, Asplund M, Mikolaitis S, Barklem PS, Masseron T, de Laverny P, Magrini L, Edvardsson B, Jonsson H, Pickering JC, Ryde N, Aran AB, Bensby T, Casey AR, Feltzing S, Jofre P, Korn AJ, Pancino E, Damiani F, Lanzafame A, Lardo C, Monaco L, Morbidelli L, Smiljanic R, Worley C, Zaggia S, Randich S, Gilmore GFet al., 2021,

    Atomic data for the Gaia-ESO Survey

    , ASTRONOMY & ASTROPHYSICS, Vol: 645, ISSN: 0004-6361
    • Cite
    • Citations: 70
  • Journal article
    Gunell H, Goetz C, Odelstad E, Beth A, Hamrin M, Henri P, Johansson FL, Nilsson H, Wieser GSet al., 2021,

    Ion acoustic waves near a comet nucleus: Rosetta observations at comet 67P/Churyumov-Gerasimenko

    , ANNALES GEOPHYSICAE, Vol: 39, Pages: 53-68, ISSN: 0992-7689
  • Conference paper
    Saboya E, Zazzeri G, Graven H, Manning AJ, Michel SEet al., 2021,

    Continuous CH₄ and δ&amp;sup1;&amp;sup3;CH₄ Measurements in London Demonstrate Under-Reported Natural Gas Leakage
  • Book chapter
    Dunlop MW, Wang TY, Dong XC, Haarland S, Shi QQ, Fu HS, De Keyser J, Shen C, Rong ZJ, Escoubet CP, Pu ZY, Eastwood Jet al., 2021,

    Multispacecraft Measurements in the Magnetosphere

    , Magnetospheres in the Solar System, Pages: 637-656

    This chapter covers a selection of the range of multispacecraft techniques that have been initially developed to analyze Cluster data. We begin the chapter with a short introduction, following this with an account of the methods and their application. The topics are separated into those dealing with magnetic field gradients and topology (which include the curlometer, magnetic rotation analysis, and least squares approach); magnetic field reconstruction and the analysis of magnetic field nulls (which are significant for magnetic reconnection and other geometries); time series analysis, adapted for multispacecraft data (including boundary identification, dimensional, and motion analysis); and wave vector analysis methods in the Fourier domain.
  • Journal article
    Ballinger TJ, Hanna E, Hall RJ, Carr JR, Brasher S, Osterberg EC, Cappelen J, Tedesco M, Ding Q, Mernild SHet al., 2021,

    The role of blocking circulation and emerging open water feedbacks on Greenland cold-season air temperature variability over the last century

    , INTERNATIONAL JOURNAL OF CLIMATOLOGY, Vol: 41, Pages: E2778-E2800, ISSN: 0899-8418
  • Journal article
    Hall RJ, Hanna E, Chen L, 2021,

    Winter Arctic Amplification at the synoptic timescale, 1979-2018, its regional variation and response to tropical and extratropical variability

    , CLIMATE DYNAMICS, Vol: 56, Pages: 457-473, ISSN: 0930-7575
  • Journal article
    Liggins FS, Pickering JC, Nave G, Ward JW, Tchang-Brillet W-ULet al., 2021,

    The Spectrum and Term Analysis of Singly Ionized Manganese

    , ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES, Vol: 252, ISSN: 0067-0049
  • Journal article
    Stawarz JE, Matteini L, Parashar TN, Franci L, Eastwood JP, Gonzalez CA, Gingell IL, Burch JL, Ergun RE, Ahmadi N, Giles BL, Gershman DJ, Le Contel O, Lindqvist P, Russell CT, Strangeway RJ, Torbert RBet al., 2021,

    Comparative analysis of the various generalized Ohm's law terms in magnetosheath turbulence as observed by magnetospheric multiscale

    , Journal of Geophysical Research: Space Physics, Vol: 126, Pages: 1-14, ISSN: 2169-9380

    Decomposing the electric field (E) into the contributions from generalized Ohm's law provides key insight into both nonlinear and dissipative dynamics across the full range of scales within a plasma. Using high‐resolution, multi‐spacecraft measurements of three intervals in Earth's magnetosheath from the Magnetospheric Multiscale mission, the influence of the magnetohydrodynamic, Hall, electron pressure, and electron inertia terms from Ohm's law, as well as the impact of a finite electron mass, on the turbulent E spectrum are examined observationally for the first time. The magnetohydrodynamic, Hall, and electron pressure terms are the dominant contributions to E over the accessible length scales, which extend to scales smaller than the electron inertial length at the greatest extent, with the Hall and electron pressure terms dominating at sub‐ion scales. The strength of the non‐ideal electron pressure contribution is stronger than expected from linear kinetic Alfvén waves and a partial anti‐alignment with the Hall electric field is present, linked to the relative importance of electron diamagnetic currents in the turbulence. The relative contribution of linear and nonlinear electric fields scale with the turbulent fluctuation amplitude, with nonlinear contributions playing the dominant role in shaping E for the intervals examined in this study. Overall, the sum of the Ohm's law terms and measured E agree to within ∼ 20% across the observable scales. These results both confirm general expectations about the behavior of E in turbulent plasmas and highlight features that should be explored further theoretically.
  • Journal article
    Hanna E, Cappelen J, Fettweis X, Mernild SH, Mote TL, Mottram R, Steffen K, Ballinger TJ, Hall Ret al., 2021,

    Greenland surface air temperature changes from 1981 to 2019 and implications for ice-sheet melt and mass-balance change

    , INTERNATIONAL JOURNAL OF CLIMATOLOGY, Vol: 41, Pages: E1336-E1352, ISSN: 0899-8418
  • Conference paper
    Kromyda L, Malaspina DM, Ergun RE, Halekas J, Stevens ML, Verniero J, Chasapis A, Vech D, Bale SD, Bonnell JW, de Wit TD, Goetz K, Goodrich K, Harvey PR, MacDowall RJ, Pulupa M, Case AW, Kasper JC, Korreck KE, Larson D, Livi R, Whittlesey Pet al., 2021,

    Electrostatic Waves with Rapid Frequency Shifts in the Solar Wind from PSP observations

    , United-States-National-Committee-of-URSI National Radio Science Meeting (USNC-URSI NRSM), Publisher: IEEE, Pages: 220-221
  • Book chapter
    Nilsson H, Behar E, Burch JL, Carr CM, Eriksson AI, Glassmeier K-H, Henri P, Galand M, Goetz C, Gunell H, Karlsson Tet al., 2021,

    Birth of a Magnetosphere

    , MAGNETOSPHERES IN THE SOLAR SYSTEM, Editors: Maggiolo, Andre, Hasegawa, Welling, Zhang, Paxton, Publisher: AMER GEOPHYSICAL UNION, Pages: 427-439, ISBN: 978-1-119-50752-9
  • Book chapter
    Keeling RF, Graven HD, 2021,

    Insights from Time Series of Atmospheric Carbon Dioxide and Related Tracers

    , ANNUAL REVIEW OF ENVIRONMENT AND RESOURCES, VOL 46, 2021, Editors: Gadgil, Tomich, Publisher: ANNUAL REVIEWS, Pages: 85-110
    • Cite
    • Citations: 12
  • Conference paper
    Valsamis A, Carr C, Rosenberg J, Unterman NA, Dallal T, Matten M, Miller J, Schur E, Sears A, Adams Met al., 2021,

    High School Students' Cosmic Ray Measurements During a Total Solar Eclipse

    , 36th International Cosmic Ray Conference (ICRC), Publisher: SISSA Medialab
  • Conference paper
    Adams M, Unterman N, Carr C, Rosenberg J, Valsamis A, Dallal T, Matten M, Miller J, Schur E, Sears Aet al., 2021,

    QuarkNet Coordination of a Cosmic Ray Experiment Outreach Project During a Total Solar Eclipse

    , 36th International Cosmic Ray Conference (ICRC), Publisher: SISSA Medialab

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