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  • Journal article
    Nair R, Halekas JS, Whittlesey PL, Larson DE, Livi R, Berthomier M, Kasper JC, Case AW, Stevens ML, Bale SD, MacDowall RJ, Pulupa MPet al., 2022,

    Switchbacks in the Young Solar Wind: Electron Evolution Observed inside Switchbacks between 0.125 au and 0.25 au

    , ASTROPHYSICAL JOURNAL, Vol: 936, ISSN: 0004-637X
  • Journal article
    Halekas JS, Whittlesey P, Larson DE, Maksimovic M, Livi R, Berthomier M, Kasper JC, Case AW, Stevens ML, Bale SD, MacDowall RJ, Pulupa MPet al., 2022,

    The Radial Evolution of the Solar Wind as Organized by Electron Distribution Parameters

    , ASTROPHYSICAL JOURNAL, Vol: 936, ISSN: 0004-637X
    • Cite
    • Citations: 32
  • Journal article
    Tigik SF, Vaivads A, Malaspina DM, Bale SDet al., 2022,

    Parker Solar Probe Observations of Near-<i>f</i> <sub>Ce</sub> Harmonic Emissions in the Near-Sun Solar Wind and Their Dependence on the Magnetic Field Direction

    , ASTROPHYSICAL JOURNAL, Vol: 936, ISSN: 0004-637X
  • Conference paper
    Lewis Z, Beth A, Altwegg K, Eriksson A, Galand M, Götz C, Henri P, Héritier K, O'Rourke L, Richter I, Rubin M, Stephenson P, Vallieres Xet al., 2022,

    Ionospheric composition of comet 67P near perihelion with multi-instrument Rosetta datasets

    , Publisher: Copernicus GmbH

    <jats:p>&amp;lt;p&amp;gt;The European Space Agency Rosetta mission escorted comet 67P/Churyumov-Gerasimenko for two years, during which it acquired an extensive dataset, revealing unprecedented detail about the neutral and plasma environment of the coma. The measurements were made over a large range of heliocentric distances, and therefore of outgassing activities, as Rosetta witnessed 67P evolve from a low-activity icy body at 3.8 AU to a dynamic object with large-scale plasma structures and rich ion and neutral chemistry near perihelion at 1.2 AU. One such plasma structure is the diamagnetic cavity, a region of negligible magnetic field surrounding the comet nucleus. It is formed through the interaction of the unmagnetized outwardly expanding cometary plasma with the incoming solar wind. This region was encountered many times by Rosetta between April 2015 and February 2016, as the comet moved towards and away from perihelion.&amp;lt;/p&amp;gt;&amp;lt;p&amp;gt;In this study, we focus on the changing role of chemistry during the escort phase, particularly on trends in the detection of high proton affinity species near perihelion and within the diamagnetic cavity. NH&amp;lt;sub&amp;gt;4&amp;lt;/sub&amp;gt;&amp;lt;sup&amp;gt;+&amp;lt;/sup&amp;gt; is produced through the protonation of NH&amp;lt;sub&amp;gt;3&amp;lt;/sub&amp;gt; which has the highest proton affinity of the neutral species and is therefore the terminal ion. The ratio of this species to the major ion species H&amp;lt;sub&amp;gt;3&amp;lt;/sub&amp;gt;O&amp;lt;sup&amp;gt;+&amp;lt;/sup&amp;gt; can then be an indicator of the importance of ion-neutral chemistry as an ion loss process compared to transport. We use data from the high resolution mode of the ROSINA (Rosetta Orbital Spectrometer for Ion-Neutral Analysis)/DFMS (Double Focussing Mass Spectrometer) instrument, which allows certain ions of the
  • Journal article
    Aizawa S, Persson M, Menez T, Andre N, Modolo R, Genot V, Sanchez-Cano B, Volwerk M, Chaufray J-Y, Baskevitch C, Heyner D, Saito Y, Harada Y, Leblanc F, Barthe A, Penou E, Fedorov A, Sauvaud J-A, Yokota S, Auster U, Richter I, Mieth J, Horbury TS, Louarn P, Owen CJ, Murakami Get al., 2022,

    LatHyS global hybrid simulation of the BepiColombo second Venus flyby

    , PLANETARY AND SPACE SCIENCE, Vol: 218, ISSN: 0032-0633
  • Journal article
    Ding M, Pickering JC, 2022,

    Comment on: "Hyperfine structure measurements of Co I and Co II with Fourier transform spectroscopy" by Fu et al. [JQSRT 2021, 107590]

    , JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER, Vol: 288, ISSN: 0022-4073
  • Journal article
    Franci L, Papini E, Del Sarto D, Hellinger P, Burgess D, Matteini L, Landi S, Montagud-Camps Vet al., 2022,

    Plasma Turbulence in the Near-Sun and Near-Earth Solar Wind: A Comparison via Observation-Driven 2D Hybrid Simulations

    , UNIVERSE, Vol: 8
  • Journal article
    Teoh R, Schumann U, Gryspeerdt E, Shapiro M, Molloy J, Koudis G, Voigt C, Stettler MEJet al., 2022,

    Aviation contrail climate effects in the North Atlantic from 2016 to 2021

    , Atmospheric Chemistry and Physics, Vol: 22, Pages: 10919-10935, ISSN: 1680-7316

    Around 5 % of anthropogenic radiative forcing (RF) is attributed to aviation CO2 and non-CO2 impacts. This paper quantifies aviation emissions and contrail climate forcing in the North Atlantic, one of the world's busiest air traffic corridors, over 5 years. Between 2016 and 2019, growth in CO2 (+3.13 % yr−1) and nitrogen oxide emissions (+4.5 % yr−1) outpaced increases in flight distance (+3.05 % yr−1). Over the same period, the annual mean contrail cirrus net RF (204–280 mW m−2) showed significant inter-annual variability caused by variations in meteorology. Responses to COVID-19 caused significant reductions in flight distance travelled (−66 %), CO2 emissions (−71 %) and the contrail net RF (−66 %) compared with the prior 1-year period. Around 12 % of all flights in this region cause 80 % of the annual contrail energy forcing, and the factors associated with strongly warming/cooling contrails include seasonal changes in meteorology and radiation, time of day, background cloud fields, and engine-specific non-volatile particulate matter (nvPM) emissions. Strongly warming contrails in this region are generally formed in wintertime, close to the tropopause, between 15:00 and 04:00 UTC, and above low-level clouds. The most strongly cooling contrails occur in the spring, in the upper troposphere, between 06:00 and 15:00 UTC, and without lower-level clouds. Uncertainty in the contrail cirrus net RF (216–238 mW m−2) arising from meteorology in 2019 is smaller than the inter-annual variability. The contrail RF estimates are most sensitive to the humidity fields, followed by nvPM emissions and aircraft mass assumptions. This longitudinal evaluation of aviation contrail impacts contributes a quantified understanding of inter-annual variability and informs strategies for contrail mitigation.
  • Journal article
    Sharan S, Langlais B, Amit H, Thebault E, Pinceloup M, Verhoeven Oet al., 2022,

    The Internal Structure and Dynamics of Jupiter Unveiled by a High-Resolution Magnetic Field and Secular Variation Model

    , GEOPHYSICAL RESEARCH LETTERS, Vol: 49, ISSN: 0094-8276
    • Cite
    • Citations: 13
  • Journal article
    Wang S, Toumi R, 2022,

    Author Correction: On the intensity decay of tropical cyclones before landfall.

    , Sci Rep, Vol: 12
  • Journal article
    Rasca AP, Farrell WM, Whittlesey PL, MacDowall RJ, Bale SD, Kasper JCet al., 2022,

    Magnetic Field Dropouts and Associated Plasma Wave Emission near the Electron Plasma Frequency at Switchback Boundaries as Observed by the Parker Solar Probe

    , ASTROPHYSICAL JOURNAL, Vol: 935, ISSN: 0004-637X
  • Journal article
    Telloni D, Zank GP, Sorriso-Valvo L, D'Amicis R, Panasenco O, Susino R, Bruno R, Perrone D, Adhikari L, Liang H, Nakanotani M, Zhao L, Hadid LZ, Sanchez-Cano B, Verscharen D, Velli M, Grimani C, Marino R, Carbone F, Mancuso S, Biondo R, Pagano P, Reale F, Bale SD, Kasper JC, Case AW, de Wit TD, Goetz K, Harvey PR, Korreck KE, Larson D, Livi R, MacDowall RJ, Malaspina DM, Pulupa M, Stevens ML, Whittlesey P, Romoli M, Andretta V, Da Deppo V, Fineschi S, Heinzel P, Moses JD, Naletto G, Nicolini G, Spadaro D, Stangalini M, Teriaca L, Capobianco G, Capuano GE, Casini C, Casti M, Chioetto P, Corso AJ, De Leo Y, Fabi M, Frassati F, Frassetto F, Giordano S, Guglielmino SL, Jerse G, Landini F, Liberatore A, Magli E, Massone G, Messerotti M, Pancrazzi M, Pelizzo MG, Romano P, Sasso C, Schuhle U, Slemer A, Straus T, Uslenghi M, Volpicelli CA, Zangrilli L, Zuppella P, Abbo L, Auchere F, Cuadrado RA, Berlicki A, Ciaravella A, Lamy P, Lanzafame A, Malvezzi M, Nicolosi P, Nistico G, Peter H, Solanki SK, Strachan L, Tsinganos K, Ventura R, Vial J-C, Woch J, Zimbardo Get al., 2022,

    Linking Small-scale Solar Wind Properties with Large-scale Coronal Source Regions through Joint Parker Solar Probe-Metis/Solar Orbiter Observations

    , ASTROPHYSICAL JOURNAL, Vol: 935, ISSN: 0004-637X
    • Cite
    • Citations: 12
  • Journal article
    Sioulas N, Huang Z, Velli M, Chhiber R, Cuesta ME, Shi C, Matthaeus WH, Bandyopadhyay R, Vlahos L, Bowen TA, Qudsi RA, Bale SD, Owen CJ, Louarn P, Fedorov A, Maksimovic M, Stevens ML, Case A, Kasper J, Larson D, Pulupa M, Livi Ret al., 2022,

    Magnetic Field Intermittency in the Solar Wind: Parker Solar Probe and SolO Observations Ranging from the Alfven Region up to 1 AU

    , ASTROPHYSICAL JOURNAL, Vol: 934, ISSN: 0004-637X
    • Cite
    • Citations: 20
  • Journal article
    Shi C, Panasenco O, Velli M, Tenerani A, Verniero JL, Sioulas N, Huang Z, Brosius A, Bale SD, Klein K, Kasper J, de Wit TD, Goetz K, Harvey PR, MacDowall RJ, Malaspina DM, Pulupa M, Larson D, Livi R, Case A, Stevens Met al., 2022,

    Patches of Magnetic Switchbacks and Their Origins

    , ASTROPHYSICAL JOURNAL, Vol: 934, ISSN: 0004-637X
    • Cite
    • Citations: 25
  • Journal article
    Zhao L-L, Zank GP, Adhikari L, Telloni D, Stevens M, Kasper JC, Bale SD, Raouafi NEet al., 2022,

    Turbulence and Waves in the Sub-Alfvenic Solar Wind Observed by the Parker Solar Probe during Encounter 10

    , ASTROPHYSICAL JOURNAL LETTERS, Vol: 934, ISSN: 2041-8205
    • Cite
    • Citations: 25
  • Journal article
    Ergun RE, Pathak N, Usanova ME, Qi Y, Vo T, Burch JL, Schwartz SJ, Torbert RB, Ahmadi N, Wilder FD, Chasipis A, Newman DL, Stawarz JE, Hesse M, Turner DL, Gershman Det al., 2022,

    Observation of Magnetic Reconnection in a Region of Strong Turbulence

    , ASTROPHYSICAL JOURNAL LETTERS, Vol: 935, ISSN: 2041-8205
    • Cite
    • Citations: 19
  • Journal article
    Sulaiman A, Mauk B, Szalay J, Allegrini F, Clark G, Gladstone R, Kotsiaros, Kurth W, Bagenal F, Bonfond B, Connerney J, Ebert R, Elliott S, Gershman D, Hospodarsky G, Hue V, Lysak R, Masters A, Santolik, Saur J, Bolton Set al., 2022,

    Jupiter’s low-altitude auroral zones: Fields, particles, plasma waves, and density depletions

    , Journal of Geophysical Research: Space Physics, Vol: 127, ISSN: 2169-9380

    The Juno spacecraft's polar orbits have enabled direct sampling of Jupiter's low-altitude auroral field lines. While various data sets have identified unique features over Jupiter's main aurora, they are yet to be analyzed altogether to determine how they can be reconciled and fit into the bigger picture of Jupiter's auroral generation mechanisms. Jupiter's main aurora has been classified into distinct “zones”, based on repeatable signatures found in energetic electron and proton spectra. We combine fields, particles, and plasma wave data sets to analyze Zone-I and Zone-II, which are suggested to carry upward and downward field-aligned currents, respectively. We find Zone-I to have well-defined boundaries across all data sets. H+ and/or H3+ cyclotron waves are commonly observed in Zone-I in the presence of energetic upward H+ beams and downward energetic electron beams. Zone-II, on the other hand, does not have a clear poleward boundary with the polar cap, and its signatures are more sporadic. Large-amplitude solitary waves, which are reminiscent of those ubiquitous in Earth's downward current region, are a key feature of Zone-II. Alfvénic fluctuations are most prominent in the diffuse aurora and are repeatedly found to diminish in Zone-I and Zone-II, likely due to dissipation, at higher altitudes, to energize auroral electrons. Finally, we identify significant electron density depletions, by up to 2 orders of magnitude, in Zone-I, and discuss their important implications for the development of parallel potentials, Alfvénic dissipation, and radio wave generation.
  • Journal article
    Clear CP, Pickering JC, Nave G, Uylings P, Raassen Tet al., 2022,

    Wavelengths and energy levels of singly ionized nickel (Ni ii) measured using fourier transform spectroscopy

    , The Astrophysical Journal Supplement Series, Vol: 261, Pages: 35-35, ISSN: 0067-0049

    High-resolution spectra of singly ionized nickel (Ni ii) have been recorded using Fourier transform spectroscopy in the region 143–5555 nm (1800–70,000 cm−1) with continuous, nickel–helium hollow cathode discharge sources. An extensive analysis of identified Ni ii lines resulted in the confirmation and revision of 283 previously reported energy levels, from the ground state up to the 3d8(ML)6s subconfigurations. Typical energy-level uncertainties are a few thousandths of a cm−1, representing at least an order-of-magnitude reduction in uncertainty with respect to previous measurements. Twenty-five new energy levels have now been established and are reported here for the first time. Eigenvector compositions of the energy levels have been calculated using the orthogonal operator method. In total, 159 even and 149 odd energy levels and 1424 classified line wavelengths of Ni ii are reported and will enable more accurate and reliable analyses of Ni ii in astrophysical spectra.
  • Journal article
    Park C, Shin S-W, Kim G, Cha D-H, Min S-K, Lee D, Byun Y-H, Kim J-Uet al., 2022,

    What determines future changes in photovoltaic potential over East Asia? (vol 185, pg 338, 2022)

    , RENEWABLE ENERGY, Vol: 195, Pages: 1480-1480, ISSN: 0960-1481
  • Journal article
    Brunmayr AS, Graven H, 2022,

    Comment on “Probability Distributions of Radiocarbon in Open Linear Compartmental Systems at Steady-State” by I. Chanca, S. Trumbore, K. Macario, and C. A. Sierra

    <jats:p>Chanca et al. (2022) construct radiocarbon (14C) distributions forcompartmental ecosystem models and compare them to the variability ofmeasured 14C data for soil respiration. However, their 14C distributionsdo not represent a measurable quantity and may not be used to draw anyconclusions on the variability of 14C measurements.</jats:p>
  • Journal article
    Schwartz SJ, Goodrich KA, III LBW, Turner DL, Trattner K, Kucharek H, Gingell I, Fuselier SA, Cohen IJ, Madanian H, Ergun RE, Gershman DJ, Strangeway RJet al., 2022,

    Energy partition at collisionless supercritical quasiperpendicular shocks

    <jats:p>Collisionless shocks in astrophysical plasmas are importantthermalizers, converting some of the incident flow energy into thermalenergy, and non-thermalizers, partitioning that energy in unequal waysto different particle species, sub-populations thereof, and fieldcomponents. This partition problem, or equivalently the shock equationof state, lies at the heart of shock physics. Here we employsystematically a framework to capture all the incident and downstreamenergy fluxes at two example traversals of the Earth's bow shock by theMagnetospheric Multiscale Mission. Here and traditionally such data hasto be augmented by information from other spacecraft, e.g., to providemore accurate measurements of the cold solar wind beam. With some careand fortuitous choices, the energy fluxes are constant, includinginstantaneous measurements through the shock layer. The dominantincident proton ram energy is converted primarily into downstream protonenthalpy flux, the majority of which is actually carried by a smallfraction of suprathermal protons. Fluctuations include both real andinstrumental effects. Separating these, resolving the solar wind beam,and other considerations point the way to a dedicated mission to solvethis energy partition problem across a full range of plasma and shockconditions.</jats:p>
  • Journal article
    Graven H, Keeling R, Xu X, 2022,

    Radiocarbon dating: going back in time

    , NATURE, Vol: 607, Pages: 449-449, ISSN: 0028-0836
  • Journal article
    Fargette N, Lavraud B, Rouillard AP, Reville V, Bale SD, Kasper Jet al., 2022,

    The preferential orientation of magnetic switchbacks and its implications for solar magnetic flux transport

    , ASTRONOMY & ASTROPHYSICS, Vol: 663, ISSN: 0004-6361
    • Cite
    • Citations: 21
  • Journal article
    Kilpua EKJ, Good SW, Ala-Lahti M, Osmane A, Pal S, Soljento JE, Zhao LL, Bale Set al., 2022,

    Structure and fluctuations of a slow ICME sheath observed at 0.5 au by the Parker Solar Probe

    , ASTRONOMY & ASTROPHYSICS, Vol: 663, ISSN: 0004-6361
  • Journal article
    Davies EE, Winslow RM, Scolini C, Forsyth RJ, Moestl C, Lugaz N, Galvin ABet al., 2022,

    Multi-spacecraft Observations of the Evolution of Interplanetary Coronal Mass Ejections between 0.3 and 2.2 au: Conjunctions with the Juno Spacecraft

    , ASTROPHYSICAL JOURNAL, Vol: 933, ISSN: 0004-637X
  • Journal article
    Trotta D, Pecora F, Settino A, Perrone D, Hietala H, Horbury T, Matthaeus W, Burgess D, Servidio S, Valentini Fet al., 2022,

    On the Transmission of Turbulent Structures across the Earth's Bow Shock

    , ASTROPHYSICAL JOURNAL, Vol: 933, ISSN: 0004-637X
  • Journal article
    Tsui EYL, Toumi R, 2022,

    Pacific subsurface temperature as a long‐range indicator of El Niño, regional precipitation, and fire

    , Quarterly Journal of the Royal Meteorological Society, Vol: 148, Pages: 2102-2117, ISSN: 0035-9009

    The SubNiño4 index based on the subsurface potential temperature around the thermocline beneath the west Pacific warm pool, the Niño 4 region, is examined as a long-range indicator of the surface El Niño–Southern Oscillation (ENSO) and ENSO-driven atmospheric response. The SubNiño4 index captures the evolution of subsurface ocean heat content between the El Niño and La Niña phases of the ENSO cycle, allowing it to serve as a long-range indicator of surface ENSO and hence also many ENSO-driven atmospheric anomalies. The SubNiño4 index has more temporally stable correlations with Niño 3.4 than the widely used western equatorial Pacific warm-water volume indicator. For a lead time of the order of 12 months, Niño 3.4 correlations afforded by the lead observed SubNiño4 index become similar to and can exceed those produced by typical dynamical ENSO predictions. The value and viability of the SubNiño4 index as a simple statistical long-range indicator of ENSO-driven atmospheric response is shown for regional precipitation anomalies throughout the Tropics and fires in Continental and Maritime Southeast Asia.
  • Journal article
    Gangopadhyay A, Seshadri AK, Sparks NJ, Toumi Ret al., 2022,

    The role of wind-solar hybrid plants in mitigating renewable energy-droughts

    , Renewable Energy, Vol: 194, Pages: 926-937, ISSN: 0960-1481

    Increasing the share of weather-dependent renewables in the electricity grid is essential to deeply decarbonize the electricity system. Wind and solar “droughts” or low generation days can severely impact grid stability in a renewable-rich grid. This paper analyzes for the first time wind, solar, and hybrid energy-droughts in India using a stochastic weather generator. Available literature analyze the observational data that is of limited duration (30–40 years). Therefore, discussion of low-probability high-impact renewable energy-droughts that have long return periods (in the range of 30 years) is limited in the literature. The present study seeks to address this research gap by exploring the risk of wind, solar, and wind-solar powered energy-droughts based on simulated long time series (5000 years). It is found that the weather generator captures mean, seasonality, and correlation between wind speed and solar irradiance and is therefore used to estimate return periods of extreme wind and solar-droughts. Our analysis shows that wind-droughts are more intense than solar-droughts in India. We examine the role that wind-solar hybridization can play in offsetting low wind energy episodes. The benefits of hybridization are regionally dependent. In South India, hybrid plants have advantages over either wind or solar plants alone. In comparison, for Rajasthan, the benefits of hybridization are limited. When one of the regions (South India or Rajasthan) has a renewable drought, the other region has only a 10% probability of having a similar drought. Our findings highlight the need for having robust inter-regional grid connections to mitigate regional level renewable droughts.
  • Journal article
    Gryspeerdt E, McCoy DT, Crosbie E, Moore RH, Nott GJ, Painemal D, Small-Griswold J, Sorooshian A, Ziemba Let al., 2022,

    The impact of sampling strategy on the cloud droplet number concentration estimated from satellite data

    , Atmospheric Measurement Techniques, Vol: 15, Pages: 3875-3892, ISSN: 1867-1381

    Cloud droplet number concentration (Nd) is of central importance to observation-based estimates of aerosol indirect effects, being used to quantify both the cloud sensitivity to aerosol and the base state of the cloud. However, the derivation of Nd from satellite data depends on a number of assumptions about the cloud and the accuracy of the retrievals of the cloud properties from which it is derived, making it prone to systematic biases.A number of sampling strategies have been proposed to address these biases by selecting the most accurate Nd retrievals in the satellite data. This work compares the impact of these strategies on the accuracy of the satellite retrieved Nd, using a selection of in situ measurements. In stratocumulus regions, the MODIS Nd retrieval is able to achieve a high precision (r2 of 0.5–0.8). This is lower in other cloud regimes but can be increased by appropriate sampling choices. Although the Nd sampling can have significant effects on the Nd climatology, it produces only a 20 % variation in the implied radiative forcing from aerosol–cloud interactions, with the choice of aerosol proxy driving the overall uncertainty. The results are summarised into recommendations for using MODIS Nd products and appropriate sampling.
  • Journal article
    McManus MD, Verniero J, Bale SD, Bowen TA, Larson DE, Kasper JC, Livi R, Matteini L, Rahmati A, Romeo O, Whittlesey P, Woolley Tet al., 2022,

    Density and Velocity Fluctuations of Alpha Particles in Magnetic Switchbacks

    , ASTROPHYSICAL JOURNAL, Vol: 933, ISSN: 0004-637X
    • Cite
    • Citations: 15

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