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  • Journal article
    Breneman AW, Wygant JR, Tian S, Cattell CA, Thaller SA, Goetz K, Tyler E, Colpitts C, Dai L, Kersten K, Bonnell JW, Bale SD, Mozer FS, Harvey PR, Dalton G, Ergun RE, Malaspina DM, Kletzing CA, Kurth WS, Hospodarsky GB, Smith C, Holzworth RH, Lejosne S, Agapitov O, Artemyev A, Hudson MK, Strangeway RJ, Baker DN, Li X, Albert J, Foster JC, Erickson PJ, Chaston CC, Mann I, Donovan E, Cully CM, Krasnoselskikh V, Blake JB, Millan R, Halford AJet al., 2022,

    The Van Allen Probes Electric Field and Waves Instrument: Science Results, Measurements, and Access to Data (Vol 218, 69, 2022)

    , SPACE SCIENCE REVIEWS, Vol: 218, ISSN: 0038-6308
  • Journal article
    Goetz C, Behar E, Beth A, Bodewits D, Bromley S, Burch J, Deca J, Divin A, Eriksson AI, Feldman PD, Galand M, Gunell H, Henri P, Heritier K, Jones GH, Mandt KE, Nilsson H, Noonan JW, Odelstad E, Parker JW, Rubin M, Simon Wedlund C, Stephenson P, Taylor MGGT, Vigren E, Vines SK, Volwerk Met al., 2022,

    The plasma environment of comet 67P/Churyumov-Gerasimenko

    , Space Science Reviews, Vol: 218, Pages: 1-120, ISSN: 0038-6308

    The environment of a comet is a fascinating and unique laboratory to study plasma processes and the formation of structures such as shocks and discontinuities from electron scales to ion scales and above. The European Space Agency’s Rosetta mission collected data for more than two years, from the rendezvous with comet 67P/Churyumov-Gerasimenko in August 2014 until the final touch-down of the spacecraft end of September 2016. This escort phase spanned a large arc of the comet’s orbit around the Sun, including its perihelion and corresponding to heliocentric distances between 3.8 AU and 1.24 AU. The length of the active mission together with this span in heliocentric and cometocentric distances make the Rosetta data set unique and much richer than sets obtained with previous cometary probes. Here, we review the results from the Rosetta mission that pertain to the plasma environment. We detail all known sources and losses of the plasma and typical processes within it. The findings from in-situ plasma measurements are complemented by remote observations of emissions from the plasma. Overviews of the methods and instruments used in the study are given as well as a short review of the Rosetta mission. The long duration of the Rosetta mission provides the opportunity to better understand how the importance of these processes changes depending on parameters like the outgassing rate and the solar wind conditions. We discuss how the shape and existence of large scale structures depend on these parameters and how the plasma within different regions of the plasma environment can be characterised. We end with a non-exhaustive list of still open questions, as well as suggestions on how to answer them in the future.
  • Journal article
    Shi C, Velli M, Bale SD, Reville V, Maksimovic M, Dakeyo J-Bet al., 2022,

    Acceleration of polytropic solar wind: Parker Solar Probe observation and one-dimensional model

    , PHYSICS OF PLASMAS, Vol: 29, ISSN: 1070-664X
  • Journal article
    Breneman AW, Wygant JR, Tian S, Cattell CA, Thaller SA, Goetz K, Tyler E, Colpitts C, Dai L, Kersten K, Bonnell JW, Bale SD, Mozer FS, Harvey PR, Dalton G, Ergun RE, Malaspina DM, Kletzing CA, Kurth WS, Hospodarsky GB, Smith C, Holzworth RH, Lejosne S, Agapitov O, Artemyev A, Hudson MK, Strangeway RJ, Baker DN, Li X, Albert J, Foster JC, Erickson PJ, Chaston CC, Mann I, Donovan E, Cully CM, Krasnoselskikh V, Blake JB, Millan Ret al., 2022,

    The Van Allen Probes Electric Field and Waves Instrument: Science Results, Measurements, and Access to Data

    , SPACE SCIENCE REVIEWS, Vol: 218, ISSN: 0038-6308
  • Journal article
    Fowler CM, Hanley KG, McFadden J, Halekas J, Schwartz SJ, Mazelle C, Chaffin M, Mitchell D, Espley J, Ramstad R, Dong Y, Curry Set al., 2022,

    A MAVEN Case Study of Radial IMF at Mars: Impacts on the Dayside Ionosphere

    , JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS, Vol: 127, ISSN: 2169-9380
  • Journal article
    Benseguane S, Guilbert-Lepoutre A, Lasue J, Besse S, Leyrat C, Beth A, Sitja MC, Grieger B, Capria MTet al., 2022,

    Evolution of pits at the surface of 67P/Churyumov-Gerasimenko

    , Astronomy and Astrophysics: a European journal, Vol: 668, ISSN: 0004-6361

    Context. The observation of pits at the surface of comets offers the opportunity to take a glimpse into the properties and the mechanisms that shape a nucleus through cometary activity. If the origin of these pits is still a matter of debate, multiple studies have recently suggested that known phase transitions (such as volatile sublimation or amorphous water ice crystallization) alone could not have carved these morphological features on the surface of 67P/Churyumov-Gerasimenko (hereafter 67P).Aims. We want to understand how the progressive modification of 67P’s surface due to cometary activity might have affected the characteristics of pits and alcoves. In particular, we aim to understand whether signatures of the formation mechanism of these surface morphological features can still be identified.Methods. To quantify the amount of erosion sustained at the surface of 67P since it arrived on its currently observed orbit, we selected 380 facets of a medium-resolution shape model of the nucleus, sampling 30 pits and alcoves across the surface. We computed the surface energy balance with a high temporal resolution, including shadowing and self-heating contributions. We then applied a thermal evolution model to assess the amount of erosion sustained after ten orbital revolutions under current illumination conditions.Results. We find that the maximum erosion sustained after ten orbital revolutions is on the order of 80 m, for facets located in the southern hemisphere. We thus confirm that progressive erosion cannot form pits and alcoves, as local erosion is much lower than their observed depth and diameter. We find that plateaus tend to erode more than bottoms, especially for the deepest depressions, and that some differential erosion can affect their morphology. As a general rule, our results suggest that sharp morphological features tend to be erased by progressive erosion.Conclusions. This study supports the assumption that deep circular pits, such as Seth_01, a
  • Journal article
    Arola A, Lipponen A, Kolmonen P, Virtanen TH, Bellouin N, Grosvenor DP, Gryspeerdt E, Quaas J, Kokkola Het al., 2022,

    Aerosol effects on clouds are concealed by natural cloud heterogeneity and satellite retrieval errors

    , Nature Communications, Vol: 13, Pages: 1-8, ISSN: 2041-1723

    One major source of uncertainty in the cloud-mediated aerosol forcing arises from the magnitude of the cloud liquid water path (LWP) adjustment to aerosol-cloud interactions, which is poorly constrained by observations. Many of the recent satellite-based studies have observed a decreasing LWP as a function of cloud droplet number concentration (CDNC) as the dominating behavior. Estimating the LWP response to the CDNC changes is a complex task since various confounding factors need to be isolated. However, an important aspect has not been sufficiently considered: the propagation of natural spatial variability and errors in satellite retrievals of cloud optical depth and cloud effective radius to estimates of CDNC and LWP. Here we use satellite and simulated measurements to demonstrate that, because of this propagation, even a positive LWP adjustment is likely to be misinterpreted as negative. This biasing effect therefore leads to an underestimate of the aerosol-cloud-climate cooling and must be properly considered in future studies.
  • Journal article
    Wang B, Nishimura Y, Hietala H, Angelopoulos Vet al., 2022,

    Investigating the Role of Magnetosheath High-Speed Jets in Triggering Dayside Ground Magnetic Ultra-Low Frequency Waves

    , GEOPHYSICAL RESEARCH LETTERS, Vol: 49, ISSN: 0094-8276
  • Journal article
    Wilson LB, Goodrich KA, Turner DL, Cohen IJ, Whittlesey PL, Schwartz SJet al., 2022,

    The need for accurate measurements of thermal velocity distribution functions in the solar wind

    , FRONTIERS IN ASTRONOMY AND SPACE SCIENCES, Vol: 9, ISSN: 2296-987X
  • Journal article
    Wimmer-Schweingruber RF, Andre N, Barabash S, Brandt PC, Horbury TS, Iess L, Lavraud B, McNutt RL, Provornikova EA, Quemerais E, Wicks R, Wieser M, Wurz Pet al., 2022,

    STELLA-Potential European contributions to a NASA-led interstellar probe

    , FRONTIERS IN ASTRONOMY AND SPACE SCIENCES, Vol: 9, ISSN: 2296-987X
  • Book chapter
    Beth A, Galand M, Simon Wedlund C, Eriksson Aet al., 2022,

    Cometary Ionospheres: An Updated Tutorial

    , Comets III, Editors: Meech, Combi, Publisher: University of Arizona Press

    This chapter aims at providing the tools and knowledge to understand and model the plasma environment surrounding comets in the innermost part near the nucleus. In particular, our goal is to give an updated post-Rosetta view of this ionised environment: what we knew, what we confirmed, what we overturned, and what we still do not understand.
  • Journal article
    Short B, Malaspina DMM, Halekas J, Romeo O, Verniero JL, Finley AJJ, Kasper JCC, Rahmati A, Bale SDD, Bonnell JWW, Case AWW, de Wit TD, Goetz K, Goodrich K, Harvey PRR, Korreck KEE, Larson D, Livi RJ, MacDowall RJ, Pulupa M, Stevens MLL, Whittlesey Pet al., 2022,

    Observations of Quiescent Solar Wind Regions with Near-<i>f</i> <sub>ce</sub> Wave Activity

    , ASTROPHYSICAL JOURNAL, Vol: 940, ISSN: 0004-637X
  • Journal article
    Maunder ML, Foullon C, Forsyth R, Barnes D, Davies Jet al., 2022,

    Multi-Spacecraft Observations of an Interplanetary Coronal Mass Ejection Interacting with Two Solar-Wind Regimes Observed by the Ulysses and Twin-STEREO Spacecraft

    , Solar Physics, Vol: 297, ISSN: 0038-0938

    We present a combined study of a coronal mass ejection (CME), revealed in a unique orbital configuration that permits the analysis of remote-sensing observations on 27 June 2007 from the twin Solar Terrestrial Relations Observatory (STEREO)-A and -B spacecraft and of its subsequent in situ counterpart outside the ecliptic plane, the interplanetary coronal mass ejection (ICME) observed on 04 July 2007 by Ulysses at 1.5 AU and heliographic-Earth-ecliptic coordinates system (HEE) 33° latitude and 49° longitude. We apply a triangulation method to the STEREO Sun Earth Connection Coronal and Heliospheric Investigation (SECCHI) COR2 coronagraph images of the CME, and a self-similar expansion fitting method to STEREO/SECCHI Heliospheric Imager (HI)-B. At Ulysses we observe: a preceding forward shock, followed by a sheath region, a magnetic cloud, a rear forward shock, followed by a compression region due to a succeeding high-speed stream (HSS) interacting with the ICME. From a minimum variance analysis (MVA) and a length-scale analysis we infer that the magnetic cloud at Ulysses, with a duration of 24 h, has a west-north-east configuration, length scale of ≈0.2 AU, and mean expansion speed of 14.2 km s−1. The relatively small size of this ICME is likely to be a result of its interaction with the succeeding HSS. This ICME differs from the previously known over-expanding types observed by Ulysses, in that it straddles a region between the slow and fast solar wind that in itself drives the rear shock. We describe the agreements and limitations of these observations in comparison with 3D magneto-hydrodynamic (MHD) heliospheric simulations of the ICME in the context of a complex solar-wind environment.
  • Journal article
    Masters A, Sergis N, Sulaiman A, Palmaerts B, Hunt Get al., 2022,

    Near-magnetic-field-aligned energetic electrons above Saturn’s dark polar regions

    , Journal of Geophysical Research: Space Physics, Vol: 127, Pages: 1-14, ISSN: 2169-9380

    Saturn's main auroral emissions define two oval-shaped regions, one encircling each magnetic pole. The regions at higher latitudes are generally “dark” (i.e., devoid of auroras), and are magnetically connected to the distant planetary magnetosphere where there is a much-debated interaction with the solar wind. Electric currents flow into the atmosphere along the magnetic field within these polar regions. Establishing whether polar magnetic flux is “open” or “closed” is key for diagnosing how the solar wind interaction works. Because energetic electrons moving almost parallel or anti-parallel to the magnetic field shed light on the field topology, we survey Cassini energetic particle data for rare instances when the spacecraft was able to measure these parts of the distribution in the polar field environment close to the planet. Over the entire mission we find 16 intervals when measurements at ∼0urn:x-wiley:21699380:media:jgra57498:jgra57498-math-0001 and ∼180urn:x-wiley:21699380:media:jgra57498:jgra57498-math-0002 pitch angles were made simultaneously without sunlight contamination. Across all the events, above-background field-aligned fluxes were measured intermittently by the >15 keV electron channels, extending up to ∼300 keV when present. Uni-directional anti-planetward fluxes were observed during 10 of the events, and bi-directional fluxes were observed during 6 of the events. We suggest the uni-directional anti-planetward fluxes indicate the presence of field-aligned beams, and that the bi-directional fluxes indicate regions of locally closed magnetic field. These results either mean the solar wind interaction is predominantly via global magnetic reconnection but is more complex than initially proposed, or that the interaction is instead predominantly “viscous-like” at Saturn.
  • Journal article
    Beth A, Gunell H, Simon Wedlund C, Goetz C, Nilsson H, Hamrin Met al., 2022,

    First investigation of the diamagnetic cavity boundary layer with a 1D3V PIC simulation

    , Astronomy and Astrophysics: a European journal, Vol: 667, Pages: 1-16, ISSN: 0004-6361

    Context. Amongst the different features and boundaries encountered around comets, one remains of particular interest to the plasma community: the diamagnetic cavity. Crossed for the first time at 1P/Halley during the Giotto flyby in 1986 and later met more than 700 times by the ESA Rosetta spacecraft around Comet 67P/Churyumov-Gerasimenko, this region, almost free of any magnetic field, surrounds nuclei of active comets. However, previous observations and modelling of this part of the coma have not yet provided a definitive answer as to the origin of such a cavity and on its border, the diamagnetic cavity boundary layer.Aims. We investigate which forces and equilibrium might be at play and balance the magnetic pressure at this boundary down to the spatial and temporal scales of the electrons in the 1D collisionless case. In addition, we scrutinise assumptions made in magneto-hydrodynamic and hybrid simulations of this environment and check for their validity.Methods. We simulated this region at the electron scale by means of 1D3V particle-in-cell simulations and SMILEI code.Results. Across this layer, depending on the magnetic field strength, the electric field is governed by different equilibria, with a thin double-layer forming ahead. In addition, we show that the electron distribution function departs from Maxwellian and/or gyrotropic distributions and that electrons do not behave adiabatically. We demonstrate the need to investigate this region at the electron scale in depth with fully kinetic simulations.
  • Journal article
    Pollock CJ, Chen L-J, Schwartz SJ, Wang S, Avanov L, Burch JL, Gershman DJ, Giles BL, Raptis S, Russell CTet al., 2022,

    Dynamics of Earth's bow shock under near-radial interplanetary magnetic field conditions

    , PHYSICS OF PLASMAS, Vol: 29, ISSN: 1070-664X
  • Journal article
    Goren T, Feingold G, Gryspeerdt E, Kazil J, Kretzschmar J, Jia H, Quaas Jet al., 2022,

    Projecting stratocumulus transitions on the albedo-cloud fraction relationship reveals linearity of albedo to droplet concentrations

    , Geophysical Research Letters, Vol: 49, ISSN: 0094-8276

    Satellite images show solid marine stratocumulus cloud decks (Sc) that break up over the remote oceans. The Sc breakup is initiated by precipitation and is accompanied by a strong reduction in the cloud radiative effect. Aerosol has been shown to delay the Sc breakup by postponing the onset of precipitation, however its climatic effect is uncertain. Here we introduce a new approach that allows us to re-cast currently observed cloud cover and albedo to their counterfactual cleaner world, enabling the first estimate of the radiative effect due to delayed cloud breakup. Using simple radiative approximation, the radiative forcing with respect to pre-industrial times due to delayed Sc breakup is −0.39 W m−2. The radiative effect changes nearly linearly with aerosol due to the droplet concentration control on the cloud cover, suggesting a potentially accelerated warming if the current trend of reduction in aerosol emissions continues.
  • Journal article
    Li Y, Tang Y, Toumi R, Wang Set al., 2022,

    Revisiting the definition of rapid intensification of tropical cyclones by clustering the initial intensity and inner-core size

    , Journal of Geophysical Research: Atmospheres, Vol: 127, ISSN: 2169-8996

    Rapid intensification (RI) of tropical cyclones (TCs) provides a great challenge in operational forecasting and contributes significantly to the development of major TCs. RI is commonly defined as an increase in the maximum sustained surface wind speed of at least a certain threshold within 24 hr. The most widely used threshold is 30 kt (15.4 m/s), which was determined statistically. Here we propose a new definition for RI by objectively clustering TCs using the intensification rate, initial intensity, and radius of the maximum wind speed (RMW). A group of 770 samples is separated at a threshold of 45 kt (23.2 m/s). The threshold is 40 kt (20.6 m/s) for the western North Atlantic, where TC size measurements are more reliable. Monte Carlo experiments demonstrate that the proposed threshold is robust even considering the uncertainty in RMW of as high as 30 km. We show that, when a TC undergoes RI, its maximum wind speed is approximately 60 ± 15 kt (30.9 ± 7.7 m/s) and the RMW is 45 ± 20 km. The new threshold outperforms the conventional threshold of 30 kt/24 hr in describing the bimodal distribution of lifetime maximum intensity and explaining the annual count of Category 5 TCs. This new definition provides a more physically based threshold and describes a more reliable representation of extreme events. Although more comparisons are needed for operational application, it is likely to be desirable for case-based process studies and could provide a more valuable metric for TC intensification classification and research.
  • Journal article
    Archer MO, Hartinger MD, Rastatter L, Southwood DJ, Heyns M, Eggington JWB, Wright AN, Plaschke F, Shi Xet al., 2022,

    Auroral, Ionospheric and Ground Magnetic Signatures of Magnetopause Surface Modes
  • Journal article
    Trotta D, Vuorinen L, Hietala H, Horbury T, Dresing N, Gieseler J, Kouloumvakos A, Price D, Valentini F, Kilpua E, Vainio Ret al., 2022,

    Single-spacecraft techniques for shock parameters estimation: a systematic approach

    , Frontiers in Astronomy and Space Sciences, Vol: 9, Pages: 1-16, ISSN: 2296-987X

    Spacecraft missions provide the unique opportunity to study the properties of collisionless shocks utilising in situ measurements. In the past years, several diagnostics have been developed to address key shock parameters using time series of magnetic field (and plasma) data collected by a single spacecraft crossing a shock front. A critical aspect of such diagnostics is the averaging process involved in the evaluation of upstream/downstream quantities. In this work, we discuss several of these techniques, with a particular focus on the shock obliquity (defined as the angle between the upstream magnetic field and the shock normal vector) estimation. We introduce a systematic variation of the upstream/downstream averaging windows, yielding to an ensemble of shock parameters, which is a useful tool to address the robustness of their estimation. This approach is first tested with a synthetic shock dataset compliant with the Rankine-Hugoniot jump conditions for a shock, including the presence of noise and disturbances. We then employ self-consistent, hybrid kinetic shock simulations to apply the diagnostics to virtual spacecraft crossing the shock front at various stages of its evolution, highlighting the role of shock-induced fluctuations in the parameters’ estimation. This approach has the strong advantage of retaining some important properties of collisionless shock (such as, for example, the shock front microstructure) while being able to set a known, nominal set of shock parameters. Finally, two recent observations of interplanetary shocks from the Solar Orbiter spacecraft are presented, to demonstrate the use of this systematic approach to real events of shock crossings. The approach is also tested on an interplanetary shock measured by the four spacecraft of the Magnetospheric Multiscale (MMS) mission. All the Python software developed and used for the diagnostics (SerPyShock) is made available for the public, including an example of parameter estimation fo
  • Journal article
    Randich S, Gilmore G, Magrini L, Sacco GG, Jackson RJ, Jeffries RD, Worley CC, Hourihane A, Gonneau A, Vazquez CV, Franciosini E, Lewis JR, Alfaro EJ, Allende Prieto C, Bensby T, Blomme R, Bragaglia A, Flaccomio E, Francois P, Irwin MJ, Koposov SE, Korn AJ, Lanzafame AC, Pancino E, Recio-Blanco A, Smiljanic R, Van Eck S, Zwitter T, Asplund M, Bonifacio P, Feltzing S, Binney J, Drew J, Ferguson AMN, Micela G, Negueruela I, Prusti T, Rix H-W, Vallenari A, Bayo A, Bergemann M, Biazzo K, Carraro G, Casey AR, Damiani F, Frasca A, Heiter U, Hill V, Jofre P, de Laverny P, Lind K, Marconi G, Martayan C, Masseron T, Monaco L, Morbidelli L, Prisinzano L, Sbordone L, Sousa SG, Zaggia S, Adibekyan V, Bonito R, Caffau E, Daflon S, Feuillet DK, Gebran M, Gonzalez Hernandez J, Guiglion G, Herrero A, Lobel A, Maiz Apellaniz J, Montes D, Morel T, Soubiran C, Spina L, Tabernero HM, Traven G, Valentini M, Van der Swaelmen M, Villanova S, Wright NJ, Abbas U, Borsen-Koch VA, Alves J, Balaguer-Nunez L, Barklem PS, Barrado D, Berlanas SR, Binks AS, Bressan A, Capuzzo-Dolcetta R, Casagrande L, Casamiquela L, Collins RS, D'Orazi V, Dantas MLL, Debattista VP, Delgado-Mena E, Di Marcantonio P, Drazdauskas A, Evans NW, Famaey B, Franchini M, Fremat Y, Friel ED, Fu X, Geisler D, Gerhard O, Solares EAG, Grebel EK, Gutierrez Albarran ML, Hatzidimitriou D, Held E, Jimenez-Esteban F, Jonsson H, Jordi C, Khachaturyants T, Kordopatis G, Kos J, Lagarde N, Mahy L, Mapelli M, Marfil E, Martell SL, Messina S, Miglio A, Minchev I, Moitinho A, Montalban J, Monteiro MJPFG, Morossi C, Mowlavi N, Mucciarelli A, Murphy DNA, Nardetto N, Ortolani S, Paletou F, Palous J, Paunzen E, Pickering JC, Quirrenbach A, Fiorentin PR, Read J, Romano D, Ryde N, Sanna N, Santos W, Seabroke GM, Spagna A, Steinmetz M, Stonkute E, Sutorius E, Thevenin F, Tosi M, Tsantaki M, Vink JS, Wright N, Wyse RFG, Zoccali M, Zorec J, Zucker DB, Walton NAet al., 2022,

    The <i>Gaia</i>-ESO Public Spectroscopic Survey: Implementation, data products, open cluster survey, science, and legacy

    , ASTRONOMY & ASTROPHYSICS, Vol: 666, ISSN: 0004-6361
  • Journal article
    Gilmore G, Randich S, Worley CC, Hourihane A, Gonneau A, Sacco GG, Lewis JR, Magrini L, Francois P, Jeffries RD, Koposov SE, Bragaglia A, Alfaro EJ, Allende Prieto C, Blomme R, Korn AJ, Lanzafame AC, Pancino E, Recio-Blanco A, Smiljanic R, Van Eck S, Zwitter T, Bensby T, Flaccomio E, Irwin MJ, Franciosini E, Morbidelli L, Damiani F, Bonito R, Friel ED, Vink JS, Prisinzano L, Abbas U, Hatzidimitriou D, Held E, Jordi C, Paunzen E, Spagna A, Jackson RJ, Maiz Apellaniz J, Asplund M, Bonifacio P, Feltzing S, Binney J, Drew J, Ferguson AMN, Micela G, Negueruela I, Prusti T, Rix H-W, Vallenari A, Bergemann M, Casey AR, de Laverny P, Frasca A, Hill V, Lind K, Sbordone L, Sousa SG, Adibekyan V, Caffau E, Daflon S, Feuillet DK, Gebran M, Gonzalez Hernandez J, Guiglion G, Herrero A, Lobel A, Montes D, Morel T, Ruchti G, Soubiran C, Tabernero HM, Tautvaisiene G, Traven G, Valentini M, Van der Swaelmen M, Villanova S, Vazquez CV, Bayo A, Biazzo K, Carraro G, Edvardsson B, Heiter U, Jofre P, Marconi G, Martayan C, Masseron T, Monaco L, Walton NA, Zaggia S, Borsen-Koch VA, Alves J, Balaguer-Nunez L, Barklem PS, Barrado D, Bellazzini M, Berlanas SR, Binks AS, Bressan A, Capuzzo-Dolcetta R, Casagrande L, Casamiquela L, Collins RS, D'Orazi V, Dantas MLL, Debattista VP, Delgado-Mena E, Di Marcantonio P, Drazdauskas A, Evans NW, Famaey B, Franchini M, Fremat Y, Fu X, Geisler D, Gerhard O, Solares EAG, Grebel EK, Gutierrez Albarran ML, Jimenez-Esteban F, Jonsson H, Khachaturyants T, Kordopatis G, Kos J, Lagarde N, Ludwig H-G, Mahy L, Mapelli M, Marfil E, Martell SL, Messina S, Miglio A, Minchev I, Moitinho A, Montalban J, Monteiro MJPFG, Morossi C, Mowlavi N, Mucciarelli A, Murphy DNA, Nardetto N, Ortolani S, Paletou F, Palous J, Pickering JC, Quirrenbach A, Fiorentin PR, Read J, Romano D, Ryde N, Sanna N, Santos W, Seabroke GM, Spina L, Steinmetz M, Stonkute E, Sutorius E, Thevenin F, Tosi M, Tsantaki M, Wright N, Wyse RFG, Zoccali M, Zorec J, Zucker DBet al., 2022,

    The <i>Gaia</i>-ESO Public Spectroscopic Survey: Motivation, implementation, GIRAFFE data processing, analysis, and final data products☆

    , ASTRONOMY & ASTROPHYSICS, Vol: 666, ISSN: 0004-6361
  • Journal article
    Sparks N, Toumi R, 2022,

    The dependence of tropical cyclone pressure tendency on size

    , Geophysical Research Letters, Vol: 49, ISSN: 0094-8276

    Current theories of tropical cyclone (TC) intensification give little direct indication of the role of the TC size in intensity changes, although there are observations showing a relationship. We develop a new model of TC central pressure tendency where the pressure change can be expressed as exponential with a time constant determined by the ratio of radius maximum wind (Rmax) and the column inflow or outflow speed. An analysis of observations confirms the relationship which becomes more important for a larger pressure tendency and suggests an upper bound on pressure tendency for a given Rmax. The dependence of the pressure tendency on size poses a challenging constraint on the accurate forecasting of TCs in numerical weather prediction and climate models.
  • Journal article
    Bowen TA, Chandran BDG, Squire J, Bale SD, Duan D, Klein KG, Larson D, Mallet A, McManus MD, Meyrand R, Verniero JL, Woodham LDet al., 2022,

    In situ signature of cyclotron resonant heating in the solar wind

    , Physical Review Letters, Vol: 129, Pages: 1-8, ISSN: 0031-9007

    The dissipation of magnetized turbulence is an important paradigm for describing heating and energy transfer in astrophysical environments such as the solar corona and wind; however, the specific collisionless processes behind dissipation and heating remain relatively unconstrained by measurements. Remote sensing observations have suggested the presence of strong temperature anisotropy in the solar corona consistent with cyclotron resonant heating. In the solar wind, in situ magnetic field measurements reveal the presence of cyclotron waves, while measured ion velocity distribution functions have hinted at the active presence of cyclotron resonance. Here, we present Parker Solar Probe observations that connect the presence of ion-cyclotron waves directly to signatures of resonant damping in observed proton-velocity distributions using the framework of quasilinear theory. We show that the quasilinear evolution of the observed distribution functions should absorb the observed cyclotron wave population with a heating rate of 10−14  W/m3, indicating significant heating of the solar wind.
  • Journal article
    Watson-Parris D, Christensen MW, Laurenson A, Clewley D, Gryspeerdt E, Stier Pet al., 2022,

    Shipping regulations lead to large reduction in cloud perturbations.

    , Proceedings of the National Academy of Sciences of USA, Vol: 119, Pages: 1-5, ISSN: 0027-8424

    Global shipping accounts for 13% of global emissions of SO2, which, once oxidized to sulfate aerosol, acts to cool the planet both directly by scattering sunlight and indirectly by increasing the albedo of clouds. This cooling due to sulfate aerosol offsets some of the warming effect of greenhouse gasses and is the largest uncertainty in determining the change in the Earth's radiative balance by human activity. Ship tracks-the visible manifestation of the indirect of effect of ship emissions on clouds as quasi-linear features-have long provided an opportunity to quantify these effects. However, they have been arduous to catalog and typically studied only in particular regions for short periods of time. Using a machine-learning algorithm to automate their detection we catalog more than 1 million ship tracks to provide a global climatology. We use this to investigate the effect of stringent fuel regulations introduced by the International Maritime Organization in 2020 on their global prevalence since then, while accounting for the disruption in global commerce caused by COVID-19. We find a marked, but clearly nonlinear, decline in ship tracks globally: An 80% reduction in SO[Formula: see text] emissions causes only a 25% reduction in the number of tracks detected.
  • Journal article
    Kourgialas NN, Hliaoutakis A, Argyriou A, Morianou G, Voulgarakis AE, Kokinou E, Daliakopoulos IN, Kalderis D, Tzerakis K, Psarras G, Papadopoulos N, Manios T, Vafidis A, Soupios Pet al., 2022,

    A web-based GIS platform supporting innovative irrigation management techniques at farm-scale for the Mediterranean island of Crete

    , SCIENCE OF THE TOTAL ENVIRONMENT, Vol: 842, ISSN: 0048-9697
  • Journal article
    Laker R, Horbury TS, Matteini L, Bale SD, Stawarz JE, Woodham LD, Woolley Tet al., 2022,

    Switchback deflections beyond the early parker solar probe encounters

    , Monthly Notices of the Royal Astronomical Society, Vol: 517, Pages: 1001-1005, ISSN: 0035-8711

    Switchbacks are Aflvénic fluctuations in the solar wind, which exhibit large rotations in the magnetic field direction. Observations from Parker Solar Probe’s (PSP’s) first two solar encounters have formed the basis for many of the described switchback properties and generation mechanisms. However, this early data may not be representative of the typical near-Sun solar wind, biasing our current understanding of these phenomena. One defining switchback property is the magnetic deflection direction. During the first solar encounter, this was primarily in the tangential direction for the longest switchbacks, which has since been discussed as evidence, and a testable prediction, of several switchback generation methods. In this study, we re-examine the deflection direction of switchbacks during the first eight PSP encounters to confirm the existence of a systematic deflection direction. We first identify switchbacks exceeding a threshold deflection in the magnetic field and confirm a previous finding that they are arc-polarized. In agreement with earlier results from PSP’s first encounter, we find that groups of longer switchbacks tend to deflect in the same direction for several hours. However, in contrast to earlier studies, we find that there is no unique direction for these deflections, although several solar encounters showed a non-uniform distribution in deflection direction with a slight preference for the tangential direction. This result suggests a systematic magnetic configuration for switchback generation, which is consistent with interchange reconnection as a source mechanism, although this new evidence does not rule out other mechanisms, such as the expansion of wave modes.
  • Journal article
    Badman ST, Carley E, Canizares LA, Dresing N, Jian LK, Lario D, Gallagher PT, Martinez Oliveros JC, Pulupa M, Bale SDet al., 2022,

    Tracking a Beam of Electrons from the Low Solar Corona into Interplanetary Space with the Low Frequency Array, Parker Solar Probe, and 1 au Spacecraft

    , ASTROPHYSICAL JOURNAL, Vol: 938, ISSN: 0004-637X
  • Journal article
    Telloni D, Adhikari L, Zank GP, Hadid LZ, Sanchez-Cano B, Sorriso-Valvo L, Zhao L, Panasenco O, Shi C, Velli M, Susino R, Verscharen D, Milillo A, Alberti T, Narita Y, Verdini A, Grimani C, Bruno R, D'Amicis R, Perrone D, Marino R, Carbone F, Califano F, Malara F, Stawarz JE, Laker R, Liberatore A, Bale SD, Kasper JC, Heyner D, de Wit TD, Goetz K, Harvey PR, MacDowall RJ, Malaspina DM, Pulupa M, Case AW, Korreck KE, Larson D, Livi R, Stevens ML, Whittlesey P, Auster H-U, Richter Iet al., 2022,

    Observation and Modeling of the Solar Wind Turbulence Evolution in the Sub-Mercury Inner Heliosphere

    , ASTROPHYSICAL JOURNAL LETTERS, Vol: 938, ISSN: 2041-8205
  • Journal article
    Montagud-Camps V, Hellinger P, Verdini A, Papini E, Franci L, Landi Set al., 2022,

    Quantification of the Cross-helicity Turbulent Cascade in Compressible MHD Simulations

    , ASTROPHYSICAL JOURNAL, Vol: 938, ISSN: 0004-637X

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