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  • Journal article
    Page B, Lecacheux A, Pulupa M, Bale SDet al., 2025,

    Calibration of Electrically Short Antennas Using the <i>l</i>=2 Spherical Harmonic Expansion Coefficients of the Radio Brightness Distribution on the Sky Between 0.5 and 6.8 MHz

    , RADIO SCIENCE, Vol: 60, ISSN: 0048-6604
  • Journal article
    Van de Koot EK, Byrne MP, Woollings T, 2025,

    Tropical Cloud Feedbacks Estimated from Observed Multidecadal Trends

    , Journal of Climate, Vol: 38, Pages: 3185-3199, ISSN: 0894-8755

    <jats:title>Abstract</jats:title><jats:p>Tropical cloud feedbacks are an important source of uncertainty in estimates of climate sensitivity. The extent to which changes in atmospheric circulation contribute to these feedbacks remains an open question. Here, all-sky radiative flux observations and an atmospheric reanalysis are used to estimate tropical cloud feedbacks from multidecadal trends (1985–2020) in cloud radiative effect and surface temperature. We decompose the observed feedbacks into dynamic and nondynamic components to quantify the impact of circulation trends. Narrowing and strengthening of tropical ascent lead to substantial dynamic feedbacks on regional scales that are similar in magnitude to the nondynamic feedbacks. However, as previously shown for high- and low-resolution climate models, large dynamic feedbacks in different circulation regimes are connected by the atmospheric mass budget and approximately cancel when averaged across the tropics due to the quasi-linear relationship between cloud radiative effect and vertical velocity. This results in small dynamic contributions to the tropical-mean net, longwave, and shortwave feedbacks. We suggest that this result will hold in future and thus that isolating the nondynamic components associated with individual cloud types can provide important insights into the processes controlling the tropical-mean cloud feedback and its uncertainty. Additionally, we show that feedbacks estimated from multidecadal trends differ from those estimated from interannual variability. We demonstrate that, for dynamic feedbacks, this is because changes are controlled by different mechanisms and this leads to a differing spatial distribution of temperature sensitivity. Finally, we provide new estimates of the uncertain combined tropical anvil area and albedo feedback using both multidecadal trends and interannual variability.</jats:p>
  • Journal article
    Kretzschmar M, Brochot J-Y, Horbury TS, Rackovic K, Maksimovic M, Alexandrova O, Bonnin X, Jannet G, O'Brien H, Crabtree A, Morris J, Krasnoselskikh V, Dudok de Wit T, Le Contel O, Chust T, De Gelis P-M, Da Silva Goncalves L, Fauchon-Jones Eet al., 2025,

    The Solar Orbiter merged magnetic field

    , ASTRONOMY & ASTROPHYSICS, Vol: 699, ISSN: 0004-6361
  • Journal article
    Pulupa M, Bale SD, Jebaraj IC, Romeo O, Krucker Set al., 2025,

    Highly Polarized Type III Storm Observed with Parker Solar Probe

    , ASTROPHYSICAL JOURNAL LETTERS, Vol: 987, ISSN: 2041-8205
  • Journal article
    Niwa Y, Tohjima Y, Terao Y, Saeki T, Ito A, Umezawa T, Yamada K, Sasakawa M, Machida T, Nakaoka SI, Nara H, Tanimoto H, Mukai H, Yoshida Y, Morimoto S, Takatsuji S, Tsuboi K, Sawa Y, Matsueda H, Ishijima K, Fujita R, Goto D, Lan X, Schuldt K, Heliasz M, Biermann T, Chmura L, Necki J, Xueref-Remy I, Sferlazzo Det al., 2025,

    Multi-observational estimation of regional and sectoral emission contributions to the persistent high growth rate of atmospheric CH4 for 2020-2022

    , Atmospheric Chemistry and Physics, Vol: 25, Pages: 6757-6785, ISSN: 1680-7316

    Atmospheric methane (CH4) growth rates reached unprecedented values in the years 2020-2022. To identify the main drivers of this increase, an inverse modeling study estimated regional and sectoral emission changes for 2016-2022. Three inverse estimates based on different sets of atmospheric CH4 observations (surface observations only, surface and aircraft observations, and GOSAT observations) consistently suggest notable emission increases from 2016-2019 to 2020-2022 in the tropics (15° S-10° N) (10-18 Tg CH4 yr-1) and in northern low latitudes (10-35° N) (ca. 20 Tg CH4 yr-1), the latter of which likely contributed to the growth rate surge from 2020. The emission increase in the northern low latitudes is attributed to emissions in South Asia and northern Southeast Asia, which abruptly increased from 2019 to 2020, and elevated emissions continued until 2022. Meanwhile, the tropical emission increase is dominated by Tropical South America and Central Africa, but emissions were continuously increasing before 2019. Agreement was found in the sectoral estimates of the three inversions in the tropics and northern low latitudes, suggesting the largest contribution of biogenic emissions. Uncertainty reductions demonstrate that the flux estimates in Asia are well constrained by surface and aircraft observations. Furthermore, a sensitivity test with the probable reduction of OH radicals showed smaller emissions by up to 2-3 Tg CH4 yr-1 in each Asian region for 2020, still suggesting notable emission contributions. These results highlight the importance of biogenic emissions in Asian regions for the persistent high growth rate observed during 2020-2022.
  • Journal article
    Wilson III LB, Mitchell JG, Szabo A, Jebaraj IC, Stevens ML, Malaspina DM, Berland GD, Kouloumvakos A, Bale SD, Livi R, Halekas JS, Cohen CMSet al., 2025,

    Large-amplitude Whistler Precursors and >MeV Particles Observed at a Weak Interplanetary Shock by Parker Solar Probe

    , ASTROPHYSICAL JOURNAL, Vol: 987, ISSN: 0004-637X
  • Journal article
    Turc L, Archer MO, Zhou H, PfauKempf Y, Suni J, Kajdič P, BlancoCano X, Dahani S, Battarbee M, Raptis S, Liu TZ, Zhang H, Escoubet CP, LaMoury AT, Tao S, Lipsanen V, Hao Y, Palmroth Met al., 2025,

    Interplay between a foreshock bubble and a hot flow anomaly forming along the same rotational discontinuity

    , Geophysical Research Letters, Vol: 52, ISSN: 0094-8276

    Solar wind directional discontinuities can generate transient mesoscale structures such as foreshock bubbles and hot flow anomalies (HFAs) upstream of Earth's bow shock. These structures can have a global impact on near-Earth space, so understanding their formation conditions is essential. We investigate foreshock transient generation at a rotational discontinuity using a global 2D hybrid-Vlasov simulation. As expected, a foreshock bubble forms on the sunward side of the discontinuity. Later, when the discontinuity reaches the shock, new structures identified as HFAs develop, despite the initial discontinuity not being favorable to HFA formation. We demonstrate that the foreshock bubble provides the necessary conditions for their generation. We then investigate the evolution of the transient structures and the large-scale bow shock deformation they induce. Our results provide new insights on the formation and evolution of foreshock transients and their impact on the shock.
  • Journal article
    Goodwin P, Williams RG, Ceppi P, Cael BBet al., 2025,

    Climate Feedbacks Derived From Spatial Gradients in Recent Climatology

    , JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES, Vol: 130, ISSN: 2169-897X
  • Journal article
    Ren T, Yang P, Brindley HE, L'Ecuyer TS, Maestri Tet al., 2025,

    Temperature-Dependent Optical Properties of Ice Crystals in the Far-Infrared Regime

    , GEOPHYSICAL RESEARCH LETTERS, Vol: 52, ISSN: 0094-8276
  • Journal article
    Kartavykh Y, Rodriguez-Garcia L, Heber B, Wimmer-Schweingruber RF, Trotta D, Gieseler J, Droege H, Kollhoff A, Droege W, Kilpua E, Horbury T, Espinosa Lara F, Gomez-Herrero R, Rodriguez-Pacheco J, Lario D, Dresing N, Klassen A, Vainio Ret al., 2025,

    A statistical study of energetic particle events associated with interplanetary shocks observed by Solar Orbiter in solar cycle 25

    , ASTRONOMY & ASTROPHYSICS, Vol: 699, ISSN: 0004-6361
  • Journal article
    Dakeyo J-B, Demoulin P, Rouillard A, Maksimovic M, Chapiron A, Bale Set al., 2025,

    Generalized Two Thermal Regime Approach: Bipoly Fluid Modeling

    , ASTROPHYSICAL JOURNAL, Vol: 986, ISSN: 0004-637X
  • Journal article
    Huang J, Larson DE, Ervin T, Liu M, Ortiz O, Martinovic MM, Huang Z, Chasapis A, Chu X, Alterman BL, Huang Z, Wei W, Verniero JL, Jian LK, Szabo A, Romeo O, Rahmati A, Livi R, Whittlesey P, Alnussirat ST, Kasper JC, Stevens M, Bale SDet al., 2025,

    The Temperature Anisotropy and Helium Abundance Features of Alfvénic Slow Solar Wind Observed by Parker Solar Probe, Helios, and Wind Missions

    , ASTROPHYSICAL JOURNAL LETTERS, Vol: 986, ISSN: 2041-8205
  • Journal article
    Phan TD, Romeo OM, Drake JF, Larson D, Oieroset M, Eriksson S, Lavraud B, Bale SD, Rahmati A, Livi R, Whittlesey P, Pulupa M, Huang J, Halekas J, Stevens ML, Szabo A, Raouafi Net al., 2025,

    Parker Solar Probe Observations of a Highly Energetic and Asymmetric Reconnecting Heliospheric Current Sheet during Encounter 13

    , ASTROPHYSICAL JOURNAL, Vol: 986, ISSN: 0004-637X
  • Journal article
    Seo G-Y, Min S-K, Lee D, Son S-W, Park C, Cha D-Het al., 2025,

    Hourly extreme rainfall projections over South Korea using convection permitting climate simulations

    , NPJ CLIMATE AND ATMOSPHERIC SCIENCE, Vol: 8, ISSN: 2397-3722
  • Journal article
    Grillakis M, Voulgarakis A, 2025,

    Diverse wildfire impacts on river flows across the globe

    , Communications Earth & Environment, Vol: 6, ISSN: 2662-4435

    Forest fires can significantly impact the hydrological regime of river basins, affecting short-term flood propensity and long-term water resource availability until vegetation is reestablished. While basin-level studies have extensively investigated these impacts, regional and global-scale assessments remain limited. Here we use a comprehensive global dataset of river discharge observations to systematically assess the hydrological response to wildfires for a range of hydrologically homogenous world regions and biomes. Our analysis reveals contrasting hydrological impacts by region, with high-latitude discharge ratios declining by 7.5% and 16% in the first and second year after wildfire, respectively, while Northern mid-latitude regions showing a marginal 3.3% median increase in discharge ratio the first-year post-fire. Sub-tropical and equatorial regions display negative and positive effects, respectively. We further discuss how potential ecological and hydroclimatic factors, along with human river and watershed management, shape these diverse hydrological responses per hydroclimatic region.
  • Journal article
    Zomerdijk-Russell S, Jasinski J, Masters A, 2025,

    Variation of model-predicted reconnection voltages applied to Uranus’ dayside magnetosphere

    , JGR: Space Physics, ISSN: 2169-9402

    Uranus provides a key missing piece for fundamentally understanding solar wind-magnetospheric interactions due to its location in the outer solar system. Whether the viscous-like interaction overtakes global magnetic reconnection as the dominant process at the magnetopauseof the outer planets remains unresolved. Here, we present theoretical predictions of dayside reconnection voltages applied to the Uranian system under different magnetospheric configurations to assess the effectiveness of global magnetic reconnection in the driving of Uranus’magnetosphere. We find the median model-predicted dayside reconnection voltage applied to Uranus’ magnetosphere is 22.4 kV. Over just one full planetary rotation, the reconnection voltages are found to vary by tens of kV under Uranus’ magnetospheric configuration during its solstice and equinox seasons with fixed solar wind conditions. However, we do not find a significant difference between average voltages at the different seasons, despite the large differences in magnetospheric configuration between solstice and equinox at Uranus. An increase from ~17 kV to ~31 kV in the modeled reconnection voltages is observed when the strength of the interplanetarymagnetic field is increased corresponding to expected conditions during solar maximum. Our results suggest that variability resulting from the planet’s diurnal rotation and changing solar wind conditions, are more important in controlling the reconnection voltages than seasonaldependencies.
  • Journal article
    Horner G, Gryspeerdt E, 2025,

    How does the lifetime of detrained cirrus impact the high-cloud radiative effect in the tropics?

    , Atmospheric Chemistry and Physics, Vol: 25, Pages: 5617-5631, ISSN: 1680-7316

    The lifetime of cirrus clouds from deep convection plays an important role in determining their overall cloud radiative effect (CRE). The net CRE of cirrus clouds from deep convection is close to zero over their whole lifetime. This CRE is the result of a near-cancellation of a large shortwave (SW) cooling and large longwave (LW) warming, such that small changes in cirrus properties have the potential to produce a significant net radiative effect. Changes in the atmospheric and sea surface temperature structure, along with changes in anthropogenic aerosol, have been hypothesised to impact the lifetime of detrained cirrus clouds, altering this radiative balance. Constraining the potential CRE response to changes in cirrus lifetime is therefore vital to understand the strength of these proposed climate forcings and feedbacks.This paper tracks the evolution of detrained cirrus clouds along trajectories from deep convection. The total cirrus CRE in the tropics is found to be warming, at 11.2 ± 0.4 W m−2. It is found that cirrus clouds along trajectories from oceanic origin convection have a warming CRE of 10.0 ± 0.4 W m−2. In contrast, cirrus clouds along trajectories from land convection have a warming of 15.9 ± 0.7 W m−2 throughout their lifetime. This contrast is predominantly due to differences in the diurnal cycle of the initial convection over land and ocean.A proposed extension to the lifetime of the detrained cirrus leads to changes in the total cirrus CRE in the tropics. In all cases, doubling the lifetime of the detrained cirrus leads to an increase in the total cirrus CRE of 0.6 ± 0.1 W m−2. Whilst there is uncertainty in the strength of mechanisms responsible for a change in cirrus lifetime, this work provides an important constraint on the impact that any potential lifetime extension may have.
  • Journal article
    Hamilton CW, Mcewen AS, Keszthelyi L, Carter LM, Davies AG, de Kleer K, Jessup KL, Jia X, Keane JT, Mandt K, Nimmo F, Paranicas C, Park RS, Perry JE, Pommier A, Radebaugh J, Sutton SS, Vorburger A, Wurz P, Borlina C, Haapala AF, DellaGiustina DN, Denevi BW, Horst SM, Kempf S, Khurana KK, Likar JJ, Masters A, Mousis O, Polit AT, Bhushan A, Bland M, Matsuyama I, Spencer Jet al., 2025,

    Comparing NASA Discovery and New Frontiers Class Mission Concepts for the Io Volcano Observer

    , PLANETARY SCIENCE JOURNAL, Vol: 6
  • Journal article
    Desai MI, Drake JF, Phan T, Yin Z, Swisdak M, Mccomas DJ, Bale SD, Rahmati A, Larson D, Matthaeus WH, Dayeh MA, Starkey MJ, Raouafi NE, Mitchell DG, Cohen CMS, Szalay JR, Giacalone J, Hill ME, Christian ER, Schwadron NA, McNutt Jr RL, Malandraki O, Whittlesey P, Livi R, Kasper JCet al., 2025,

    Magnetic Reconnection-driven Energization of Protons up to ∼400 keV at the Near-Sun Heliospheric Current Sheet

    , ASTROPHYSICAL JOURNAL LETTERS, Vol: 985, ISSN: 2041-8205
  • Journal article
    Lozinski AR, Kellerman AC, Bortnik J, Horne RB, Desai RT, Glauert SAet al., 2025,

    Modeling the Internal Redistribution of Earth's Proton Radiation Belt by Interplanetary Shocks

    , JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS, Vol: 130, ISSN: 2169-9380
  • Journal article
    Mauritsen T, Tsushima Y, Meyssignac B, Loeb NG, Hakuba M, Pilewskie P, Cole J, Suzuki K, Ackerman TP, Allan RP, Andrews T, Bender FA-M, Bloch-Johnson J, Bodas-Salcedo A, Brookshaw A, Ceppi P, Clerbaux N, Dessler AE, Donohoe A, Dufresne J-L, Eyring V, Findell KL, Gettelman A, Gristey JJ, Hawkins E, Heimbach P, Hewitt HT, Jeevanjee N, Jones C, Kang SM, Kato S, Kay JE, Klein SA, Knutti R, Kramer R, Lee J-Y, Mccoy DT, Medeiros B, Megner L, Modak A, Ogura T, Palmer MD, Paynter D, Quaas J, Ramanathan V, Ringer M, von Schuckmann K, Sherwood S, Stevens B, Tan I, Tselioudis G, Sutton R, Voigt A, Watanabe M, Webb MJ, Wild M, Zelinka MDet al., 2025,

    Earth's Energy Imbalance More Than Doubled in Recent Decades

    , AGU ADVANCES, Vol: 6
  • Journal article
    Kim K, Edberg NJT, Modolo R, Morooka M, Wilson RJ, Coates AJ, Wellbrock A, Wahlund J-E, Vigren E, Sulaiman A, Bertucci C, Desai R, Regoli Let al., 2025,

    Electron Structures in Titan's Induced Magnetosphere and Low-Frequency Wave Activity

    , JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS, Vol: 130, ISSN: 2169-9097
  • Journal article
    Colomban L, Agapitov OV, Krasnoselskikh V, Choi KE, Kretzschmar M, Dudok de Wit T, Mozer FS, Bonnell JW, Bale S, Malaspina D, Raouafi NE, Pulupa Met al., 2025,

    Polarization Properties of Whistler Waves From the First 17 Parker Solar Probe Encounters

    , GEOPHYSICAL RESEARCH LETTERS, Vol: 52, ISSN: 0094-8276
  • Journal article
    Alnussirat ST, Larson DE, Livi R, Whittlesey PL, Rahmati A, Romeo O, Huang J, Liu M, Pulupa M, Bale SD, Raouafi N, McComas DJet al., 2025,

    Impulsive Solar Flares in the Parker Solar Probe Era. I. Low-energy Electron, Proton, and Alpha Beams

    , ASTROPHYSICAL JOURNAL, Vol: 985, ISSN: 0004-637X
  • Journal article
    Bowen TA, Dunn CI, Mallet A, Squire J, Badman ST, Bale SD, Dudok de Wit T, Horbury TS, Klein KG, Larson D, Matteini L, McManus MD, Sioulas Net al., 2025,

    Nonlinear Interactions in Spherically Polarized Alfvénic Turbulence

    , ASTROPHYSICAL JOURNAL, Vol: 985, ISSN: 0004-637X
  • Journal article
    Cuesta ME, Livadiotis G, Mccomas DJ, Khoo LY, Farooki HA, Bandyopadhyay R, Bale SDet al., 2025,

    Transfer of Entropy between the Magnetic Field and Solar Energetic Particles during an Interplanetary Coronal Mass Ejection

    , ASTROPHYSICAL JOURNAL LETTERS, Vol: 984, ISSN: 2041-8205
  • Journal article
    Shen MM, Szalay JR, Pokorny P, Mitchell JG, Hill ME, Mitchell DG, McComas DJ, Christian ER, Cohen CMS, Schwadron NA, Bale SD, Malaspina DMet al., 2025,

    Diverse Dust Populations in the Near-Sun Environment Characterized by PSP/IS⊙IS

    , ASTROPHYSICAL JOURNAL, Vol: 984, ISSN: 0004-637X
  • Journal article
    Vallim D, Grillakis M, Manoudakis S, Giannakopoulou A, Schmid A, Phillis A, Voulgarakis A, Arampatzis G, Altsitsiadis E, Fróes Iet al., 2025,

    Stakeholder Engagement Drivers: Insights from an Information System Innovation Project Supporting Wildfire Evacuation in Greece

    , Proceedings of the International Iscram Conference

    The Samaria Gorge, a tourist destination in Crete, faces wildfire risk due to its dense forest, topography, number of visitors, and climate. As part of a H2020 project, the Gorge serves as a testing pilot for a new wildfire management platform that integrates technologies to improve fire detection, risk assessment, and resource allocation during a wildfire evacuation. A central component of the project is a multi-stakeholder network, which supports both governance and acceptance of solutions. To understand the drivers of network formation, we used a Social Network Analysis and Exponential Random Graphs Model approaches to identify the drivers of stakeholder collaboration. Our findings indicate that sectoral and wildfire management focus phase are factors driving connections, while the working in intersecting jurisdictions is not. The results highlight the challenges of multi-stakeholder collaboration, suggesting that policy frameworks and information systems need to develop specific mechanisms to encourage stakeholders to bridge collaborative gaps.
  • Journal article
    Beggan CD, Eastwood JP, Eggington JWB, Forsyth C, Freeman MP, Henley E, Heyns M, Hübert J, Jackson DR, LaMoury AT, Richardson GS, Smith AW, Thomson AWPet al., 2025,

    Implementing an operational cloud‐based now‐ and forecasting system for space weather ground effects in the UK

    , Space Weather, Vol: 23, ISSN: 1539-4956

    The enhanced variation of the magnetic field during severe to extreme geomagnetic storms induces a large geoelectric field in the subsurface. Grounded infrastructure can be susceptible to geomagnetically induced currents (GICs) during these events. Modeling the effect in real-time and forecasting the magnitude of GICs are important for allowing operators of critical infrastructure to make informed decisions on potential impacts. As part of the UK-funded Space Weather Innovation, Measurement, Modeling and Risk (SWIMMR) program, we implemented nine research-level models into operational codes capable of running consistently and robustly to produce estimates of GICs in the Great Britain high voltage power transmission network, the high pressure gas pipeline network and the railway network. To improve magnetic coverage and geoelectric field modeling accuracy, three new variometer sites were installed in the UK and a 3 year campaign of magnetotelluric measurements at 53 sites was undertaken. The models rely on real-time ground observatory data and solar wind data from satellites at the L1 Lagrange point. A mixture of empirical machine learning and numerical magnetohydrodynamic models are used for forecasting. In addition to nowcast capabilities, contextual information on the likelihood of substorms, sudden commencements and large rates of change of the magnetic field were developed. The final nowcast and forecast codes were implemented in a cloud-based environment using modern software tools and practices. We describe the process to move from research to operations (R2O).
  • Journal article
    Nair R, Halekas JS, Cattell C, Johnson M, Hanson E, Whittlesey PL, Larson DE, Livi R, Kasper JC, Stevens ML, Bale SD, Malaspina DM, Pulupa MPet al., 2025,

    Suprathermal Electron Scattering by Narrowband Whistler Waves and Broadband Electrostatic Waves: Parker Solar Probe Observations

    , ASTROPHYSICAL JOURNAL, Vol: 984, ISSN: 0004-637X

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