Blar i University of Bergen Library på tidsskrift "Geophysical Research Letters"

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    • The Micro-Macro Coupling of Mass-Loading in Symmetric Magnetic Reconnection With Cold Ions 

      Spinnangr, Susanne Flø; Hesse, Michael; Tenfjord, Paul Arne Riksheim; Norgren, Astrid Elisabet Cecilia; Kolstø, Håkon Midthun; Kwagala, Norah Kaggwa; Jørgensen, Therese Moretto (Journal article; Peer reviewed, 2021)
      We investigate how magnetic reconnection is influenced by an inflow of a dense cold ion population. We compare two 2.5D Particle-In-Cell simulations, one containing the cold population and one without. We find that the ...

    • MMS Measurements of the Vlasov Equation: Probing the Electron Pressure Divergence Within Thin Current Sheets 

      Shuster, JR; Gershman, Daniel J; Chen, LJ; Wang, S; Bessho, Naoki; Dorelli, John C; da Silva, DE; Giles, Barbara L; Paterson, William R.; Denton, Richard E; Schwartz, S. J.; Norgren, Astrid Elisabet Cecilia; Wilder, F.D.; Cassak, P.A.; Swisdak, M; Uritsky, Vadim; Schiff, C.; Rager, AC; Smith, S; Avanov, LA; Vinas, AF (Journal article; Peer reviewed, 2019)
      We investigate the kinetic structure of electron‐scale current sheets found in the vicinity of the magnetopause and embedded in the magnetosheath within the reconnection exhaust. A new technique for computing terms of the ...

    • MMS Observations of Multiscale Hall Physics in the Magnetotail 

      Alm, Love; André, Mats; Graham, Daniel B.; Khotyaintsev, Yuri V.; Vaivads, Andris; Chappell, Charles Richard; Dargent, Jérémy; Fuselier, Stephen A.; Haaland, Stein; Lavraud, Benoit; Li, Wenya; Tenfjord, Paul; Toledo-Redondo, Sergio; Vines, Sarah K. (Journal article; Peer reviewed, 2019)
      We present Magnetospheric Multiscale mission (MMS) observations of Hall physics in the magnetotail, which compared to dayside Hall physics is a relatively unexplored topic. The plasma consists of electrons, moderately cold ...

    • Multi-Pulse Corona Discharges in Thunderclouds Observed in Optical and Radio Bands 

      Li, Dongshuai; Luque, Alejandro; Lehtinen, Nikolai Grigorievich; Gordillo-Vázquez, F.J.; Neubert, Torsten; Lu, Gaopeng; Chanrion, Olivier; Zhang, Hongbo; Østgaard, Nikolai; Reglero, Víctor (Journal article; Peer reviewed, 2022)
      How lightning initiates inside thunderclouds remains a major puzzle of atmospheric electricity. By monitoring optical emissions from thunderstorms, the Atmosphere-Space Interactions Monitor (ASIM) onboard the International ...

    • Necessary Conditions for Warm Inflow Toward the Filchner Ice Shelf, Weddell Sea 

      Daae, Kjersti; Hattermann, Tore; Darelius, Elin Maria K.; Mueller, Rachael D.; Naughten, Kaitlin A; Timmermann, Ralph; Hellmer, Hartmut H. (Journal article; Peer reviewed, 2020)
      Understanding changes in Antarctic ice shelf basal melting is a major challenge for predicting future sea level. Currently, warm Circumpolar Deep Water surrounding Antarctica has limited access to the Weddell Sea continental ...

    • Northward shifts in the polar front preceded Bølling and Holocene warming in southwestern Scandinavia 

      Cowling, Owen C.; Thomas, Elizabeth K.; Svendsen, John-Inge; Mangerud, Jan; Vasskog, Kristian; Haflidason, Haflidi (Journal article; Peer reviewed, 2020)
      The last deglaciation in northern Europe provides an opportunity to study the hydrologic component of abrupt climate shifts in a region with complex interactions between ice sheets and oceanic and atmospheric circulation. ...

    • Observational Evidence of Magnetic Reconnection in the Terrestrial Bow Shock Transition Region 

      Wang, Shan; Chen, Li-Jen; Bessho, Naoki; Hesse, Michael; Wilson, Lynn B.; Giles, Barbara; Moore, Thomas E.; Russell, Christopher T.; Torbert, Roy B.; Burch, James L. (Journal article; Peer reviewed, 2019)
      We report evidence of magnetic reconnection in the transition region of the Earth's bow shock when the angle between the shock normal and the immediate upstream magnetic field is 65°. An ion‐skin‐depth‐scale current sheet ...

    • Observations of Blue Corona Discharges in Thunderclouds 

      Husbjerg, Lasse Skaaning; Neubert, Torsten; Chanrion, Olivier; Dimitriadou, Krystallia; Li, Dongshuai; Stendel, Martin; Kaas, Eigil; Østgaard, Nikolai; Reglero, Victor (Journal article; Peer reviewed, 2022)
      Blue electric streamer discharges in the upper reaches of thunderclouds are observed as flashes of 337.0 nm (blue) with faint or no emissions of 777.4 nm (red). Analyzing 3 years of measurements by the Atmosphere-Space ...

    • On the Impact of a Streaming Oxygen Population on Collisionless Magnetic Reconnection 

      Kolstø, Håkon Midthun; Hesse, Michael; Norgren, Astrid Elisabet Cecilia; Tenfjord, Paul; Spinnangr, Susanne Flø; Kwagala, Norah Kaggwa (Journal article; Peer reviewed, 2020)
      Using 2.5-D Particle-In-Cell (PIC) simulations, we investigate how magnetotail reconnection is affected by a cold, streaming, oxygen plasma population, attributed to an ionospheric source, in the inflow region. As the ...

    • Overview of the Rocket Experiment for NeutralUpwelling Sounding Rocket 2 (RENU2) 

      Lessard, Marc R.; Fritz, Bruce; Sadler, Brent; Cohen, Ian J.; Kenward, David; Godbole, Niharika; Clemmons, James H.; Hecht, James H.; Lynch, Kristina A.; Harrington, Meghan; Roberts, Thomas M.; Hysell, David; Crowley, Geoff; Sigernes, Fred; Syrjäsuo, Mikko; Ellingsen, Pål Gunnar; Partamies, Noora; Moen, Jøran Idar; Clausen, Lasse Boy Novock; Oksavik, Kjellmar; Yeoman, Timothy (Journal article; Peer reviewed, 2020)
      The Rocket Experiment for Neutral Upwelling 2 (RENU2) rocket was launched on 13 December 2015 at 07:34 UT. The payload transited the cusp region during a neutral upwelling event, supported by a comprehensive set of onboard ...

    • Possible Ionospheric Influence on Substorm Onset Location 

      Elhawary, Reham Zakaria Ahmed Mohamed; Laundal, Karl Magnus; Reistad, Jone Peter; Hatch, Spencer Mark (Journal article; Peer reviewed, 2022)
      Auroral substorm onset locations are highly unpredictable. Previous studies have shown that the By component of the interplanetary magnetic field (IMF) explains ∼5% of the variation in onset magnetic local time (MLT), while ...

    • Predictable Variations of the Carbon Sinks and Atmospheric CO2 Growth in a Multi-Model Framework 

      Ilyina, Tatiana; Hongmei, Li; Spring, Aaron; Müller, Wolfgang A.; Bopp, Laurent; Chikamoto, Megumi O.; Danabasoglu, Gokhan; Dobrynin, Mikhail; Dunne, John P. Patrick; Fransner, Filippa; Friedlingstein, Pierre; Lee, Woo-Sung; Lovenduski, Nicole; Merryfield, William J.; Mignot, Juliette; Park, Jong-Yeon; Séférian, Roland; Sospedra-Alfonso, Reinel; Watanabe, Michio; Yeager, Stephen G. (Journal article; Peer reviewed, 2021)
      Inter-annual to decadal variability in the strength of the land and ocean carbon sinks impede accurate predictions of year-to-year atmospheric carbon dioxide (CO2) growth rate. Such information is crucial to verify the ...

    • The Quasi-Linear Absolute Angular Momentum Slope of Tropical Cyclones Under Rapid Intensification 

      Tao, Dandan; Nystrom, Robert; Bell, Michael (Journal article; Peer reviewed, 2023)
      Tropical cyclone (TC) low-level tangential wind structure is known to be an important input for risk assessment (e.g., storm surge). However, a realistic TC wind structure model with easy implementation is still needed for ...

    • Reversals in Temperature-Precipitation Correlations in the Northern Hemisphere Extratropics During the Holocene 

      Herzschuh, Ulrike; Böhmer, Thomas; Li, Chenzhi; Cao, Xianyong; Hébert, Raphaël; Dallmeyer, Anne; Telford, Richard James; Kruse, Stefan (Journal article; Peer reviewed, 2022)
      Future precipitation levels remain uncertain because climate models have struggled to reproduce observed variations in temperature-precipitation correlations. Our analyses of Holocene proxy-based temperature-precipitation ...

    • The Role of Mid-latitude Westerly Jet in the Impacts of November Ural Blocking on Early-Winter Warmer Arctic-Colder Eurasia Pattern 

      Xu, Xinping; He, Shengping; Zhou, Botao; Wang, Huijun; Outten, Stephen (Journal article; Peer reviewed, 2022)
      Based on statistical analysis using observations and idealized model simulations, previous studies have revealed the potential response of early-winter atmospheric circulation and temperature anomalies to November Ural ...

    • The Seasonal and Regional Transition to an Ice-Free Arctic 

      Årthun, Marius; Onarheim, Ingrid H.; Dörr, Jakob; Eldevik, Tor (Journal article; Peer reviewed, 2021)
      The Arctic sea ice cover is currently retreating and will continue its retreat in a warming world. However, the loss of sea ice is neither regionally nor seasonally uniform. Here, we present the first regional and seasonal ...

    • Snow-Atmosphere Humidity Exchange at the Ice Sheet Surface Alters Annual Mean Climate Signals in Ice Core Records 

      Dietrich, Laura Jasmin; Steen-Larsen, Hans Christian; Wahl, Sonja; Jones, Tyler R.; Town, Michel Stephen; Werner, Martin (Journal article; Peer reviewed, 2023)
      Surface processes alter the water stable isotope signal of the surface snow after deposition. However, it remains an open question to which extent surface post-depositional processes should be considered when inferring ...

    • Spectral Observations of Optical Emissions Associated With Terrestrial Gamma-Ray Flashes 

      Heumesser, Matthias; Chanrion, Olivier; Neubert, Torsten; Christian, Hugh J.; Dimitriadou, Krystallia; Gordillo-Vazquez, Francisco J.; Luque, Alejandro; Pérez-Invernón, F. J.; Blakeslee, Richard J.; Østgaard, Nikolai; Reglero, Victor; Köhn, Christoph (Journal article; Peer reviewed, 2021)
      The Atmosphere-Space Interactions Monitor measures Terrestrial Gamma-Ray Flashes (TGFs) simultaneously with optical emissions from associated lightning activity. We analyzed optical measurements at 180–230, 337, and 777.4 ...

    • Substorm Impact on Dayside Ionospheric Currents 

      Elhawary, Reham Zakaria Ahmed Mohamed; Laundal, Karl Magnus; Reistad, Jone Peter; Madelaire, Michael; Ohma, Anders (Journal article; Peer reviewed, 2023)
      Ionospheric dayside dynamics is strongly controlled by the interaction between the Interplanetary Magnetic Field (IMF) and the Earth's magnetic field near the dayside magnetopause, while nightside ionospheric dynamics ...

    • Supercooled Southern Ocean Waters 

      Haumann, F. Alexander; Moorman, Ruth; Riser, Stephen C.; Smedsrud, Lars H.; Maksym, Ted; Wong, Annie P. S.; Wilson, Earle A.; Drucker, Robert; Talley, Lynne D.; Johnson, Kenneth S.; Key, Robert M.; Sarmiento, Jorge L. (Journal article; Peer reviewed, 2020)
      In cold polar waters, temperatures sometimes drop below the freezing point, a process referred to as supercooling. However, observational challenges in polar regions limit our understanding of the spatial and temporal ...