Browsing University of Bergen Library by Journals "Geophysical Research Letters"

Now showing items 1-20 of 67

    • Analysis of Blue Corona Discharges at the Top of Tropical Thunderstorm Clouds in Different Phases of Convection 

      Dimitriadou, Krystallia; Chanrion, Olivier; Neubert, Torsten; Protat, Alain; Louf, Valentin; Heumesser, Matthias; Husbjerg, Lasse; Köhn, Christoph; Østgaard, Nikolai; Reglero, Victor (Journal article; Peer reviewed, 2022)
      We report on observations of corona discharges at the uppermost region of clouds characterized by emissions in a blue band of nitrogen molecules at 337 nm, with little activity in the red band of lightning leaders at 777.4 ...

    • Arctic Warming and Eurasian Cooling: Weakening and Reemergence 

      Xu, Xinping; He, Shengping; Zhou, Botao; Wang, Huijun; Sun, Bo (Journal article; Peer reviewed, 2023)
      The observed Eurasian winter surface cooling from the 1990s to the early 2010s, which is contrary to global warming, has been extensively studied. Previous studies revealed that the surface cooling trend has significantly ...

    • Atmosphere-Snow Exchange Explains Surface Snow Isotope Variability 

      Wahl, Sonja; Steen-Larsen, Hans Christian; Hughes, A.G.; Dietrich, Laura Jasmin; Zuhr, A.; Behrens, M.; Faber, Anne-Katrine; Hörhold, M. (Journal article; Peer reviewed, 2022)
      The climate signal imprinted in the snow isotopic composition allows to infer past climate variability from ice core stable water isotope records. The concurrent evolution of vapor and surface snow isotopic composition ...

    • Atmospheric signature of the Agulhas current 

      Nkwinkwa Njouodo, Arielle Stela; Koseki, Shunya; Keenlyside, Noel; Rouault, Mathieu (Journal article; Peer reviewed, 2018)
      Western boundary currents play an important role in the climate system by transporting heat poleward and releasing it to the atmosphere. While their influence on extratropical storms and oceanic rainfall is becoming ...

    • Cancellation of the precessional cycle in δ18O records during the Early Pleistocene 

      Morée, Anne; Sun, Tianyi; Bretones, Anaïs; Straume, Eivind Olavson; Nisancioglu, Kerim Hestnes; Gebbie, Geoffrey (Journal article; Peer reviewed, 2021)
      The dominant pacing of glacial‐interglacial cycles in deep‐ocean δ18O records changed substantially during the Mid‐Pleistocene Transition. The precessional cycle (∼23 ky) is absent during the Early Pleistocene, which we ...

    • The Climate Response to Emissions Reductions Due to COVID-19: Initial Results From CovidMIP 

      Jones, Chris D.; Hickman, Jonathan; Rumbold, Steven T; Walton, Jeremy; Lamboll, Robin; Skeie, Ragnhild Bieltvedt; Fiedler, Stephanie; Forster, Piers M.; Rogelj, Joeri; Abe, Manabu; Botzet, Michael; Calvin, Katherine; Cassou, Christophe; Cole, Jason N S; Davini, Paolo; Deushi, Makoto; Dix, Martin; Fyfe, John; Gillett, Nathan P.; Ilyina, Tatiana; Kawamiya, Michio; Kelley, Maxwell; Kharin, Slava; Koshiro, Tsuyoshi; Li, Hongmei; MacKallah, Chloe; Müller, Wolfgang A.; Nabat, Pierre; Van Noije, Twan; Nolan, Paul; Ohgaito, Rumi; Oliviè, Dirk Jan Leo; Oshima, Naga; Parodi, Jose; Reerink, Thomas J.; Ren, Lili; Romanou, Anastasia; Séférian, Roland; Tang, Yangming; Timmreck, Claudia; Tjiputra, Jerry; Tourigny, Etienne; Tsigaridis, Kostas; Wang, Hailong; Wu, Mingxuan; Wyser, Klaus; Yang, Shuting; Yang, Yang; Ziehn, Tilo (Journal article; Peer reviewed, 2021)
      Many nations responded to the corona virus disease-2019 (COVID-19) pandemic by restricting travel and other activities during 2020, resulting in temporarily reduced emissions of CO2, other greenhouse gases and ozone and ...

    • Collisionless Magnetic Reconnection in an Asymmetric Oxygen Density Configuration 

      Kolstø, Håkon Midthun; Hesse, Michael; Norgren, Astrid Elisabet Cecilia; Tenfjord, Paul; Spinnangr, Susanne Flø; Kwagala, Norah Kaggwa (Journal article; Peer reviewed, 2020)
      Combined with the magnetic field, the distribution of charged particles in the inflow region is expected to control the rate of magnetic reconnection. This paper investigates how the reconnection process is altered by a ...

    • Constraining Spectral Models of a Terrestrial GammaRay Flash From a Terrestrial Electron Beam Observation by the Atmosphere-Space Interactions Monitor 

      Sarria, David Alexandre Stephan; Østgaard, Nikolai; Kochkin, Pavlo; Lehtinen, Nikolai Grigorievich; Mezentsev, Andrey; Marisaldi, Martino; Lindanger, Anders; Maiorana, Carolina; Carlson, Brant Edward; Neubert, Torsten; Reglero, Victor; Ullaland, Kjetil; Yang, Shiming; Genov, Georgi; Qureshi, Bilal Hasan; Budtz-Jørgensen, Carl; Kuvvetli, Irfan; Christiansen, Freddy; Chanrion, Olivier; Navarro-Gonzalez, Javier; Connel, P.; Eyles, Chris (Journal article; Peer reviewed, 2021)
      Terrestrial Gamma ray Flashes (TGFs) are short flashes of high energy photons, produced by thunderstorms. When interacting with the atmosphere, they produce relativistic electrons and positrons, and a part gets bounded to ...

    • Control of Barents Sea wintertime cyclone variability by large-scale atmospheric flow 

      Madonna, Erica; Hes, Gabriel; Li, Camille; Michel, Clio; Siew, Yu Feng (Journal article; Peer reviewed, 2020)
      Extratropical cyclones transport heat and moisture into the Arctic, which can promote surface warming and sea ice melt. We investigate wintertime cyclone variability in the Barents Sea region to understand what controls ...

    • Crustal Conditions Favoring Convective Downward Migration of Fractures in Deep Hydrothermal Systems 

      Halldorsdottir, Sæunn; Berre, Inga; Keilegavlen, Eirik; Axelsson, Gudni (Journal article; Peer reviewed, 2023)
      Cooling magma plutons and intrusions are the heat sources for hydrothermal systems in volcanic settings. To explain system longevity and observed heat transfer at rates higher than those explained by pure conduction, the ...

    • Current models underestimate future irrigated areas 

      Saltelli, Andrea; Puy, Arnald; Lo Piano, Samuele (Journal article; Peer reviewed, 2020)
      Predictions of global irrigated areas are widely used to guide strategies that aim to secure environmental welfare and manage climate change. Here we show that these predictions, which range between 240 and 450 million ...

    • The Cusp as a VLF Saucer Source: First Rocket Observations of Long‐Duration VLF Saucers on the Dayside 

      Moser, Chrystal; LaBelle, James William; Hatch, Spencer Mark; Moen, Jøran Idar; Spicher, Andres; Takahashi, Toru; Kletzing, Craig A.; Bounds, Scott Randolph; Oksavik, Kjellmar; Sigernes, Fred; Yeoman, Timothy K. (Journal article; Peer reviewed, 2021)
      Auroral whistler‐mode radio emissions called saucers are of fundamental interest because they require an unusually stationary emission process in the dynamic auroral environment, and it is a mystery how that can happen in ...

    • Dayside Field-Aligned Current Impacts on Ionospheric Irregularities 

      Follestad, Anna Kristine Fæhn; Herlingshaw, Katie; Ghadjari, Hossein; Knudsen, David J.; McWilliams, Kathryn A.; Moen, Jøran Idar; Spicher, Andres; Wu, Jingjing; Oksavik, Kjellmar (Journal article; Peer reviewed, 2020)
      Global Navigation Satellite Systems (GNSS) are subject to disturbances caused by plasma irregularities in the ionosphere. Studies have suggested that in addition to the gradient drift and Kelvin‐Helmholtz instabilities, ...

    • Decadal Predictability of the North Atlantic Eddy-Driven Jet in Winter 

      Marcheggiani, Andrea; Robson, Jon; Monerie, Paul-Arthur; Bracegirdle, Thomas J.; Smith, Doug (Journal article; Peer reviewed, 2023)
      This paper expands on work showing that the winter North Atlantic Oscillation (NAO) is predictable on decadal timescales to quantify the skill in capturing the North Atlantic eddy-driven jet's location and speed. By focusing ...

    • Deconstructing Future AMOC Decline at 26.5°N 

      Asbjørnsen, Helene; Årthun, Marius (Journal article; Peer reviewed, 2023)
      The Atlantic Meridional Overturning Circulation (AMOC) is frequently used to diagnose the state of the North Atlantic circulation, but as an integrated quantity the AMOC strength does not necessarily mirror changes in the ...

    • The Dependence of Cold and Hot Patches on Local Plasma Transport and Particle Precipitation in Northern Hemisphere Winter 

      Zhang, Duan; Zhang, Qing-He; Ma, Y.-Z.; Oksavik, Kjellmar; Lyons, L.R.; Xing, Zan-Yang; Hairston, Marc; Deng, Z.-X.; Liu, J.-J. (Journal article; Peer reviewed, 2022)
      By using a database of 4,634 cold patches (high density and low electron temperature) and 4,700 hot patches (high density and high electron temperature) from Defense Meteorological Satellite Program F16 in 2005–2018 winter ...

    • Dependence of Sudden Stratospheric Warmings on Internal and External Drivers 

      Salminen, Antti; Asikainen, T.; Maliniemi, Ville Aleksi; Mursula, K. (Journal article; Peer reviewed, 2020)
      A sudden stratospheric warming (SSW) is a large-scale disturbance of the wintertime stratosphere, which occurs especially in the Northern Hemisphere. Earlier studies have shown that SSW occurrence depends on atmospheric ...

    • Diabatic Heating as a Pathway for Cyclone Clustering Encompassing the Extreme Storm Dagmar 

      Weijenborg, Christian; Spengler, Thomas (Journal article, 2020)
      Contrary to the general notion that extratropical cyclones reduce baroclinicity, the baroclinicity is found to be enhanced in the wake of the extreme winter storm Dagmar. Thus, individual storms can increase baroclinicity, ...

    • The Direct Effect of Medium Energy Electron Precipitation on Mesospheric Dynamics During a Sudden Stratospheric Warming Event in 2010 

      Zuniga Lopez, Hector Daniel; Tyssøy, Hilde Nesse; Smith-Johnsen, Christine; Maliniemi, Ville Aleksi (Journal article; Peer reviewed, 2022)
      Medium energy electron (MEE) (30–1,000 keV) precipitation enhances the production of nitric (NOx) and hydrogen oxides (HOx) throughout the mesosphere, which can destroy ozone (O3) in catalytic reactions. The dynamical ...

    • Do the Throat Auroras Create Polar Cap Patches? 

      Zhang, Duan; Zhang, Qing-He; Oksavik, Kjellmar; Xu, Tong; Xing, Zan-Yang; Lyons, L.R.; Han, De-Sheng; Zhang, Hong-Bo; Ma, Yu-Zhang; Hu, Ze-Jun; Liu, Jian-Jun; Wang, Yong; Wang, Xiang-Yu (Journal article; Peer reviewed, 2023)
      Throat auroras and polar cap patches are common phenomena in the polar ionosphere resulting from magnetosphere-ionosphere coupling. A campaign was organized, with all-sky imagers at Yellow River Station, the European ...