• Bedymo: A combined quasi-geostrophic and primitive equation model in σ coordinates 

      Spensberger, Clemens; Thorsteinsson, Trond; Spengler, Thomas (Journal article; Peer reviewed, 2022)
      This paper introduces the Bergen Dynamical Model (Bedymo), an idealized atmospheric circulation model, which combines the quasi-geostrophic approximation and the hydrostatic primitive equations into one modelling framework. ...
    • Characteristics of cyclones following different pathways in the Gulf Stream region 

      Tsopouridis, Leonidas; Spensberger, Clemens; Spengler, Thomas (Journal article; Peer reviewed, 2021)
      The Northwest Atlantic is a region of strong temperature gradients and hence is a favourable location for wintertime cyclone intensification co-located with the storm track. The temperature gradient is associated with both ...
    • The COMBLE Campaign: A Study of Marine Boundary Layer Clouds in Arctic Cold-Air Outbreaks 

      Geerts, Bart; Giangrande, Scott E.; McFarquhar, Greg M.; Xue, Lulin; Abel, Steven J.; Comstock, Jennifer M.; Crewell, Susanne; DeMott, Paul J.; Ebell, Kerstin; Field, Paul; Hill, Thomas C. J.; Hunzinger, Alexis; Jensen, Michael P.; Johnson, Karen L.; Juliano, Timothy W.; Kollias, Pavlos; Kosovic, Branko; Lackner, Christian; Luke, Ed; Lüpkes, Christof; Matthews, Alyssa A.; Neggers, Roel; Ovchinnikov, Mikhail; Powers, Heath; Shupe, Matthew D.; Spengler, Thomas; Swanson, Benjamin E.; Tjernström, Michael; Theisen, Adam K.; Wales, Nathan A.; Wang, Yonggang; Wendisch, Manfred; Wu, Peng (Journal article; Peer reviewed, 2022)
      One of the most intense air mass transformations on Earth happens when cold air flows from frozen surfaces to much warmer open water in cold-air outbreaks (CAOs), a process captured beautifully in satellite imagery. Despite ...
    • Complementing Scientific Monsoon Definitions with Social Perception in Bangladesh 

      Reeve, Mathew Alexander; Syed, Mohammed Abu; Spengler, Thomas; Spinney, Jennifer A.; Hossain, Rumana (Peer reviewed; Journal article, 2015-01)
      The monsoon onset is a critical event in the Bangladesh calendar, especially for the domestic agricultural sector. Providing information about the monsoon onset for the past, present, and future has potential benefit for ...
    • The connection between the Southern Annular Mode and a feature-based perspective on Southern Hemisphere mid-latitude winter variability 

      Spensberger, Clemens; Reeder, Michael John; Spengler, Thomas; Patterson, Matthew (Journal article; Peer reviewed, 2020)
      This article provides a reconciling perspective on the two main, but contradictory, interpretations of the southern annular mode (SAM). SAM was originally thought to characterize meridional shifts in the storm track across ...
    • Coupled atmosphere–ocean observations of a cold-air outbreak and its impact on the Iceland Sea 

      Renfrew, Ian A.; Huang, Jie; Semper, Stefanie; Barrell, Christopher; Terpstra, Annick; Pickart, Robert S.; Våge, Kjetil; Elvidge, Andrew D.; Spengler, Thomas; Strehl, Anna-Marie; Weiss, Alexandra (Journal article; Peer reviewed, 2023)
      Marine cold-air outbreaks (CAOs) are vigorous equatorward excursions of cold air over the ocean, responsible for the majority of wintertime oceanic heat loss from the subpolar seas of the North Atlantic. However, the impact ...
    • Cyclone Intensification in the Kuroshio Region and its relation to the Sea Surface Temperature Front and Upper‐Level Forcing 

      Tsopouridis, Leonidas; Spensberger, Clemens; Spengler, Thomas (Journal article; Peer reviewed, 2021)
      The Northwest Pacific features strong sea surface temperature (SST) gradients providing favourable conditions for wintertime cyclone intensification in the midlatitudes. To estimate the relative contribution of the SST ...
    • 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, ...
    • Direct and Indirect Effects of Surface Fluxes on Moist Baroclinic Development in an Idealized Framework 

      Haualand, Kristine Flacké; Spengler, Thomas (Journal article; Peer reviewed, 2020-09)
      The convoluted role of surface sensible and latent heat fluxes on moist baroclinic development demands a better understanding to disentangle their local and remote effects. Including diabatic effects in the Eady model, the ...
    • Driving Mechanisms of an Extreme Winter Sea Ice Breakup Event in the Beaufort Sea 

      Davy, Richard; Olason, Einar; Rampal, Pierre; Spensberger, Clemens; Williams, Timothy; Korosov, Anton; Spengler, Thomas; Rheinlænder, Jonathan W. (Journal article; Peer reviewed, 2022)
      The thick multiyear sea ice that once covered large parts of the Arctic is increasingly being replaced by thinner and weaker first-year ice, making it more vulnerable to breakup by winds. We use the neXtSIM sea ice model ...
    • The Effect of Sea Surface Temperature Fronts on Atmospheric Frontogenesis 

      Reeder, Michael J; Spengler, Thomas; Spensberger, Clemens (Journal article; Peer reviewed, 2021)
      It is thought that the sensible heat fluxes associated with sea surface temperature (SST) fronts can affect the genesis and evolution of atmospheric fronts. An analytic model is developed and used to explore this idea. The ...
    • Factors affecting extreme rainfall events in the South Pacific 

      Pariyar, Sunil Kumar; Keenlyside, Noel; Sorteberg, Asgeir; Spengler, Thomas; Bhatt, Bhuwan Chandra; Ogawa, Fumiaki (Journal article; Peer reviewed, 2020)
      Extreme rainfall events in the South Pacific are widespread and affected by various factors on different time scales. We use daily rainfall data from 20 stations over the South Pacific to investigate the characteristics ...
    • Feature-Based Jet Variability in the Upper Troposphere 

      Spensberger, Clemens; Spengler, Thomas (Journal article; Peer reviewed, 2020)
      Jets in the upper troposphere constitute a cornerstone of both synoptic meteorology and climate dynamics, providing a direct link between weather and midlatitude climate variability. Conventionally, jet variability is often ...
    • FLOHOF 2007: an overview of the mesoscale meteorological field campaign at Hofsjökull, Central Iceland 

      Reuder, Joachim; Ablinger, Markus; Ágústsson, Hálfdán; Brisset, Pascal; Brynjólfsson, Sveinn; Garhammer, Markus; Jóhannesson, Tómas; Jonassen, Marius O.; Kühnel, Rafael; Lämmlein, Stephan; de Lange, Tor; Lindenberg, Christian; Malardel, Sylvie; Mayer, Stephanie; Müller, Martin; Ólafsson, Haraldur; Rögnvaldsson, Ólafur; Schäper, Wolfgang; Spengler, Thomas; Zängl, Günther; Egger, Joseph (Peer reviewed; Journal article, 2012-04)
      The FLOHOF field campaign took place in the period July 21 to August 24, 2007 on and in the surroundings of Hofsjökull glacier in Central Iceland. During the campaign, 18 automatic weather stations (AWS) recording temperature, ...
    • Formation of maritime convergence zones within cold air outbreaks due to the shape of the coastline or sea ice edge 

      Watanabe, Shun-ichi I.; Niino, Hiroshi; Spengler, Thomas (Journal article; Peer reviewed, 2022)
      Maritime cold air outbreaks often feature convergence zones that provide a conducive environment for the development of polar mesoscale cyclones and polar lows. This study examines the formation mechanisms of these convergence ...
    • How does latent cooling affect baroclinic development in an idealized framework? 

      Haualand, Kristine Flacké; Spengler, Thomas (Peer reviewed; Journal article, 2019)
      Latent cooling by evaporating or melting hydrometeors has recently been shown to contribute to the positive low-level potential vorticity (PV) anomaly below the layer of latent heating in midlatitude cyclones. While the ...
    • The Iceland Greenland seas project 

      Renfrew, Ian Alasdair; Pickart, RS; Våge, Kjetil; Moore, GWK; Bracegirdle, TJ; Elvidge, AD; Jeansson, Emil; Lachlan-Cope, T; McRaven, LT; Papritz, L; Reuder, Joachim; Sodemann, Harald; Terpstra, Annick; Waterman, S; Valdimarsson, H; Weiss, A; Almansi, M; Bahr, F; Brakstad, Ailin; Barrell, C; Brooke, JK; Brooks, BJ; Brooks, IM; Brooks, ME; Bruvik, Erik Magnus; Duscha, Christiane; Fer, Ilker; Golid, Heidi M.; Hallerstig, Matilda; Hessevik, Idar; Huang, J; Houghton, L; Jonsson, S; Jonassen, Marius Opsanger; Jackson, Kristin; Kvalsund, Karsten; Kolstad, Erik Wilhelm; Konstali, Kjersti; Kristiansen, Jørn; Ladkin, R; Lin, P; MacRander, A; Mitchell, A; Olafsson, H; Pacini, A; Payne, C; Palmason, B; Perez-Hernandez, MD; Peterson, Algot Kristoffer; Petersen, GN; Pisareva, MN; Pope, JO; Seidl, Andrew; Semper, Stefanie; Sergeev, D; Skjelsvik, Silje; Søiland, Henrik; Smith, D; Spall, MA; Spengler, Thomas; Touzeau, Alexandra; Tupper, G; Weng, Yongbiao; Williams, KD; Yang, X; Zhou, Shenjie (Peer reviewed; Journal article, 2019)
      The Iceland Greenland Seas Project (IGP) is a coordinated atmosphere–ocean research program investigating climate processes in the source region of the densest waters of the Atlantic meridional overturning circulation. ...
    • IsoTrotter: Visually Guided Empirical Modelling of Atmospheric Convection 

      Palenik, Juraj; Spengler, Thomas; Hauser, Helwig (Journal article; Peer reviewed, 2020)
      Empirical models, fitted to data from observations, are often used in natural sciences to describe physical behaviour and support discoveries. However, with more complex models, the regression of parameters quickly becomes ...
    • Linking Instantaneous and Climatological Perspectives on Eddy-Driven and Subtropical Jets 

      Spensberger, Clemens; Li, Camille; Spengler, Thomas (Journal article; Peer reviewed, 2023)
      The distinction between eddy-driven and subtropical jets is conceptually important and well-founded based on different driving mechanisms and dominant types of variability. This climatological perspective may be augmented ...
    • A New Look at Deformation as a Diagnostic for Large-Scale Flow 

      Spensberger, Clemens; Spengler, Thomas (Peer reviewed; Journal article, 2014-11)
      Deformation plays a key role in atmospheric dynamics because it provides a dynamical measure of the interaction between different scales, such as in frontogenesis. A climatology of deformation constructed from Interim ECMWF ...