Browsing Institutt for geofag by Author "Lacasce, Joseph Henry"

Now showing items 1-18 of 18

  • The atmospheric response to surface heating under maximum entropy production 
    Gjermundsen, Ada; Lacasce, Joseph Henry; Graff, Lise Seland (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2014)
    In numerous studies, midlatitude storm tracks have been shown to shift poleward under global warming scenarios. Among the possible causes, changes in sea surface temperature (SST) have been shown to affect both the intensity ...
  • Baroclinic modes over rough bathymetry and the surface deformation radius 
    Lacasce, Joseph Henry; Groeskamp, Sjoerd (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2020)
    Abstract The deformation radius is widely used as an indication of the eddy length scale at different latitudes. The radius is usually calculated assuming a flat ocean bottom. However, bathymetry alters the baroclinic modes ...
  • Comparing the linear and nonlinear buoyancy-driven circulation 
    Gjermundsen, Ada; Lacasce, Joseph Henry (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2017)
    The buoyancy-driven circulation is studied in an idealized domain using two models, one based on the linearized planetary geostrophic equations and a fully nonlinear GCM. The surface buoyancy is specified (relaxed) to a ...
  • Deep-Reaching Global Ocean Overturning Circulation Generated by Surface Buoyancy Forcing 
    Klocker, Andreas; Munday, David; Gayen, Bishakhdatta; Roquet, Fabien; Lacasce, Joseph Henry (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2023)
    In contrast with the atmosphere, which is heated from below by solar radiation, the ocean is both heated and cooled from above. To drive a deep-reaching overturning circulation in this context, it is generally assumed that ...
  • Dynamical Stability Indicator based on Autoregressive Moving-Average Models: Critical Transitions and the Atlantic Meridional Overturning Circulation 
    Rodal, Marie; Krumscheid, Sebastian; Madan, Gaurav; Lacasce, Joseph Henry; Vercauteren, Nikki (Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2022)
    A statistical indicator for dynamic stability, known as the [Formula: see text] indicator, is used to gauge the stability and, hence, detect approaching tipping points of simulation data from a reduced five-box model of ...
  • Experimental investigation of airflow above waves in a horizontal pipe 
    Vollestad, Petter; Ayati, Anis Awal; Angheluta, Luiza; Lacasce, Joseph Henry; Jensen, Atle (Journal article / Tidsskriftartikkel / AcceptedVersion; Peer reviewed, 2018)
    We investigate the effect of waves on the airflow in horizontal two-phase pipe flow. Velocity fields in the gaseous phase were acquired by particle image velocimetry (PIV), while interfacial elevation was measured with ...
  • Full-Depth Eddy Kinetic Energy in the Global Ocean Estimated From Altimeter and Argo Observations 
    Ni, Qinbiao; Zhai, Xiaoming; Lacasce, Joseph Henry; Chen, Dake; Marshall, David P. (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2023)
    Abstract Although the surface eddy kinetic energy (EKE) has been well studied using satellite altimeter and surface drifter observations, our knowledge of EKE in the ocean interior is much more limited due to the sparsity ...
  • Full‐Depth Global Estimates of Ocean Mesoscale Eddy Mixing From Observations and Theory 
    Groeskamp, Sjoerd; Lacasce, Joseph Henry; McDougall, Trevor J.; Rogé, Marine (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2020)
    Mixing by mesoscale eddies profoundly impacts climate and ecosystems by redistributing and storing dissolved tracers such as heat and carbon. Eddy mixing is parameterized in most numerical models of the ocean and climate. ...
  • Gateway-driven weakening of ocean gyres leads to Southern Ocean cooling 
    Sauermilch, Isabel; Whittaker, Joanne M.; Klocker, Andreas; Munday, David R.; Hochmuth, Katharina; Bijl, Peter K.; Lacasce, Joseph Henry (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2021)
    Abstract Declining atmospheric CO 2 concentrations are considered the primary driver for the Cenozoic Greenhouse-Icehouse transition, ~34 million years ago. A role for tectonically opening Southern Ocean gateways, initiating ...
  • Jet Instability over Smooth, Corrugated, and Realistic Bathymetry 
    Lacasce, Joseph Henry; Escartin, Javier; Chassignet, Eric P.; Xu, Xiaobiao (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2019)
    The stability of a horizontally and vertically sheared surface jet is examined, with a focus on the vertical structure of the resultant eddies. Over a flat bottom, the instability is mixed baroclinic/barotropic, producing ...
  • Lateral Heat Transport in the Lofoten Basin: Near-Surface Pathways and Subsurface Exchange 
    Dugstad, Johannes Sandang; Fer, Ilker; Lacasce, Joseph Henry; Sanchez de la Lama, Marta; Trodahl, Marta (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2019)
    The Lofoten Basin in the Nordic Seas plays a central role in the Atlantic overturning circulation by acting as a reservoir for the warm and saline Atlantic Water flow toward the Arctic Ocean. The mass and heat exchange ...
  • Prevalence of Deformation-Scale Surface Currents 
    Paloczy Filho, André; Lacasce, Joseph Henry (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2023)
    Abstract Understanding the transport of large ocean currents, like the Gulf Stream, has been of interest since the early days of oceanography. There has been less attention on the widths of the currents, although there ...
  • The Prevalence of oceanic surface modes 
    Lacasce, Joseph Henry (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2017)
    Satellite observations have revolutionized oceanography, capturing diverse phenomena over much of the globe. However, it remains to understand how surface fields, like sea surface height, reflect the motion occurring at ...
  • Rapid response of the Norwegian Atlantic Slope Current to wind forcing 
    Brown, Nicola; Mauritzen, Cecilie; Li, Camille; Madonna, Erica; Isachsen, Pål Erik; Lacasce, Joseph Henry (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2022)
    Abstract We explore drivers of variability in the Norwegian Atlantic Slope Current, which carries relatively warm Atlantic Water towards the Barents Sea and Arctic Ocean, using CMEMS satellite altimetry data and TOPAZ4 ...
  • Surface currents in operational oceanography: Key applications, mechanisms, and methods 
    Röhrs, Johannes; Sutherland, Graig; Jeans, Gus; Bedington, Michael; Sperrevik, Ann Kristin; Dagestad, Knut-Frode; Gusdal, Yvonne; Mauritzen, Cecilie; Dale, Andrew; Lacasce, Joseph Henry (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2021)
    This paper reviews physical mechanisms, observation techniques and modelling approaches dealing with surface currents on short time scales (hours to days) relevant for operational oceanography. Key motivations for this ...
  • The finite size lyapunov exponent and the finite amplitude growth rate 
    Meunier, Thomas; Lacasce, Joseph Henry (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2021)
    The finite size Lyapunov exponent (FSLE) has been used extensively since the late 1990s to diagnose turbulent regimes from Lagrangian experiments and to detect Lagrangian coherent structures in geophysical flows and ...
  • The weakening AMOC under extreme climate change 
    Madan, Gaurav; Gjermundsen, Ada; Iversen, Silje Christine; Lacasce, Joseph Henry (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2023)
    Abstract Changes in the Atlantic Meridional Overturning Circulation (AMOC) in the quadrupled CO 2 experiments conducted under the sixth Coupled Model Intercomparison Project (CMIP6) are examined. Increased CO 2 triggers ...
  • The thermally-driven ocean circulation with realistic bathymetry 
    Gjermundsen, Ada; Lacasce, Joseph Henry; Denstad, Liv (Journal article / Tidsskriftartikkel / PublishedVersion; Peer reviewed, 2018)
    The global circulation driven solely by relaxation to an idealized surface temperature profile and to interior mixing is examined. Forcing by winds and evaporation/precipitation is excluded. The resulting circulation ...