- Phone+47 55 58 98 46
- Visitor AddressGeophysical InstituteAllegaten 705020 BergenRoom229
- Postal AddressPostboks 78035020 BERGEN
I am a meteorologist focusing on the combination of theory, observations, and modelling, specialized on scales ranging from meso, synoptic, to large-scale flow and participated and coordinated several field campaigns.
Since 2015, I am the director of the RCN funded Norwegian Research School on Changing Climates in the Coupled Earth System (CHESS).
I am currently leading research projects focusing on atmosphere-ocean-ice interactions in higher latitudes as well as air-sea interactions and cyclone development in the midlatitude storm tracks.
In 2012 I was elected as a member of the International Commission for Dynamic Meteorology and was elected President of ICDM in 2019. From 2015-2019, I was the elected as Chair of the Atmospheric Working Group of the International Arctic Science Committee (IASC).
I was awarded the prize for best lecturer of the academic year 2012/2013 at the Faculty for Mathematics and Natural Sciences at the University of Bergen and nominated for the IAMAS early career scientist medal in 2013.
- Air-Ice-Sea Interactions in the Marginal Ice Zone
- Jet Stream Dynamics and Variability
- Polar Lows
- Tropical-Extratropical Interactions
- Baroclinic and Diabatic Intensification of Extratropical Cyclones
- Heat Lows
- Orographic Slope and Valley Winds
- Flow over and around Topography
I am leading a science outreach project together with the Bergen Philharmonic Orchestra in which we feature four concerts as part of the regular concert series for the season 2019-2020. The themes of the four concerts are: Space, Ocean, Climate, and Humankind. More information about the project can be found on https://nestesteg.w.uib.no/.
Introduction to Methods in Weather Forecasting (GEOF321)
Dynamics of the Atmosphere (GEOF326)
Advanced Atmospheric Dynamics (GEOF352)
Mesoscale Dynamics (GEOF328)
Seminar in Atmospheric Sciences (GEOF351)
Polar Meteorology and Climate (AGF-213)
The Arctic Atmospheric Boundary Layer and Local Climate Processes (AGF-350)
Supervision of PhD students:
Kristine Flacké Haualand: Diabatic intensification of baroclinic evolution and the role of surface fluxes. 2016-2020
Leonidas Tsopouridis: Air-sea interaction processes in the Gulf Stream and Kurishio Rregions. 2016-2020
Clemens Spensberger: New approaches to investigate the influence of orographic and dynamic blocking on large-scale atmospheric flow. 2011-2015
Annick Terpstra: Dynamical perspectives on the formation and intensification of polar lows. 2011-2014
Mathew Reeve: Monsoon onset in Bangladesh: reconciling scientific and societal perspectives. 2010-2015
Stefan Keiderling: Jet Dynamics, Evolution, and Forcing. 2013-2017
Qi Kong: Interactions of Cyclones with steep Topography. 2011-2013
Supervision of Master students:
Kjersti Konstali: A Coupled Atmosphere-Ocean-Ice Mixed Layer Model for Cold Air Outbreaks. 2018-2019
Lars Andreas Selberg: Dynamics and Predictability of extreme winter storm Nina. 2015-2016
Kristine Flacké Haualand: Diabatic intensification of baroclinic evolution. 2015-2016
Ståle Dahl-Eriksen: Influence of SST gradients on cyclones and storm tracks. 2015-2016
Magnus Haukeland: Polar Low Climatology and Impact on Norway: Present and Future. 2015-2016
Musa Ssemujju: Early Season Rainfall in North-East Bangladesh. 2015-2016
Matthias Gottschalk: An idealized study on the influence of the sea ice edge on the development of polar lows. 2015
Ragnhild Nordhagen: Forecast Challenges associated with Cold Pools in Norwegian Valleys. 2013-2014
Linda Green: Influence of Surface Fluxes on Polar Low Development: Idealised Simulations. 2013-2014
Bas Creeze: Polar low detection and tracking. 2013
Trond Thorsteinsson: The development and evaluation of an idealized ocean model for the Bergen Dynamic Model. 2013
Angus Munro: What can flow deformation tell us about Rossby wave breaking in the atmosphere? 2012-2013
Espen Karlsen: Extreme precipitation in Norway: Present and Future Changes based on Regional Climate Simulations. 2012-2013
Stefan Keiderling: Low Level Jet Streams at the Sea Ice Edge - Numerical Simulations using WRF. 2012-2013
Cecilie Villanger: Exteme winds in Norway - an analysis based on observations and reanalyses. 2012-2013
Elin Tronvoll: Cyclone Interaction with the Topography of Greenland: A Catalog of Cyclone Motion. 2011-2012
- 2021. The Effect of Sea Surface Temperature Fronts on Atmospheric Frontogenesis. Journal of the Atmospheric Sciences. 1753-1771.
- 2021. Sensitivity of Air-Sea Heat Exchange in Cold-Air Outbreaks to Model Resolution and Sea-Ice Distribution. Journal of Geophysical Research (JGR): Atmospheres. 13 pages.
- 2021. Relative importance of tropopause structure and diabatic heating for baroclinic instability. Weather and Climate Dynamics (WCD). 695-712.
- 2021. Polar Lows - Moist Baroclinic Cyclones in Four Different Vertical Wind Shear Environments. Weather and Climate Dynamics (WCD). 19-36.
- 2021. On the Influence of Sea Surface Temperature distributions on the Development of Extratropical Cyclones. Journal of the Atmospheric Sciences. 1173-1188.
- 2020. The connection between the Southern Annular Mode and a feature-based perspective on Southern Hemisphere mid-latitude winter variability. Journal of Climate. 115-129.
- 2020. SST fronts along the Gulf Stream and Kuroshio affect the winter climatology primarily in the absence of cyclones. Weather and Climate Dynamics (WCD). 1-27.
- 2020. IsoTrotter: Visually Guided Empirical Modelling of Atmospheric Convection. IEEE Transactions on Visualization and Computer Graphics. 775-784.
- 2020. Feature-Based Jet Variability in the Upper Troposphere. Journal of Climate.
- 2020. Factors affecting extreme rainfall events in the South Pacific. Weather and Climate Extremes.
- 2020. Direct and Indirect Effects of Surface Fluxes on Moist Baroclinic Development in an Idealized Framework. Journal of the Atmospheric Sciences.
- 2020. Diabatic Heating as a Pathway for Cyclone Clustering Encompassing the Extreme Storm Dagmar. Geophysical Research Letters.
- 2020. Cyclone Intensification in the Kuroshio Region and its relation to the Sea Surface Temperature Front and Upper‐Level Forcing. Quarterly Journal of the Royal Meteorological Society. 485-500.
- 2020. Characteristics of cyclones following different pathways in the Gulf Stream region. Quarterly Journal of the Royal Meteorological Society. 392-407.
- 2019. Prevailing Surface Wind Direction during Air-Sea Heat Exchange. Journal of Climate. 5601-5617.
- 2019. Polar low workshop. Bulletin of The American Meteorological Society - (BAMS). ES89-ES92.
- 2019. How does latent cooling affect baroclinic development in an idealized framework? Journal of the Atmospheric Sciences. 2701-2714.
- 2018. The North Atlantic waveguide and downstream impact experiment. Bulletin of The American Meteorological Society - (BAMS). 1607-1637.
- 2018. Polar Mesoscale Cyclone Climatology for the Nordic Seas Based on ERA-Interim. Journal of Climate. 2511-2532.
- 2018. Non-Uniqueness of Attribution in Piecewise Potential Vorticity Inversion. Journal of the Atmospheric Sciences. 875-883.
- 2018. Modification of Polar Low Development by Orography and Sea Ice. Monthly Weather Review. 3325-3341.
- 2017. Upper-Tropospheric Jet Axis Detection and Application to the Boreal Winter 2013/14. Monthly Weather Review. 2363-2374.
- 2017. Synoptic Systems interacting with the Rocky Mountain Barrier: Observations and Theories. Monthly Weather Review. 783-794.
- 2017. Polar Low Workshop Summary. Bulletin of The American Meteorological Society - (BAMS). ES139-ES142.
- 2017. Inversion of potential vorticity density. Journal of the Atmospheric Sciences. 801-807.
- 2016. Structure of a shear-line polar low. Quarterly Journal of the Royal Meteorological Society. 12-26.
- 2016. New Tools for Comparing Beliefs about the Timing of Recurrent Events with Climate Time Series Datasets. Weather, Climate, and Society. 493-506.
- 2016. Forward and reverse shear environments during polar low genesis over the North East Atlantic. Monthly Weather Review. 1341-1354.
- 2016. Diabatic heating and jet stream shifts: A case study of the 2010 negative North Atlantic Oscillation winter. Geophysical Research Letters. 9994-10,002.
- 2016. Comment on "Incorporating the Effects of Moisture into a Dynamical Parameter: Moist Vorticity and Moist Divergence". Weather and forecasting. 1393-1396.
- 2016. Climatology of polar lows over the Sea of Japan using the JRA-55 reanalysis. Journal of Climate. 419-437.
- 2016. A Lagrangian climatology of wintertime cold air outbreaks in the Irminger and Nordic seas and their role in shaping air-sea heat fluxes. Journal of Climate. 2717-2737.
- 2015. Rossby waves, extreme fronts, and wildfires in southeastern Australia. Geophysical Research Letters. 2015-2023.
- 2015. Idealised simulations of polar low development in an Arctic moist-baroclinic environment. Quarterly Journal of the Royal Meteorological Society. 1987-1996.
- 2015. Complementing scientific monsoon definitions with social perception in Bangladesh. Bulletin of The American Meteorological Society - (BAMS). 49-57.
- 2015. Aspects of potential vorticity fluxes: Climatology and impermeability. Journal of the Atmospheric Sciences. 3257-3267.
- 2015. Analysis of the slope of isentropic surfaces and its tendencies over the North Atlantic. Quarterly Journal of the Royal Meteorological Society. 3226-3238.
- 2015. An initialization method for idealized channel simulations. Monthly Weather Review. 2043-2051.
- 2014. Testing a flexible method to reduce false monsoon onsets. PLOS ONE.
- 2014. A new look at deformation as a diagnostic for large-scale flow. Journal of the Atmospheric Sciences. 4221-4234.
- 2013. Reflection of Barotropic Rossby Waves in Sheared Flow and Validity of the WKB Approximation. Journal of the Atmospheric Sciences. 2170-2178.
- 2012. Potential vorticity attribution and causality. Journal of the Atmospheric Sciences. 2600-2607.
- 2012. FLOHOF 2007: an overview of the mesoscale meteorological field campaign at Hofsjokull, Central Iceland. Meteorology and atmospheric physics (Print). 1-13.
- 2011. The Norwegian IPY-THORPEX. Polar Lows and Arctic Fronts during the 2008 Andøya Campaign. Bulletin of The American Meteorological Society - (BAMS). 1443-1466.
- 2011. How does rain affect surface pressure in a one-dimensional framework? Journal of the Atmospheric Sciences. 347-360.
- 2011. Dynamics of Heat Lows over elevated terrain. Quarterly Journal of the Royal Meteorological Society. 250-263.
- 2010. The Modulation of the Subtropical and Extratropical Atmosphere in the Pacific Basin in Response to the Madden Julian Oscillation. Monthly Weather Review. 2761-2779.
- 2009. Thermally driven Flows at an asymmetric valley exit: Observations and Model Studies at the Lech Valley exit. Monthly Weather Review. 3437-3455.
- 2009. Multi-event analysis of the westerly Greenland tip jet based upon 45 winters in ERA-40. Quarterly Journal of the Royal Meteorological Society. 1999-2011.
- 2009. Comments on "Dry-Season Precipitation in Tropical West Africa and Its Relation to Forcing from the Extratropics". Monthly Weather Review. 3149-3150.
- 2008. The dynamics of heat lows over flat terrain. Quarterly Journal of the Royal Meteorological Society. 2157-2172.
- 2005. The Dynamics of Heat Lows in Simple Background Flows. Quarterly Journal of the Royal Meteorological Society. 3147-3166.
- 2002. The Prediction of low-level convergence lines over northeastern Australia. Australian meteorological magazine. 13-23.
- 2015. Polar lower-latitude linkages and their role in weather and climate prediction. Bulletin of The American Meteorological Society - (BAMS). ES197-ES200.
- 2014. Influence of surface fluxes of polar low development: idealised simulations.
- 2013. Low Level Jet Streams at the Ice Edge-Numerical Studies using WRF.
- 2013. Extreme winds in Norway - an analysis based on observations and reanalyses.
- 2013. An objective climatology of Polar Lows: structure and forcing mechanism.
- 2012. Cyclone Interaction with the Topography of Greenland.
- 2015. Iskantens ekstreme klima. Bergens Tidende. 12-13.
- 2012. Hva er egentlig monsunen? Klima.
- 2014. Dynamical perspectives on the formation and intensification of polar lows.
- 2016. High-latitude dynamics of atmosphere-ice-ocean interactions. Bulletin of The American Meteorological Society - (BAMS). ES179-ES182.
- 2019. Local versus Remote Influence of Surface Fluxes in Idealised Baroclinic Development.
- 2019. How do Extratropical Cyclones respond to the North Atlantic Sea Surface Temperature Front? .
- 2019. How Do Latent Cooling and Surface Heat Fluxes Influence Baroclinic Development in an Idealised Framework?
- 2019. Diabatic Effects on Baroclinic Development.
- 2018. Polar Mesoscale Cyclone Climatology for the Nordic Seas.
- 2018. Midlatitude Storm Development and Intensification.
- 2018. Maintenance of Baroclinicity: Global Climatology of the Slope of Isentropic Surfaces and their Tendencies.
- 2018. Influence of the SST Fronts on the evolution of North Atlantic Storms.
- 2018. Global Climatology of Baroclinicity and its Variations: Role or Air-Sea Interactions.
- 2018. Effects of Surface Fluxes and Latent Heating on Extratropical Cyclones in an Idealised Linear Framework.
- 2018. Difference between Mean and Instantaneous Wind Direction associated with Air-Sea Fluxes.
- 2017. New Tools for Comparing Beliefs about the Timing of Recurrent Events with Climate Time Series Datasets.
- 2017. Latent heating and surface fluxes in baroclinic development.
- 2017. Influence of the Gulf Stream Sea Surface Temperature Front on the evolution of Storms.
- 2017. Impact of moisture on storm development.
- 2017. Air-Sea Interaction Processes along the Gulf Stream region.
- 2016. Climatology and Genesis Environment of North Atlantic Polar Lows.
- 2015. Relating objectively detected jet axes, blocking and wave-breaking events.
- 2015. Present and future climatologies of polar lows over the Norwegian Sea.
- 2015. Environmental Conditions for Polar Lows in the Nordic Seas.
- 2015. Disentangling the co-variability of the jet location and intensity.
- 2014. Two types of westerly Greenland tip jets.
- 2014. Tropical Diabatic Heating and its Influence on the Extratropical Jets during Winter .
- 2014. Climatology and dynamical aspects of polar lows over the Nordic Seas.
- 2013. Synoptic Evolution and Dynamic Characteristics of the Extreme Norwegian Winter Storm Dagmar.
- 2013. Low Level Jet Streams at the Ice Edge-Numerical Studies using WRF.
- 2013. Low Level Jet Streams at the Ice Edge-Numerical Studies using WRF.
- 2012. The Diabatic Rossby Vortex as a mechanism for polar low initiation and intensification.
- 2019. The Iceland Greenland seas project. Bulletin of The American Meteorological Society - (BAMS). 1795-1817.
Unifying Perspectives on Atmosphere-Ocean Interactions during Cyclone Development (UNPACC)
2017-2020 (10 Mio NOK)
Extratropical cyclones are a key feature of the mid-latitude climate and weather, where unresolved mesoscale air-sea interactions are thought to play a crucial role in their genesis and intensification, yielding model uncertainties and forecast challenges. Understanding these mesoscale interactions between ocean sea surface temperature fronts, ocean eddies, and the atmosphere is thus essential for understanding the role of diabatic processes in extratropical cyclones and constraining uncertainty.
While recent studies highlight the importance of mesoscale air-sea interactions for the development and intensification of cyclones, we are still lacking a theoretical framework unifying moist baroclinic and frontal-wave instability under the influence of air-sea interaction and diabatic processes. How do oceanic fronts and eddies influence the genesis and intensification of cyclones? What is the role of mesoscale air-sea interaction processes for the upscale growth of instabilities? Can such instabilities trigger or inhibit the intensification of extratropical cyclones? What are the underlying mechanisms for diabatic amplification of energy conversion in extratropical cyclones?
We will establish an innovative collaboration in atmospheric dynamics and air-sea interactions by combining key and complementary expertise from the Universities of Bergen, Monash (Australia), East Anglia (UK), Texas A&M (USA), Tokyo (Japan) as well as ECMWF (UK). The central goal of the collaboration is to elucidate and quantify the mechanisms responsible for extratropical cyclone intensification associated with mesoscale air-sea interactions. Our approach utilizes novel detection routines on high-resolution coupled model datasets and reanalyzes as well as idealized and real case simulations. As the integrated framework is grounded in fundamental dynamics, we expect UNPACC to yield a unified framework for moist frontal-baroclinic instability theory including the influence of air-sea interactions.
Awards and Nominations
2013 Nominee for the IAMAS Early Career Science Medal