Stockholm university

Inga KoszalkaAssociate professor

About me

Inga Monika Koszalka
Associate Professor of Coastal Oceanography
- Baltic Sea Fellow

Research Gate, Google Scholar, ORCID


2023-09-20: Hanna Winge defended her master thesis, congratulations Hanna!

2023-06-02Johan Tengholm defended his bachelor thesis, congratulations Johan!

2023-05-27: Our FORMAS project ALGOTL was featured in TV4: link

2023-05-21: My PhD student Jonathan Wiskandt paper has been accepted to TC!: link (2023-07-13 published)

2023-05-16: FORMAS project ALGOTL had a very successful workshop with stakeholdes on Gotland.

2023-05-11: Claudia Cenedese visiting MISU and showing us how to perform lab simple Rossby Wave experiments with an ice cube (which we will incorporate to the rotating table lab in the GFD course MO8009)

2023-03-22: Meet the high school students at the Baltic Sea Centre Skansen under Forskardagarna and talking about ocean currents, eddies and algae blooms -  great experience and pleasure to meet three classes of young scholars interested in oceanography!

2023-03-16: Application for the Fall semester courses is open! Are you interested in oceanography? Check MISU's introductory course Oceanografins grunder (taught in Swedish; MO1002, register here) and the free-choice master courses Physical Oceanography (MO8013) and Geophysical Fluid Dynamics (MO8009) taught in English. Register now! (Deadline 2023-04-17).

2023-01-11: We had a kick-off meeting for the FORMAS project ALGOTL. Preparations for the summer sampling and modelling activities are in the pipeline!

2022-12-01: My MISU group participated in "Swedish marine modelling symposium" at SMHI, Norrköping. Enjoyed very much the networking and scientific exchange with colleagues- marine modellers from across Sweden.

2022-11-23: Great news! My FORMAS project "A new forecast framework for algae bloom hazard to secure future water supply and development of tourism on Gotland" got funded! I will lead a collaboration between Stockholm University, the Swedish Meteorological and Hydrological Institute (SMHI) and Region Gotland n a four-year project to inform sustainable management of water resources on Gotland and the aim of the project is to develop a novel forecast framework for intense algae blooms due to heatwaves as well as their impact on water resources, with a focus on the negative effects on desalination plants. More information: sv, eng1, sv1, sv2.eng2

2022-11-21: Stefano Berti (Unité de Mécanique de Lille, UML, France) is visiting as IMI guest this week! (undounted by the winter snowy weather).

2022-11-10: We had a very successful student cruise with R/V ELECTRA to the Western Gotland Basin! The cruise has been a part of the master course MO8013 "Physical Oceanography" since I started at MISU in 2019 and is a collaboration between MISU and The Stockholm University Baltic Sea Centre. The students learn basic techniques for observational oceanography, but we also collected data for research projects of my PhD students. We have also tested surface drifters that Joachim Dillner and I are developing at MISU. See also: ang, sv.


I am Associate Professor of Coastal Oceanography at the Department of Meteorology, Stockholm University (MISU) and a research fellow (Baltic Sea Fellow) at the Stockholm University Baltic Sea Centre.

The focus of my current research is on mesoscale- and regional ocean circulation, its variability as well as ocean interactions with atmosphere, cryosphere and biosphere. In my research, I employ observations, idealized ocean models and regional ocean model output, Lagrangian analysis and modelling, statistical methods, and theory. My studies often address ocean turbulence and turbulent dispersion which are not well understood yet important element of the climate system and require hollistic and novel approaches. My study domain considers primarily the Atlantic Ocean, the Nordic Seas, Greenland shelves and fjords as well as the Baltic Sea where I started my oceanographic studies as an undergraduate student. I have a broad background and scientific interests spanning various topics of Geophysical Fluid Dynamics. See also the link RESEARCH at the bottom of the page.


Since I joined MISU in 2019, I have been course responsible for the MISU Master's Programme in Atmospheric Sciences, Oceanography and Climate Physics courses: Geophysical Fluid Dynamics and Physical Oceanography. I have developed the later course including an oceanographic cruise on R/V ELECTRA and a data analysis lab in collaboration with the Stockholm University Baltic Sea Centre. I am also contributing teacher to the PhD courses Advanced Oceanography and Advanced Mathematical Methods (now a responsible teacher for the latter). In 2019 I organized and co-taughed two Machine Learning workshops for PhD students (SeRC and CIM). I served as a Director of Undergraduate Studies at MISU in spring semester 2021.

During my earlier work appointments in US and Germany, I taught several courses at the undergraduate, master and doctorate levels, including Geophysical Fluid Dynamics, sea-going physical oceanography, Regional climate variability, Statistics for climate scientists, Thermohaline circulation, and Lagrangian analysis and dispersion (a self-developed master course). I have also organized and taught workshops in Statistics and Machine Learning. More information about my teaching can be found under the link TEACHING at the bottom of the page.


2005-2008: PhD in Fluid Dynamics, Politecnico di Torino, Turin, Italy
1999-2004: M.Sc in Physical Oceanography, University of Gdansk, Poland
2001-2002: Student in Arctic Geophysics, UNIS (University Courses on Svalbard)


2019-present: Associate Professor, MISU, Stockholm University, Sweden
2015-2019: Junior Professor, GEOMAR and Kiel University, Germany
2011-2014: Assistant Research Scientist, Johns Hopkins University, Baltimore, USA
2008-2011: Postdoctoral Researcher, University of Oslo, Norway

Visiting appointments

2010, Oct-Nov: Norwegian Polar Institute, Tromsoe, Norway
2006, May-July: Woods Hole Oceanographic Institution, USA (Mary Sears Fellow)
2005, Jun-Aug: Woods Hole Oceanographic Institution, USA (GFD Fellow)
2004, Oct-Dec: International Centre for Theoretical Physics, Trieste, Italy

Fellowships and awards

2019: AGU 2018 Editor’s Citation for Excellence in Refereeing
2005: GFD Fellow, Woods Hole Oceanographic Institution, USA
2004: PhD Scholarship `Progetto Lagrange', Politecnico di Torino, Turin, Italy
2003: Scholarship Award, Ministry of National Education and Sport, Poland

Oceanographic cruise experience

Western Gotland Basin MO8013 (leader, teacher), R/V ELECTRA, 10/11/2022
Tvären Basin MO8013 (leader, teacher), R/V ELECTRA, 12/11/2021
Western Gotland Basin Cockteil (participant), R/V ELECTRA, 26/08/2021 (DriftBloomClim drifter deployments)
Western Gotland Basin (leader), R/V ELECTRA, 17/06/2021
Landsort Deep MO8013 (leader, teacher), R/V ELECTRA, 15/11/2019
Gotland Basin (researcher), R/V Elisabeth Mann Borgese, 8-24/07/2019
Baltic Sea Student cruise (teacher), R/V , 3 days, 09/2018
Baltic Sea Student cruise (teacher), R/V Alkor, 4 days, 08/2017
Baltic Sea Student cruise (teacher), R/V Alkor, 4 days, 08/2016
Baltic Sea Student cruise (teacher), R/V Poseidon, 4 days, 10/2015
Barents Sea (researcher), POLEWARD project, R/V G. O. Sars, 24/06–1.07/2009
Norwegian Sea (researcher), POLEWARD project, R/V Hakon Mosby, 6–11/10/2008
East Coast US (researcher), SW06, R/V Endeavor, 3–17 08/2006
Baltic Sea student cruises (student), R/V Oceanonograf II, 15–21/07/2003
Fram Strait Greenland Sea (UNIS student), R/V Lance, 22–26/08/2002
Kongsfjord, Svalbard (UNIS student), R/V Haakon Mosby, 6–8/09/2001


Dimitrios Antivachis will join my group as a PhD student in summer 2023 (FORMAS project ALGOTL).

In Fall 2023, I will have a PhD position available within the CoastClim PhD school and the ALGOTL postdoc position will be announced soon as well.

Current members

Hanna Winge, Master student (co-advised with Joakim Hansen, Baltic Sea Centre)
03/2023-present (Hydrodynamics of coastal bays).

Matteo Masini, PhD student (MISU), Main advisor.
09/2021-present (Dynamics of upwellling systems).

Jonathan Wiskandt, PhD student (MISU), Main advisor.
05/2020-present (Proj: Ice-FEM-Ocean).

Jonas Friedriksson, PhD student (IGV), Co-advisor.

Past members

Johan Tengholm, Bachelor student (MISU). Defense: 06/23. Thesis title: "ENSO-En sammanställning och modellering av ett betydelsefullt fenomen".

Foucaut Tachon, Master student (ERASMUS-CIVIS, Aix-Marseille University), Main advisor. Defense: 06/2022. Thesis title: "Disentangling plankton dynamics in a turbulent sea from Lagrangian trajectories". Now PhD student in Quebec.

Stefano Ottolenghi, PhD student (Dpt. Mathematics, SU), Co-advisor.
10/2019-09/2022 (Proj: Ice-FEM-Ocean).

Johannes S. Dugstad, PhD student (University of Bergen), Co-advisor. Graduated: 11/2020.
Thesis title: "Water mass exchange, pathways and the mesoscale eddy field in the Lofoten Basin of the Norwegian Sea". (Proj: ProVoLo). Now teacher at the Elvebakken videregående skole i Oslo.

Ziqi Yin, Master student (MISU), Main advisor. Defense: 06/2020.
Thesis title: "Ice-ocean interactions in a Greenland fjord". Now PhD student in Colorado.

Mia Sophie Specht, Master student (GEOMAR/CAU Kiel), Main advisor. Graduated: 10/2018.
Thesis title: "Variability of Atlantic Water inflow onto the Northeast Greenland continental shelf" (Proj: FeedMeltPath/GROCE). Mia defended her PhD at International Max Planck Research School (IMPRS-ESM) 24-03-2023. Congratulations, Mia!

Joost Hemmen, Master student (GEOMAR/CAU Kiel), Main advisor. Graduated: 10/2018.
Thesis title: "Transport by mesoscale and submesoscale flows of the central Baltic Sea in a high resolution regional ocean model". Now data scientist at Helmholtz-Zentrum Geesthacht.

Patrick Wagner, Master student (GEOMAR/CAU Kiel), Co-advisor. Graduated: 03/2017.
Thesis title: "Eulerian and Lagrangian tracer spreading in an high resolution Ocean General Circulation Model". Now PhD student at GEOMAR.

Jan Spliethoff, Bachelor student (GEOMAR/CAU Kiel), Main advisor. Graduated: 10/2018.
Thesis title: "Rafting through the 2015/2016 El-Nino: Oceanographic analysis of the Kon-Tiki2 expedition".

Regina-Maria Keller, Bachelor Student (GEOMAR/CAU Kiel), Co-advisor. Graduated: 07/2016.
Thesis title: "Cross-frontal mixing in the Agulhas Current induced by its meandering".

Niko Schmidt, Student research assistant, Dpt. Math, CAU Kiel (08-12/2018).
(Proj: FeedMeltPath/GROCE).


Teaching certificates:

Basics of University Teaching (Stefan Braun, 2017.

Professional development course (Universitetslärarutbildning UL1), 7.5 ECTS, Stockholm University, 2020.

Professional development course NatFak (Universitetslärarutbildning UL2), 7.5 ECTS, Stockholm University, 2020.

Course development:

Developed Master Course Physical Oceanography (MO8013 MISU) by adding an observational module (a student cruise and data analysis lab) in  collaboration with the Baltic Sea Centre (2019-): eng, sv

Organized and co-taught three PhD-level courses on Neural Networks for Beginners (2019; 2 days each; 1 in Germany, 2 SeRC/CIM in Sweden accredited 3 ECTS each)

Self-designed Master Course Lagrangian Analysis and Dispersion (5 ECTS; 2016 & 2018)

Self-designed PhD course Statistics for Climate Applications (2 days; 2018)

Teaching experience at MISU (2019-):

In HT23 (Fall) I will be the lecturer and course responsible for Geophysical Fluid Dynamics (MO8009), Physical Oceanography (MO8013) as well as Dynamical Meteorology (MO4002/MO8002).

Lecturer and course responsible for Master Course Physical Oceanography (MO8013), Lecture + Tutorial including oceanographic cruise with students (R/V ELECTRA, in collaboration with the Baltic Sea Centre). 7.5 ECTS: 2019, 2020, 2021, 2022-

Lecturer and course responsible for Master Course Geophysical Fluid Dynamics (MO8009), Lecture. 7.5 ECTS: 2019, 2020, 2021, 2022-

Co-teacher for PhD Course Advanced Oceanography, Lectures: 2020 & 2023.

Co-teacher for PhD Course Advanced Mathematical Methods, Lectures: 2021- (bi-annual; course responsible from 2023 onwards).

Co-teacher of a PhD course Neural Networks for Beginners featuring an invited
lecturer Prof. Ribana Roscher, University of Bonn and Osnabrück, Germany. The course
consisted of 3 days of lectures and tutorials with Python/TensorFlow. The course was given twice, as a SeRC (Swedish e-Science Centre) course on Frescati Campus, and as a CIM (Centre for Interdisciplinary Mathematics) course at Uppsala University. The courses were accredited 3 ECTS each and given in 2019.

Teaching experience at GEOMAR/CAU-Kiel (2015-2018)

During years 2015-2019 I held a position of Junior Professor at the GEOMAR Helmholtz Centre for Ocean Research Kiel and Kiel University (CAU), Germany, where I contributed to the Bachelor Program in Physics of the Earth System (Physik des Erdsystems), the Master Program in Climate Science (bi-annual turnover) and PhD–level courses.

Bachelor level:

Measurement Methods in Oceanography (tutor on oceanographic students, 2015, 2016, 2017, 2018);

Introduction to Oceanography (Lecture, co-teacher, 2016, 2017)

Master level:

Data Analysis and Statistics Lecture, 5 ECTS (2017, 2018)

Lagrangian analysis and Dispersion (Lecture+Tutorial, self-designed), 5 ECTS (2016, 2018)

Thermohaline Circulation Tutorial, 2.5 ECTS (2015, 2017);

PhD level:

Statistics for Climate Applications 2 days (2018)

Research Integrity, 1 ECTS (2017)

Neural Networks for Beginners (organizer), 2 days (2019).

Other teaching experience:

Spring 2013: Geophysical Turbulence and Transport Graduate Course (AS.270.620), Johns Hopkins University, co-lecturer with Prof. Anand Gnanadesikan.

2001/2002: Teaching Assistant in Remote Sensing and Polar Meteorology for Prof. Yngvar Gjessing at University Courses of Svalbard (UNIS).





The Baltic sea
DYNAMICS, Turbulent flows and ALGAE BLOOMS



The Baltic Sea Fellows

I am one of the members of the interdisciplinary network of young Baltic Sea researchers at Stockholm University. More information about our group can be found here.


Dynamics of the upwelling/downwelling systems in the Baltic Sea


Matteo Masini joined my group as a PhD student in September, 2021 and has been working with me, Johan Nilsson (MISU) and Bo Gustafsson (The Stockholm University Baltic Sea Centre). He is currently a protocol of idealized MITgcm model configurations to investigate development of the upwelling/downwelling coastal jets in the Western Gotland Basin and the baroclinic instability processes, with focus on the impact of the bathymetry. Contact Matteo if you would like to learn more!


Figure 1. The model setup and results from an idealized simulation of upwelling in the Western Gotland Basin by Matteo Masini.



DriftBloomClim Project

The surface drifter project DriftBloomClim (Founder: The Bolin Centre for Climate Research RA3 and the SU Baltic Sea Centre)
Six specially designed surface drifters were deployed in the Western Gotland Basin in August/October 2021 to quantify turbulent transport and wind drift in the Baltic Sea and to evaluate the available ocean forecast models to represent these processes. The first results suggest that the velocity output from ocean forecast models is able to represent the drift within a few km over a 2-3 day, and further improvement can be achieved through adjusting time step and the Lagrangian model. The project is a collaboration between the Bolin Centre for Climate Research and the Stockholm University Baltic Sea Centre. This is a first phase of an larger effort by the team Inga Koszalka (MISU)  and Agnes Karlson (DEEP) to develop forecast models for algae blooms in the Baltic Sea, that we aim at conducting in the future. Read more about the project here: sv, eng



Drifter project 2022

Wind drift, turbulent transport and impacts on biogeochemistry

The surface drifter project continues and we are developing own drifters for studies of circulation in the Baltic Sea and its impacts on biogeochemical processes like oxygen dynamics and plankton blooms (Founder: The Bolin Centre for Climate Research RA2)

Under 2022 I got funding support from the Bolin Centre RA2 and teamed up with MISUs engineer Joachim Dillner to develop and build surface drifter platforms at MISU tailored to study coastal flows in the Baltic Sea and their impact on biogeochemistry and marine ecosystem. We estimated that making drifters ourselves would decrease the cost per unit drifter and make the design more flexible (anchoring drifters at various depths, possible montage of additional sensors in the future). In spring 2022 MISU’s technician Joachim Dillner and myself designed the drifters based on existing platforms (CODE, CARTHE), tech-oceanographic literature as well as Joachim Dillner’s experience. Joachim prototyped several possible designs for the drifter float and drogue, optimizing between the material cost, durability and working time. We built 10 drifter platforms with flexible mounting solutions (two different designs of floating buoy made of foam, additive anchors plastic and wooden versions for two different deployment depths). We got a deal with Global Telesat Communications (GTC) to purchase and test 8 of their new solar-paneled Iridium EdgeSolar units for satellite tracking of the drifters. The larger EdgeSolar units required a re-design of the drifters and a new solution for the waterproof casing (eventually, the Tefal lunch boxes proved the most optimal solution).

We test-deployed 3 drifters during the Master Course MO8013 cruise with R/V ELECTRA to the Western Gotland Basin on 2022-11-10. All 3 drifters transmitted their positions during ca. 3 h test period and were recovered on the way back. Two of the drifters were redeployed at the end of the cruise for a “long mission” to sample in-situ a development of an upwelling jet. The drifter trajectories confirmed the expectation regarding the ocean circulation. The two drifters followed the coastal upwelling jet in the north-east direction, but while one of them continued doing so for 4.5 days straight, the second drifter made an slight excursion offshore over the slope after about two days where it got trapped in an eddy, taking a swing around the Landsort Deep. Around 16 November the winds changed the direction to south easterly and then easterly, causing the drifters to turn south and towards the eastern coast of Sweden. These easterly winds brought also a historic snowfall (50 cm/day over two days) and snowstorms during the weekend 19-21 November. One of the drifters was recovered by the Sjöfärtsverket. The second drifter stranded on the island of Häradsskär at the end of November. It was left transmitting in the hope of the recovery as well as to further test the solar-paneled EdgeSolar and waterproof casing solution. At the time of the writing, the drifter has been transmitting its positions for 3 months straight at 15 min sampling rate. 


Figure 2. Left: Mounting our MISU-made drifters for a floating test in the lake of Brunnsviken. Right: Drifter trajectories from the “long” deployment Nov’22 – Jan’23 (including deployment and recovery periods).


In summary, the drifter experiment was very successful. The design worked well, and we collected a lot of information about the technical aspects with drifters as well as the regional circulation in the Western Gotland Basin. The Edgesolar and Tefal waterproof cases worked very well - in spite of the harsh weather conditions and stranding.

A press release from the student cruise with R/V ELECTRA in November 2022 is available here: cruise-nov22


Impacts of physical processes on coastal oxygen variability

I am also working in a project led by Volker Brüchert, Stockholm University, investigating variability of the bottom oxygen in the coastal Baltic Sea. I am supporting the PhD student, Jonas Friedriksson, with analyses in a detective work trying to pin down the role of physical processes (Ekman flows, baroclinic Kelvin waves, internal waves, seiche) on measured oxygen variability.



Figure 3. A schematic of various ocean flows (Kelvin waves. Ekman jets and return bottom flows, recirculation) that iimpact bottom oxygen variability at the station B1 near Askö.


Back to home page: Inga Homepage.


the Greenland's shelves and fjords
Greenland Ice Sheet-Ocean interactions



Basal melt and melt driven circulation in Greenland's fjords

In spring 2020, master student Ziqi Yin completed a master thesis about idealized simulations of a glacial fjord using the VEROS model.  I am continuing syudies of basal melt and melt-driven circulation in fjord under Ice-FEM-Ocean, a collaborative pair-PhD project with Josefin Ahlkrona (Dpt. Math, SU) our PhD students Stefano Ottolenghi and Jonathan Wiskandt and colleagues Christian Helanow (Math) and Johan Nilsson (MISU)



Figure 4. A schematic for the FEM model for ice sheet-ocean circulations and first model configuration and results.


Alongside the FEM model development, my PhD student Jonathan Wiskandt used an idealized configuration of the MITgcm model to study the basal melt and melt-driven circulation in the ice cavity beneath the Ryder Glacier, nortwestern Greenland, based on observations collected by Prof. Johan Nilsson and colleagues during Ryder 2019 expedition. Jonathan's model experiments elucidated dependence of the basal melt rates on oceanic thermal forcing due to Atlantic Water intruding into deep layers of the Shepard Osborn fjord where the Ryder Glacier terminates, as well as impact of the subglacial discharge. We submitted a manuscript in late November 2022. Contact Jonathan if you would like to learn more about this study.


Figure 5. Results from an idealized configuration of the MITgcm showing basal melt rates and melt-driven circulation beneath the Ryder Glacier tongue, northwest Greenland, by Jonathan Wiskandt.


Ocean circulation in the Irminger Basin & the East Greenland Shelf

The Greenland's shelf circulation was the focus of researcher appointment at the Johns Hopkins University, Baltimore, US. In Koszalka et al 2013b, I used Lagrangian simulations and a high resolution regional (MITgcm) model output to map pathways of the dense Denmark Strait Overflow (DSO) on the East Greenland Shelf hinted previously by sparse observations. I also investigated travel times and property transformation of dense water masses represented by model particles. In Von Appen et al 2014 we used backward Lagrangian simulations to investigate origins of a recently discovered current in the Irminger Basin, the intermediate-water Spill Jet, a potential contributor to the variability of the Deep Western 2Boundary Current (and the Atlantic Meridional Overturning Circulation). In Von Gerderloos et al 2017 we used backward Lagrangian simulations to map Atlantic warm water pathways toward the Kangerdlugssuaq fjord-glacier system. I have further studied inflow of the warm Atlantic Water towards the Greenland's marine-terminating glaciers under the FeedMeltPath–GROCE project at GEOMAR Centre for Ocean Research Kiel, Germany, and with a master student, Mia Sophie Specht.



Figure 6. Pathways of the dense Denmark Strait Overflow on the East Greenland Shelf mapped with help of Lagrangian simulations, and travel time distributions between the Denmark Strait Sill and the Angmassalik section further south in the Irminger Basin. The waters taking the shelf pathway and spilling to the deep basin exhibit longest travel times and undergo strong temperature and salinity changes (Koszalka et al 2013b).


Back to home page: Inga Homepage.


Lagrangian analysis and turbulent dispersion




Figure 7. Lagrangian analysis of the POLEWARD drifter trajectories in the Nordic Seas (from top-left): drifter trajectories, relative diffusivity, the principle for clustering of drifter segments and single particle diffusivity. From Koszalka et al (2009a) and Koszalka et al (2011).

The turbulent flows (eddies, jets, fronts) determine distribution of constituents suspended in the ocean (tracers): temperature, salinity, nutrients, marine algae and polluting agents. The turbulence also mediate the energy transfer between the large scale currents and the small scales where it is dissipated. The observation, quantification, as well as proper representation (parameterization) of turbulent transport in ocean climate models remains a major challenge for oceanography. The turbulent transport can be quantified by the spreading (dispersion) and the rate of spreading (diffusivity) of a cloud of drifting instruments (drifters, floats) deployed in a real ocean flow. Equivalently, it can be quantified by the rate of spreading of a cloud of numerical particles dispensed in a modelled ocean flow. Lagrangian analysis is a research field that studies ocean flow though analysis of motion of particles or instruments carried by ocean flow. Lagrangian modelling considers simulations of particles using velocity data outputted from ocean models or estimated from satellite pictures.

Lagrangian analysis modelling has been in my focus since my doctoral study of mesoscale ocean vortices (eddies) and the associated turbulent transport (Koszalka et al 2009a). Subsequently, I worked as a postdoctoral researcher at the University of Oslo under a POLEWARD project that featured a then-date-largest drifter pair experiment that took place in the Nordic Seas. It allowed to exhaustively assess surface turbulent transport with help of relative particle statistics (Koszalka et al 2009b). I also worked on development of methods for Lagrangian analysis including machine learning techniques (Koszalka & LaCasce 2010) that allowed to map the surface flow field in the Nordic Seas at an unprecended resolution (Koszalka et al 2011); to develop and apply stochastic particle (Markov) models to study propagation of warm water anomalies in the Nordic Seas poleward toward the Arctic (Koszalka et al 2013a) and to compare the surface turbulent transport diagnostics (eddy fluxes) from drifter data, satellite imagines and model output (Isachsen et al 2012). For full publication list from this project, see here.




Figure 8. Lagrangian trajectories in the Nordic Seas simulated using a stochastic particle model with different parameters and compared to the observed drifter trajectories. The tuned model was employed was used to estimate travel time for warm water anomalies toward the Arctic (Koszalka et al 2013a).


I also worked with my students and colleagues addressing application of turbulent dispersion and diffusivity to evaluate transport representation in regional ocean models (Rühs et al 2018), comparison of the tracer-derived and Lagrangian diagnostics for turbulent transport (Wagner et al 2019) as well as quantification of cooling of the warm Atlantic Water in the Lofoten Basin using 2D and 3D Lagrangian simulations and with respect to the seasonal variations (Dugstad et al 2019).



Figure 9. Turbulent diffusivity (a measure for turbulent transport) estimated from Lagrangian trajectories deployed in an ocean model runs of different resolution and compared to the observations (Rühs et al 2018).





Figure 10. Comparison of spreading of a numerical tracer and Lagrangian particles in a regional three-dimensional ocean model. For the diffusivity and other diagnostics see Wagner et al (2019).



Figure 11. Left: Density maps for 3D Lagrangian particles experiencing cooling and warming in the Lofoten Basin in different seasons. Right: Comparison of density maps for 2D vs 3D Lagrangian particles deployed close to the surface. See Dugstad et al (2019)..

I have also contributed to a community review article about Lagrangian analysis (Van Sebille et al 2018) and another one about drifting instruments (Centurioni et al 2019) where you can find more background information about Lagrangian analysis, modelling and observations.

Back to home page: Inga Homepage.



Dynamics of mesoscale eddies
and their role in oceanic transport processes




Figure 12. Diagnostics from a idealized study of eddies developing in a wind-forced ocean with a strong stratification. Top: Maps of surface relative vorticity [f] and verticakl velocity [m/s]. Bottom: Frequency spectra and vertical section of the vertical velocity ( Koszalka et al 2009a; Koszalka et al 2010).

During my PhD work I studies dynamics of ocean eddies using quasigeostrophic (QG) models as well as an idealized-realistic configuration of a strongly stratified ocean forced by wind of a regional circulation model (ROMS). Major findings were a strong dominance of anticyclonic vortices linked to the straining field exerted by vortex Rossby waves and strong vertical velocities due to interplay of eddies, vortex Rossby waves, and internal waves (Koszalka et al 2009a). In Koszalka et al (2010) I demonstrated that the vortices can act like islands of increased penetration of wind energy into the ocean interior and enhanced vertical mixing, and assessed how these eddy.mediated processes relate to the ambient stratification and how they can be affected by the climate change.

In my PhD I also studies interactions between the turbulent flow and plankton dynamics represented by theoretical mathematical models. For example, in Koszalka et al (2007), I showed that spatio-temporal variability coupled with advection by mesoscale eddies can disguise limit-cycle behavior in observed plankton abundance, thus prompting for a greater care in interpreting results from homogeneous plankton models.

The questions of the turbulent eddy dynamics and the associated transport have been returning in different context thoughout my career.


Back to home page: Inga Homepage.


Research projects