
Lina BoljkaUniversity of Bergen | UiB · Geophysical Institute
Lina Boljka
PhD Atmosphere, Ocean and Climate
About
18
Publications
2,626
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66
Citations
Citations since 2017
Introduction
Lina Boljka currently works at the Geophysical Institute, University of Bergen. Lina does research in climate dynamics, looking at ocean-atmosphere interactions, stratosphere-troposphere interactions, storm tracks, wave-mean flow interactions, and climate variability, prediction and change. For more see: https://lina-boljka.github.io
Additional affiliations
Education
September 2014 - September 2018
October 2012 - September 2013
October 2009 - July 2012
Publications
Publications (18)
The wintertime extratropical general circulation may be viewed as being primarily governed by interactions between Rossby waves and the background flow. These Rossby waves propagate vertically and meridionally away from their sources and amplify within the core of the tropopause-level jet, which acts as a waveguide. The strength of this waveguide i...
Tropical Pacific is home to climate variability on different timescales, including El Niño Southern Oscillation (ENSO) – one of the most prominent quasi-periodic modes of variability in the Earth’s climate system. It is a coupled atmosphere-ocean mode of variability with a 2-8-year-timescale and oscillates between a warm (El Niño) and a cold (La Ni...
Northern Hemisphere (NH) climate has experienced various coherent wintertime multidecadal climate trends in stratosphere, troposphere, ocean, and cryosphere. However, the overall mechanistic framework linking these trends is not well established. Here we show, using long-term transient forced coupled climate simulation, that large parts of the cohe...
This study compares trends in the Hadley cell (HC) strength using different metrics applied to the ECMWF ERA5 and ERA-Interim reanalyses for the period 1979–2018. The HC strength is commonly evaluated by metrics derived from the mass-weighted zonal-mean stream function in isobaric coordinates. Other metrics include the upper tropospheric velocity p...
This study explores the possible drivers of the recent Hadley circulation strengthening in the modern reanalyses. Predominantly, two recent generations of reanalyses provided by the European Centre for Medium-Range Weather Forecasts are used: the fifth-generation atmospheric reanalysis (ERA5) and the interim reanalysis (ERA-Interim). Some results a...
This study compares the trends of Hadley cell (HC) strength using different HC measures applied to the ECMWF ERA5 and ERA-Interim reanalyses in the period 1979-2018. The HC strength is commonly evaluated by indices derived from the mass-weighted zonal-mean stream function. Other measures include the velocity potential and the vertical velocity. Six...
Baroclinic waves drive both regional variations in weather and large-scale variability in the extratropical general circulation. They generally do not exist in isolation, but rather often form into coherent wave packets that propagate to the east via a mechanism called downstream development. Downstream development has been widely documented and ex...
Atmospheric planetary waves play a fundamental role in driving stratospheric dynamics, including sudden stratospheric warming (SSW) events. It is well established that the bulk of the planetary wave activity originates near the surface. However, recent studies have pointed to a planetary wave source near the tropopause that may play an important ro...
Abstract. Atmospheric planetary waves play a fundamental role in driving stratospheric dynamics, including sudden stratospheric warming (SSW) events. It is well established that the bulk of the planetary wave activity originates near the surface. However, recent studies have pointed to a planetary wave source near the tropopause that may play an im...
Climate change and air pollution are closely linked; climate change is caused by air pollution, and climate change makes air pollution worse. Air pollution from human society is the key factor currently driving climate change. As it is a significant existential threat to society, climate change is not only the subject of intense scientific research...
As experts researching weather, climate and climate change impacts, we have a professional and moral obligation to
urge You, the policy makers, to take immediate action on improving the Slovenian climate change mitigation and
adaptation policy. Climate change is already happening and its impacts will become increasingly more severe if we
do not ins...
Barotropic variability plays an important role in a variety of extratropical atmospheric processes, such as annular modes, teleconnections, and baroclinic life cycles, which occur on a wide range of timescales. Extratropical dynamics is dominated by high‐frequency (periods shorter than 10 days) transient waves, which drive barotropic variability th...
Baroclinic and barotropic processes are the key components of midlatitude tropo- spheric dynamics. Baroclinic processes are involved in the growth of extratropical storms, whereas barotropic processes are involved in their decay, suggesting the two processes are closely linked. Their links are conventionally studied through wave- mean flow interact...
Multiscale asymptotic methods are used to derive wave activity equations for planetary- and synoptic-scale eddies and their interactions with a zonal mean flow. The eddies are assumed to be of small amplitude, and the synoptic-scale zonal and meridional length scales are taken to be equal. Under these assumptions, the zonal-mean and planetary-scale...
The baroclinic and barotropic components of atmospheric dynamics are usually viewed as interlinked through the baroclinic life cycle, with baroclinic growth of eddies connected to heat fluxes, barotropic decay connected to momentum fluxes, and the two eddy fluxes connected through the Eliassen–Palm wave activity. However, recent observational studi...
Projects
Projects (2)
The project RESCCCUE (REminding Slovenian authorities Climate Change Crisis requires Urgent Effort) strives to advance climate literacy and science-based policy making in Slovenia. For more details see: https://www.emetsoc.org/wp-content/uploads/2020/06/oc2020_RESCCCUE_project-description.pdf
The goal of this project is to elucidate the interplay between the baroclinic and barotropic parts of the atmospheric flow, as well as to address the interaction between the planetary and synoptic scale waves.
Blog posts describing a part of the project (annular modes), model hierarchies (and how this project fits in) and analysis of large datasets:
https://socialmetwork.blog/author/lboljka/
Thesis: http://centaur.reading.ac.uk/82282/1/21024384_Boljka_thesis.pdf