Recent Changes in Mid-latitude Wave Propagation
Permanent lenke
https://hdl.handle.net/10037/34027Dato
2024-06-12Type
MastergradsoppgaveMaster thesis
Forfatter
Attema, RonnieSammendrag
In recent years climate change in the polar areas has attracted a lot of attention.
Not only for its consequences in polar areas, but also for its possible effects
on lower latitudes. A reduced temperature gradient between the polar areas
is expected to weaken the mid-latitude jet stream. This weaker jet stream is
hypothesised to lead to a reduction in the propagation velocity of atmospheric
Rossby waves and lead to more persistent weather. In this study we will
investigate these changes in wave propagation by computing the wave activity
and wave activity flux from the ERA5 reanalysis for the time period 1990-
2020. We find that there are significant changes in the wave activity and wave
activity flux, but not in the wave forcing of the mean flow. We find a seasonal
and geographic dependency for the trends in the wave activity and its flux.
We furthermore provide evidence that these changes can be linked to low
sea ice concentrations. In addition we explore the relationship between the
wave activity and the temperature. For this we find that a high wave-activity
in general results in a negative temperature anomaly, but during the winter
a high wave-activity is related to a positive temperature anomaly for some
areas.
Forlag
UiT Norges arktiske universitetUiT The Arctic University of Norway
Metadata
Vis full innførselSamlinger
Copyright 2024 The Author(s)
Følgende lisensfil er knyttet til denne innførselen: