Research topics

Atmospheric Blocking

^ Atmospheric blocking episode from January 23, 1987 00 UTC, over the Euro-Atlantic region. The coloured surface represents the height of the dynamical tropopause (2pvu).

dynamical blocking identification - a novel dynamically-based blocking identification routine is presented which makes use of the three-dimensional information of the potential vorticity (PV) distribution (Schwierz et al., 2004). This leads to a two-dimensional representation of the exact blocking location starting from blocking genesis to blocking lysis. more >>

blocking climatology - A detailed climatology of atmospheric blocking could help provide a better understanding of the phenomenon's dynamics and also be useful for assessing its link to and implications for climate and climate change. In particular it would be helpful if the climatology catalogued the phenomenon's structure, spatial scale, intensity, duration, location and space-time evolution.

blocking trends - linear trends of the blocking distribution can yield serious impacts on a variety of atmospheric variables such as precipitation or temperature. Therefore, accurate information about the occurreence and origin of atmospheric blocking trends can be of importance in the understanding of the recent climate change.

blocking relation to large-scale climate modes - the enhanced blocking occurrence in the two ocean basins and the relatively long blocking life times, prompts consideration of a possible link between atmospheric blocking and the large scale climate modes (NAO, PNA) of the Northern Hemisphere.

Tropopause folds

tropopause fold identification - vertical intrusions of the dynamical tropopause (2pvu - isosurface) into the troposphere, which are folded due to differential isentropic advection, are called tropopause folds. A puerly geometric tropopause definition is introduced here (Sprenger et al., 2003).

tropopause fold climatology - a tropopause climatology of the entire 44-year period from the ERA40 data set is presented. Therefore the folds are subdivided into i) shallow, ii) medium and iii) deep folds.