Conditioning stochastic weather generator on atmospheric circulation - preliminary assessment

0493440 - ÚFA 2019 DE eng A - Abstract
Lhotka, Ondřej - Dubrovský, Martin
Conditioning stochastic weather generator on atmospheric circulation - preliminary assessment.
EMS Annual Meeting Abstracts, Vol. 15. Berlín: European Meteorological Society, 2018.
[EMS Annual Meeting: European Conference for Applied Meteorology and Climatology 2018. 03.09.2018-07.09.2018, Budapest]
R&D Projects: GA ČR(CZ) GA16-04676S; GA ČR(CZ) GA18-15958S
Institutional support: RVO:68378289
Keywords : climate change impact studies * stochastic weather generator * atmospheric circulation types
OECD category: Meteorology and atmospheric sciences
https://meetingorganizer.copernicus.org/EMS2018/EMS2018-62.pdf

Synthetic data series provided by stochastic weather generators are often used in climate change impact studies
which require local climatological information. The aim of this study is to analyse links between larger-scale circulation
patterns and surface meteorological variables over Central Europe during the course of the year. Atmospheric
circulation will be described using circulation indices (flow strength, direction and vorticity) calculated from daily
sea level pressure data taken from the NCEP/NCAR reanalysis (available from 1948 to present) and classified into
27 circulation types. This classification consist of 2 types with large absolute vorticity (strongly cyclonic and anticyclonic
type), 8 directional types, 16 hybrid types (combinations of directional and cyclonic/anticyclonic types)
and the last type represents an unclassified pressure field. In the next step, annual courses of minimum temperature,
maximum temperature, mean temperature and precipitation (taken from the E-OBS gridded dataset) will be
calculated individually for each circulation type. Comparison of these annual courses will allow us to study links
between the surface meteorological variables and atmospheric circulation in sub-monthly temporal resolution. First
results suggest substantial temperature deviations from the mean annual course for certain circulation types and the
magnitude of these anomalies varies over the year. The results are expected to be useful for conditioning an existing
stochastic spatial weather generator on atmospheric circulation, which may result in more realistic weather data
produced by the generator. In addition, variable warming (or cooling) effects of certain circulation types during
the course of the year may be used as an objective method for delimiting climatological seasons in the changing
climate.
Permanent Link: http://hdl.handle.net/11104/0286806