how typical were the meteorological conditions in the cops area during the summer 2007?
DESCRIPTION
How typical were the meteorological conditions in the COPS area during the summer 2007? Heini Wernli Stephan Pfahl Jörg Trentmann University of Mainz. Approach and Outline Data: ECMWF analysis (2007 op. ana. vs. ERA40 1979-2001). Approach and Outline - PowerPoint PPT PresentationTRANSCRIPT
How typical were the meteorological conditions in the COPS area during the summer 2007?
Heini WernliStephan PfahlJörg Trentmann
University of Mainz
Approach and Outline
Data: ECMWF analysis (2007 op. ana. vs. ERA40 1979-2001)
Approach and Outline
Data: ECMWF analysis (2007 op. ana. vs. ERA40 1979-2001)
Consider domain-average for COPS area of:- T, , e, q, ... at 925, 850, 700 hPa- simple variant of KO-index (thermodynamic stability)- wind velocity and direction at 500 hPa- Eady growth rate (baroclinicity at 700 hPa)- cyclone frequency- frequency of upper-level PV cut-offs (small-scale troughs)
Approach and Outline
Data: ECMWF analysis (2007 op. ana. vs. ERA40 1979-2001)
Consider domain-average for COPS area of:- T, , e, q, ... at 925, 850, 700 hPa- simple variant of KO-index (thermodynamic stability)- wind velocity and direction at 500 hPa- Eady growth rate (baroclinicity at 700 hPa)- cyclone frequency- frequency of upper-level PV cut-offs (small-scale troughs)
Show:- maps of seasonal mean & deviation from climatology- probability density functions (2007 vs. climatology)- quantile-quantile plots (2007 vs. climatology)
Approach and Outline
Data: ECMWF analysis (2007 op. ana. vs. ERA40 1979-2001)
Consider domain-average for COPS area of:- T, , e, q, ... at 925, 850, 700 hPa- simple variant of KO-index (thermodynamic stability)- wind velocity and direction at 500 hPa- Eady growth rate (baroclinicity at 700 hPa)- cyclone frequency- frequency of upper-level PV cut-offs (small-scale troughs)
Show:- maps of seasonal mean & deviation from climatology- probability density functions (2007 vs. climatology)- quantile-quantile plots (2007 vs. climatology)
Caveat:2007 and climatology have different model resolution!
T at 925 hPa
- colder than clim over F- warmer than clim over E Europe- very close to clim in COPS area
climatology1979-2001
2007
deviation from climatology in
climatology1979-2001
2007
deviation from climatology in
e at 925 hPa
- slightly above clim in COPS area
climatology1979-2001
2007
deviation from climatology in
Cyclone frequency
- above clim over UK / Benelux- below clim in Central Europe
climatology1979-2001
2007
deviation from climatology in
Freq. of upper-level cutoffs(short wave disturbances)
- strongly above clim over UK- above clim in W Europe / COPS
PDFs of domain-average values at 12 UTC
Temperature on 925 hPa [°C] specific hum. on 925 hPa [g/kg]
PDFs of domain-average values at 12 UTC
KO-Index: e, 500 - e, 850 [K]
PDFs of domain-average values at 12 UTC
wind direction on 500 hPa
more SW winds
Quantile-quantile plots of domain-averages at 12 UTC
T at 925 K
Quantile-quantile plots of domain-averages at 12 UTC
Q at 925 K
Quantile-quantile plots of domain-averages at 12 UTC
KO Index
Conclusion
In summer 2007, the COPS area was characterised by ...
++ cyclones to the NW
+ passage of short wave troughs+ frequency of SW winds at 500 hPa+ BL specific humidity (mainly average not extremes)+ low tropospheric baroclinicity
0 BL temperature
- TD stability (mainly average not extremes)
climatology1979-2001
2007
deviation from climatology in
Eady growth rate(low tropospheric baroclinicty)
- slightly above clim near 45°N (i.e., over Alps / COPS)
PDFs of domain-average values at 12 UTC
KO-Index: e, 500 - e, 850 [K] Eady growth rate