Substructure of a MAP-Streamer
Mark A. Liniger (MeteoSwiss)
Huw C. Davies (IACETH)
QJRMS, 129, 633-651
(MAP special issue)
12 UTC 6 Nov 1999 (MAP IOP-15)
Evolution of PV @ 320 K
18 UTC 5 Nov. 12 UTC 6 Nov. 06 UTC 7 Nov.
Aim
• Are measured meso-scale features detectable in GCM analyzed fields?
• How far are observed structures linked to synoptic scale transport processes?
data sources:• ECMWF analysis fields (T319L60)• Meteosat water vapour (WV)• WV DIAL (DIfferential Absorption Lidar) flown on the
Falcon aircraft of DLR (Deutsches Zentrum für Luft- und Raumfahrt)
Lagrangian Forward Projection
t =
t =
• bases on RDF technique (Sutton et al. 1994)
• 3D – Trajectories backwardsfrom a prespecified domain
• Projection of a geographical marker or conserved (or non-conserved) tracer from an earlier position to the prespecified domain.
horizontal WV reconstruction
Meteosat WV vertically integrated WV of analysis
vertically integrated WV of LFP for 24 hours
white = dry
Interpretation
LFP for 24 hours to the 450 hPa surface
increase in pressure increase in pot. temperature
WV DIAL & analysis
Longitude
water vapour observed by DIAL (DLR)
Hei
ght (
km)
10
6
8
Hei
ght (
km)
0 E 4 E 8 E
0.01 0.02 0.04 0.08 0.12 g/kg
8
6
10
water vapour from ECMWF analysis, interpolated to observation time.
dry humid
WV DIAL & LFP
10
6
8
0 E 4 E 8 E
8
6
10
Longitude
water vapour observed by DIAL (DLR)
Hei
ght (
km)
H
eigh
t (km
)
0.01 0.02 0.04 0.08 0.12 g/kg
water vapour,LFP for 15h, based on ECMWF analyses
dry humid
WV DIAL & long LFP
10
6
8
8
6
10
0 E 4 E 8 E
water vapour,LFP for 39h, based on ECMWF analyses
Longitude
water vapour observed by DIAL (DLR)
Hei
ght (
km)
H
eigh
t (km
)
0.01 0.02 0.04 0.08 0.12 g/kg
dry humid
10
6
8
0 E 4 E 8 E
8
6
10
Longitude
backscatter ratio (aerosols) observed by DIAL (DLR)H
eigh
t (km
)
H
eigh
t (km
)
0.01 0.02 0.04 0.08 0.12 g/kg
water vapour,LFP for 39h, based on ECMWF analyses
backscatter ratio & long LFP
(from Hoinka et al., 2003)
dry humid
Striation: Interpretation
Streamers breakup, 18 hours composite
contours: LFP for 24 hours to the 310 K surface
increase in pressure increase in pot. temperature
composite 12 UTC 06 to 06 UTC 07
PV @ 310 K
Conclusions
Pronounced dry intrusion of stratospheric origin Spiral structure: arms of distinct origins Striation across western flank: sandwiched boundary layer
air mixing by diffusion Breakup over Alps:
persistent diabatic processes north of Alpsand corresponding upper level negative PV anomaly
Large scale advection explains significant portion of mesoscale structures
LFP relates Lagrangian evolution to Eulerian fields
21. May 2003
21. May 2003
21. May 2003
21. May 2003