Kein Folientitel

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Polar Stratospheric Clouds above Scandinavia,
Svalbard and Greenland
Andreas Dörnbrack
T. Birner, A. Fix, and H. Flentje
DLR Oberpfaffenhofen
Institut für Physik der Atmosphäre
Rigel Kivi and Esko Kyrö
Marion Maturilli
Arctic Research Center
Alfred-Wegner Institut für Polarforschung
Potsdam, Germany
Finnish Meteorological Institute
Sodankylä
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Polar Stratospheric Clouds above Scandinavia,
Svalbard and Greenland
PSCs above Finland as seen from DLR Falcon, 26
Jan 2000
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Kiruna, SWE
Sodankylä, FIN
1000 km
200 km
MODIS 15 March 2002 10 UT
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Ground-based LIDAR observations
Sodankylä, 22 January 1997
Rigel Kivi, FMI
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T
ICE
Sodankylä, 22 January 1997
Rigel Kivi, FMI
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SOLVE campaign 1999/2000
Flight legs DLR Falcon on 26 January 2000
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Temperature from MM5 hindcast
26 January 2000 14UT
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Temperature from MM5 hindcast
26 January 2000 14UT
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Real time display onboard DLR Falcon
PSCs above Finland looking west
26 Jan 2000 1450UT
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Lidar Backscatter Ratio at 1064 nm ? from
MM5 hindcast
Sweden
Finland
Baltic Sea
Norwegian Sea
RoU/fL15ms /(10 s 250km)0.6
-1
-4
26 Jan 2000 14UT
Mesoscale T-anomalies generated by hydrostatic
mountain waves ? 20...500km ? 2000m
?T 6..14K, T 175K (-98 C) dT/dt lt
-50K/h, t 5.5h
H
MAX
o
?
MIN
proc
Queney, 1948
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T - TICE
T - TNAT
DLR Lidar 25 January 2000
ice particles
small NAT-particles
STS droplets
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? 1000m
Lidar Ed Browell, NASA Langley
MTP-Sensor MJ Mahonney,JPL
NASA DC8 25 Jan 2001 - SOLVE/THESEO 2000
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NASA DC8 25 Jan 2001 - SOLVE/THESEO 2000
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NASA DC8 25 Jan 2001 - SOLVE/THESEO 2000
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2
2
Ri N / S lt 0.25
NASA DC8 25 Jan 2001 - SOLVE/THESEO 2000
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MODIS, 10 November 2001, 1400 UT
Greenland
Penninsula
Cloud Shadow
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MODIS, 10 November 2001, 1535 UT
Greenland
Cloud Shadow
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NOAA AVHRR 10 November 2001, 1522 UT
Channel 1 (vis)
Channel 5 (IR)
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10 November 2001 16 UT
?TT-T
ice
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9 November 2001 18 UT (6h)
Horizontal Divergence
10 November 2001 18 UT (30h)
MM5, domain 1
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ECMWF - Analyses 11 Nov 2001 12 UT
Divergence _at_ 5 hPa
Modified PV _at_ 1100 K
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January 2005
24 January
25 January
26 January
27 January
Svalbard
Courtesy MLS Team (Jiménez et al. 2006)
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Polar Stratospheric Ice Cloud above Spitsbergen
Marion Maturilli and Andreas Dörnbrack JGR 2006
in press
26 January 2005 19 UTC
all obs 1991/92 - 2004/05
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Polar Stratospheric Ice Cloud above Spitsbergen
Marion Maturilli and Andreas Dörnbrack JGR 2006
in press
26 January 2005
19 UTC
20 UTC
11 and 23 UTC
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? and VH on 2 PVU - VT 26 Jan 05 12 UTC
26
30 hPa
181.0
50 hPa
181.8
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30 hPa
178.7
50 hPa
181.9
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30 hPa
177.8
50 hPa
182.1
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30 hPa
176.5
50 hPa
182.0
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30 hPa
175.1
50 hPa
180.5
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26 January 2005
12 UTC
06 UTC
18 UTC
21 UTC
T and Wind at z 20 km, Z at 900 hPa
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12 UTC
06 UTC
18 UTC
21 UTC
26 January 2005
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Backward Trajectories
ECMWF
Mesoscale Model
50 hPa
50 hPa
30 hPa
30 hPa
hours
hours
Sipw/psat(T) pw partial pressure of water
vapor psat saturation vapor pressure over a plane
ice surface
26 January 2005
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January 2005
24 January
25 January
26 January
27 January
Sodankylä/Finland
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26 January 2005 16 UTC
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26 January 2005 18 UTC
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26 January 2005 12 UTC
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26 January 2005 06 UTC
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26 January 2005 00 UTC
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25 January 2005 18 UTC
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25 January 2005 12 UTC
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25 January 2005 06 UTC
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Some thoughts

• Mesoscale temperature fluctuations essential for
  the formation of ice super saturated regions, i.e
  ice clouds (PSCs and cirrus)
• horizontal scales of gravity waves span from O(10
  km) to O (500 km)
• horizontal propagation of IGWs might modify the
  cloud field far away from the actual source
  region
• proper analysis requires multi-scale atmospheric
  modelling or super-clever parameterizations ....
• investigate ECMWF T799/L91 forecast and analyse
  model to quantify the resolved part of the GW
  spectrum

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Case studies formation and evolution of ice
supersaturation

• Combination of
• corrected radiosoundings (RS 80A, Met.
  Obs. Lindenberg, Germany) and
• operational meteorological analyses
  (ECMWF)
• Check of cloud presence with METEOSAT IR data
• Trajectory calculations with a Lagrangian
  trajectory model
• (LAGRANTO, H. Wernli, University of Mainz)
• Mesoscale simulations with MM5 (Andreas
  Dörnbrack, DLR)

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Ice supersaturation in the vicinity of a warm
conveyor belt
29 November 2000, 0600 UTC
Spichtinger et al., 2004a, ACPD
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Synoptic situation

• potential vorticity (in PVU, colours) and
  horizontal wind on a 320 K isentropic surface

surface temperature (in K, colours) and sea level
pressure
27 Nov, 18 UTC 28 Nov, 18 UTC 29 Nov, 06
UTC
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Moist ascending airstream - warm conveyor belt
pressure in hPa
forward trajectory calculation (48 h), starting
at
26 Nov, 18 UTC 27 Nov, 06 UTC
27 Nov, 18 UTC
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New perception of ISSRs- more system analytic
approach -

• ISSRs are large dynamic regions of supersaturated
  air
• at some locations cirrus clouds are embedded
• at some locations there is clear air

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Summary of case 1

• very cold supersaturation layer -70C lt T lt
  -60C
• cloud free ice supersaturation (ISSR) or if
  cloudy at all very thin cloud
• formation of the ice supersaturation triggered by
  the outflow of the warm conveyor belt
• formation of the ISSR measured by the radiosonde
  due to adiabatic cooling induced by a slow
  synoptic scale upward motion
• lifecycle ice supersaturation forms and
  disappears without formation of a (thick) cirrus
  cloud supersaturation remains about 24 (6
  2.5) h

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Ice supersaturation induced by mesoscale gravity
waves

20 March 2000, 2330 UTC
21 March 2000, 0000 UTC
Spichtinger et al, 2004b, ACPD
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• MM5 simulation 21 March, 0100 UTC horizontal
  and vertical wind (colours) on 318 K isentropic
  surface

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trajectories obtained from MM5 simulation (left)
starting at grid point nearest to Lindenberg at
t0
specific humidity in column following the
trajectories (right)
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Summary of case 2

• formation of the ice supersaturation triggered by
  superposition of two different gravity waves
• formation due to adiabatic cooling induced by a
  mesoscale upward motion
• an (optical) thick cloud forms from the
  supersaturation within about two hours
• lifecycle ISSR / cirrus cloud forms, remains
  about 6 (6 2.5) h

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30 hPa
50 hPa
26 January 2005 18 UTC
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VHgt10 m/s (m/s,?VH10 m/s), Tlt190K (K,?T2K,
shaded), ? (K,??2K), and DIV (10-5 s-1,red/blue
contour lines)
SouthWest NyAlesund
NorthEast
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