Diapositiva 1

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Climas Extraños usando PLASIM René Garreaud
Alejandra Molina DGF-UCH
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Climas Extraños usando PLASIM René Garreaud
Alejandra Molina DGF-UCH
Model Description
Model Validation
Rotation Experiments
Topography Experiments
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RG Conoces algun modelo climatico simple de
usar? SS Claro chehay algo llamado Puma
Model Pero buscar Puma Model en Interner
puede ser peligroso
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Model Validation
SON mean SST
Full (atmosoceanice)
Atmos-only (prescribed ocean/ice)
Weak cold tongue, small warm pool, too much ice ?
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Model Validation
Zonal mean, annual mean
CMAP
Full (AtmosOceanIce)
Atmos only
Precipitation mm/day
SLP hPa
Latitude
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Model Validation
DJF Precip
JJA Precip
Full
Atmos only
Obs.
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Model Validation
DJF mean SLP
Full
Atmos only
Obs NNR
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Model Validation
DJF mean 200 hPa winds
Full
Atmos only
Obs NNR
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Model Validation
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Model Validation
Atmos-Ocean model includes more processes but it
has a less realistic representation of the basic
state
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Rotation Experiments
Full (a-o-i) Control
Full, Inverse rotation
Full, slow rotation (10 days)
Annual mean precipitation mm/month
Control (lines) and slow-rot (shaded) annual mean
precip mm/month
150
150
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DJF surface winds
Control
Rotation Experiments
Slow Rot
Inv. Rot
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Rotation Experiments
Inverse-Rot minus Control SST/SAT
SON
MAM
C
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Rotation Experiments
DJF mean Precip
JJA mean Precip
mm/month
Control
InvRot
InvRot Minus Control
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Rotation Experiments
DJF mean Precipitation
(a) Control
(b) Inverse Rotation
(c) InvRot minus Control
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Topography Experiments
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Topography Experiments
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Topography Experiments
Motivated by the previous wisdoms in the
paleo-climate and geological communities, we set
up a numerical experiment using PLASIM
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Topography Experiments
0.3Topo minus Control (DJF)
900 hPa winds and Precip
Precip (?P/Pc)
?

mm/day

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Topography Experiments
DJF Precipitation
Rgt100 mm/month
Rlt 10 mm/month
Control
Control
0.3Andes
0.3Andes
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fTopo minus Control (DJF)
f 0.1
f 0.3
f 0.7
f 0.5
Topography Experiments
f 0.9
f 0.3
mm/day
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Topography Experiments
Austral Andes (45-50S 80-70W)
Andes only
Precipitation change Pe/Pc100
SESA (15-25S 60-50W)
Interannual variability (?)
Topographic reduction factor
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Control
Deep convections warms the tropical / subtropical
tropospher, producing a warm-core upper-level
anticyclone
-27C
-37C
-47C
Rodwell-Hoskins Mechanism
Rgt100 mm/month
Control
Strong cold advection occurs where the westerly
flow encounters the upper-level warm region.
Thermal balance requires enhanced susbidence,
strengthening the SEP subtropical anticyclone
Topography Experiments
Subsidence
Upward
Cold Adection
0.3Andes - Control
Smaller Andes reduce rainfall over the interior
of the continent and thus reduce the warming of
the upper-troposphere less thermal
gradient less cold advection. less subsidence?
?P (less precip)
?T (cooling)
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Topography Experiments
DJF 400 hPa South American Region (60S-20N,
220-360E)
Subsidence
SEP anticyclone
Vertical velocity cm/s
SACZ
Central SA
Upsidence
Temperature advection 10K/day
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Topography Experiments
DJF, 400 hPa
w ? 0.3 cm/s
Control
0.3Andes
Vertical velocity cm/s
0.3Andes
Control
Temperature advection 10K/day
0.3Andes
Control