Post on 13-Feb-2016
description
transcript
Klaus M. Weickmann
NOAA/ESRL/PSD
Edward K. Berry
NOAA/NWS
A synoptic-dynamic model with application to subseasonal monitoring and forecasting
eddies
convectionbase state
mountains
Snellman Forecast Funnel
Global Mean
THERE IS NOCOOK
BOOK!!!
Global Synoptic-Dynamic Model(GSDM)
Seek to extract repeatable behavior by the the global circulation
Includes four subseasonal time scales: MJO - 30-60 day quasi-oscillation, baroclinic wave packets - 1-2 day decay timeteleconnections - ~6-10 day decay time20-30 day quasi-oscillation
Keyed to the time tendency of global atmospheric angular momentum (AAM)
some averaging necessary – vertical, zonal, etc.mountain, friction torques, momentum flux conv.
GSDM combined with rigorous daily monitoring and synoptic analysis
animations of daily, 7-day, 30-day, etc averagestime-latitude/longitude/height plotszonal and global AAM budget
Indices used for lag regressions
Madden-JulianOscillation: EOF1 of 20-100 day filtered OLR
Teleconnections or“M-F index cycle”:global friction torquewith MJO removed
Baroclinic waves and wave packets:Global AAM timetendency filtered at< 30 days
Stage 1
Stage 2
Stage 3
Stage 4
LL L H
HH
HL
L LH
L LH H H
H
L
H
L H LL
LH
LH
L
L
L
HL
H
L
H
H
H
L
L
L
H
L
HH
HH
LL HH
H
HH LL
L
L LH H L L H
L LH HHL
L H
HH
L
L
H
H
L
HHL L
H
HL L
HH LL H L
Application of GSDM
Case 1: May 4-10, 2003
Several Severe Local Storms Outbreaks
Strong MJO
GSDM Stage 1
Case 2: June 2006
Excessive East Coast Rainfall Event
Hot/Dry Regime Intensifies for Western and Central USA
Evaluating real time signals in tropical convection, atmospheric angular momentum, baroclinic wave packets,
SST anomalies, persistent regimes,etc.
Case 2June 2006
• Generally persistent tropical convection across western Pacific as part of a ENSO/global warming signal
• Poleward propagation of zonal mean anomalous easterly flow off the equator leads to strong North Atlantic trades
• ~ 50-60 day “oscillatory” tropical convective variations across the western Pacific
• ~30 day tropical convective variability with coherent eastward propagation
• Baroclinic wave packets/Rossby wave energy dispersion processes
• GSDM Stage 2
MJO#2
#3
#4
#5
#6
#7
A
wetwet dry
Stage 3
Stage 1
Stage 2
Stage 4
Stage 2
EE
E
EW
W
6/16
6/17
6/18
L LH
LH
HH
H
H
H HH
LHH
LL
L
H
LH H
L H
L
H
L
H
H
H
H
H
H
H
HH
H
H
LH
H
H
L
H
6/19
6/20
6/21
HH
HH
HL
HLHL
LL
L
HHL
HH
HL
L
HH
H
H
H
H
H
H
H
L L
LL
LH
H
6/22
6/23
6/24
HH H
H
LL
L
HH
HH
HH
HH
HH
H H
LH
L L
L
LL
6/25
6/26
6/27
H H H
HH H
HH H H
L LH
H
H
H L
H
L
LLL
H
L
6/28
6/29
6/30
H
H
H
LH L H L
LL
HHL
L L
L
L
LH
L
H
Questions???
Case 1 November – December 2005
• Strong North Pacific December Jet despite La-Nina and Indonesian tropical convective forcing
• Initiated during early November from Rossby Wave linked to west Pacific tropical forcing
• Recurrent Kamchatka blocks eventually overspread polar latitudes
• Postulated feedbacks include positive mountain torques, East Asia cold outbreaks and strong flux convergence of AAM ~30N
• GSDM Stage 3 circulation with Stage 1 convection
• Break down during early January as Kelvin wave/MJO develops across Indian Ocean
Madden-Julian Oscillation Activity
EH Consolidation
~30 days
~40 days
~20-30 days
~20 days
#1
#2
#3
#4
#5
WH
WH
WH
A
B
C
D E
Stage 3 circStage 1-2 conv
Stage 1 circStage 1-2 conv
Stage 2 circStage 2 conv
Relative Atmospheric Angular Momentum (AAM)
Global AAM
Nov Dec Jan Feb Mar
12/03/05 to 01/02/06
12/03/05 to 01/01/06
03/03/06 to 04/02/06
03/03/06 to 04/01/06
LH L
HLH
H
L
LH
LH
HL L
H L HLHH
L L
HLL
H
L
L
LHH
HL
HLL
12/03/05 to 01/02/06
12/03/05 to 01/02/06
03/03/06 to 04/02/06
03/03/06 to 04/02/06
+
+--
+--
--
4 Dec
9 Nov
15 Nov
28 Nov
HH
H
H
HL L
LHH H
HH
H
L
L LL
H HH
H
H
HL
LL L
L
LLL
H H
H
H
L
L
12 Dec
21 Dec
4 Jan
12 Feb
L
L
L
L
LH
H H
L
HH
HH
H
H
HLL
H
H
H H
HH
HL
H
HL
H
LH H HL
H
LL
H
L
L
L
L
L
H
H
H
L LL
L
H
H