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Unified Model Developments 2002. Clive Wilson NWP Met Office. Outline. Configurations & Users Global and UK Mesoscale Changes Regional European Model New supercomputer Plans. Operational Versions & External Users. Global 38 levels, N216= 432x325 (~60km) UK Mesoscale - PowerPoint PPT Presentation
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1 10/2002 © Crown copyright
Unified Model Developments 2002
Clive Wilson
NWP
Met Office
2 10/2002 © Crown copyright
Outline
Configurations & Users
Global and UK Mesoscale Changes
Regional European Model
New supercomputer
Plans
3 10/2002 © Crown copyright
Operational Versions & External Users
Global 38 levels, N216= 432x325 (~60km)
UK Mesoscale 38 levels, 0.11 deg (12km)
Stratospheric 42 levels (~1.3km @ 100-1hpa), N48=96x73 (~300km)
Crisis models (LAMS) Middle East, Former Yugoslavia,SW Asia
External CGAM UK, ICM Warsaw, Thai Met Service, New Zealand, DNMI
4 10/2002 © Crown copyright
Changes
Global G26 16 Oct 3dvar upgrade
Increase Observation errors for AMVs
Revise thinning of ATOVS to give preference to microwave-clear over IR-clear
Use of fractional sea-ice in ATOVS processing
G27 7 August 2002 New Dynamics and HadAM4
G28 1 Oct Introduce NOAA17
UK Mesoscale G27 7 August 2002 New Dynamics
5 10/2002 © Crown copyright
New Dynamics ( Hadam4 )PhysicsSemi -Lagrangian advection(With monotone advection of potentialtemperature)
* Edwards-Slingo Radiation
Semi-implicit time integration * Mixed phase precipitation Including iterative freezing level
Horizontal staggering - C grid * New Boundary Layer + 38LVertical Staggering - Charney Philips * MOSES IINon-hydrostatic formulation * Effective area cloud fraction Vertical
gradient cloud fractionNew physics compared to current
operationalLateral boundaries (8 points -5 outerglobal)
Orography -smoothed (Raymond =1) Lateral boundaries 6 global, 10 point
linear transition to mesoscaleConvection CAPE closure, 30 min timescale Momentum transportNew Gravity wave dragVisibility in snow correction
*Already operational in Mesoscale Model
6 10/2002 © Crown copyright
Expected benefits of New Dynamics
Non-hydrostatic capability – ability to increase resolution in UK area.
Improved stability and accuracy - less noise in forecasts
Improved physics for global model - improved coupling to dynamics.
Unify physics between global and UK area - Better boundary conditions.
Better coupling with 3D-Var which was designed around new grid.
7 10/2002 © Crown copyright
New Dynamics levels
Dec 2001- Jan 2002
-10
-5
0
5
10
15
Mar - Apr 2001
-10
-5
0
5
10
15
Jun-Jul 2001
-10
-5
0
5
10
15
Sep-Oct 2001
-10
-5
0
5
10
15
MS
LP
24
MS
LP
48
MS
LP
72
MS
LP
96
MS
LP
120
H50024
H50048
H50072
W25024
W85024
W85048
W85072
W25024
MS
LP
24
MS
LP
48
MS
LP
72
MS
LP
96
MS
LP
120
H50024
H50048
H50072
W25024
Bars show the %change in RMSE (NDHadAM4 - OP/OP) for the components, which make up the NWP index. Verification is against observations. Blue signifies Northern Hemisphere, red the Tropics and Green is the Southern Hemisphere. A negative value implies NDHadAM4 is an improvement over OP.
9 10/2002 © Crown copyright
10 10/2002 © Crown copyright
Typhoon Phanfone
18 August 2002
11 10/2002 © Crown copyright
12 10/2002 © Crown copyright
Screen temperature Shadow suite (16/1-4/2), all stations
mean
rms
OPND
forecast range
0 12 24 36
forecast range
13 10/2002 © Crown copyright
10-metre wind Shadow suite (16/1-4/2), all UK stations
mean
speed
rms
vector
OPND
0 12 24 36
14 10/2002 © Crown copyright
Relative Humidity Shadow suite (16/1-4/2), all stations
mean
rms
OPND
forecast range
0 12 24 36
15 10/2002 © Crown copyright
Visibility Shadow suite (6/12-4/2), all stations
16 10/2002 © Crown copyright
Rainfall (skill) Shadow suite (6/12-28/1)
v Nimrod 6-hourly accumulations
17 10/2002 © Crown copyright
Rainfall (bias) Shadow suite (6/12-28/1)
v Nimrod 6-hourly accumulations
18 10/2002 © Crown copyright
Strong summer convection
19 10/2002 © Crown copyright
French Storm Vt 12Z
27/12/1999
T+0
T+72
OP ND
20 10/2002 © Crown copyright
Danish Storm Vt 12Z
03/12/1999
T+0
T+24
OP ND
21 10/2002 © Crown copyright
Reduced Noise in New Dynamics
22 10/2002 © Crown copyright
New Dynamics Summary
Reduced NH RMSE in summer and at early FC ranges in winter
Deeper extratropical cyclones
Reduced temperature biases
Improved stratospheric circulation statistics (eddy temperature fluxes)
Reduced noise in ND forecasts.
Improved radiative balance - OLR
Tropical upper level wind RMSE too large (~6-10%)
SH T+24 wind RMSE too large (vs analysis) - corrections ready
Grid point storms at N216.
Tuning of orographic and BL drag and diffusion still required.
Low cloud in UK mesoscale
Poor initial precipitation in UK Mes
Benefits Problems
23 10/2002 © Crown copyright
New Regional European model
Opportunity to reorganise Operational suite
– New dynamics model formulation (August 2002) Better Global performance but double cost
2X number of processors to keep to delivery time
Mesoscale ~same as current
—relatively more efficient than global
– Remove duplication of Global Preliminary/Main runs
24 10/2002 © Crown copyright
Resources
Make full use of operational time & processors
Processors
– global 288, UKmes 108 factor of 2.8
Release duplicate Prelim/main
– analysis +2 day forecast (=40min)
60min slot (=20 min gap + “duplicate time”)
~5X UKmes cost
25 10/2002 © Crown copyright
Proposed Domain
Current UK mesoscale
New Euro Mes 20km resolution
548
320
Current Operational Schedule
Ocean, wave, surge+4:50
00/12
+1:502 Days Prelim Run
Boundary Forcing
+2:40
2 Days
+3:00
Main Run
6 Days
00/12
2 Days
2 Days+7:50 Prelim Run
Proposed Operational Schedule
Boundary Forcing
2 Days
+2:40
Ocean, wave, surge+4:50
2 Days Main Run part 1
00/12
+1:50
Continued Main Run
Days 2-6+3:40
00/12
+3:002 Days Euro Run
28 10/2002 © Crown copyright
Estimated Skill score change for extended "Preliminary" Global model. Period =200012-200111
-0.04
-0.03
-0.02
-0.01
0
0.01
0.02
0.03
0.04
0.05
T+24PMSL
NH
T+48PMSL
NH
T+72PMSL
NH
T+96PMSL
NH
T+120PMSLNH
T+24H500NH
T+48H500NH
T+72H500NH
T+24W250
NH
T+24W850Trop
T+48W850Trop
T+72W850Trop
T+24W250Trop
T+24PMSL
SH
T+48PMSL
SH
T+72PMSL
SH
T+96PMSL
SH
T+120PMSLSH
T+24H500SH
T+48H500SH
T+72H500SH
T+24W250
SH
Parameter
unweighted skill diff Wtd Skill diff
Estimated Global worsening
250hPa winds
estimated
29 10/2002 © Crown copyright
Estimated effect on Global Index
Index Impact (%)
-1.2
-1
-0.8
-0.6
-0.4
-0.2
0
0.2Oct
-00
Nov-0
0
Dec-0
0
Jan-
01
Feb-0
1
Mar
-01
Apr-0
1
May
-01
Jun-
01
Jul-0
1
Aug-0
1
Sep-0
1
Oct-0
1
Nov-0
1
Dec-0
1
Jan-
02
Feb-0
2
Mar
-02
Apr-0
2
May
-02
Jun-
02
Mea
n
Index Impact (%)
30 10/2002 © Crown copyright
31 10/2002 © Crown copyright
Timetable 5 November - Merge Prelim/Main model +digital filter
intitialisation instead of incremental analysis update
– but leave split of run until next year
12 Nov -Forecast only European Model introduced
Post November -products and downstream use developed
14 Jan - basic data assimilation
25 March- model & DA upgrade
June 03 - Declare Euromodel operational (high risk -Exeter transition)
32 10/2002 © Crown copyright
New supercomputer need Improve NWP systems:
Satellite data volumes
New Dynamics
4D-VAR
Higher resolutions
Very fine resolution mesoscale (~2km)
European Mesoscale model
Short range Ensembles
Operational Suite creaking at the seams
33 10/2002 © Crown copyright
What are we getting?
Initially - NEC SX-6
– 30 nodes
– Each node has 8 CPUs sharing 64Gb of memory
– Each CPU is equivalent to approx 30 T3E CPUs
– Overall performance:
» 6x T3E’s for “performance work”
» > 6x T3E’s for “throughput work”
34 10/2002 © Crown copyright
And in the future
In 2005 - joined by SX-6 successor:
– 15 nodes
– Each CPU twice as powerful
– Overall performance
» 12.5x T3Es for “performance work”
» >12.5x T3Es for “throughput work”
35 10/2002 © Crown copyright
Benchmark Results (N324L50)
0.00
1.00
2.00
3.00
4.00
5.00
6.00
7.00
8.00
9.00
10.00
11.00
12.00
13.00
14.00
15.00
0.0% 10.0% 20.0% 30.0% 40.0% 50.0% 60.0% 70.0% 80.0% 90.0% 100.0%
% System
Facto
r
Performance Throughput
36 10/2002 © Crown copyright
Met Office Networks
FC
Sw
itch
Mirrored filesystemsUser
filesystems
FibreChannel
Fro
nt
En
d12xIA
64
Fro
nt
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d12xIA
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Gigabit Etherne
t
The BitsN
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NO
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(8
CP
Us)
NO
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CP
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NO
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NO
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NO
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NO
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NO
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NO
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NO
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IXS(Interconne
ct)
IXS
Timetable Installation
Sep 02Oct 02Nov 02Dec 02Jan 03Feb 03Mar 03Apr 03May 03Jun 03Jul 03Aug 03Sep 03Oct 03Nov 03Dec 03
Date Bracknell SX-6
1 node syste
m
Upgrade:4 nodes
Front end
Move to Exeter
T3E-A
Move to Exeter
02/09-06/10
T3E-B
Move to Exeter
17/06-22/07
ExeterSX-6(B)
15 node system
ExeterSX-6(A)
15 node system
Acceptance tests
38 10/2002 © Crown copyright
Plans 2002- 2003 November UK Mes DA-improved covariances
December Global model & DA
January New Dynamics in Stratospheric model
Data assimilation in Euro model
Feb-March -Global, UK mes & Euro model+DA upgrades
Transition to Exeter
– Moratorium May 03 - October 03
Future Plans 4dVar
Practicable global synoptic scale ready for test on new computer end 03
Inclusion physical processes 04
operational early(?) 2004
Increased resolution » 40km , 50L Global; 10km , 50L Euro mesoscale
Physics —new gravity wave drag
—new convection
—new cloud (prognostic cloud and condensate)