1 Recent development of the data assimilation, model and deterministic forecast at ECMWF Adrian...
-
Upload
haley-hogan -
Category
Documents
-
view
214 -
download
0
Transcript of 1 Recent development of the data assimilation, model and deterministic forecast at ECMWF Adrian...
1
Recent development of the data assimilation, model and
deterministic forecast at ECMWF
Adrian Simmons Data Division, Research Department
and
Alfred Hofstadler Met. Apps. Section, Operations Department
2
Operational data assimilation before 29 June 2004
12h 4D-Var with long data cut-off
00 03 06 09 12 15 18 21 00 03 06 09 12 15 18 21 00
Long cut-off4D-Var (12
h)
AN
AN
00 UTC FC
12 UTC FC
3
From 29 June 2004
The Early Delivery System
00 03 06 09 12 15 18 21 00 03 06 09 12 15 18 21 00
Delayed cut-off
4D-Var (12 h)
ANAN
FCFC
AN ANEarly Delivery Analysis4D-Var (6 h)
00 UTC FC
12 UTC FC
Early Delivery System gains from:
- using 00 and 12UTC data earlier in window of 12h 4D-Var
- using slightly more data in 12h 4D-Var
Early Delivery System loses from
- using less data in 6h 4D-Var
4
Radiosondes arriving between 0401 and 0800 UTC
25 March 2004 Number of soundings = 35
5
Four subsequent operational changes
• 28 September 2004 – IFS cycle 28r3
• 18 October 2004 – IFS cycle 28r4
• 5 April 2005 – IFS cycle 29r1
• 28 June 2005 – IFS cycle 29r2
Day
Anomaly correlation of 500hPa forecasts for Europe
Mean over 186 days since 1 Dec 2004
Cycle 29r2
Cycle 29r1
6
EUMETSAT ATOVS Retransmission Service (EARS)
7
Relative humidity along Greenwich meridian
5.0m/s
80°S80°S
70°S 70°S
60°S60°S
50°S 50°S
40°S40°S
30°S 30°S
20°S20°S
10°S 10°S
0°0°
10°N 10°N
20°N20°N
30°N 30°N
40°N40°N
50°N 50°N
60°N60°N
70°N 70°N
80°N80°N
160°W
160°W 140°W
140°W 120°W
120°W 100°W
100°W 80°W
80°W 60°W
60°W 40°W
40°W 20°W
20°W 0°
0° 20°E
20°E 40°E
40°E 60°E
60°E 80°E
80°E 100°E
100°E 120°E
120°E 140°E
140°E 160°E
160°E
5.0m/s
80°S80°S
70°S 70°S
60°S60°S
50°S 50°S
40°S40°S
30°S 30°S
20°S20°S
10°S 10°S
0°0°
10°N 10°N
20°N20°N
30°N 30°N
40°N40°N
50°N 50°N
60°N60°N
70°N 70°N
80°N80°N
160°W
160°W 140°W
140°W 120°W
120°W 100°W
100°W 80°W
80°W 60°W
60°W 40°W
40°W 20°W
20°W 0°
0° 20°E
20°E 40°E
40°E 60°E
60°E 80°E
80°E 100°E
100°E 120°E
120°E 140°E
140°E 160°E
160°E
300hPa wind Meteosat-7 increments Meteosat-8 increments
Assimilation of MSG water-vapour radiances
8
Total ozone9 Sept 2004
Operations, no SCIAMACHY
Pre-operational test, including SCIAMACHY retrievals from KNMI
TOMS
9
Wavelet Jb: horizontal and vertical correlations for vorticity North America
Equatorial Pacific
Average vertical correlations
Horizontal correlations at level 39 (~500hPa)
10
New moist boundary layer scheme
METEOSAT visible 10 Dec 2004 Impact on low-cloud cover 8-16 Dec 2004
-0.4
-0.3
-0.2
-0.10.1
0.2
0.3
0.4
KM
K
Stratocumulusdry PBL
zcbzi
zi
KMMoist combined
mass-flux/K-diffusion PBL
11
Bias-correction of surface-pressure observations
Altamera, Brazil
December 2004 April 2005
12
Assimilation of rain-affected microwave radiancesand improvement of humidity analysis
Rain Asm
Hurricane CharleyTrack forecasts from 12 UTC 11 Aug
2004
e-suite ops
Global 1.74 1.90N. Hemisphere 1.63 1.71Tropics 2.12 2.43S. Hemisphere 1.53 1.62N. Atlantic 1.63 1.69N. Pacific 1.57 1.69
(kg/m2)
Comparison of cycle 29r2e-suite and operations
with independent TCWV retrievals from Jasonmicrowave radiometer
13
Also included:
• Refinements to use of ATOVS and AIRS
• Improved use of TEMP and SYNOP humidity observations
• Monitoring of TCWV from ground-based GPS receivers
• Use of METAR observations; discontinue use of PAOBS
• Lower surface-pressure obs errors for automatic stations
• Use of Meteosat-8 (MSG) winds
• MODIS winds from second satellite, and with reduced errors
• Simulated GEO imagery as forecast product
• Jb statistics from new ensemble data assimilation
• Use of SMHI Baltic sea-ice analysis
• Small revisions to surface, convection and cloud schemes
• Radiation frequency reduced from three hourly to hourly
• Better vertical diffusion in first minimization of 4D-Var
14
T799 orography
T799 model resolution for deterministic forecast
T95/255/799 for 4D-Var
10m wind T799
15
91-level vertical resolution
used UJPprofiler-windspeed Japanexp:eilv L91/L60 2004010500-2004013112(12)
nobsexp
0 33568 56445 26291 7821 681 0 0 0 0 0 0 0 0 0 0
exp - ref
+0 -11 -13 -5
+10 +14 +0 +0 +0 +0 +0 +0 +0 +0 +0 +0
0 2 4 6 8
STD.DEV
1000 850 700 500 400 300 250 200 150 100 70 50 30 20 10 5
-6 -4 -2 0 2 4 6
BIAS OF SPEED
1000 850 700 500 400 300 250 200 150 100 70 50 30 20 10 5
background departure o-b(ref)background departure o-banalysis departure o-a(ref)analysis departure o-a
used TTEMP-T N.Hemisexp:eilv L91/L60 2004010500-2004013112(12)
nobsexp
50366 75192 85693 72586 53338 48908 45852 48907 45909 50690 41975 41264 37500 32256 28557 6947
exp - ref
-71 -12 +21 +27 +24 +115 +295 +432 +228 +215 +189 +227 +61 +5 -73 -61
0 1 2 3 4
STD.DEV
1000 850 700 500 400 300 250 200 150 100 70 50 30 20 10 5
-3 -2 -1 0 1 2 3
BIAS
1000 850 700 500 400 300 250 200 150 100 70 50 30 20 10 5
background departure o-b(ref)
background departure o-banalysis departure o-a(ref)analysis departure o-a
used TTEMP-T Tropicsexp:eilv L91/L60 2004010500-2004013112(12)
nobsexp
8334 9927 14484 14627 11266 8419 6054 5486 6117 5953 6199 6455 5770 4483 3160 687
exp - ref
+12 -2
+10 +6 -3 -1 -2 -4 -1
+220 +189 +136 +119
-73 -53 -4
0 1 2 3 4
STD.DEV
1000 850 700 500 400 300 250 200 150 100 70 50 30 20 10 5
-3 -2 -1 0 1 2 3
BIAS
1000 850 700 500 400 300 250 200 150 100 70 50 30 20 10 5
background departure o-b(ref)
background departure o-banalysis departure o-a(ref)analysis departure o-a
Fit of L91 and L60 background and analysis to NH radiosonde T
K
L60
L91
16
Higher horizontal and vertical resolution
Anomaly correlation of 500hPa height for northern hemisphere
T511 L60
T799 L91
Day
Mean over 148 cases from 1 August 2004
17
Higher horizontal and vertical resolution
Anomaly correlation of 500hPa height for Europe
T511 L60
T799 L91
Day
Mean over 148 cases from 1 August 2004
18
Higher horizontal and vertical resolution
Anomaly correlation of 500hPa height for Europe
T799 L60
T799 L91
Day
Mean over 148 cases from 1 August 2004
19
Resolution Upgrades – Atmosphere (A.Hofstadler)
Deterministic EPS MOFC
Current Upgrade Current Upgrade Current Upgrade
Spectral T511 T799 T255 T399 T159 T159
Gaussian N256 N400 N128 N200 N80 N80
Dissemination (LL)
0.5 0.25 1.0 0.5 1.5 1.5
ML - Vertical Resolution
60 91 40 62 40 62
• No increase in pressure levels planned
20
Resolution Upgrades - Waves
Deterministic EPS European shelf MOFC
Current Upgrade Current Upgrade Current Upgrade Current Upgrade
Lat/Lon 0.5 0.36 1.0 1.0 0.25 0.25 1.5 1.5
Dissemination/LL 0.5 0.25 1.0 1.0 0.25 0.25 1.5 1.5
Frequencies 30 30 25 30 30 30 25 25
Directions 24 24 12 24 24 24 12 12
21
Timetable for resolution changes
• Mid June: First operational testing
• End June: First technical test datasets for selected operational suites available in MARS
• July-September: Operational e-suite
‑ Meteorological test datasets for all operational suites available in MARS
‑ Parallel test dissemination for selected dates
• End September: Implementation
• December: increase in run-length for medium-range from 10 to 15 days, including VAREPS
• Spring 2006: linking MOFC to VAREPS
22
Technical impact on users
• Field sizes‑ Model output (SH and GG) -> x 2.5
‑ Lat/Lon -> x 4
‑ Extra model levels -> x 1.5
• Dissemination‑ Problem with GG/AUTOMATIC
‑ Choosing of nearest “new” model level
‑ Nearest GRID point coordinates for Weather Parameter requests will
change. Member States have to choose new GRID point coordinates or
rely on interpolation.
‑ Line capacity
‑ Production schedule should stay the same
• MS jobs‑ Check new disk space, memory, CPU, line bandwidth requirements
23
Technical impact on users (cont.)
• MS projects‑ Use test data sets to run “e-suites” and decide on new
configuration
‑ Review resource requirements (disk space, memory, CPU, line bandwidth)
• EMOSLIB 281‑ New Gaussian definitions
‑ New automatic truncation
‑ Will become default version
‑ MARS and Metview_new have been relinked
‑ MS graphics applications (Metview and MAGICS) need to be relinked