Long range forecast services in KMA and Introduction of Joint

Byoung-Kwon Park
Climate Prediction Division, KMA
1/29
2/29
Organization in Climate Science Bureau
Climate Science Bureau
Climate Policy
Division
Climate
Prediction
Division
Director
Marine
Meteorology
Division
Climate
Change
Monitoring
Division
Planning and management 3
Forecast 3
Climate monitoring and analysis 2
Model assessment and analysis 4
Extreme climate/event monitoring and analysis 2
Weather Forecast services in KMA
Chief Forecasters Division
Climate Prediction Division
4/29
1month outlook period
Mon
Tue
Wed
Thu
Fri
Sat
Sun
5. 9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
6. 1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
Short-range
Forecast
Medium-range
Forecast
1st week
2nd week
3rd week
4th week
1month outlook
5/29
Long-range Forecast products
Date of issue / interval
Contents
1-month f • Every Thursday
orecast • Outlook for the 1-month after the next 2-week
• Weekly mean temperature and precipitation
• Loading pressure pattern
rd
3-month f • Every 23
• Outlook for the next three months
orecast • Special : February, May, August, November
• Monthly mean temperature and precipitation
• Loading pressure pattern
• Elnino/La Nina update
• Asian dust in February supported by Environmental Meteorology Research Division
• Typhoon in May and August
supported by National Typhoon center
• 23rd in Feb, May, Aug, Nov
• Outlook for the season after next season
6-month f • Four times a year
- outlook for summer in February
orecast - outlook for autumn in May
- outlook for winter in August
- outlook for next spring in November
• Seasonal mean temperature and precipitation
• El Nino/La Nino update
1-year
forecast
• 23 December
• Outlook for one-year
• Once a year
Type
• Probabilistic
three
categories
• Probabilistic
three
categories
• Annual mean temperature and precipitation
* Asian dust outlook is issued in late February including frequency and density of Asian dust expected
to affect Korea for the upcoming Spring.
* Typhoon outlook is issued in late May and Aug regarding number of Typhoon expected to affect
Korea for the upcoming Summer and Fall.
6/29
Procedure for long-range forecasting
10 Forecast areas and Local forecasters
Climate monitoring & analysis
Observational analysis
Pressure pattern, OLR, MJO, AO,
snow cover, Arctic sea ice, PDO etc.
Extreme events, Pressure pattern,
Trend in temperature and precipitation, etc.
Glosea5 prediction results
Other model results
Weekly, Monthly
El Nino prediction model
NCEP / ECMWF / JMA
WMO LC-LRFMME, APCC
Briefing and discussion
to make a draft forecast
EASCOF, FOCRAII
Seasonal Climate Expert
Meeting out of KMA
Video teleconference and discussion
with local forecasters
Seasonal Press briefing
Issue and distribute
7/29
1-month Outlook
8/29
3-month Outlook
Monthly outlook (Trends)
Summary for 3 months over Korea
Probabilistic Forecast over Korea
Probabilistic Forecast of 10 local area
9/29
WMO Lead Centre for Long-Range-Forecast
Multi Model Ensemble (WMO LC-LRFMME)
operated by KMA and NCEP
GPC
CBS / CCL /
ET-OPSLS
(Advisory body)
RCC
RCC
GPC
KMA/NCEP LC-LRFMME is
envisioned to provide a conduit
between GPCs and NMHSs,
RCCs, RCOFs etc.
GPC
•
•
•
GPC
RCC
RCC
Lead Centre
for LRF MME
APEC Climate
Center
(R&D brench of LCLRFMME)
•
•
•
GPC
GPC
NMHS
NMHS
• Function of WMO LC-LRFMME
- To collect hindcast and forecast data from 12 Global Producing Centers
- Quality check, standardize all data and produce Multi Model Ensemble (MME)
- To distribute to all WMO members through Website (www.wmolc.org)
10/29
WMO LC-LRFMME Web site
• Level A (GPCs)
- Upload & download
digital data (limited)
- Download image plots
• Level B (NMHSs, RCCs)
- Download
digital data (limited) &
image plots
• Level C (Others)
- Image plots
11/29
12/29
Joint Seasonal Forecasting System
June 2010, the collaboration agreement was made between KMA and UK Met Office
for a joint seasonal forecasting system.
 To establish a joint seasonal forecasting system with the joint aim of
developing and providing operational seasonal forecasting products.
KMA
Major advantages are to share ensemble members as many as possible.
The Joint system was launched at December 2014.
13/29
Joint Seasonal Forecasting System
Initial Field
ICE & OCEAN
ICE & OCEAN
KMA
4DVAR(N512)
Met Office
4DVAR(N512)
Forecast
GloSea5
GloSea5
Ensemble Prediction
42 members
42 members
Joint System
Share the ensemble
members
14/29
GloSea5 : Global Seasonal forecasting system
GlosSea5 is the fifth version of the Met Office ensemble prediction system for
seasonal forecasting, and was upgraded dynamics and physics package from
GA3 to GC2 at May 2016 in KMA
OASIS3
(coupler)
UM-JULES
(Atmosphere & Land)
NEMO-CICE
(Ocean & Sea Ice)
Atmosphere
Ocean & Sea Ice
Model
UM
(UM 8.6, JULES 8.6)
NEMO-CICE
(NEMO 3.4, CICE 4.1)
Horizontal res.
N216 (0.83° x 0.56°)
ORCA tri-polar grid at 0.25°
Vertical res.
85 levels (~85km)
75 levels
•
•
•
•
•
UM (Met Office Unified Model) for Atmosphere
JULES (Joint UK Land Environment Simulator) for Land Surface
NEMO (Nucleus for European Modeling of the Ocean) for Ocean
CICE (Los Alamos National Laboratory) for Sea-ice
OASIS (CERFACS) for coupling between component models
15/29
GloSea5 : Generation of ensemble member
Simulation length : 7 months ( 2 members) / 60 days (2 members)
Model uncertainties represented by Stochastic Kinetic Energy Backscatter (SKEB2) scheme
Initial conditions uncertainties represented by lagged initialization
Number of Ensemble member
1-month : 28 members (4 members a day x 7days)
3-month : 42 members (2 members a day x 21days)
※ SKEB2(Tennant et al, 2010) : adds vorticity perturbations to the forecast
in order to counteract the damping of small-scale features in advection
16/29
Ensemble System for 1-month forecast
2 members x 7month
″
″
″
″
″
″
2 members x 60days
″
″
″
″
″
″
1w
Days ago
T
W
T
F
S
S
2w
3w
4w
5w
6w
7w
M
0
0
0
0
0
0
0
1
1
1
1
1
1
1
10
10
10
10
10
10
10
11
11
11
11
11
11
11
1month outlook
17/29
GloSea5 : Generation of ensemble member
Period : 1991~2010 (20years)
Simulation length : 8 months / 3 members per start date on 1st, 9th,
17th and 25th of each month
Sample size for model climate :
1-month : 120~180 members (3 members x 20 years x 2~3 sets)
3-month : 360 members (3 members x 20 years x 6 sets)
18/29
Model Climate for 1month forecast
Hindcast
Start date
0225
11-17
0.07
0301
6-12
0.53
13-19
0.10
0309
0-4
0.41
5-11
0.56
0317
11-17
0.22
0307
3-9
0.58
10-16
0.25
0-3
0.34
12-18
0.16
Issue date
0325
0401
0-2
0.20
3-9
0.57
4-10 0-2
0.58 0.20
0314
0321
0409
9-15
0.38
1-7
0.56
0-1
0.18
10-16
0.30
0328
0417
0404
0509
0-6
0.54
0
0.11
0411
0501
0
0.05
8-14
0.46
2-8
0.58
0425
7-13
0.42
0418
0425
1-7
0
0.53 0.05
0502
19/29
Global Seasonal Forecast System Based on Glosea5
• Geopotential
Height Anomaly
(500hPa)
• Temperature
& Wind Anomaly
(850hPa)
• SLP Anomaly
• Prcp. Departure
from climatology
• 1.5m Temperature
Anomaly
• Wind Anomaly
(200hPa)
20/29
GloSea5 forecast products
Ensemble Mean
Probability
PDF
21/29
1.5m Temperature BIAS (MAM, ‘96~’09)
2week forecast (GA3)
4week forecast (GA3)
6week forecast (GA3)
2week forecast (GC2)
4week forecast (GC2)
6week forecast (GC2)
22/29
1.5m Temperature RMSE (MAM, ‘96~’09)
diff
1w
2w
3w
4w
5w
6w
-0.40
-0.21
-0.20
-0.20
-0.23
-0.22
23/29
1.5m Temperature ACC (MAM, ‘96~’09)
2week forecast (GA3)
4week forecast (GA3)
6week forecast (GA3)
2week forecast (GC2)
4week forecast (GC2)
6week forecast (GC2)
24/29
H500, T850, MSLP and Prec. Biases (JJA)
H500
T850
MSLP
PREC.
25/29
SST and prec. Anomaly (JJA & DJF 1997)
26/29
Future Plan for seasonal prediction system
Soil moisture anomaly initialization
Improve the forecast skill of Surface Air temperature over Eurasian continent
Cooperate with Chonnam National University
Upgrade GloSea5-GC2 to GloSea5-GC3
Warm sea surface temperature bias over the Southern Ocean
The lack of precipitation over land in tropical monsoons(india and the Sahel)
Tropical tropopause layer temperature/humidity errors
Conservation of energy and freshwater
Increase Hindcast period to 25 years (1991~2015)
27/29
28/29
29/29
Thank you