The next NCEP Climate Forecast System Status

Hua-Lu Pan and Suru SahaEMC/NCEP

CFSRR• We are starting to work towards an

implementation of the next CFS in 2011– Reanalysis of the atmosphere, ocean, land and sea

ice, using a coupled background guess forecast– Reforecasts using the same model used in the

reanalysis– Real time data assimilation and forecast will use

the same system as the reanalysis and reforecast

CFSRR Plan (I)• Reanalysis

– Using the CFS as the model to provide the first guess to the data assimilation of atmosphere, ocean, land, and sea ice

– Using the highest resolution we can afford (we did dream big hoping that we will get mist and dew when the power 6 machine arrives)

– Using the newest data assimilation and model versions tested (drawbacks do exist)

Reanalysis• T382L64 for atmosphere with GSI, 0.25 - 0.5 degree 40 layer

ocean with stronger SST constraint, NOAH land model plus observed precipitation for GLDAS, extend the new sea-ice analysis back to 1979

• Coupling is on ocean and ice-atmosphere time steps

• All satellite instruments calibrated using 3-month spin up runs.

• Calibrated SSU and MSU data included

• Running on Haze (5-6 streams since June 2008)

• CPC has developed and undertaken close monitoring of the CFSR

• We have, within our limit, tried to correct mistakes. A few glitches, which would have necessitated complete restarts, have been left as features.

CFSRR Production ConfigurationCovers 31 years (1979-2009) + 25 overlap months

6 Simultaneous Streams

• Jan 1979 – Dec 1985 7 years 1983/01• Nov 1985 – Feb 1989 3 years 1987/09• Jan 1989 – Feb 1994 5 years 1991/02• Jan 1994 – Dec 1998 5 years 1996/02• Apr 1998 – Dec 2004 6 years 2002/11• Apr 2004 – Dec 2009 5 years 2007/08

overlap months are for ocean and land spin ups

Reforecast• All coupled reforecasts will be run at T126L64 resolution

• 9-month hindcasts will be initiated every 5th day and will be run from all 4 cycles of that day, beginning Jan 1 of every year, over a 28 year period from 1982-2009.

• In addition, there will be a single 35-day hindcast run initiated from every cycle between these five days, over the entire period.

MID JANUARY SEASONAL RELEASE (24 members)

MonthDay Hour

12 12 0, 6, 12, 18

12 17 0, 6, 12, 18

12 22 0, 6, 12, 18

12 27 0, 6, 12, 18

1 1 0, 6, 12, 18

1 6 0, 6, 12, 18

JANUARY MONTHLY (35-DAY) HINDCAST SCHEDULE

MonthDay Hour

12 27 0, 6, 12, 18

12 28 0, 6, 12, 18

12 29 0, 6, 12, 18

12 30 0, 6, 12, 18

12 31 0, 6, 12, 18

1 1 0, 6, 12, 18

Reforecast• Initially, make complete reforecast for CPC’s mid-May and

mid-November forecast release, to assess skill. Once we can demonstrate comparable or better skills for ENSO, US temperature and precip for winter and summer forecasts, we can start the implementation process

• Forecasts generated from high resolution data assimilation may allow for a useful monthly forecast product for CPC. Month one in the CPC parlance is really week3 – week 6 forecast

Real Time Configuration for next CFS• There will be 4 control runs per day, out to 9 months,

from the 0, 6, 12 and 18 UTC cycles of the CFS real-time data assimilation system.

• In addition to the control run, there will be 3 additional runs per cycle, out to 35 days. These 3 runs per cycle will be initialized as in current operations.

• There will be a total of 16 runs every day out to 35 days (weeks 1-5), four of which will go out to 9 months (monthly and seasonal)

Haze75 Compute

7 Class 1100 TB

Zephyr16 Compute

1 Class 140 TB

Mist140 Compute

8 Class 175 TB

Dew140 Compute

8 Class 175 TB

3 Streams 28 Streams 28 Streams15 Streams

Number of 9 month Hindcasts to be made is 292 per year X 28 years = 8176

CFSRR Computer Configurations for Retrospective Forecasts

Legend of available systems:

Each one-year run on power 5 requires 5 nodes for 40 hours

Number of extra 35-day Hindcasts to be made is 1196 per year X 28 years = 33488 (~ 4000 9-month runs)

Resources

• Human resources

• Funding

• Computer

Human resources– Suru Saha is the leader of the group who maintain the continuous

running of the reanalysis and the reforecast– Xingren Wu, Jiande Wang, Sudhir Nadiga and Patrick Tripp do the

actual monitoring of jobs and runs– S. Moorthi built the reanalysis and reforecast scripts from end to end– Suru and Patrick Tripp built the scripts for HPSS archives– Jack Woollen provides most of the observation support– Bob Kistler provides overall support of the reanalysis– CPC formed four teams of about 20 people to provide monitoring of the

reanalysis– Huiya and Wesley provided continued support for the NCEP post and

the GRIB2 conversions– Xingren worked on the ice model and assimilation, Jiande worked on

the checkout of MOM4 for our configuration– Jun Wang worked with Xingren to produce the MOM4-GFS coupler– Lidia helped with the assimilation and evaluation of CHAMP and

COSMIC data

Human resources (II)– Haixia Liu from the data assimilation group provided help with the satellite

instrument bias estimates– Glenn White has provided diagnostics of the stratus– Diane Stokes provided SST data support as well as general data support– Dave Behringer provided GODAS– Jesse, Ken and the NOAH land team provided GLDAS– Bob Grumbine provided sea ice analysis– NESDIS provided recalibrated SSU and MSU data (Goldberg’s team)– Yutai Hou provided CO2 changes as well as codes to incorporate the CO2

changes– Paul van Delst updated the CRTM for all the instruments– Several people from the assimilation team (Daryl and Russ in particular) helped

with the initial set up and running of the GSI– Pingping Xie and others from CPC provided the gauge only global precip data for

GLDAS– George Gayno provided snow analysis with guidance from Ken– Computing support from Doris, Carolyn and George are crucial

Funding

• Funding is provided by the Climate Program Office for reanalysis, ocean data assimilation and climate forecasting

• Funding for Reanalysis should continue. As there are other reanalysis proposals within NOAA, our shares of the funding may change. We hope to fund three positions for data collection, data assimilation, and transfer of corporate experience

Computer

• CFS upgrade can only be done when there is a computer upgrade– Only way to do the reanalysis and reforecast

is to leverage the usage of old computers after EMC and NCO migrated to the new ones

– R&D computer is helpful but not sufficient– Delivery of the milestone depends entirely on

the availability of the computers

• Reanalysis is run entirely on Haze

What’s new

• New data:– SST, SSU, AMMA, CO2

• New assimilation system:– GSI with FOTO; GODAS with strong SST constraint and

asymmetric data window, GLDAS with observed precip; simple sea-ice initialization using observed ice fraction

• New model:– The package that was in parallel in 2007 for GFS– Key portion is RRTM short-wave which allowed for easy CO2

updates– MOM4 with a sea-ice model– NOAH for land

Anticipated improvements

• R1 had a very quiet tropics and R2 had a very noisy tropics

• The GFS system since 2000 has shown a much improved tropical analysis

• Tropical ocean is crucial to the seasonal prediction so better forcing from the atmosphere should lead to better ocean analysis

• This benefit can start in week two and go to monthly and seasonal

• We plan to interact with CPC to evaluate the monthly hindcasts and the skill estimate issues

Problems encountered• New data

– SST and sea ice mask problems– Sea ice over land and sea– AMMA data issue

• New model– Stratus

• New assimilation system– QBO, SAO and background error estimates

• New compiler– A bug was introduced when converting to new compiler. Took a long time to

realize and correct• Human resource issue

– 24/7 monitoring takes the toll. The length of the project becomes an issue if we suffer delays in the production

• Computer resource issue– Delays of the computer upgrade continues to cause delays in our planned

implementation

Samples of the monitoring of the reanalysis

Web site for monitors

Monitoring of 5-day forecast skill (500 hPa height anomaly correlation) for 2005

Green line is operational GFS at high resolution, black line is CFSRR with forecast made at T126, Red line is with CFS system but with both data assimilation and forecasts done at T62 with a yearly cold start)

Monitoring of 5-day forecast skill (500 hPa height anomaly correlation) for 1980

Black line is CFSRR with forecast made at T126, Red line is with CFS system but with both data assimilation and forecasts done at T62 with a yearly cold start)

Sample of daily monitor of the reanalysis using short-range forecast skill to check

Comparing analysis with other reanalysis results. Here the comparison is with R2

Comparing analysis with other reanalysis results. Here the comparison is with era40

Monitoring MJO in the data assimilation system against R1, R2, and era40 against R1 climatology

CFSRR GFS operational

Monitoring of fits of analysis and first guess to surface observations showed improved fit of the CFSRR over the then operational system

(12-48 hour forecasts for CFSRR were made with lower resolution so gives slightly worse fits to obs)

Monitoring land surface temperature against independent observations

Monitoring land surface energy balance

Monitoring sea ice distribution against data used in operation

Monitoring SST against OISST

Monitoring depth of 20C against offline analysis