Design of the 30-year NCEP CFS
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Suru Saha and Hua-Lu Pan, EMC/NCEP With Input from Stephen Lord, Mark Iredell, Shrinivas Moorthi, David Behringer, Ken Mitchell, Bob Kistler, PowerPoint PPT Presentation


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Design of the 30-year NCEP CFS RR. T382L64 Global R eanalysis and T126L64 Seasonal R eforecast Project (1979-2008). Suru Saha and Hua-Lu Pan, EMC/NCEP With Input from Stephen Lord, Mark Iredell, Shrinivas Moorthi, David Behringer, Ken Mitchell, Bob Kistler,

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Suru Saha and Hua-Lu Pan, EMC/NCEP With Input from Stephen Lord, Mark Iredell, Shrinivas Moorthi, David Behringer, Ken Mitchell, Bob Kistler,

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Suru saha and hua lu pan emc

Design of the 30-year NCEP CFSRR

T382L64 Global Reanalysis and T126L64 Seasonal Reforecast Project(1979-2008)

Suru Saha and Hua-Lu Pan, EMC/NCEP

With Input from

Stephen Lord, Mark Iredell, Shrinivas Moorthi,

David Behringer, Ken Mitchell, Bob Kistler,

Jack Woollen, Huug van den Dool, Catherine Thiaw and others


Suru saha and hua lu pan emc

  • An upgrade to the coupled atmosphere-ocean-seaice-land

  • NCEP Climate Forecast System (CFS) is being planned for Jan 2010.

  • This upgrade involves changes to all components of the CFS, namely:

    • improvements to the data assimilation of the atmosphere with the new NCEP Gridded Statistical Interpolation Scheme (GSI) and major improvements to the physics and dynamics of operational NCEP Global Forecast System (GFS)

    • improvements to the data assimilation of the ocean and ice with the NCEP Global Ocean Data Assimilation System, (GODAS) and a new GFDL MOM4 Ocean Model

    • improvements to the data assimilation of the land with the NCEP Global Land Data Assimilation System, (GLDAS) and a new NCEP Noah Landmodel


Suru saha and hua lu pan emc

For a new Climate Forecast System (CFS) implementation

Two essential components:

A new Reanalysis of the atmosphere, ocean, seaice and land over the 31-year period (1979-2009) is required to provide consistent initial conditions for:

A complete Reforecast of the new CFS over the 29-year period (1981-2009), in order to provide stable calibration and skill estimates of the new system, for operational seasonal prediction at NCEP


Suru saha and hua lu pan emc

  • For a new CFS implementation (contd)

  • Analysis Systems :Operational DAS:Atmospheric (GSI)Ocean (GODAS) andLand (GLDAS)

  • 2. Atmospheric Model :Operational GFS

  • New Noah Land Model

  • 3. Ocean Model :New MOM4 Ocean Model

  • New SEA ICE Model


Suru saha and hua lu pan emc

  • For a new CFS implementation (contd)

  • An atmosphere at high horizontal resolution (spectral T382, ~35 km) and high vertical resolution (64 sigma-pressure hybrid levels)

  • An interactive ocean with 40 levels in the vertical, to a depth of 4737 km, and high horizontal resolution of 0.25 degree at the tropics, tapering to a global resolution of 0.5 degree northwards and southwards of 10N and 10S respectively

  • An interactive sea-ice model

  • An interactive land model with 4 soil levels


Suru saha and hua lu pan emc

  • There are three main differences with the earlier two NCEP Global Reanalysis efforts:

  • Much higher horizontal and vertical resolution (T382L64) of the atmosphere (earlier efforts were made with T62L28 resolution)

  • The guess forecast will be generated from a coupled atmosphere – ocean – seaice - land system

  • Radiance measurements from the historical satellites will be assimilated in this Reanalysis

  • To conduct a Reanalysis with the atmosphere, ocean, seaice and land coupled to each other will be a novelty, and will hopefully address important issues, such as the correlations between sea surface temperatures and precipitation in the global tropics, etc.


Suru saha and hua lu pan emc

UPGRADES TO THE ATMOSHERIC MODEL

  • Hybrid vertical coordinate (sigma-pressure)

  • NOAH Land Model : 4 soil levels. Improved treatment of snow and frozen soil

  • Sea Ice Model : Prediction of ice concentration and ice fraction

  • Sub grid scale mountain blocking

  • Reduced vertical diffusion

  • RRTM long wave radiation

  • ESMF (3.0)


Suru saha and hua lu pan emc

SOME TEST UPGRADES TO THE ATMOSHERIC MODEL

  • Enthalpy

  • MODIS Albedo

  • AER RRTM Shortwave Radiation

  • Ferrier-Moorthi Microphysics

  • New Boundary Layer Parameterization

  • New Shallow Convection

  • New Aerosol Treatment

  • New Convection Scheme (RAS)

  • New convective gravity wave drag formulation

  • Inclusion of historical CO2, solar cycle and volcanic aerosols


Suru saha and hua lu pan emc

4 Simultaneous Streams

  • Oct 1978 – Sep 19868 years

  • Apr 1986– Oct 19937 1/2 years

  • Apr 1993 – Oct 20007 1/2 years

  • Apr 2000 – Dec 200910 years

    6 month overlap for ocean and land spin ups

    Total of 31 years (1979-2009)

    +

    21 overlap months


Suru saha and hua lu pan emc

ONE DAY OF REANALYSIS

12Z GSI

18Z GSI

0Z GSI

6Z GSI

0Z GLDAS

12Z GODAS

18Z GODAS

0Z GODAS

6Z GODAS

9-hr coupled T382L64 forecast guess(GFS + MOM4 + Noah)

1 Jan 0Z

1 Jan 6Z

1 Jan 12Z

1 Jan 18Z

2 Jan 0Z

2-day T382L64 coupled forecast ( GFS + MOM4 + Noah )


Suru saha and hua lu pan emc

ONE DAY OF REANALYSIS

  • Atmospheric T382L64 (GSI) Analysis at 0,6,12 and 18Z, using radiance data from satellites, as well as all conventional data

  • Ocean and Sea Ice Analysis (GODAS) at 0,6,12 and 18Z

  • From each of the 4 cycles, a 9-hour coupled guess forecast (GFS at T382L64) is made with half-hourly coupling to the ocean (MOM4 at 1/4o equatorial, 1/2o global)

  • Land (GLDAS) Analysis using observed precipitation with Noah Land Model at 0Z

  • Coupled 2-day forecast from initial conditions from every cycle, will be made with the T382L64 GFS with half-hourly coupling to the ocean (MOM4 at 1/4o equatorial, 1/2o global) for sanity check.


Suru saha and hua lu pan emc

CFS REFORECASTS

1 Jan 0Z

2 Jan 6Z

3 Jan 12Z

4 Jan 18Z

6 Jan 0Z

1 year T126L64 coupled forecast ( GFS + MOM4 + Noah )

Coupled one-year forecast from initial conditions 30 hours apart will be made for 2 initial months (April and October) with the T126L64 GFS with half-hourly coupling to the ocean (MOM4 at 1/4o equatorial, 1/2o global). Total number of forecasts = 28 x 2 x 30 = 1680

For each cycle, there will be approximately 7 members per month, with a total of 210 members over a 30-year period. This ensures stable calibration for forecasts originating from each cycle, for a given initial month


Suru saha and hua lu pan emc

CFS REFORECASTS (contd)

Example : Skill Estimation for the Initial Month of February

In real time operational prediction, the latest members would be used. For instance, the earliest forecasts release for CPC would be the 15th of the month. Therefore, all members up to the 9th of the month could be used, since operations would run in near real time.

For skill estimation, the following 16 members would be used for February starts (going backwards) :

Feb 9 18z, Feb 8 12z, Feb 7 06z, Feb 6 00z, Feb 5 18z…… Jan 25 00z

This includes 4 days of 4 different cycles (Jan 25 00z – Feb 9 18z), smoothly separated by 30 hours. This is in contrast to the present system, where we use 15 members from Jan 9 00z – Feb 3 00z, in 5-day chunks.


Suru saha and hua lu pan emc

OPERATIONAL CFS CONFIGURATION

In the operational settings, there will have 4 runs per day. So to make an lagged ensemble of 40 members, we will use forecasts from initial conditions Feb 1 – Feb 10, for calibration of a forecast released on Feb 15. In this instance, the initial conditions will all be in February.

Therefore, most of the members will have initial conditions that are after the 1st of the month, which may be better than the paradigm used at other operational centers, where all 60 members are generated on, or around, the 1st of the month.


Suru saha and hua lu pan emc

T382L64 CFS REANALYSIS AND T126L64 REFORECASTS


Suru saha and hua lu pan emc

SOME NOTES - 3

PROPOSED TIME LINE FOR COMPLETION OF CFSRR

  • January to December 2008: Begin Production and Evaluation of the CFS Reanalysis for the full period from 1979 to 2008 (30 years)

  • January to December 2008: Begin running CFS Retrospective Forecasts for 2 initial months: October and April, and evaluate the monthly forecasts as well as the seasonal winter (Lead-1 DJF) and summer (Lead-1 JJA) forecasts.

  • January to October 2009: Continue running the CFS Reforecasts (for the rest of the 10 calendar months)

  • November 2009: Begin computing calibration statistics for CFS daily, monthly and seasonal forecasts.

  • January 2010: Operational implementation of the next CFS monthly and seasonal forecast suite.


Suru saha and hua lu pan emc

Guess T382L64 Hourly Output

Hourly

Standard pressure GRIB (0.5x0.5) 155 MB

Standard flux GRIB (Gaussian 1152x576) 70 MB

Radiation flux GRIB (Gaussian 1152x576) 60 MB

Per hour 285 MB

Total for 1 day 185 x 24 = 6.84 GB


Suru saha and hua lu pan emc

Analysis T382L64 Atmospheric Output

6-hourly

Prepbufr Analysis 28 MB

Sigma hybrid analysis 228 MB

Surface analysis 117 MB

3-D diagnostic model level GRIB 976 MB

3-D diagnostic pressure level GRIB 454 MB

Isentropic diagnostic GRIB 100 MB

Total 2 GB

Total for 1 day 2 x 4 = 8 GB


Suru saha and hua lu pan emc

Analysis Ocean Output from MOM4

6-Hourly:

Ocean Analysis 1240 MB

Ocean standard grid 200 MB

Ocean standard grid GRIB (0.5 x 0.5) 20 MB

Total 1.5 GB

Total for 1 day1.5 x 4 = 6 GB


Suru saha and hua lu pan emc

Analysis T382 Land GLDAS/Noah Output

6-Hourly:

Land Forcing GRIB( hourly, Gaussian 1152X576 ) X 6 60 MB

Land Analysis GRIB( hourly, Gaussian 1152X576 ) X 6 260 MB

Total 320 MB

Total for 1 day 320 x 4 = 1.3 GB


Suru saha and hua lu pan emc

2-day T382L64 Coupled Forecast Output

6-hourly T382L64 Atmospheric :

Standard pressure GRIB (0.5x0.5) 155 MB

Standard flux GRIB (Gaussian 1152x576) 70 MB

Per day of forecast 225 x 4 = 900 MB

For one 2-day forecast 900 x 2 = 1.8 GB

Once Daily Ocean:

Ocean standard grid GRIB (0.5x0.5) 20 MB

For one 2-day forecast 20 x 2 = 40 MB

Total for one 2-day coupled forecast 1.85 GB

Total for 4 forecasts (one per cycle) 7.40 GB


Suru saha and hua lu pan emc

2-day T382L64 Coupled Forecast Output

6-hourly T382L64 Atmospheric :

Standard pressure GRIB (2.5x2.5) 7 MB

Per day of forecast7 x 4 = 28 MB

For one 2-day forecast 28 x 2 = 56 MB

Total for one 2-day coupled forecast 56 MB

Total for 1 day of Reanalysis forecasts 224 MB


Suru saha and hua lu pan emc

1 year T126L64 Coupled Forecast Output

6-hourly T126L64 Atmospheric :

Sigma hybrid forecast 25 MB

Surface forecast 13 MB

Standard pressure GRIB (2.5 x 2.5) 7 MB

Standard flux GRIB (Gaussian 384 x 190) 8 MB

Per day of forecast 53 x 4 = 212 MB

For one 1-year forecast 366 x 212 = 78 GB

Once Daily Ocean:

Ocean standard grid GRIB (0.5 x 0.5) 20 MB

For one 1-year forecast 366 x 20 = 8 GB

Total for one 1-year coupled forecast 86 GB


Suru saha and hua lu pan emc

HUMAN REQUIREMENTS

Project Managers

Suru Saha and Hua-Lu Pan

REFORECASTS

REANALYSIS

6 people (TBD) managing

4 streams and rotating

through

3 people (TBD) managing

4 streams and rotating

through

Internal Advisory Panels

SCIENTIFIC : Huug van den Dool, Mark Iredell, Shrinivas Moorthi, Glenn White,

Ken Mitchell, Dave Behringer, Stephen Lord and others

TECHNICAL :Bob Kistler, Jack Woollen, Catherine Thiaw, Diane Stokes and others

DATA and DIAGNOSTICS:Wesley Ebisusaki, Wanqiu Wang, Jae Schemm and others


Suru saha and hua lu pan emc

SOME NOTES - 1

DATA ARCHIVAL

Using 1 TB tapes, we would need more than 1500 tapes to make the master copy (with second copy parity, maybe 15% more ?)

EMC does not have the resources to do any data distribution, except that CPC will be provided with whatever data they need for their operational CFS predictions.

NCDC/NOAA has shown an interest in the archival and distribution of both the CFS Reanalysis and Reforecasts, through their NOMADS system. If they decide to participate, they will poll the community for data requests. They will work with EMC to siphon all data, while it is being generated in real time.


Suru saha and hua lu pan emc

SOME NOTES - 2

REANALYSIS WITH CONVENTIONAL DATA

CPC may be interested in using the same CFS Reanalysis system, but with conventional data only (no satellite data) to go back to 1948, and continue into the future with the same system.

This Reanalysis may be more homogeneous over a longer period (60+ years) and be more suitable for CPC’s monitoring of the atmosphere, land and ocean.

EMC will help in this endeavor.


Suru saha and hua lu pan emc

THANK YOU !!

YOUR FEEDBACK WILL BE APPRECIATED

[email protected]


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