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Coupled Modeling for Seasonal to Interannual

Presented By Suru Saha (EMC/NCEP)

Contributors: Jack Woollen, Daryl Kleist, Dave Behringer, Steve Penny, Xingren Wu, Bob Grumbine, Mike Ek, Jiarui Dong,

Shrinivas Moorthi, Xu Li, Sarah Lu, Yu-Tai Hou, Arun Chawla, Henrique Alves (all EMC)

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Operational System Attribute(s)

System Name Acronym Areal Coverage

Horz Res Cycle Freq

Fcst Length

(hr)

Climate Forecast System(operational, coupled atmosphere-ocean-sea-ice-land)

CFS Global 110km 6hrs 45days – seasonal -9 months

System Attributes

CFS DA: 3DVar for atmosphere (CDAS)+ocean (GODAS)+land (GLDAS)+seaice analysis4 control (unperturbed) members are out to 9 months, 12 perturbed members per 24 hours are out to 45 or 90 days.

System Data Assimilation or Initialization Technique

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Why System(s) are Operational

Primary stakeholders and requirement driversThe need for seasonal prediction is great , given societal vulnerabilities, such as:

• the impact of El Nino on the prediction of US temperature and precipitation (especially, since this winter 2015/16 may shape up to be a major event)

• the drought community, which require accurate predictions for water management purposes• industry, such as energy, transportation, etc. • Participation in the National and International MME

What products are the models contributing to? At CPC: Global Hazards Assessment, Seasonal Prediction (lead 0.5-12.5 months) of US T&P and global SST, ENSO Diagnostic Discussion, MJO, Drought Outlook, African Desk products,

Seasonal Hurricane Outlooks, Arctic Sea-ice prediction. Outside NCEP: Commercial, Regional Climate Centers, etc.

What product aspects are you trying to improve with your development plans? Better guidance through improved forecast skill. Increased availability of products.

Top 3 System Performance Strengths• Strength 1: ENSO Prediction (6-month, Nino 3.4 SST)• Strength 2: MJO Prediction out to 45 days• Strength 3: Prediction of Global SST and oceanic precipitation

Top 3 System Performance Challenges • Challenge 1 : Keeping up with constant changes in the observing system• Challenge 2 : Keeping up with changing CO2 concentrations in the system• Challenge 3 : Keeping up with changing computer systems

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System Evolution Over the Next 5 Years

Major forcing factors• We need a unified approach to global modeling for all spatial and temporal resolutions for

better management of modeling activities at NCEP. Science and development priorities

• UGCS Unified Global Coupled System• Atmosphere-Land-Ocean-Seaice-Waves-Aerosol-Ionosphere interactions• Timely Reanalysis and Reforecast for each implementation

What are you top challenges to evolving the system(s) to meet stakeholder requirements?• Challenge 1 : Using a unified hybrid ensemble approach to DA of the coupled system• Challenge 2 : Testing the following models within the NEMS framework:

MOM5.1/MOM6 and/or HYCOM for the oceanSIS2/CICE/KISS for sea-ice WAVEWATCH III for wavesNoah-MP for land GOCART for aerosol WAM for ionosphere

• Challenge 3 : Making the next CFS a community model Potential opportunities for simplification going forward

• Unified global modeling allows for better use of resources with respect to core / physics / coupling development, but is can we unified on the different scales involved.

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Top 3 Things You Need From the UMAC

1. Help with finding the required resources for:ComputingArchivalDissemination

2. Where and how should this system be run.

3. Should a focus be on unified global modeling, and how can this e approached as a community modeling effort.