Development of U.S. Navy Coupled Atmosphere-Ocean-Sea Ice Earth
System Model for Polar Predictions
N.P. Barton1 ([email protected]) E.J. Metzger2,
P.G.Posey2, B.C. Ruston1, A.J. Wallcraft2, C. Reynolds1, J.
Richman3, and M.W. Phelps4
NAVY’S EARTH SYSTEM MODEL (NESM):
1Naval Research Laboratory - Marine Meteorology Division; 2Naval
Research Laboratory – Oceanography Division; 3Florida State
University; 4Jacobs Technology
SPONSORS:
LOOSELY COUPLED DATA ASSIMILATION: GOFS 3.1/NCODA COMPARISON
NESM NAVGEM
Mediator/Coupler (ESMF, NUOPC)
Atmosphere (NAVGEM)
Sea Ice (CICE)
Ocean (HYCOM)
The Marine Meteorology and the Oceanography divisions of the
Naval Research Laboratory are developing its new global coupled
model that builds on the existing operational models: NAVy Global
Environmental Model (NAVGEM) for the Atmosphere, and Global Ocean
Forecasting System (GOFS) 3.1, which consist of the HYbrid
Coordinate Ocean Model (HYCOM) for the ocean and the Community Ice
CodE (CICE) for the sea ice.
MORE REALISTIC SEA ICE FOR THE ATMOSPHERE MODEL:
MODEL DESIGNED FOR SUB-SEASONAL TO SEASONAL PREDICTIONS:
Long-range sea ice predictions have been produced using the
Navy’s ESPC coupled system in 2015 and 2016 through an
international effort called the Sea Ice Prediction Network
(https://www.arcus.org/sipn) to forecast the September minimum
Arctic sea ice extent months in advance. Shown are predictions from
July initial conditions. The Navy ESPC model performed well and was
comparable with the more mature Navy GOFS 3.1 and other
international models (green bar lines below).
NESM NAVGEM NESM minus NAVGEM
Data Assimilative Runs • July to October 2015 • NAVGEM v1.4 •
NESM
NESM is configured to run within a loosely coupled data
assimilation cycle, which uses the mature atmosphere (NAVDAS-AR)
and ocean/ice (NCODA) Navy data assimilation schemes, but
information between the DA schemes is not exchanged. NESM produces
very similar results to the operational GOFS 3.1.
The currently uncoupled NAVGEM uses simple static sea ice
properties with the surface albedo being constant (right figure).
In NESM, sea ice properties are from the sea ice model, CICE, which
are much more sophisticated and result in more realistic sea ice
properties (left figure).
NAVGEM/NAVDAS-AR COMPARISON
Atmospheric results between NESM and stand-alone NAVGEM differ
the most over Antarctica for these runs due to using the CICE sea
ice model .
Region NESM GOFS 3.1
Arctic 24.9 24.9
Greenland/ Norwegian 21.4 21.2
Barents/ Kara 21.2 21.2
Laptev/ E. Siberian 28.1 27.9
Bering/ Chukchi/ Beaufort 25.8 25.7
Canadian Archipelago 26.7 27.2
NESM GOFS 3.1
Sea
Ice
Th
ickn
ess
(m)
Sea
Ice
C
once
ntra
tion
(%)
NESM GOFS 3.1
Ice Edge Error (km) relative to NIC ice edge
Observed Value
4.72m km2
NESM Prediction: 4.8m km2
Predictions from July
NH September 2016 Sea Ice Prediction Network July (left) and
August (right) Reports
Predictions from August
NESM
GOFS 3.1
NESM
GOFS 3.1
Slide Number 1
