24 Hour Clock

This is an official U.S. Navy web site.

Naval Research Laboratory

HYCOM Consortium for Data-Assimilative Ocean Modeling

Real-time 1/12° Arctic Cap HYCOM/CICE/NCODA Nowcast/Forecast System (ACNFS) with NAVGEM atmospheric forcing

As of 30 Sept 2017, ACNFS will be replaced by the Global Ocean Forecast System (GOFS 3.1). Daily Arctic and Antarctic ice products are available from the GOFS 3.1web page. The ACNFS webpage will remain in service for historical purposes but will not be updated with real-time ice forecast products.

Arctic Cap Nowcast/Forecast System (ACNFS)

Experiment Number

Date of Update


Expt_03.5 1 January 2012 NOGAPS atmospheric forcing

08 August 2013

02 October 2013
NAVGEM 1.1 atmospheric forcing
Expt_03.9 08 April 2014 NAVGEM 1.2 atmospheric forcing
Expt_04.0 02 February 2015 NAVGEM 1.2 atmospheric forcing
Includes assimilation of blended high resolution AMSR2/IMS ice concentration.
Starting on 5 May 2015 erroneous SST observations over ice covered regions were inadvertently assimilated warming the underlying ocean. This caused excessive ice melting and a freshening of the surface salinity.
Expt_04.1 1 May 2015 NAVGEM 1.2 atmospheric forcing
Initialized from expt_04.0 on May 1 2015 witholding the erroneous SST observations.
Expt_04.2 18 April 2016 NAVGEM 1.3 atmospheric forcing
Expt_04.6 19 June 2016 NAVGEM 1.3 atmospheric forcing
Initialized from expt_04.2 on June 16 2016 to include more ice concentration observations in ACNFS

System information

Arctic Beaufort

Send questions or comments to: Webmaster

Naval Research Laboratory
Stennis Space Center, MS 39529

Disclaimer: NRL is providing the INFORMATION on an "as is" basis. NRL does not warrant or represent this INFORMATION is fit for any particular purpose, and NRL does not guarantee availability, service, or timely delivery of data.

Please read this privacy and security notice.
U.S. Navy    Navy recruiting    Navy FOIA    ONR