.. _nextGEMS_cycle2:

nextGEMS Cycle 2
----------------
The nextGEMS Cycle 2 simulations build up on the Cycle 1 simulations for both models, IFS/FESOM and ICON.
They include improvements in the configuration (new schemes and features) and a change in the output.
The simulations will be analyzed during the Cycle 2 hackathon in Vienna end of June 2022.

ICON
~~~~~
What's new in Cycle 2?
    * radiation scheme changed from psRad to RRTMGp
    * river discharge coupling
    * new ocean spin-up with nudging to observed SST
    * new ocean vertical coordinate (z*) with thin surface levels
    * bug fix of dry static energy over land

Up to date we provide a 2-year simulation at 5 km resolution called `ngc2009` and a 10-year simulation at 10 km resolution called `ngc2012`.

.. toctree::
   :maxdepth: 1

   Models/c2_icon_ngc2009
   Models/c2_icon_ngc2012

Monthly quicklook images for both runs are available on the `DKRZ SWIFT browser <https://swiftbrowser.dkrz.de/public/dkrz_cc566461dff84e59964ced89d96324d8/dyamond_2020/>`_.

As of Nov 2022, we have two 30-year simulations at 10km resolution called `ngc2013` and `rthk001`. They both use TTE scheme for atmospheric turbulence (instead of Smagorinsky). The two differ only by thickness of the surface ocean layer. 

.. toctree::
   :maxdepth: 1

   Models/c2_icon_ngc2013
   Models/c2_icon_rthk001


In addition, we provide two simulations with and without aerosol perturbations over 10 days at 5 km resolution called `ngc2009_irad32` and `ngc2009_irad33`.

.. toctree::
   :maxdepth: 1

   Models/c2_icon_ngc2009_irad32
   Models/c2_icon_ngc2009_irad33 

Jupyter notebooks for an initial analysis are collected on the `GitLab of DKRZ <https://gitlab.dkrz.de/b381642/analysis_aerosols.git>`_.

IFS
~~~~~
What's new in Cycle 2?
    * Based on IFS cycle 47r3.3  
    * Signficantly reduced global water and energy imbalances
    * Several upgrades in the surface-atmosphere interaction:
        - Multi-layer snow scheme
        - Improved high-resolution land, sea, lake, and glacier masks
        - Revised surface orographic drag
    * In FESOM:
        - Refactored code allowing hybrid MPI/OpenMP support; significantly faster in the single-executable setup with IFS
        - Newly developed NG5-grid with about 7.5 million surface nodes; down to ~5km resolution
        - New NG5 stand-alone ocean spin-up forced by ERA5 (without nudging to observed SST compared to ICON)
        - Allows for linear kinematic features (sea ice cracks)
        - Eddy-resolving in large areas of the globe; Tropical Instability Waves also resolved
    * WAM wave model:
       - For Cycle 2, we provide for the first time output of the wave model
    * High-frequency model output ('DDH'): 
       - At 30 selected points over the globe

The IFS model in combination with the FESOM and NEMO ocean models was run in 3 different **main** experiments for Cycle 2:

8 months-long and highest-resolved simulation with atmosphere at 2.5 km (IFS) coupled to ~5 km ocean (FESOM); Deep convection parameterization OFF:

.. toctree::
   :maxdepth: 1

   Models/c2_ifs_tco3999-ng5

Main Cycle 2 simulation over 1 full year with atmosphere at 4 km (IFS) coupled to ~5 km ocean (FESOM); Deep convection parameterization OFF:

.. toctree::
   :maxdepth: 1

   Models/c2_ifs_tco2559-ng5

Baseline simulation with atmosphere at 9 km (IFS) coupled to 0.25 degree ocean (NEMO); Deep convection parameterization ON:

.. toctree::
   :maxdepth: 1

   Models/c2_ifs_tco1279-orca025


To get an idea what the data can provide, animations of selected variables from the IFS-FESOM2 simulations (with date string) are available at the `AWI Nextcloud <https://nextcloud.awi.de/s/BGadRKES5fbNd5C>`_ (last access: 27 June 2022).