PAMIP Known Issues

• August 2019: An issue has been discovered in the sea-surface temperature (SST) forcing for experiment 1.3:i piSST-pdSIC (tos_input4MIPs_SSTsAndSeaIce_PAMIP_piSST_pdSIC_gn.nc). Experiment 1.3 was originally designed to have exact same present-day sea ice as in 1.1 and 1.4, with preindustrial SST outside of the sea ice zone and present-day SST inside the sea ice zone. However, to be consistent with other PAMIP experiments SST has to be set to preindustrial values where sea ice has been lost from pre-industrial to present-day periods, i.e., the SST for 1.1-1.3 should be identical to 1.5-1.2 in the Northern Hemisphere and identical to 1.7-1.2 in the Southern Hemisphere, and the SST for 1.3-1.2 should be identical to 1.1-1.5 in the Northern Hemisphere and identical to 1.1-1.7 in the Southern Hemisphere. The 1.3 SSTs in the Arctic and Antarctic have been updated to reflect this (compare Figure 1 and 2). These changes may impact the calculation for polar sea ice loss effect (1.1-1.3) and remote SST warming effect (1.3-1.2). We recommend that all modeling groups download the updated 1.3 SST file and rerun this simulation. The new SST forcing file can be downloaded from input4MIPs:
  https://esgf-node.llnl.gov/search/input4mips/?institution_id=UCI&target_mip_list=PAMIP&query=version:20191002

  

  Figure 1. (Top panel): Annual-mean sea-surface temperature (SST) forcing for 1.1-1.3, 1.5-1.2, and 1.5-1.2 minus 1.1-1.3, 1.1-1.3, 1.7-1.2 and 1.7-1.2 minus 1.1-1.3. (Bottom panel): Annual-mean sea-surface temperature for 1.3-1.2, 1.1-1.5 and 1.1-1.5 minus 1.3-1.2, 1.3-1.2, 1.1-1.7 and 1.1-1.7 minus 1.3-1.2. The plots are based on the original 1.3 SST forcing.

  

  Figure 2. As in Figure 1, but based on the updated 1.3 SST forcing.

• February 2020: A note on the prescription of sea ice thickness in the PAMIP ocean-atmosphere coupled runs: The prescription of sea ice thickness (SIT) in simulations 2 (short coupled runs) should be made to render these simulations as comparable as possible to the AGCM simulations 1.1, 1.5-1.8. For instance, if constant SIT is prescribed in the AGCM runs, it should also be set to constant in runs 2.1-2.5. Therefore it is not recommended to use the present/future SIT fields of runs 1.9-1.10 for these simulations. However, the 1.9-1.10 SIT fields should be used as an ice target for the long coupled runs 6.1-6.3 that explore the climate response after long-term adjustment of the ocean.

To report any issue, please email Lantao Sun
[ lantao.sun@colostate.edu ]