Identification

Title

CESM2 Mechanically Decoupled

Abstract

The CESM2 Mechanically Decoupled Model (MDM) is designed to simulate buoyancy coupled climate variability. The MDM consists of the same model components, including the dynamic ocean model POP2, as the CESM2 fully coupled model (FCM), but lacks anomalous wind stress driven ocean dynamics. Ocean variability in the MDM is therefore primarily buoyancy driven. Different from a slab ocean model (SOM) with a time invariant mixed layer depth, the MDM includes a freely evolving seasonally varying mixed layer depth, seasonally varying mean ocean circulation, and time varying buoyancy driven ocean circulation variability like the AMOC. Key sources of ocean damping are present in the MDM, including vertical mixing, entrainment, and advection by the mean ocean circulation, whereas many dynamical sources of ocean variability, as facilitated through anomalous wind stress driven ocean dynamics, are absent. Comparing the SOM and MDM can uncover the collective role of mixed layer depth variability, buoyancy coupled ocean circulation variability, and ocean damping on climate variations, whereas comparing the MDM and FCM can uncover the role of anomalous wind driven ocean dynamics on climate variability. The CESM2 MDM is implemented using the CESM2 B1850 configuration (i.e., pre-industrial radiative forcing) with 1 degree horizontal resolution. To mechanically decouple POP2 from the CAM6, the wind stress forcing on the ocean is prescribed as the 6-hourly climatology. The climatology is computed from hourly wind stress CIME output from a 50-yr CESM2 FCM pre-industrial control simulation. The 6-hourly climatology is linearly interpolated to the hourly coupling frequency between CAM6 and POP2. Wind variability still is applied to the bulk formula for turbulent heat fluxes, thus the MDM remains thermodynamically coupled.

Resource type

dataset

Resource locator

https://www.earthsystemgrid.org/dataset/id/947aa399-c25c-4ac5-bb11-027e74be5d9e.html

protocol: https

applicationProfile: browser

name: CESM2 Mechanically Decoupled

description: Metadata Link

function: download

Unique resource identifier

code

codeSpace

Dataset language

Spatial reference system

code identifying the spatial reference system

Classification of spatial data and services

Topic category

Keywords

Keyword set

keyword value

Dataset

originating controlled vocabulary

title

reference date

date type

revision

effective date

2014-10-16

Geographic location

West bounding longitude

East bounding longitude

North bounding latitude

South bounding latitude

Temporal reference

Temporal extent

Begin position

End position

Dataset reference date

date type

publication

effective date

2022-08-18

date type

modified

effective date

2022-08-08

Frequency of update

Quality and validity

Lineage

Conformity

Data format

name of format

version of format

Constraints related to access and use

Constraint set

Use constraints

Creative Commons Attribution 4.0 International License.

Limitations on public access

N/A

Responsible organisations

Responsible party

organisation name

UCAR/NCAR - Climate and Global Dynamics Laboratory

email address

esg-support@earthsystemgrid.org

responsible party role

pointOfContact

Metadata on metadata

Metadata point of contact

organisation name

UCAR/NCAR - Climate and Global Dynamics Laboratory

email address

esg-support@earthsystemgrid.org

responsible party role

pointOfContact

Metadata date

2023-11-12T10:05:02

Metadata language