New Experiment abrupt-127k

[christian-stepanek]

Experiment ID

abrupt-127k

Experiment Title

abrupt imposure of the orbit and greenhouse gases of 127 ka before present

Description

Suggested experiment description for the last column of https://wcrp-cmip.github.io/CMIP6_CVs/docs/CMIP6_experiment_id.html:

Conceptually similar to abrupt-4xCO2 DECK experiment, except that orbital forcing and greenhouse gas conditions are abruptly changed from those of piControl, that also serves as an initial state, to their configuration of 127,000 years ago, with high boreal spring to autumn insolation leading to low sea-ice in the Arctic.

More information regarding points 1-6, it must still be decided which parts of this information are included in any databases or documents:

1. AOGCM initialized from a spun-up piControl with constant-in-time forcing of orbital parameters and greenhouse gas concentrations indicative of 127,000 years before present
2. as piControl, but specifying orbital configuration (eccentricity, obliquity, length of perihelion) and greenhouse gas concentrations as per PMIP4 lig127k (Otto-Bliesner et al., 2017; also refer to Sime et al. in prep.); use of components AER, CHEM, BGC is allowed, yet it must be ensured that relevant greenhouse gas concentrations in the atmosphere stay constant at the specified values throughout the simulation
3. orbital configuration (eccentricity, obliquity, length of perihelion) and greenhouse gas concentrations changed with respect to piControl
4. Otto-Bliesner et al. (2017), https://gmd.copernicus.org/articles/10/3979/2017/; Guarino et al (2020), https://www.nature.com/articles/s41558-020-0865-2; Sime et al. (2023), https://cp.copernicus.org/articles/19/883/2023/
5. piControl (but with differences in top of the atmosphere insolation and greenhouse gas concentrations); abrupt-4xCO2 (but with differences in the type of boundary conditions/forcing changed at initialisation)
6. orbital configuration (eccentricity, obliquity, length of perihelion) and greenhouse gas concentrations

MIP / Activity ID (registered)

PMIP

MIP / Activity ID (unregistered)

No response

Parent Experiment

piControl

Custom Parent Experiment

No response

Sub-experiment

none

Priority Tier

1

Source type codes for required model components

AOGCM

Source type codes for additional allowed model components

AER, BGC, CHEM

Start Date

none

Branch Date

none

(Minimum) Number of Years

100

Issue Type

experiment

Issue Kind

new

[github-actions]

Validation failed:

1 issues found.

Validation Errors

Field	Error Message	Error Type
branch-date	Value error, Invalid date format for value: none (equilibrated piControl is expected as the initial state)	value_error

[github-actions]

Validation failed:

1 issues found.

Validation Errors

Field	Error Message	Error Type
start-date	Value error, Invalid date format for value: No response	value_error

[christian-stepanek]

I suggest to change the field that failed validation to "none". I have done this via editing the initial form. Nevertheless, it may be important to highlight that the branching should happen from a piControl that is sufficiently spun up. Just as it is the case for other simulations of similar type. Not sure how to best achieve this. Modify the description? Or provide this highlight in the model description paper that is currently being prepared by Sime et al.? Any hints are welcome.

[github-actions]

New Pull Request: #71