The Adjustment of the Coupled Climate Model HadGEM1 toward Equilibrium and the Impact on Global Climate
Bibliographic record
Abstract
Abstract Coupled climate models generally have a small residual radiative flux at the top of the atmosphere. In the Met Office climate model, Hadley Centre Global Environmental Model version 1 (HadGEM1), it is incoming (heating the planet) and reduces over a 350-yr period from 0.4 to 0.1 W m−2. The process of the adjustment in HadGEM1 is examined and is shown to be linked to excessive heat gain. In the tropical and South Atlantic, cold, fresh Antarctic Intermediate Water is replaced by anomalously warm, salty intermediate water. The loss of Antarctic Intermediate Water in the South Atlantic is related to a weak Agulhas retroflection. The erosion is enhanced in the tropical Atlantic by strong upwelling. The warm, salty anomalies are advected northward outcropping in the North Atlantic subpolar gyre. In the outcrop zone, sea surface temperature and salinity are increased, which lead to an increase in global mean surface temperature and a reduction in the sea ice area. This adjusts the top of the atmosphere balance via increased outgoing longwave radiation and is partly offset by a decrease in outgoing shortwave radiation. The increased surface salinity triggers convection in the Labrador Sea and leads to a strong flushing of the thermohaline circulation. These results demonstrate that adjustment time scales for coupled climate models can be in excess of 350 yr. The potential implications of the adjustment time scale of climate models need to be considered when planning scenario and sensitivity experiments, as model drifts can be nonlinear.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.006 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".