Water mass transformation in the North Atlantic over 1985-2002 simulated in an eddy-permitting model
Bibliographic record
Abstract
Abstract. Water mass transformation in the North Atlantic is examined in an eddy-permitting simulation with the OCCAM ocean general circulation model, forced by realistic surface fluxes over the period 1985–2002. Three regions are considered: the Subtropics, the Mid-latitudes and the Northeast Atlantic. The oceanic boundaries of each region coincide with hydrographic sections occupied in recent years. These regions broadly represent the formation sites of Subtropical Mode Water (STMW) and Subpolar Mode Water (SPMW). A water mass budget is obtained for each region and year. Terms in the budget comprise surface-forced transformation rates, boundary exchanges and unsteadiness. Unsteadiness is relatively small, so that regional net water mass transformation is largely balanced by net boundary exchanges. Transformation rates due to mixing are then obtained as the difference between net and surface transformation rates. Transports at the boundaries are compared with recent observations, and reasonable agreement is obtained. For the period 1985-1993, model surface transformation rates are broadly in agreement with equivalent rates computed using the globally-balanced SOC fluxes of heat and freshwater, derived from ship observations. In each Atlantic region, surface transformation rates reach 10-15 Sv, based on both model and SOC fluxes. Higher spatial and temporal resolution in the OCCAM surface fluxes may improve the realism of surface transformation rates in some regions, notably the Labrador Sea. However, the unrealistic location of the North Atlantic Current too far south leads to spurious surface heating east of the Grand Banks in OCCAM. Period-mean transformation rates due to mixing reveal the formation of intermediate waters in each region due to the "consumption" of lighter and denser waters formed by surface fluxes, and are comparable with recent inverse estimates. There is, however, strong interannual-to-decadal variability in the consumption rates. In the subtropics, STMW consumption rates co-vary with STMW formation rates. In the subpolar gyre, anomalies in SPMW consumption rate appear to lag anomalies in the surface formation rate by up to 4 years.
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 machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.001 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.001 |
| Bibliometrics | 0.000 | 0.001 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.001 | 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 source (direct Gemma or distilled Codex), 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".