Transmittance of upwelling radiance at the sea surface measured in the field
Bibliographic record
Abstract
The transmittance of upwelling radiance at the air-water interface is a critical quantity in ocean color remote sensing and is usually approximated as a constant (~0.54) for nadir-viewing geometries. Despite its important role, the radiance transmittance has never been measured and validated. In this paper, we present direct measurements of the spectral radiance transmittance in calm seas. The measurements were obtained by a customized instrument package equipped with two collocated radiometers. One radiometer measures the upwelling radiance just below the surface (Lu(0-)) while the other one directly records the water-leaving radiance (Lw) simultaneously. The ratio of measured Lw to Lu(0-) provides the transmittance. Our analyses suggest that the transmittance remains constant within ultraviolet and visible domain (350–700 nm) and is generally consistent with the theoretical approximations. In particular, the observed transmittance is within ±10% of the theoretical value for most portions of the spectral bands (350–600 nm). Within the red portion of the spectrum, the deviations are larger but are still less than 20%. The field observations suggest an optical closure is reached.
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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 | 0.000 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.001 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.002 | 0.001 |
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".