Archive — the preprint’s additive (β) formulation#
Archived material
This page preserves the additive multivariate formulation used in the
initial submission (preprint) of the TEXAS manuscript and in the posteriors
currently archived on Zenodo. The revised manuscript supersedes it with
the T₀-shift parameterization (γ on the curve location T₀), which
keeps predicted Scaled RI inside its physical bounds by construction. This
page exists so readers arriving from the preprint, or working with the
archived GHEA posteriors, can map what they see onto the current model. The
Stan model itself now lives at
archive/submission-2026-04/stan_models/gen_logi_fixed_hier_crtp_multiv_priorApprox_eiv.stan;
see archive/README.md for what else is archived and why.
The additive model#
In the preprint, the nonthermal predictors entered outside the logistic, as offsets added to the response:
The β coefficients carry Scaled-RI units per predictor unit. Because the offsets act on the response, sufficiently large predictor values can push predictions outside the index’s physical range (b, 1) — the objection raised in review, and the reason the revised model moves the predictors inside the logistic instead.
Preprint coefficient estimates#
From the additive errors-in-variables coretop fit (SST, scaledRI_cren3,
NO₃ cutoff 1.0):
Coefficient |
Posterior mean ± SD |
P(β < 0) |
|---|---|---|
β_{G₂/₃} |
−0.0058 ± 0.0004 |
≈ 1.0 |
β_{NO₃} |
−0.0329 ± 0.0025 |
≈ 1.0 |
Both are resolved away from zero with essentially full posterior probability (reported as the posterior probability of the expected sign, not a frequentist p-value). The negative signs mean elevated G₂/₃ or nitrate lower the Scaled RI recorded at a given temperature — the same direction the T₀-shift model expresses as positive γ (a shift toward apparently colder water), since locally β ≈ −γ·f′(T) where f′ is the calibration slope.
The archived posteriors are this model#
The multivariate posteriors on the current Zenodo record are additive-arm
fits — compset GHEA (A = additive):
Case id |
Legacy (archived) file name |
|---|---|
|
|
|
|
They carry beta_G23_crtp / beta_NO3_crtp variables. From v0.3.0 of the
data record, the archive carries the revised calibration instead (GHEB,
T₀-shift, gamma_* variables in °C per predictor unit) under case-id file
names; the additive posteriors remain permanently available on the record’s
v0.2.0 version, and TEXAS.download_posteriors() still resolves their
legacy names (and the tx.GHEA.* case ids) to that version. The package’s
ensemble and inverse machinery auto-detects which arm a posterior belongs to
from its variable names, so both remain fully usable.
What carries over unchanged#
The evidence that the nonthermal effects exist — residual regressions and the variance partitioning (thermal ≈ 75 %, G₂/₃ and NO₃ each a small but robustly non-zero share) — is response-space analysis that does not depend on which parameterization consumes the effects, and remains part of the revised manuscript. Only the placement of the correction changed: from β on the response to γ on T₀.