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Biosphere

Canopy greenness (MODIS NDVI)

Canopy vigour relative to what this time of year normally looks like. A negative NDVI anomaly marks vegetation under stress before it is visible from the ground.

Scheduled pullTrusted
data updated 2026-10-02 19:05 KSTnext refresh --:--8/8 public sources
Forecast & calibrated interval
90% conformal · adaptive α=0.10 · for 2026-08-29
0.190.380.570.760.95forecast19-08-1323-02-0226-08-13NDVI
Last observed · 2026-08-13
0.837 NDVI
Forecast
0.799 NDVI
90 % band
0.726 – 0.872
Trust Core verdict
Stress sub-index
2/100
Confidence
65%
Stress band (propagated)
0.000.30 – 14100
Rationale

Inputs in-distribution, members in agreement, interval tight — the Trust Core stands behind this number.

Stress basis: NDVI anomaly vs the same composite in prior years: +0.077 NDVI versus the 8-year seasonal mean of 0.722.

01Calibrated uncertainty + disagreement

Ensemble spread

Six heterogeneous members — a GRU, an MLP, a ridge autoregression, Holt smoothing, a seasonal baseline and persistence — each vote on the next value. Their weighted scatter relative to the recent one-step error is the disagreement signal; wide scatter means the members have genuinely split.

seasonal
moving-avg
drift
Holt
AR(7)
m5
0.71 NDVIensemble mean 0.799 NDVI0.89 NDVI

Trust signals

Ensemble disagreement0.236

Spread of members vs expected one-step error.

Out-of-distribution0.254

Standardised distance of today's 8-feature input row from the training set. Furthest feature: Clear-pixel fraction (-2.63σ).

Confidence0.647

The combined trust the Core assigns this output.

02Explainability

What drove this prediction

Input×Gradient attribution: the gradient of the neural members' forecast with respect to every input, multiplied by the input, summed over the window — so each named driver carries a sign and a magnitude. The AR member's coefficients fold into the target's own history.

Latest day-to-day change−1.00

Yesterday → today difference

Composite-window temperature+0.99

Mean temperature over the 16-day composite

Recent history of the target−0.97

The series' own recent values (autoregressive memory)

Season (cos)+0.96

Day-of-year phase

Clear-pixel fraction−0.81

Share of the 9×9 MODIS window passing QA

Composite-window radiation+0.50

Mean shortwave radiation over the composite

Season (sin)+0.26

Day-of-year phase

Composite-window rainfall+0.18

Rain over the 16-day composite period

03Open monitoring

This stream, audited

idealnominalempirical
Recent coverage (adaptive)
90%static band 93% · 90 steps
Recent MAE
0.022 NDVIrolling 90-step backtest
Drift (PSI)
0.86elevated
Full monitoring →
04Horizon path + rolling backtest

2-step path

The ensemble is rolled forward recursively; each horizon carries its own conformal quantile from the calibration window, scaled by the adaptive factor, so the band widens honestly with lead time. Drivers are held at their last value and only the season advances.

0.250.420.590.760.9308-2909-1402-18last obs 08-13ensemble path (NDVI)90 % band per horizon
h1 · 08-29
0.799
[0.726, 0.872] · held-out cov 96%
h2 · 09-14
0.764
[0.695, 0.832] · held-out cov 86%

Rolling backtest, last 90 steps

Every point is a real one-step forecast made from the data available at the time, against what the feed then reported. Misses outside the band are marked. Adaptive conformal inference nudges α each step toward the 90 % target — currently α=0.100 (band ×1.00 vs static).

0.150.330.520.700.8908-2906-1003-2101-1711-1708-13observed (NDVI)one-step forecast90 % adaptive bandmiss
05Model card + physical layer

Model card

trained 2026-10-02

A heterogeneous ensemble: two neural networks trained by backpropagation on the archive, two classical forecasters, and two baselines every member must beat. Weights are set by validation error, never by the test window.

MemberKindWeightTest MAE*
GRU recurrent net1,217 paramsneural · recurrent
43%
0.021
MLP feed-forward net809 paramsneural · feed-forward
27%
0.020
AR(4) ridgestatistical
10%
0.033
Holt smoothingstatistical
1%
0.085
Seasonal naivebaseline
15%
0.054
Persistencebaseline
4%
0.043

* held-out test window, native units

Held-out MAE
0.021NDVI
Persistence MAE
0.043NDVI
Skill vs persistence
+50.4%beats the baseline
Test coverage (static)
96%90 % band
Time-ordered split
train 2018-01-17 → 2023-02-02 · 117 steps × 6 sites
validation 2023-02-18 → 2023-12-19 (early stopping, member weights)
calibration 2024-01-01 → 2025-04-07 · 29 residuals
test 2025-04-23 → 2026-08-13 · 30 never-seen steps
Inputs · window of 6 steps
Recent history of the targetClear-pixel fractionComposite-window temperatureComposite-window rainfallComposite-window radiationSeason (sin)Season (cos)Latest day-to-day change
horizons: h1 cov 96% skill 50% · h2 cov 86% skill 55%

Canopy context

The latest 16-day composite against its own seasonal climatology, with the QA fraction that says how much of the window was cloud-free.

Latest composite
0.837NDVI
2026-08-13 → 2026-08-28
Seasonal climatology
0.729NDVI
same composite period, 7 other years
Anomaly
+0.107NDVI
negative = canopy below its seasonal norm
Clear-pixel fraction
55%
pixels passing MODIS reliability QA in the 9×9 window
06Today's input row
z = standardised against the training window
Recent history of the target0.837+1.94σ
Clear-pixel fraction0.546-2.63σ
Composite-window temperature24.631+1.35σ
Composite-window rainfall103.625+0.6σ
Composite-window radiation15.122+0.19σ
Season (sin)-0.751-1.08σ
Season (cos)-0.66-0.95σ
Latest day-to-day change0.08+1.26σ

Provenance

Scheduled pullnewest observation 2026-08-13lag 50 d

Governed quantity: Next 16-day composite corridor-mean NDVI.

MODIS MOD13Q1 vegetation index (ORNL DAAC subset service)
250 m NDVI, 16-day composite, with pixel reliability QA
NASA · ORNL DAAC
16-day composite · latency ≈2–3 weeks
archive 2000 → present
live: archive is current (no newer composite published)
source ↗
ERA5 / ERA5-Land reanalysis (Open-Meteo archive)
Daily temperature, humidity, VPD, precipitation, wind, shortwave radiation, ET₀
ECMWF Copernicus · Open-Meteo
daily · latency ≈1 day (preliminary), 5 days (final)
archive 1940 → present
live: 6 sites, 11 days
source ↗

archive pulled 2026-10-02 10:02 UTC · live tail merged at request time · all sources publicly available · nothing on this page is simulated