MétaCan
Menu
Back to cohort
Record W2039272861 · doi:10.4319/lom.2009.7.833

Extraction of interannual trends in seasonal events for ecological time series

2009· article· en· W2039272861 on OpenAlexaffabout
Elizabete Almeida, Michael K. Dowd, Joanna Mills Flemming, William K. W. Li

Bibliographic record

VenueLimnology and Oceanography Methods · 2009
Typearticle
Languageen
FieldEconomics, Econometrics and Finance
TopicComplex Systems and Time Series Analysis
Canadian institutionsBedford Institute of OceanographyDalhousie University
Fundersnot available
KeywordsSeasonalityTime seriesKalman filterContext (archaeology)Environmental scienceSeasonal adjustmentSampling (signal processing)Trend analysisSeries (stratigraphy)GeographyClimatologyStatisticsMeteorologyComputer scienceFilter (signal processing)Mathematics

Abstract

fetched live from OpenAlex

The statistical analysis of environmental monitoring data is an important issue in detecting year‐to‐year changes in levels and timings of important ecological events. In many cases, this trend detection must explicitly view interannual changes from the context of an evolving seasonal cycle. This study analyses weekly sampling data from a long‐term ocean monitoring program near Halifax, Nova Scotia, Canada. A state space model of evolving seasonality with a quadratic trend is fit to these time series to extract the signal from the noisy and irregularly sampled data. The procedure uses Kalman filter innovations to estimate model parameters. A fixed interval smoother is then applied to estimate the system state. The resultant state estimates are subjected to a trend analysis carried out with respect to key ecological events: the level and timing of the peak, trough, spring, and fall abundances. These events are identified using derivative information, followed by a regression‐based trend analysis. The analysis found a number of significant linear trends in the biogeochemical variables considered. More generally, the approach used here is suitable for use with monitoring data exhibiting a unimodal seasonal signal with noise and missing values.

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 imitation

Not 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.

metaresearch head score (Codex)0.001
metaresearch head score (Gemma)0.000
Version: codex-gemma-dda1882f352aValidation status: machine_predicted_unvalidated
Candidate categoriesnone
Consensus categoriesnone
DomainCandidate signal: none · Consensus signal: none
Study designCandidate signal: Observational · Consensus signal: none
GenreCandidate signal: Empirical · Consensus signal: Empirical
Teacher disagreement score0.497
Threshold uncertainty score0.486

Codex and Gemma teacher scores by category

CategoryCodexGemma
Metaresearch0.0010.000
Meta-epidemiology (narrow)0.0000.000
Meta-epidemiology (broad)0.0010.000
Bibliometrics0.0010.000
Science and technology studies0.0000.000
Scholarly communication0.0000.000
Open science0.0000.000
Research integrity0.0000.000
Insufficient payload (model declined to judge)0.0000.000

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.

Opus teacher head0.030
GPT teacher head0.317
Teacher spread0.288 · how far apart the two teachers sit on this one work
Validation statusscore_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from it

Classification

machine, unvalidated

Machine predicted; a candidate call from one teacher head, not a consensus.

The models applied no category: nothing in the taxonomy fit this work.
Study designObservational
Domainnot available
GenreEmpirical

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".

Quick stats

Citations0
Published2009
Admission routes2
Has abstractyes

Explore more

Same venueLimnology and Oceanography MethodsSame topicComplex Systems and Time Series AnalysisFrench-language works237,207