Incorporating Correlated Nugget Effects in Multivariate Spatial Models: An Application to Argo Ocean Data

Fuente: arXiv
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Hauptverfasser: Saduakhas, Damilya, Bolin, David, Jin, Xiaotian, Simas, Alexandre B., Wallin, Jonas
Format: Preprint
Veröffentlicht: 2025
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author Saduakhas, Damilya
Bolin, David
Jin, Xiaotian
Simas, Alexandre B.
Wallin, Jonas
author_facet Saduakhas, Damilya
Bolin, David
Jin, Xiaotian
Simas, Alexandre B.
Wallin, Jonas
contents Accurate analysis of global oceanographic data, such as temperature and salinity profiles from the Argo program, requires geostatistical models capable of capturing complex spatial dependencies. This study introduces Gaussian and non-Gaussian hierarchical multivariate Matérn-SPDE models with correlated nugget effects to account for small-scale variability and measurement error correlations. Using simulations and Argo data, we demonstrate that incorporating correlated nugget effects significantly improves the accuracy of parameter estimation and spatial prediction in both Gaussian and non-Gaussian multivariate spatial processes. When applied to global ocean temperature and salinity data, our model yields lower correlation estimates between fields compared to models that assume independent noise. This suggests that traditional models may overestimate the underlying field correlation. By separating these effects, our approach captures fine-scale oceanic patterns more effectively. These findings show the importance of relaxing the assumption of independent measurement errors in multivariate hierarchical models.
format Preprint
id arxiv_https___arxiv_org_abs_2506_03042
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Incorporating Correlated Nugget Effects in Multivariate Spatial Models: An Application to Argo Ocean Data
Saduakhas, Damilya
Bolin, David
Jin, Xiaotian
Simas, Alexandre B.
Wallin, Jonas
Methodology
Applications
Accurate analysis of global oceanographic data, such as temperature and salinity profiles from the Argo program, requires geostatistical models capable of capturing complex spatial dependencies. This study introduces Gaussian and non-Gaussian hierarchical multivariate Matérn-SPDE models with correlated nugget effects to account for small-scale variability and measurement error correlations. Using simulations and Argo data, we demonstrate that incorporating correlated nugget effects significantly improves the accuracy of parameter estimation and spatial prediction in both Gaussian and non-Gaussian multivariate spatial processes. When applied to global ocean temperature and salinity data, our model yields lower correlation estimates between fields compared to models that assume independent noise. This suggests that traditional models may overestimate the underlying field correlation. By separating these effects, our approach captures fine-scale oceanic patterns more effectively. These findings show the importance of relaxing the assumption of independent measurement errors in multivariate hierarchical models.
title Incorporating Correlated Nugget Effects in Multivariate Spatial Models: An Application to Argo Ocean Data
topic Methodology
Applications
url https://arxiv.org/abs/2506.03042