DOI: 10.5061/dryad.q2bvq83tw
title: Data from: Trends and drivers of hypoxic thickness and volume in the Northern Gulf of Mexico: 1985-2018

description: Hypoxia is a major environmental issue plaguing the commercially and
 ecologically important coastal waters of the northern Gulf of Mexico.
 Several modeling studies have explored this phenomenon, but primarily
 focus on the areal extent of the mid-summer hypoxic zone. Research into
 the variability and drivers of hypoxic volume and thickness is also
 important in evaluating the seasonal progression of hypoxia and its impact
 on coastal resources. In this study, we compile data from multiple
 monitoring programs and develop a geospatial model capable of estimating
 hypoxic thickness and volume across the summer season. We adopt a
 space-time geostatistical framework and introduce a rank-based inverse
 normal transformation to simulate more realistic distributions of hypoxic
 layer thickness. Our findings indicate that, on average, there is a
 seasonal lag in peak hypoxic volume and thickness compared to hypoxic
 area. We assess long-term trends in different hypoxia metrics (area,
 thickness, and volume), and while most metrics did not exhibit significant
 trends, mid-summer hypoxic thickness is found to have increased at a rate
 of 5.9 cm/year (p&lt;0.05) over the past three decades. In addition,
 spring nitrogen load is found to be the major driver of all hypoxia
 metrics, when considered along with other riverine inputs and
 meteorological factors in multiple regression models. Hypoxic volume,
 which was also often influenced by east-west wind velocities, was found to
 be more predictable than hypoxic thickness.
description: The data sets in the repository are raw simulations of a
 geostatistical model developed to calculate area, volume and thickness of
 hypoxia in the northern Gulf of Mexico. The simulations are for dissolved
 oxygen and thickness at a 3 day time step across a 5 meter square grid in
 the study area. For more details on the study area and resolution of the
 grid please refer to the published manuscript. 
description: # Data from: Trends and drivers of hypoxic thickness and volume in the
 Northern Gulf of Mexico: 1985-2018
 [https://doi.org/10.5061/dryad.q2bvq83tw](https://doi.org/10.5061/dryad.q2bvq83tw) ## Description of the data and file structure The following data are raw simulations of dissolved oxygen (DO) and thickness of hypoxia in the northern Gulf of Mexico derived using space-time geostatistical model developed in the above manuscript. These raw simulations can be processed using the code files from the repository ([10.5281/zenodo.13101750](https://zenodo.org/doi/10.5281/zenodo.13101750)) to derive summaries of area and volume and also visualize the results to determine trends in space and time.  For files in zip file thickness.zip, the first column is the date number, the second column corresponds to easting, third column corresponds to northing and the fourth column corresponds to depth of the water column at the location. The remaining columns correspond to thickness simulation at the corresponding location. Missing values are indicated by -999 and all the remaining values are simulations of thickness. The zenodo archive has code files to process these simulations. For files in zip DO.zip, the first column is the date number, the second column corresponds to easting, third column corresponds to northing and the fourth column corresponds to depth of the water column at the location. The remaining columns correspond to DO simulation at the corresponding location. The zenodo archive has code files to process these simulations. ## Sharing/Access information Data was derived from the following sources: [10.5281/zenodo.13101750](https://zenodo.org/doi/10.5281/zenodo.13101750)