Ecological Marine Units: Nutrients

A compilation of ocean nutrient (nitrate, phosphate, and silicate concentrations) data at ¼ degree spatial resolution for the entire United States Exclusive Economic Zone. The dataset is derived from the ESRI Ecological Marine Unit (EMU) dataset, which was assembled from non-supervised statistical clustering of over 52 million points from NOAA’s World Ocean Atlas (2013) WoA database, an authoritative 57 year archive of global water column data. This derived dataset is divided into three separate point shapefiles, each representing either nitrate, phosphate, or silicate concentrations (all in units of μmol l-1). Values for nutrient concentrations represent a climatological average. Each shapefile is formatted such that a single point location (i.e., unique associated latitude and longitude) contains a unique column entry for a given depth interval. Depth intervals are variable from 5 m near the surface to 100 m in the deeper regions (> 2000 m) for a total of 102 depth levels. All disclaimers provided by the original dataset authors apply to this derived dataset. For detail on these disclaimers, please refer to the following reference: Sayre, R., J. Dangermond, D. Wright, S. Breyer, K. Butler, K. Van Graafeiland, M.J. Costello, P. Harris, K. Goodin, M. Kavanaugh, N. Cressie, J. Guinotte, Z. Basher, P. Halpin, M. Monaco, P. Aniello, C. Frye, D. Stephens, P. Valentine, J. Smith, R. Smith, D.P. VanSistine, J. Cress, H. Warner, C. Brown, J. Steffenson, D. Cribbs, B. Van Esch, D. Hopkins, G. Noll, S. Kopp, and C. Convis. 2017. A New Map of Global Ecological Marine Units – An Environmental Stratification Approach. Washington, DC: American Association of Geographers. 36 pages.