DOI: 10.5061/dryad.3xsj3txtp
title: Ecological vs. climate uncertainty in future marine ecosystems: lessons learned from krill in a major upwelling region

description: Krill is a central organism in the food web of many marine ecosystems and
 eastern boundary current upwelling regions specifically. Here, a
 superensemble of climate and ecological models is used to determine
 drivers of future change, variability, and uncertainty in krill abundance
 for the California Current. While krill is projected to slowly decrease
 throughout the 21st century, the long-term trend consistently exceeds
 natural variability only under extreme warming. Similarly, unprecedented
 low krill years are expected to progressively increase, but their
 frequency of occurrence will depend on background abundances tied to
 low-frequency climate variability. The relative contributions of warming
 rate and model formulation to projected uncertainty are comparable and
 reflect latitudinal changes in the magnitude of climate forcing and
 availability of empirical data to parameterize krill models, thereby
 warranting a more pragmatic incorporation of anthropogenic and ecological
 uncertainty sources when projecting the fate of marine ecosystems in a
 changing climate.
description: # Ecological vs. climate uncertainty in future marine ecosystems: lessons
 learned from krill in a major upwelling region Dataset DOI:
 [10.5061/dryad.3xsj3txtp](10.5061/dryad.3xsj3txtp) ## Description of the
 data and file structure This dataset is a subset of an ensemble of
 downscaled regional climate projections for krill in the central
 California Current upwelling system for 2000-2100. The ensemble consists
 of 9 members that include 3 rates of warming (Lo8.5, Av8.5, and Hi8.5)
 representative of the RCP8.5 high emissions scenario and 3 functionally
 different krill model formulations (NPD, an Eulerian
 nutrient-phytoplankton-zooplankton model; GA, a Lagrangian
 growth-advection nutrient-phytoplankton-zooplankton model; and SDM, a
 statistical distribution model). For all projections, the underlying
 physical model is an implementation of the Regional Ocean Modelling System
 (ROMS; [www.myroms.org](http://www.myroms.org)) at 1/10° (~10 km)
 resolution. ### Files and variables #### File:
 krill_superensemble_rcp85_2000-2100.nc **Description:** A subset of
 variables were extracted for the central California Current region
 (34-43N, 127-120W) from the monthly model output and averaged annually
 over the upwelling season (May-Aug) using Ferret V7.1
 ([http://ferret.pmel.noaa.gov/Ferret](http://ferret.pmel.noaa.gov/Ferret)). The dataset is in NetCDF4 format (CF-1.4 compliant) with metadata describing each variable name and associated units on the native ROMS grid. **Variables names and units:** tauy_lo85: meridional surface wind stress (N m^-2^) for lower warming rate zeta_lo85: sea surface height (m) for lower warming rate temp_lo85: sea surface temperature (deg. C) for lower warming rate no3_lo85: surface nitrate concentration (mmol N m^-3^) for lower warming rate phyto_lo85: surface phytoplankton concentration (mmol N m^-3^) for lower warming rate krill_npz_lo85: surface krill abundance (mmol N m^-3^) from NPD model for lower warming rate krill_ga_lo85: surface krill abundance (mmol C m^-3^) from GA model for lower warming rate krill_sdm_lo85: surface krill abundance (CPUE) from SDM model for lower warming rate tauy_av85: meridional surface wind stress (N m^-2^) for average warming rate zeta_av85: sea surface height (m) for average warming rate temp_av85: sea surface temperature (deg. C) for average warming rate no3_av85: surface nitrate concentration (mmol N m^-3^) for average warming rate phyto_av85: surface phytoplankton concentration (mmol N m^-3^) for average warming rate krill_npz_av85: surface krill abundance (mmol N m^-3^) from NPD model for average warming rate krill_ga_av85: surface krill abundance (mmol C m^-3^) from GA model for average warming rate krill_sdm_av85: surface krill abundance (CPUE) from SDM model for average warming rate tauy_hi85: meridional surface wind stress (N m^-2^) for higher warming rate zeta_hi85: sea surface height (m) for higher warming rate temp_hi85: sea surface temperature (deg. C) for higher warming rate no3_hi85: surface nitrate concentration (mmol N m^-3^) for higher warming rate phyto_hi85: surface phytoplankton concentration (mmol N m^-3^) for higher warming rate krill_npz_hi85: surface krill abundance (mmol N m^-3^) from NPD model for higher warming rate krill_ga_hi85: surface krill abundance (mmol C m^-3^) from GA model for higher warming rate krill_sdm_hi85: surface krill abundance (CPUE) from SDM model for higher warming rate ## Code/software No code or software was shared. Content of the NetCDF data file can be visualized using publicly available software, such as Panoply (https://www.giss.nasa.gov/tools/panoply), Ncview (https://cirrus.ucsd.edu/ncview), HDFView (https://www.hdfgroup.org/download-hdfview), or other programing platforms (Python, R, Ferret). ## Access information Other publicly accessible locations of the data: * Model output can also be obtained by contacting Prof. Jerome Fiechter ([fiechter@ucsc.edu](mailto:fiechter@ucsc.edu)) at the University of California, Santa Cruz. Data was derived from the following sources: * Ensemble of downscaled regional climate projections for the California Current upwelling system.