DOI: 10.5061/dryad.8gtht76xw
title: Data from: A model of near-sea ice phytoplankton blooms

description: Phytoplankton spring blooms in the Arctic have increased in magnitude and
 extent over the past two decades, particularly in open waters near the sea
 ice edge. We develop an idealized model of phytoplankton dynamics that
 takes into account the role of sea ice meltwater flux and its impact on
 surface mixed layer depth. Satellite observations feature a characteristic
 peak in phytoplankton concentration at around 100 km from the ice edge.
 This peak, as well as the overall structure of the plankton distribution
 is captured by the model dynamics. In the model, the characteristic
 spatial scale emerges from a balance of exponential growth near the ice
 edge, horizontal advection, and increased decay with distance from the ice
 as the mixed layer deepens. Observations and data further agree in that
 meltwater impacts plankton concentrations up to 1000 km from the ice edge.
 The results suggest that reduced meltwater input under future sea ice
 retreat may suppress spring phytoplankton blooms in the region.
description: The data used in this study consists of 3 main
 components: (1) Near-surface chl-a concentration data
 for the years 2011–2019. This consists of monthly Level 3 products from
 three sensors: MODIS Aqua (NASA Ocean Biology Processing Group, GSFC
 2021), MODIS Terra (NASA Ocean Biology Processing Group, GSFC 2022), and
 VIIRS-SPNN (NASA Ocean Biology Processing Group, GSFC 2017), all at 9 km
 resolution. Note that VIIRS-SPNN only came online in late 2011 and so only
 covers the spring seasons 2012--2019. Files:
 "Chla_Modis_Aqua.zip",
 "Chla_Modis_Terra.zip","Chla_VIIRS_SNPP.zip"
 (2)  Version 1 of the monthly Level 3 Soil Moisture and Ocean
 Salinity (SMOS) Arctic Sea Surface Salinity (SSS) product provided by
 LOCEAN (Supply et al. 2020) at 25 km resolution. This product spans from
 June 2010 to November 2019 and covers the Arctic region north of 60◦N.
 Since we are interested in the spring bloom period (April–June) we limit
 our study period to years 2011–2019. File:
 "SSS_SMOS.zip" (3) Sea Ice Concentration
 (SIC) for Fram Strait spanning the years 2011 to 2019 from SMMR-SSM/I data
 processed with the NASA Team algorithm (Cavalieri et al. 1996) at 25 km
 resolution.  File:
 "SIC_NASATeam.zip" The focus of this study is
 how chl-a and SSS vary with distance from the sea ice edge. To compute
 this dependence, we determine the distance to the sea ice edge (defined as
 the SIC = 50 % contour) for each grid box on all monthly distribution
 maps. We then calculate the values of chl-a and SSS at each location and
 bin the data as a function of distance from the ice edge. Finally, we
 average over the years 2011-2019 to get the decadal-mean monthly curves
 for April, May, and June as functions of distance from the sea ice edge.
 The SIC contours for 15%, 50%, and 75% run in approximately straight and
 parallel lines from the northeast (near Svalbard) to the southwest. This
 enables us to consider how chl-a and SSS vary in the direction
 perpendicular to the ice edge by averaging the data in the direction
 parallel to the ice edge.    
description: # Data from: A model of near-sea ice phytoplankton blooms
 [https://doi.org/10.5061/dryad.8gtht76xw](https://doi.org/10.5061/dryad.8gtht76xw) ## Description of the data and file structure The data used in this study consists of 3 main components: (1) Near-surface chl-a concentration data for the years 2011–2019. This consists of monthly Level 3 products from three sensors: MODIS Aqua (NASA Ocean Biology Processing Group, GSFC 2021), MODIS Terra (NASA Ocean Biology Processing Group, GSFC 2022), and VIIRS-SPNN (NASA Ocean Biology Processing Group, GSFC 2017), all at 9 km resolution. Note that VIIRS-SPNN only came online in late 2011 and so only covers the spring seasons 2012--2019. Files: "Chla_Modis_Aqua.zip", "Chla_Modis_Terra.zip","Chla_VIIRS_SNPP.zip" (2)  Version 1 of the monthly Level 3 Soil Moisture and Ocean Salinity (SMOS) Arctic Sea Surface Salinity (SSS) product provided by LOCEAN (Supply et al. 2020) at 25 km resolution. This product spans from June 2010 to November 2019 and covers the Arctic region north of 60◦N. Since we are interested in the spring bloom period (April–June) we limit our study period to years 2011–2019. File: "SSS_SMOS.zip" (3) Sea Ice Concentration (SIC) for Fram Strait spanning the years 2011 to 2019 from SMMR-SSM/I data processed with the NASA Team algorithm (Cavalieri et al. 1996) at 25 km resolution.  Files: "SIC_NASATeam.zip", "SIC_aux_files.zip" The focus of this study is how chl-a and SSS vary with distance from the sea ice edge. To compute this dependence, we determine the distance to the sea ice edge (defined as the SIC = 50 % contour) for each grid box on all monthly distribution maps. We then calculate the values of chl-a and SSS at each location and bin the data as a function of distance from the ice edge. Finally, we average over the years 2011-2019 to get the decadal-mean monthly curves for April, May, and June as functions of distance from the sea ice edge. The SIC contours for 15%, 50%, and 75% run in approximately straight and parallel lines from the northeast (near Svalbard) to the southwest. This enables us to consider how chl-a and SSS vary in the direction perpendicular to the ice edge by averaging the data in the direction parallel to the ice edge.     ### Files and variables #### File: SIC\_NASATeam.zip **Description:** .bin files of sea ice from the NASATeam algorithm. Grid files and a script to process this data are included in "SIC_aux_files.zip". #### File: SSS\_SMOS.zip **Description:** .nc files of SSS from SMOSW #### File: Chla\_MODIS\_Aqua.zip **Description:** .nc files of chla from MODIS Aqua #### File: Chla\_MODIS\_Terra.zip **Description:** .nc files of chla from MODIS Terra #### File: Chla\_VIIRS\_SPNN.zip **Description:** .nc files of chla from VIIRS-SPNN ## Access information Other publicly accessible locations of the data: * Chl-a data available from:  * MODIS Aqua: [https://oceancolor.gsfc.nasa.gov/data/10.5067/AQUA/MODIS/L3M/CHL/2018](https://oceancolor.gsfc.nasa.gov/data/10.5067/AQUA/MODIS/L3M/CHL/2018)  * MODIS Terra: [https://oceancolor.gsfc.nasa.gov/data/10.5067/TERRA/MODIS/L3M/CHL/2018](https://oceancolor.gsfc.nasa.gov/data/10.5067/TERRA/MODIS/L3M/CHL/2018) * VIIRS-SNPP: [https://oceancolor.gsfc.nasa.gov/data/10.5067/NPP/VIIRS/L3M/CHL/2018](https://oceancolor.gsfc.nasa.gov/data/10.5067/NPP/VIIRS/L3M/CHL/2018) * Sea ice concentration data is available from [https://nsidc.org/data/NSIDC-0051](https://nsidc.org/data/NSIDC-0051) * Sea surface salinity data is available from  [https://data.catds.fr/cecos-locean/Ocean_products/SMOS_ARCTIC_SSS_L3_LOCEAN/CEC_Arctic_v1.1/netcdf_monthly_v1_1/](https://data.catds.fr/cecos-locean/Ocean_products/SMOS_ARCTIC_SSS_L3_LOCEAN/CEC_Arctic_v1.1/netcdf_monthly_v1_1/)