The abundance, photophysiology, pigmentation, bio-optical properties, cellular energy balance and instantaneous radiative forcing of glacier algal assemblages from the surface of the Greenland Ice Sheet (GrIS) are quantified throughout the 2016 ablation season. The effects of assemblages on ice surface albedo are further derived using a newly developed model of glacier algal blooms for the GrIS, radiative transfer modelling using BioSNICAR-GO, and comparisons to MODIS broadband albedo observations over the same season. Data represent a composite of in-situ observations, in-situ incubations studies, laboratory analyses, modelling and remote sensing. All in
-situ work was performed at site S6 of the K-Transect in the southwestern GrIS ablation zone as part of the Black and Bloom project.
Funding was provided by the NERC 'Black and Bloom' grant NE/M021025/1 and the Marie Sklodowska-Curie grant agreement No 675546.
Greenland Ice Sheet, albedo, glacier algae, melt, photophysiology
|Access Constraints:||No restrictions.|
|Use Constraints:||This data is governed by the NERC data policy http://www.nerc.ac.uk/research/sites/data/policy/ and supplied under Open Government Licence v.3 http://www.nationalarchives.gov.uk/doc/open-government-licence/version/3/.|
|ISO Topic Categories:||
|Organisation||British Antarctic Survey|
|Name||Christopher J Williamson|
|Role(s)||Investigator, Technical Contact|
|Organisation||University of Bristol|
|Reference:||Algal photophysiology drives darkening and melt of the Greenland Ice Sheet.
|Quality:||All analyses performed on data are available as associated script files.|
|Lineage:||Data was gathered during the 2016 Black and Bloom field campaign and processed in the LowTex and MicroLab laboratories at the University of Bristol. Details on sample collection, processing and analysis can be found in the referenced publication, and all R data analysis scripts are available here.
In-situ data collection spanned June-August 2016. Model runs spanned 1st June 2016 - 1st September 2016. All in-situ observations and incubation studies were conducted in proximity to the IMAU (Utrecht) automatic weather station S6 of the K-Transect in southwest Greenland (67.04 N, 49.07W). Model runs were performed for sites S6, S8, S9 and S10 of the K-Transect.
Algal cell abundance was quantified using a Fuchs-Rosenthal haemocytometer (Lancing, UK) on a LeicaDM 2000 epifluorescence microscope with attached MC120 HD camera (Leica, Germany). Photophysiology was assessed using a Water-PAM fluorometer with attached cuvette system (Walz GmBH, Germany).
Algal pigmentation was assessed using a combination of High-Performance
Liquid Chromatography (HPLC) using an Agilent 1100 HPLC equipped with a diode-array detector, and spectrophotometric wave-scans using a WPA Light-Wave II UV/Visible spectrophotometer (Biochrom, UK). Albedo modelling was achieved using the radiative transfer model BioSNICAR-GO. GrIS surface ice broadband albedo for June, July and August 2016 were derived from clear-sky MODIS MOD10A1 satellite observations at 500 m horizontal resolution. Glacier algal biomass was modelled in GrIS surface ice forced by hourly snowpack thickness, shortwave-down radiation and air temperature from re-analysis outputs produced by the regional climate model MARv3.8.1 forced with ERA
-Interim at 20km resolution.
|Data Storage:||Data are organised into two main sets of data files;
i) data files associated with the main R markdown script associated with this data and the associated manuscript - this script reproduces all analyses applied in the main associated manuscript including reproducing all data figures (Figures 2 - 6) and all supplementary figures (1 - 3). The following data files are provided and read in by this main script;
a. average_pigment_concentrations.csv; CSV file; 833 bytes
b. count_biomass_all_2016.csv; CSV file, 15KB
c. glacier_algae_photophysiology.csv; CSV file; 8KB
d. ICE.2016.01-12.c56.H.nc; NetCDF file; 360.9 MB
e. mass_absorption_coefficients.csv; CSV file; 24KB
f. MOD10A1.2016.006.MAR_20km.nc; NetCDF file; 1.2MB
g. phenolics_mac.csv; CSV file; 28KB
h. photophysiology_average_solvent_pigment_concentrations.csv; CSV file; 1KB
i. photophysiology_dtt_incubations.csv; CSV file; 9KB
j. pigment_data_hbio_260716.csv; CSV file; 635 bytes
k. spectral_irradiance_umolphotons.csv; CSV file; 114KB
l. spectral_irradiance_w.m2.csv; CSV file; 113KB
m. VIS_albedo_biosnicar_go.csv; CSV file; 7KB
ii) associated data files, that include data used in the associated script files - these scripts perform
some pre-processing of data before that data is read into the main R markdown script. The following data files are provided and read in by the three associated scripts:
a. all_normalised_spectra.csv; CSV file; 99KB
b. phenolic_pigmentation_concentrations.csv; CSV file; 15KB
c. phenolics_hplc_abs_spec.csv; CSV file; 20KB
d. phenolics_hplc_chromatograph.csv; CSV file; 147KB
e. williamson_et_al_2018_nep_results.csv; CSV file; 2KB
3 read me files have been created:
Data_column_headings_read_me - describes the headings in the csv files
Data_variables_read_me - describes the variables in the csv files
Williamson_README - describes the datasets, the software requirements and running the scripts