Development of a diffuse reflectance probe for in situ measurement of inherent optical properties in sea ice

Included are the data presented in the publication entitled: Development of a diffuse reflectance probe for in situ measurement of inherent optical properties in sea ice accepted for publication in The Cryosphere Journal (2021). The data set includes Data and codes:

1. Data (duplicated in .xlsx and .mat):

1.1 Sites coordinates- (figure 5) -Geolocalisation of both sea ice sampling sites visited for this study (1 and 4)

1.2 cumu_sg- (figure 6)- cumulative signal vs depth  vs source-detector distance vs scattering coefficient  obtained with Monte Carlo simulations

 —cumu_sg- cumulative signal (%)

 — depth (mm)

 —standard deviation on depth where signal is cumulated

 —ddet (mm)- radial distance between source and detection point 

 — b (m^-1)-scattering coefficient

1.3 validation-(figure 7)- Error on IOPs vs IOP value estimated measuring on microspheres solutions 

—vf (-)- microspheres volume fraction (in water)

 —a_theo (m^-1) - theoretical value of the absorption coefficient

 — mean_error_a(%) - error between theoretical value and measured value

 —std_error_a_x (%) - standard deviation on theoretical value (based on the standard deviation on microspheres diameter)

 —std_error_a_y (%) -standard deviation on  error_a 

 —rb_theo (m^-1) - theoretical value of the reduced scattering coefficient

 —mean_error_rb(%) - error between theoretical value and measured value

 —std_error_rb_x (%) - standard deviation on theoretical value (based on the standard deviation on microspheres diameter)

 —std_error_rb_y (%)) -standard deviation on  error_rb 

 —gamma_theo (-) - theoretical value of gamma

 —mean_error_gamma (%) - standard deviation on theoretical value (based on the standard deviation on microspheres diameter)

 —std_error_gamma (%) - standard deviation on  error_gamma

-1.4 T-S-(figure 8)- Vertical profiles of temperature and bulk salinity of sampled sea ice available at both snow covered site 1 and bare ice site 4

 —T (celsius) - ice temperature

 —S_si (ppt) - ice bulk salinity

 —depth (cm)

1.5 Rmes-(figure 9)-Vertical profiles of spatially resolved diffuse  Reflectance in sea ice using different covers to shade available at both snow covered site 1 and bare ice site 4

 —Rmes (-) - spatially resolved diffuse  Reflectance

 —Rmes_nbg (-) - spatially resolved diffuse  Reflectance with no background sunlight subtraction in calculation of Rmes

 —dmes (mm) - distance between source and detecting fibre (named rho in the paper)

 —depth (cm)

 — cover - cover used to shade from the sun: te=tent,nc= no cover, ta=tarp

1.6 IOPprofiles-(figure 9)-Vertical profiles of reduced scattering coefficient in sea ice using different covers to shade available at both snow covered site 1 (ice+snow) and bare ice site 4

 —infferedrb (m^-1) - reduced scattering coefficient

 —infferedrb_nbg (m^-1) - reduced scattering coefficient with no background sunlight subtraction in calculation of Rmes

 —cr1 (binary)— criteria determining if the measurement is kept or not

 —depth (cm)- depth from the surface . **watch out**  at site 1 , the measurments start from the surface of the snow. Substract 24 cm to get measurement from surface of the ice.

 — cover - cover used to shade from the sun: te=tent,nc= no cover, ta=tarp

2. Code (written in .m with MATLAB_R2018b ®) :

2.1 inversion algorithm—(figure 9 ) — used to find rb from Rmes (dmes) vertical profiles in sea ice

— Main_vprofiles_Rtorb-qik2019_article.m - Main script of the inversion alorithm to get rb from Rmes (dmes)

—importfiledata.m-subfunction to import data from .csv 

—importfiledatamay8.m-subfunction to import data from .csv (specific to may 8th because file was corrupted)

—interp1lookup_HR_enlarged_bin10.mat - lookup table of Reflectance vs dmes vs a vs b’ vs gamma used in the inversion

—calibjune6_ha_interp1_indcalib2.mat - calibration factor  with  microspheres as a reference

—site1_c20-picture of the ice core taken at site 1

—site4_c20-picture of the ice core taken at site 4

—may8th+othertests_fixed.csv-raw data from may 8 (site1)

—may9day3.csv-raw data from may 9 (site4)