We deployed a full-day bleaching field experiment with irradiated feldspar samples tethered to a pole at various positions within and above the water column to quantify: 1) the bleaching potential, i.e. the light intensity and spectrum as a function of time, depth, and tidal stage; and 2) the bleaching efficiency, i.e. the degree of bleaching of infrared stimulated luminescence (IRSL) and post-infrared IRSL (pIRIR) signals measured at 150, 225 and 290°C after a full day of light exposure above and below water.
+ Luminescence measurements
All measurements were performed on an automated Risø TL/OSL-DA-15 reader with a single-grain attachment with IR laser. A LOT I-410 interference filter was used to target the 410 nm peak emission of K-feldspar (Huntley et al., 1991). We used a multiple-elevated-temperature (MET) pIRIR measurement protocol after (Li & Li, 2011). Sixty datapoints were read-out in 2s (0.033s per datapoint), of which 50 datapoints were collected during stimulation. For each sample, 3 full single-grain discs were measured.
+ Light spectra measurements
Two TriOS RAMSES SAMIP ACC-2 VIS spectrometers, with a spectral wavelength range between 320 and 950 nm, were used to monitor the light spectra at the surface and below water. The subaqueous spectrometer was attached to a sturdy frame and moved up and down the water column with the help of a pulley to measure the subaqueous light penetration. Inundation depth was monitored using a pressure sensor. The other spectrometer was attached to the jetty and measured the subaerial light conditions. Both spectrometers faced upward and were read out simultaneously.
+ Measurement protocols and data formats
The measurement protocols were written in Riso's sequence editor software. All Riso software is downloadable at: https://www.fysik.dtu.dk/english/research/radphys/research/radiation-instruments/tl_osl_reader/software.
+ Processing and analysis scripts in R
All processing of data (modifications, calculations, etc) and analysis of data was performed in R. All scripts are commented. Per experiment an R script was written.
+ Figures and tables
All figures and tables were created through R. Refer to the R scripts for detailed information within the script.
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