ALBERT

Description: The datasets present measurements of cDOM absorption in lakesin the Lena River Delta during the summer periods from 2013-2016 and the spring periods from 2015-2016. Water samples from lakes were collected on Samoylov Island (1st terrace) and Kurungnakh Island (Pleistocene terrace). cDOM is operationally defined by the chosen filter pore size. Samples have been consistently filtrated through 0.7 µm pore size glas fibre filters. cDOM filtrates have been stored in darkness and have been measured after the expedition using the dual-beam Specord200 laboratory spectrometer (Jena Analytik) at the Otto Schmidt Laboratory OSL, Arctic and Antarctic Research Institute, St. Petersburg, Russia. The OSL cDOM protocol (Heim and Roessler, 2016) prescribes 3 Absorbance (A) measurements per sample from UV to 750 nm against ultra-pure water. The absorption coefficient, a, is calculated by a = 2.303A/L, where L is the path length of the cuvette [m], and the factor 2.303 converts log10 to loge. The output of the calculation is a continuous spectrum of a. The cDOM absorption spectra are used to determine the exponential slope value for specific wavelength ranges, S by fitting the data between min and max wavelength to an exponential function. We provide cDOM absorption coefficients for the wavelengths 254, 260, 350, 375, 400, 412, 440, 443 nm [1/m] and Slope values for three different UV, VIS, wavelength ranges: 275 to 295 nm, 350 to 400 nm, 300 to 500 nm [1/m]. Sampling and data preparation were carried out by scientists from Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung, Germany, Arctic and Antarctic Research Institute and Saint Petersburg State University of Russia during Russian-German expeditions to the Lena delta and ongoing projects "Scientific research station "Samoylov Island".