------------------------------------------------------------------ Utqiagvik (formerly Barrow), Alaska CALM grid Vegetation Data Alaska, USA, 2018 Data authors: Sergio Vargas Zesati (1), Craig E. Tweedie (1), Karl F. Huemmrich (2), Petya Campbell (2) 1. System Ecology Lab, University of Texas at El Paso 2. University of Maryland Baltimore County, NASA Goddard Space Flight Center Funding from: NASA ABoVE (Grant # NNX17AC58A) Version: 2018-05-18 ------------------------------------------------------------------ CONTENTS 1. Data overview 2. Use of data 3. Temporal and spatial characteristics 4. File information ------------------------------------------------------------------ 1. DATA OVERVIEW This dataset represents full-spectrum (i.e. 350-2500nm) plot-level spectral reflectance data along the Circumarctic Active Layer Monitoring (CALM) grid in Utqiagvik, Alaska. Scans were collected over a subset of 30, 1 x 1 m plots within the CALM grid using a Spectra Vista Corporation (SVC) HR-1024i spectrometer, standard pistol grip and fibers. Data were calibrated using a Spectralon white reference panel for changing light conditions during field sampling. ***Warning*** Some dates might be missing scans due to either bad data and/or as a result of data QC efforts. Data Uncertainty: No specific quality assessment information is provided. Correspondence concerning these data should be directed to: Dr. Sergio A. Vargas Zesati University of Texas at El Paso Systems Ecology Lab 500 W. University Ave. El Paso, Texas, 79968 email: savargas@utep.edu ctweedie@utep.edu ------------------------------------------------------------------ 2. USE OF DATA These data are made freely available to the public and the scientific community in the belief that their wide dissemination will lead to greater understanding and new scientific insights. ------------------------------------------------------------------ 3. TEMPORAL AND SPATIAL CHARACTERISTICS Temporal range: 2017-06-17 to 2017-08-22 Temporal resolution / sampling frequency: 2 times during the field season Geographic location / Transect boundaries: Westernmost Longitude: -156.607335° Easternmost Longitude: -156.578270° Northernmost Latitude: 71.314968° Southernmost Latitude: 71.305691° Site description: The Circumpolar Active Layer Monitoring (CALM) grid (1 x 1 km squared) grids were established at various locations throughout the Arctic in an effort to establish long-term observations of the climate-active layer permafrost system (Romanovsky, V.E., et al., 2003; https://www2.gwu.edu/~calm/). 1 x 1 meter vegetation plots were established during 2011 as a contribution to the International Tundra Experiment (ITEX)- Arctic Observing Network (AON) (Healey, et al., 2014, Vargas 2017). Spatial resolution: average spectral reflectance for an approximate 1 meter squared area. ------------------------------------------------------------------ 4. FILE INFORMATION Data file format: comma-separated text (.csv) Data file description: The first row in each csv data file represents the wavelength (nm) and each row following thereafter is each plot or scan and are identified using the Unique_ID in column A, which is linkable with the metadata spreadsheet information (see below). The coordinates provided in the metadata spreadsheet were acquired using either a DGPS or handheld GPS. Metadata file description: Each scan or data record is stored by row and is assigned a Unique_ID, which can be used to query a particular measurement as detailed as by day and/or time of day. As seen in the metadata sheet, the Unique_ID column is basically composed of the first 8 columns of metadata which include the “Location”, “Site_Name”, “Target_Name”, “Target_Scale_Level” (e.g. plot (PL), leaf (LF) etc.), “Measurement_Julian_Day”, “Measurement_Time_Of_Day”, “Measurement_Year”, and “Measurement_Type” (e.g. reflectance (REFL), radiance (RAD) etc.). ------------------------------------------------------------------