======================================================= Metadata file for SIZONet mass balance site near Barrow, Alaska 2014 ======================================================= Date: March 6, 2014 Updated: October 23, 2014 Author: Josh Jones (joshua.jones@gi.alaska.edu) Overview: ======== Date of deployment: January 15-18, 2014 Location: * Chukchi Sea, on landfast ice between Niksiuraq and Point Barrow * Latitude: 71.37056N * Longitude: 156.52596W * Relatively flat expanse of undeformed ice * Temperature at time of deployment: ~ -35C * Ice thickness: 0.79m Snow depth: 0.08cm Installed by: Josh Jones, Megan O'Sadnick, Marc Oggier Project: SIZONet Phase II, NSF grant # 0856967 Features: ======== Most of the equipment is the same as the 2013 ice season, and includes the CR1000 data logger, AM16/32B Multiplexor, 2GB Flash memory card, HMP155A air temperature and relative humidity sensors, four 12V 40Ah batteries, would not fit, and three SR50A pingers. Replaced equipment include two other SR50A, CS107 water temperature probe, two Benthos PSA 916 underwater sounders, and CRREL-style thermistor strings. A new wind turbine was deployed, as the previous one fell during break-up and bent the axel the blades spin on. The new turbine was a Marlec Rutland 914i. The load put on this turbine in late May was too great, and the magnets in the unit broke, ruining the turbine. The radio equipment at the site was the same as the previous year. A Yagi directional antenna and a Freewave FGR2-WC installed at the mass balance site. The transceiver radio located in the Theater (Building 2) was a Freewave FGR2-CE. Remote Site: =========== * Cables are protected from foxes by flexible metal conduit. As much as possible was recycled from the old mass balance equipment. * Data Logger: Campbell Scientific CR1000 AM/16/32B Multiplexor CFM100 Flash memory storage module * Data Link: Freewave FGR2-WC transceiver (Slave mode) Null modem Bluewave 10dB directional Yagi antenna * Batteries 4 Universal Battery UB12400 (12V 40Ah) in parallel * Thermistor String: CRREL type built in 2012 2 white PVC rods (~1.5m) containing 15 YSI type thermistors 10cm spacing between thermistors uppermost thermistor is 70cm above ice-snow interface * Under-ice Measurements Equipment attached to a dedicated mast going through the ice Ice thickness: upward looking Benthos PSA916, initial ice thickness=0.795m Water depth: downward looking Benthos PSA916, water depth during site selection=6.81m Water temperature: CS107 * Snow Depth Sounders SR50A (ID=0) above upward looking Benthos PSA916, 1.15m above ice surface, 0.065m snow SR50A (ID=1) about 10m northwest of data logger box, 1.19m above ice surface, 0.09m snow SR50A (ID=2) about 18m northwest of data logger box, 1.255m above ice surface, 0.07m snow * Air Temperature & Humidity Located on radio antenna mast, Shielded HMP155A * Wind Turbine: Aero4Gen, 12V, 100W Max LVM4SB12 temperature compensated charge controller, connected to batteries in parallel Base Station: =========== * Located at NARL, in the Theater * Data Link: Freewave FGR2-CE Bluewave 10dB directional antenna NPort 5110A-T serial device server * Virtual Machine: Data Acquisition and Processing: ========================== * File name of data logger program: BRW_MBS13_JAN15_900 * Data are acquired every 15 minutes as instantaneous measurements, except for the temperatures found by the thermistor strings. The thermistor string readings are averages of 20 readings taken in quick succession. * Snow depths, water depth, and ice thickness are calculated from distance measurements by the acoustic transducers SR50A and Benthos PSA916. Distances are temperature compensated with the HMP155A (air) and CS107 (water). Calculation of temperature compensated distance is performed on the CR1000 for the SR50A (snow depths), and performed at UAF in the processing steps for the Benthos PSA916 (water depth, ice thickness). Offsets are applied to the measurements to determine snow depth, ice thickness, and water depth in the processing steps at UAF. * The upgrade to the HMP155A allows for temperature measurements to -80C. The old CS500 only allowed for temperature measurements to -39.66C. * The thermistor strings measure voltage across a resistor, which are converted to temperatures with the Steinhart-Hart equation according to the manufacturer's specifications. T = -273.15 + 1/(0.0014661 + 0.00023857*ln((R)*1000)) + 0.00000010049*ln(((R)*1000))^3 where T is the temperature and R is R = 10*M/(1-M) and M is the measurement by the thermistor. Notes: ====== The communication link between the Virtual Machine (VM) in Barrow and the new Amaru data processing component was established this year. Amaru handles any processing of the data not performed by the data logger. The data was successfully displayed in figures on the Sea Ice Group website, and made available in near real time via a data download page. In late May, the wind turbine failed, discontinuing the charging of the batteries. Therefore, data was lost from the time the batteries were drained until MBS recovery. An issue came up the snow depth pinger named SR2 that could not be resolved before deployment. The data from this sensor is not reliable. File Format: ========== Note: This file format is for the complete file, please contact Josh Jones (joshua.jones@gi.alaska.edu) in order to get this complete file. Otherwise, all of the data can be downloaded from seaice.alaska.edu/gi/observatories/barrow_sealevel/mbs_data_download File Name: brw14_mbs_all.csv Format: ASCII, comma delimited Headers: 1 header line 1 - Column headers Invalid Values: 'NAN' Columns: 1 - Timestamp (YYYY-MM-DD HH:MM:SS) 2 - Data logger temperature 3 - Battery Voltage 4 - Water Temperature 5 - Relative Humidity 6 - Air Temperature 7 - Air Temperature * Hourly running mean 8 - SR0 distance 9 - SR1 distance 10 - SR2 distance 11 - SR0 snow depth (1.15-SR0_meter=snow depth) * 3hr median filtered 12 - SR1 snow depth (1.19-SR1_meter=snow depth) * 3hr median filtered 13 - SR2 snow depth (1.255-SR2_meter=snow depth) * 3hr median filtered 14 - Underwater sounder distance, upward looking, not corrected for temperature dependent speed of sound in water 15 - Underwater sounder distance, downward looking, not corrected for temperature dependent speed of sound in water 16 - Ice thickness * 24hr median filtered 17 - Water depth under ice * Hourly running mean 18 - Topmost thermistor of thermistor string, temperature 70cm above ice surface 19 - Second thermistor of thermistor string, temperature 60cm above ice surface ... 25 - Thermistor at ice-snow interface, temperature at ice surface 26 - Thermistor 10cm below ice-snow interface, temperature 10cm into sea ice 27 - Thermistor 20cm below ice-snow interface ... 32 - Thermistor 70cm below ice-snow interface 33 - Thermistor 80cm below ice-snow interface ... 47 - Thermistor 220cm below ice-snow interface