Micrometeorological data from an ice-floe adjacent to an open lead during the Arctic Ocean 2018 expedition

John Prytherch

Fast response (20Hz) measurements of the 3-dimensional wind vector, temperature and humidity, derived micrometeorological variables, and mean meteorological measurements. The measurements are from instrumentation mounted on a 2-metre mast at a measurement location adjacent to a lead (referred to as the open-lead site), approximately 2 km from icebreaker Oden’s mooring location during the ice-camp period of the Arctic Ocean 2018 expedition (also referred to as MOCCHA-ACAS-ICE) to the High Arctic.

Citation

John Prytherch (2019) Micrometeorological data from an ice-floe adjacent to an open lead during the Arctic Ocean 2018 expedition. Dataset version 3. Bolin Centre Database. https://doi.org/10.17043/oden-ao-2018-micromet-icefloe-3

Data description

Micrometeorology data from the open-lead mast, averaged over either 1 or 30-minute intervals. Flux data are not included in the 1-minute files. System operated by John Prytherch (MISU). Three data formats are available: Matlab (.mat), NetCDF (.nc) and comma separated value (.csv) text, with an accompanying readme (.rtf) file.

Comments

The instrumentation on the open lead mast consisted of a Metek uSonic-3 heated sonic anemometer, a LI-COR 7500 infrared gas analyser, a LI-COR 7200 infrared gas analyser and pump, a Heitronics KT15.IIp infrared temperature sensor, an aspirated TRH sensor, a TSI 3762 CPC, a GPS unit and a Pro-Oceanus CO2-Pro CV pCO₂ sensor. Power was provided by 12V batteries, exchanged daily.

The majority of the fast-response instrumentation measured at 20Hz. Atmosphere-surface fluxes were determined from the fast-response measurements using eddy covariance. All wind measurements are ice-relative (no correction for ice-drift velocity). Anemometer winds have an aliasing correction applied prior to flux calculation, removing all signal above 5Hz.

CO₂ flux and atmospheric concentration, and condensation particle counter (CPC) particle number concentrations, will be published in separate data sets and are not included here.

The surface through which the measured flux is occurring will depend on the wind direction and the (highly variable) dimensions of the open lead. Lead dimensions were measured throughout the expedition and flux footprint analysis will be published with a subsequent version of this dataset. Surface temperature measurements from the mast infrared sensor were primarily of the lead surface water (excluding periods when drifting ice was in the sensor field of view). Measurements of ice-surface temperature (from an infrared sensor mounted on Oden) are also included in this dataset for reference.

Quality control flagging follows Foken et al. (2012): Chapter 4 in Eddy Covariance: A practical guide to measurement and data analysis (eds. M. Aubinet, T. Vesala, D. Papale), Springer Atmospheric Sciences, and references therein: Foken and Wichura (1996) and Vickers and Mahrt (1997). Some of the code implementing these was adapted from the Eddycalc suite.

Data from the open-lead mast are combined into a cruise-length file. The data are time-averaged to both 1-minute and 30-minute intervals. Flux data are not included in the 1-minute files.

Version history

Version 3

Version 2

Version 1