DOI: 10.5061/dryad.z8w9ghxp3
title: Data from: Turbulence characteristics of ice-free radiatively driven convection in a deep, unstratified lake

description: This study examines data collected with an autonomous underwater glider
 during a period of vigorous radiatively driven convection (RDC) and low
 winds in deep, unstratified Lake Superior. Conductivity, temperature and
 depth (CTD) measurements reveal distinct convective plumes of warm
 downwelling water with temperature anomalies of ~0.1 °C and width scales
 on the order of 10-100 m, consistent with theoretical scalings for the
 unstratified convective regime. Shear and temperature microstructure
 measurements indicate turbulent kinetic energy (TKE) dissipation (ε) and
 temperature variance dissipation rates (ΧT) orders of magnitude greater in
 thermal plumes than laterally adjacent waters. Decay timescales of ε
 indicate highly efficient mixing is sustained throughout the night.
 Energetics, mixing efficiency, and constraints on convective plume scales
 are also discussed. These observations demonstrate that RDC can dominate
 vertical mixing dynamics even in deep ice-free systems, and these systems
 can serve as a real-scale laboratory for investigation of convective
 dynamics.
description: # Data from: Turbulence characteristics of ice-free radiatively driven
 convection in a deep, unstratified lake
 [https://doi.org/10.5061/dryad.z8w9ghxp3](https://doi.org/10.5061/dryad.z8w9ghxp3) ## Description of the data and file structure ### Files and variables #### File: heat\_budget.csv **Description:**  ##### Variables * datetime: datetime formatted string of time in local timezone (UTC - 5:00) * datenum: matlab formatted datenum * SW_Avg: incident shortwave radiation (W/m^2) * LW_net: net longwave radiation (W/m^2) * sensible_heat_flux: sensible heat flux (W/m^2) * latent_heat_flux: latent heat flux (W/m^2) #### File: buoyancy\_flux.csv **Description:**  ##### Variables * datetime: datetime formatted string of time in local timezone (UTC - 5:00) * datenum: matlab formatted datenum * B*: radiative buoyancy flux, as defined in the manuscript (W/kg) #### File: glider\_data.csv **Description:**  ##### Variables * ctd_date: datetime formatted string of time from CTD clock in local timezone (UTC - 5:00) * ctd_datenum: matlab formatted datenum from CTD clock * depth: glider depth (m) * latitude: glider location latitude (decimal degrees) * longitude: glider location longitude (decimal degrees) * m_pitch: measured glider pitch (degrees) * ww: water vertical velocity, derived from the flight model (m/s). Entires with a 'null' value are present where the glider flight is not steady-state and vertical velocity estimates are invalid. * conservative_temperature: conservative temperature derived from glider CTD with TEOS-10 (deg C) * conservative_temperature_anomaly: conservative temperature difference relative to median for each dive/climb segment (deg C) * potential density: potential density, calculated with TEOS-10 (sigma units, kg/m^3) * epsilon: TKE dissipation rate derived from MicroRider microstructure data (W/kg). Entries with a 'null' value indicate no valid estimate is available from the glider's microstructure profile window. * chi_t: Temperature variance dissipation rate derived from MicroRider microstructure data (K^2/s). Entries with a 'null' value indicate where no valid estimate is available from the glider's microstructure profile window. ## Access information Data was derived from the following sources: * Meteorological data used to calculate the heat budget are available at: [https://doi.org/10.13020/1XFM-MW95](https://doi.org/10.13020/1XFM-MW95)