Ice Fog Field Experiment at Oliktok Point

15 March 2020 - 20 November 2020

Lead Scientist: Harindra Fernando

Observatory: amf, oli

The broad aim of IFFExO is to better understand and quantify microphysical processes underlying ice-fog (IF) life cycle to help evaluate their representation in numerical weather prediction (NWP) algorithms and regional climate models. Ice-fog occurrence is defined as visibility (Vis) <1 km, caused mainly by ice crystals. Changing climate over arctic regions is occurring much faster than that of lower latitudes, which has overarching repercussions on IF formation and hence atmospheric extinction. This not only affects visibility as a direct impact, but also modifies atmospheric heat/moisture budget. Ice nuclei (IN) concentration parameterizations based on aerosol number concentration and temperature show at least one-order of uncertainty in dealing with cold clouds, and even larger uncertainty for arctic regions, yet data available on relevant crucial microphysical parameters are meager to advance scientific knowledge of IF life cycle. Broad scientific goals of IFFExO are:

  • Understand ice-fog formation in relation to nucleation/aerosol processes and aerosol dynamics
  • Study ice-fog life cycle and its dissipation mechanisms (e.g., radiation and turbulence)
  • Characterize ice-fog particle spectra and their relation to microphysical conditions
  • Evaluate impact of ice fog on surface heat and moisture budgets
  • Evaluate NWP models for ice-fog microphysics and visibility (extinction) prediction
  • Improve microphysical parameterizations for ice-fog conditions in the boundary layer.

The project capitalizes on the tethered balloon system (TBS) platform at Oliktok Point, and will allow us to gather high-quality, boundary-layer data to characterize IF microphysics in relation to radiative properties, aerosols, and flow/turbulence dynamics. IF may also provide conditions for precipitation of very light snow (LSN), for which conditions the heat and moisture budgets can be evaluated. Such information is invaluable in evaluating the effects of IF and LSN on climate change, which can be negative because of the dehydration of atmosphere, thus leading to cooling over the northern regions and underestimation of precipitation in the Arctic. Instrumentation Systems: Both ARM Mobile Facility (AMF3) and investigator-provided instruments will be used. The former include both surface-based and TBS-suspended instruments. The major investigator-provided platform is the so called Gondola (from University of Ontario Institute of Technology) with ice microphysical sensors, which will be suspended on the TBS for vertical profiling of microphysical and environmental parameters. In all, observations include aerosol spectra, condensation nuclei concentration, particle composition, particle phase, and ice crystal images. Snow crystals measured will be used to discriminate IF conditions. The Pacific Northwest National Laboratory will provide chemical filtering analysis based on TBS and on the ground for determining aerosol composition. Data Analysis: Ice-fog events will be identified based on large-scale synoptic conditions. TBS-based level sampling at100-m intervals up to 1 km taken at different times will be used to study vertical structure of IF properties in the boundary layer, an aspect that has not been studied hitherto. Profiling and ground-based measurements will be classified into various IF types (e.g., deposition, freezing, and supercooled) and investigated over their life cycles. The remote-sensing platforms will be used for describing cloud macro- and microphysical properties: for example, optical thickness and cloud-top height, liquid water path (LWP), reflectivity, and the thickness of the IF layer. WRF-CHEM and Polar WRF simulations are planned to hindcast IF periods, and evaluate efficacy of these models. A new visibility (extinction) parameterization will be attempted based on aerosol type and number concentration as well as environmental conditions. An auto-conversion algorithm will be developed to improve IF water content (IWC) prediction. All algorithms and data products resulting from IFFExO will be made available to the scientific community via the ARM Data Center after the usual QA/QC process.


Gijs de Boer Gourihar Kulkarni Michael Shaw
Ismail Gultepe Maximilian Maahn
Raghavendra Krishnamurthy Rob Newsom



Schmitt C. 2021. Next-Generation Video Ice Particle Sampler Field Campaign Report. Ed. by Robert Stafford, ARM user facility. DOE/SC-ARM-21-018. 10.2172/1826936.

Fernando HJ and I Gultepe. 2021. Ice Fog Field Experiment at Oliktok Point Campaign Report. Ed. by Robert Stafford, ARM user facility. DOE/SC-ARM-21-011. 10.2172/1806548.

View All Related Publications

Campaign Data Sets

IOP Participant Data Source Name Final Data
Carl Schmitt Video Ice Particle Sampler Probe Order Data

OLI Data Sources

Name Full Name Browse Data
AERI Atmospheric Emitted Radiance Interferometer Browse Data
AERINF AERI Noise Filtered Browse Data
AMC Ameriflux Measurement Component Browse Data
AOD-MFRSR Aerosol Optical Depth (AOD) derived from MFRSR measurements Browse Data
AOP Aerosol Optical Properties Browse Data
AOS Aerosol Observing System Browse Data
AOSMET Meteorological Measurements associated with the Aerosol Observing System Browse Data
ARMBE ARM Best Estimate Data Products Browse Data
CAMINST camera that monitors an instrument Browse Data
CAMSITE camera that monitors a site area Browse Data
CAPS-PMEX Cavity Attenuated Phase Shift Extinction Monitor Browse Data
CCN Cloud Condensation Nuclei Particle Counter Browse Data
CEIL Ceilometer Browse Data
CEILPBLHT Boundary-layer height data with CEIL Browse Data
CO-ANALYZER Carbon Monoxide Analyzer Browse Data
CPC Condensation Particle Counter Browse Data
CPC-AIR Condensation particle counter aboard aircraft Browse Data
CSPHOT Sunphotometer Browse Data
DL Doppler Lidar Browse Data
DLPROF-WIND Doppler Lidar Horizontal Wind Profiles Browse Data
DLPROF-WSTATS Doppler Lidar Wind Statistics Profiles Browse Data
ECMWFDIAG European Centre for Medium Range Weather Forecasts Diagnostic Analyses Browse Data
ECOR Eddy Correlation Flux Measurement System Browse Data
GHG Greenhouse Gas Monitor Browse Data
GNDRAD Ground Radiometers on Stand for Upwelling Radiation Browse Data
HTDMA Humidified Tandem Differential Mobility Analyzer Browse Data
INS Ice Nucleation Spectrometer for INP measurement Browse Data
INTERPSONDE Interpolated Sonde Browse Data
IRT Infrared Thermometer Browse Data
KASACR Ka-Band Scanning ARM Cloud Radar Browse Data
KAZR Ka ARM Zenith Radar Browse Data
KAZRARSCL Active Remote Sensing of CLouds (ARSCL) product using Ka-band ARM Zenith Radars Browse Data
KAZRCFRCOR Ka-Band ARM Zenith RADAR (KAZR) CF-Radial, Corrected VAP Browse Data
LDIS Laser Disdrometer Browse Data
MASC Multi-Angle Snowflake Camera Browse Data
MASCPARTICLES Multi-Angle Snowflake Camera Particle Analysis Browse Data
MAWS Automatic Weather Station Browse Data
MET Surface Meteorological Instrumentation Browse Data
MET-AIR Meteorological Instrumentation aboard Aircraft Browse Data
MFR Multifilter Radiometer Browse Data
MFRSR Multifilter Rotating Shadowband Radiometer Browse Data
MPL Micropulse Lidar Browse Data
MPLCMASK Cloud mask from Micropulse Lidar Browse Data
MPLCMASKML Micropulse Lidar Cloud Mask Machine Learning VAP Browse Data
MWR3C Microwave Radiometer, 3 Channel Browse Data
MWRRETV2 MWR Retrievals with MWRRET Version 2 Browse Data
NEPHELOMETER Nephelometer Browse Data
OZONE Ozone Monitor Browse Data
PBLHT Planetary Boundary Layer Height Browse Data
POPS-AIR portable optical particle spectrometer aboard an airborne platform Browse Data
PSAP Particle Soot Absorption Photometer Browse Data
QCECOR Quality Controlled Eddy Correlation Flux Measurement Browse Data
QCRAD Data Quality Assessment for ARM Radiation Data Browse Data
RADFLUXANAL Radiative Flux Analysis Browse Data
RL Raman Lidar Browse Data
RLPROF Raman LIDAR Vertical Profiles Browse Data
RLPROF-FEX Raman Lidar Vertical Profiles Feature Detection and Extinction Browse Data
RLPROFMR Raman Lidar Mixing Ratio Browse Data
RLPROFTEMP Raman Lidar Temperature VAP Browse Data
RWP Radar Wind Profiler Browse Data
SEBS Surface Energy Balance System Browse Data
SKYRAD Sky Radiometers on Stand for Downwelling Radiation Browse Data
SONDE Balloon-Borne Sounding System Browse Data
SONDEGRID Gridded Sonde VAP Product Browse Data
SRS Sonic Ranging Sensor Browse Data
TBS Tethered Balloon System Browse Data
TBSMERGED Tethered Balloon System (TBS) Merged Data Product Browse Data
THERMOCLOUDPHASE Thermodynamic cloud phase Browse Data
TSI Total Sky Imager Browse Data
UHSAS Ultra-High Sensitivity Aerosol Spectrometer Browse Data
WB Weighing Bucket Precipitation Gauge Browse Data
WSACR W-band Scanning ARM Cloud Radar Browse Data