Seasonal Ice Zone Reconnaisance Surveys (SIZRS)

SIZRS is a coordinated program of repeated ocean, ice, and atmospheric measurements across the Beaufort-Chukchi sea seasonal sea ice zone (SIZ) utilizing US Coast Guard Arctic Domain Awareness (ADA) flights of opportunity. SIZRS  is motivated by the rapid decline in summer ice extent that has occurred in recent years. The SIZ is the region between maximum winter sea ice extent and minimum summer sea ice extent. It contains the full range of positions of the marginal ice zone (MIZ) where sea ice interacts with open water. The increasing size and changing air-ice-ocean properties of the SIZ are central to recent reductions in Arctic sea ice extent. To understand the changes in the interplay among the ice, atmosphere, and ocean requires a combined systematic observational and modeling effort, covering up to interannual time-scales. The SIZRS project will integrate aircraft -based surveys (SIZRS) results with models and other in situ and remote sensing observations to better understand and predict air, sea, and sea ice conditions in the Beaufort/Chukchi SIZ (BCSIZ), a region that is showing substantial interannual change. Follow SIZRS on Twitter @SIZRS_APL

Schematic of SIZRS measurement programSample Atmosphere Ocean Profile and buoy Location


Ocean Profiles

SIZRS will make oceanographic profile measurements as part of a larger multidisciplinary effort to track and understand the changing seasonal sea ice zone (SIZ) of the Beaufort and Chukchi seas. . The changes in the interplay among the ice, atmosphere, and ocean require a systematic SIZ observational effort, covering up to interannual time-scales, in order to understand today’s Arctic sea ice cover.  The role of the ocean in controlling SIZ ice conditions is clearly significant. Thus, ocean property profiles are key elements of the SIZRS measurement program, and we propose to provide repeated synoptic snapshots of ocean conditions across the Beaufort and Chukchi seas SIZ (BCSIZ) by launching Air eXpendable CTDs (AXCTD) and Air eXpendable Current Profilers (AXCP) during U.S. Coast Guard Arctic Domain Awareness (ADA) flights of opportunity.



Monthly sections of salinity and temperature shown with sea ice concentration on the date of deployment. The SIZRS 150W line is also shown in context (map), with monthly ice edges, salinity from PHC3.0 climatology, and a dashed circle indicating the typical position of Beaufort Gyre circulation. From Dewey et al. 2017.

Deploying SIZRS AXCTDs and AXCPs

Upper Ocean Monitoring

We air-deploy buoys that measure the temperature profile of the upper ocean continuously and report the data via Satellite. SIZRS allows us to deploy these buoys in locations and at times that would be difficult to reach otherwise. This development of air-deployable, continously sensing measurement technology, contributes to the development of an Arctic Observing System that provides the data needed to understand changes occurring in the system.


Launching an UpTempo Buoy


UpTempo Buoy DesignSST products from different sources. UpTempo buoys are helping resolve differences and improve products. From Castro et al. 2016.

Atmospheric Observations

We conduct measurements of atmospheric temperature and humidity profiles using air-deployed drop-sondes and remote sensing measurements. The goal of these measurements is to better understand the co-evolution of the atmosphere-sea ice – ocean environment of the SIZ and to develop better models for prediction. We want to:

  • Determine the role of atmosphere sea ice interactions in  modifying the evolution of the SIZ in the Beaufort and Chukchi Sea
  • Determine how changes in sea ice and sea surface conditions in the SIZ affect changes in cloud cover.
  • Determine the role additional atmospheric profile observations may play in improving the quality of weather forecasts and ice predictions for the SIZ of the Beaufort and Chukchi Seas.
Temperature, Humidity, and Wind Profiles from SIZRS flights. Comparisons between Dropsondes, ERA Interim, GFS, and WRF model runs initialized with ERA-I and GFS are shown. From Liu et al. 2014.
Dropsonde Launch

Remote Sensing

  • Measure the temperatures of sea ice, ocean surface, and cloud tops using IR images and sensors deployed on the USCG C-130
  • Obtain Laser Profiles of surface elevation to obtain sea ice freeboard and sea ice surface variability (CULPIS-X)
  • Use satellite images of sea ice, clouds and atmospheric profiles to put SIZRS observations into large scale context and understand changes between individual flights
CULPIS-X LIDAR, Camera, IR sensor mounted on C-130   IR Remote Sensing of Clouds and Surface

Advanced Remote Sensing Platforms

Adapt a low cost, expendable, air-deployed micro-aircraft to obtain temperature and humidity profiles and cloud top and base heights

Data Hawk
Data Hawk UASSmartSonde UAS


Atmospheric Modeling

We conduct regional modeling experiments with the Weather Research Forecast model to assess the quality of current analyses, to understand the interactions between atmosphere and sea ice and to advance characterizations of clouds in the Arctic.

WRF modeled latitude-height cross section of Atmospheric Cloud Liquid Water in response to changes in sea ice concentration.


Sea ice modeling

We model sea ice variability, assess the quality of sea ice drift and ice edge forecasts, and identify how to make improvements.

 Sea Ice Forecast using the MIZMAS model. Figure shows the ice thickness between the reanalysis (OBS) and the Forecast, the initial and forecast ice edge after 3 days.