Arctic Sea Ice Drift Measured by Shipboard Marine Radar

Details

• Journal Title:
  Journal of Geophysical Research: Oceans
• Personal Author:
  Lund, B. ; Graber, H. C. ; Persson, P. O. G. ; Smith, M. ; Doble, M. ; Thomson, J. ; Wadhams, P.
• NOAA Program & Office:
  OAR (Oceanic and Atmospheric Research) ; ESRL (Earth System Research Laboratory) ; PSL (Physical Sciences Laboratory) ; CIRES (Cooperative Institute for Research in Environmental Sciences)
• Description:
  This study presents Arctic sea ice drift fields measured by shipboard marine X-band radar (MR). The measurements are based on the maximum cross correlation between two sequential MR backscatter images separated approximate to 1 min in time, a method that is commonly used to estimate sea ice drift from satellite products. The advantage of MR is that images in close temporal proximity are readily available. A typical MR antenna rotation period is approximate to 1-2 s, whereas satellite revisit times can be on the order of days. The technique is applied to approximate to 4 weeks of measurements taken from R/V Sikuliaq in the Beaufort Sea in the fall of 2015. The resulting sea ice velocity fields have approximate to 500 m and up to approximate to 5 min resolution, covering a maximum range of approximate to 4 km. The MR velocity fields are validated using the GPS-tracked motion of Surface Wave Instrument Float with Tracking (SWIFT) drifters, wave buoys, and R/V Sikuliaq during ice stations. The comparison between MR and reference sea ice drift measurements yields root-mean-square errors from 0.8 to 5.6 cms(-1). The MR sea ice velocity fields near the ice edge reveal strong horizontal gradients and peak speeds>1 ms(-1). The observed submesoscale sea ice drift processes include an eddy with approximate to 6 km diameter and vorticities <-2 (normalized by the Coriolis frequency) as well as converging and diverging flow with normalized divergences <-2 and >1, respectively. The sea ice drift speed correlates only weakly with the wind speed (r(2)=0.34), which presents a challenge to conventional wisdom.
• Source:
  Journal of Geophysical Research-Oceans, 123(6), 4298-4321.
• DOI:
  https://doi.org/10.1029/2018jc013769
• Document Type:
  Journal Article
• Rights Information:
  Other
• Compliance:
  Submitted
• Main Document Checksum:
  urn:sha256:d14757b676cdfcdae6e9b579f8b074239e3b11c2b563c26e5882392bcaf20743
• Download URL:
  https://repository.library.noaa.gov/view/noaa/21725/noaa_21725_DS1.pdf
• File Type:
  [PDF - 18.06 MB ]