ESOP

European Subpolar Ocean Project under MAST-II

Overall project description

The European Subpolar Ocean Project (ESOP) has the overall objective of understanding the role played by sea ice in the energetics of the Greenland Sea system as a whole, and in the specific ice-ocean interactions involved in the process of deep convection in the winter in the Greenland Sea with its attendant sequestration of carbon dioxide. Work began in July 1993, and will continue for three years, with 22 participating principal investigators from 7 countries of or associated with the European Union (Denmark, France, Germany, Great Britain, Iceland, Norway, Sweden). The project is funded by the Commission of the European Union under the Marine Science and Technology Programme (MAST-II), contract no. MAS2-CT93-0057.

Role and contribution of TUD (DCRS)

Ice formation and decay in the Odden area

High resolution (30-100 meters) synthetic aperture radar (SAR) data will be used to study the small scale formation and decay of ice in the Odden area. The images will be classified into various types of ice based on the statistics (texture) of pixel values inside regions. The ice motion field will primarily be derived from thermal infrared and near infrared images from the NOAA AVHRR (Advanced Very High Resolution Radiometer, 1 kilometre resolution) during cloud-free periods. These observations will be supplemented by observations made with SAR data when the area is cloud covered and/or where the very high resolution is necessary in order to distinguish individual features. A report on the Odden/Bay area of the 1993 winter is available on-line. It includes a large number of ERS-1 SAR and ssm/i passive microwave images of the Greenland Sea.
 

Daily large scale ice maps

Most recent SSM/I derived ice concentrations in the Greenland Sea area

 Shorter intervals between observations will be obtained by using data from passive microwave radiometers. These data have a spatial resolution of 10-30 kilometres and thus allow only large-scale studies. However, the swath of the sensor is almost 1400 kilometres allowing observations of the Odden region 2-4 times every 24 hours. The data can be used to derive ice concentrations and potentially distinguish between a few ice types. However, absolute calibration is a problem and requires an independent set of observations. It is the intention to use the ice information derived from the SAR data and AVHRR (VALEUR) to perform this calibration. The passive microwave data will be used to provide operational ice maps in collaboration with VALEUR if the data becomes available in near real-time

Sea ice signatures

In order to further understand the microwave signatures from various ice types it is proposed to carry out a field experiment in conjunction with the winter 1993 cruise by Polarstern. A trained ice observer will be on board the ship to collect samples of ice and snow whenever the ship is stationary (collecting oceanographic data). Also, an aircraft equipped with instruments similar to the satellite instruments will be operated. The aircraft instruments will have a much better spatial resolution (50-200 meters) than the satellite instruments, allowing a more detailed comparison of passive microwave data, SAR data and surface observations.

Historical perspective

A large historical record of satellite-based passive microwave observations exists, dating back to 1973. It is proposed to analyze this dataset in order to obtain a basis for evaluating the data collected during the one-year field experiment in 1993. The analysis will be performed using established methods (Pedersen, 1991) for calibrating the derived ice concentrations based on areas of stable ice conditions and additional visible and infrared high resolution imagery from cloud-free periods.

 

         Provisional results are available by clicking on the bargraph.

A number of MPEG encoded animations of previous years ice conditions in the odden area is under construction and may be found by clicking on the colourfull icon below.

  

Project related data

  • Ice in the Odden area January and February 1993
  • Sattellite Observations of the Odden Ice Cover during the Winter of 1995-1996
  • Preliminary report on SSM/I algorithm comparison
  • Ice edge positions at 75N, 1992-1995
  • Daily gif images from the Greenland Sea, 1993-1997

    • Leif Toudal <ltp@emi.dtu.dk>

    Last modified: Wed Aug 21 10:03:43 1996