V.V. Melentyev

Cover ERS-1/2 SAR monitoring of dangerous ice phenomena along the western part of Northern Sea Route

The Northern Sea Route ( NSR) as a part of the Arctic Ocean is very important for sea transportation to the Siberean coastal and river settlements, as well as for future transportation between Europe and the Paci® c Ocean countries. Recent opening of the gigantic oil and gas deposits on the Siberean shelf will require the build-up of a specialeet for eA cient marine oil and gas operations in this area. However, round-the-year navigation as well other marine operations (® shery, mining, oil and gas reconnaissance, etc. ) at the diA erent parts of the Arctic Ocean is a very complicated problem and an optimal choiceof the concrete sea route directions depends on numerous environmental factors. Environmental conditions which determine the high-latitude navigation in the North Pole area depend on seasonal and mean-annual distribution of water masses in the Arctic Ocean. An important factor which inuences marine operations in the Arctic Ocean is the presence of round-the-year ice. This is a complicated regional and global-scale process which depends on the location and properties of basic oceanic massif ice regime, on patterns of seasonal and mean-annual distribution of the basic massif s spurs, on the behaviour of the local ice massifs which in each area of the Arctic Ocean have their own characteristic features of the seasonal and mean-annual variability. The location and drift of the basic oceanic ice massifs spurs are variable para- meters. These spurs consist of the residual ® rst-year ice, and the second-year and multi-year pack iceoes. The thickness of this ice can be more than 3m and its invasion in the NSR area creates an especially dangerous situation for marine operations. Control of this phenomenon by all-weather remote sensing instruments is therefore extremely desirable. Another signi® cant factor which creates the favourable inuence for the ice navigation in the Arctic Ocean is the round-the-year presence of the vast recurring

Satellite radar ice monitoring for ice navigation of a tanker convoy in the Kara Sea

The international EU project Arctic Demonstration and Exploratory Voyage (ARCDEV) aimed to investigate the conditions for navigating a tanker vessel from Europe through the Kara Sea to the northwestern Siberian gas and oil fields during ice covered winter conditions in April-May 1998. This winter faced the most difficult ice conditions for 30 years. In order to perform such ship navigation operations, an escorting icebreaker support as well as detailed information on the ice conditions along the possible routes are required. The ARCDEV convoy was supported by near real-time ice information derived from both ERS-2 and RADARSAT ScanSAR synthetic aperture radar (SAR). It is demonstrated how satellite based microwave radar technology practically can support ice navigation operations to improve the safety and efficiency of the navigation.

ICEWATCH-real-time sea ice monitoring of the Northern Sea Route using satellite radar technology

ICEWATCH is the first joint project in Earth observation between Russian Space Agency (RKA) and European Space Agency (ESA). The overall objective of the project is to implement satellite monitoring by combined use of ESA ERS SAR, RKA Okean SLR and other remote sensing data to support ice navigation in the Northern Sea Route (NSR), offshore industry and environmental studies. ERS-1 SAR images have been used in ice monitoring of the NSR in several demonstration campaigns since 1991. The experience from use of SAR data onboard Russian icebreakers to assist in ice navigation is very positive although ERS-1 can only provide data in selected parts of the NSR with a limited swath width of 100 km. In the ICEWATCH project a concept for integrating ERS SAR data in the Russian ice monitoring service is demonstrated where Okean SLR data are included. The system is currently tested in pilot demonstration phase before it is planned to become operational. In addition to data acquisition and interpretation techniques for data integration, ice classification and data transmission techniques have been tested. Also user requirements have been investigated, suggesting that there are many new and potential users of SAR ice information in the NSR. In future other radar satellites will also be used such as ESA ENVISAT which will be launched in 1999. The first results of ICEWATCH were presented at the Second ERS Applications Workshop in London in December 1995.

Combined application of remote sensing and in situ measurements in monitoring environmental processes

Combined use of remote sensing in the visible, infrared and microwave spectral regions, direct in situ measurements and model numerical experiments makes it possible to study inland water bodies as elements of water bodycatchment-atmosphere-systems with good spatial and temporal resolution. In this paper examples are presented of the remote sensing methods developed for detection of hydrodynamics of large water bodies (e.g. frontal and upwelling zones, internal waves, warm and cold surface layers), monitoring of chlorophyll concentration, suspended minerals and dissolved organic matter (DOM) in lakes, mapping of shallow water zones, wetlands and landscape structures, monitoring of ecological condition and changes of drainage basins, and studying the state of the atmosphere over lakes and catchment areas.

Near-real-time sea ice monitoring in the northern sea route using ERS-1 sar and DMSP SSM/I microwave data

Abstract Active and passive microwave sensor data from satellites are useful for studies of the sea ice in the polar regions, including the Eurasian Arctic. Their ability to acquire data regardless of darkness or cloudiness is an essential attribute in these regions. Here the scientific objective is to use the European Remote Sensing satellite (ERS-1) ERS-1 Synthetic Aperture Radar (SAR) data to investigate various sea ice phenomena and processes in the Kara Sea north of Russia. The technical objective is to assess the usefulness of ERS-1 SAR and Defense Meteorological Satellite Program (DMSP) Special Sensor Microwave Imager (SSM/I) data for near-real-time monitoring of the ice conditions along the Northern Sea Route (the Northeast Passage) in support of navigation. The SAR data are seen to be very useful for small-scale ice studies, whereas the SSM/I data provide large-scale ice information, including the ice edge position. The SAR data are acquired in near real-time from the Tromso Satellite Station in order to transmit detailed sea ice maps to icebreakers operating in the Kara Sea. The use of SAR and SSM/I data in support of ice navigation there has been very successful.

Integrated Satellite — Airborne Technology for Monitoring Ice Cover Parameters and Ice-Associated forms of Seals in the Arctic

Airborne observations of the Arctic Ocean have become an indispensable part of fish industry and marine ecology. An application of satellite data for monitoring sea mammals has been attractive for a long time. However, the practical use of satellite information was restrained by the low spatial resolution of satellite data. Additional limits are related to daytime illumination and the effects of clouds at the polar regions.

Ice regime study for the Ob-Yenisey estuaries using ERS SAR data

The ice parameters of the Ob-Yenisey estuaries are studied using synthetic aperture radar (SAR) data from ERS and RADARSAT satellites. Specific features of the Ob, Gyda Bays, Yenisey Gulf ice cover and Ob-Enisey recurring polynya has been accomplished and compared with wind and temperature observations. Based on the multi-temporal SAR, SLR radar and in situ observations the method for the support of practical navigation and off-shore operations at the western part of Siberia and Arctic is developed. A climatic study has also been made.

RADAR IMAGERY IN THE STUDY OF ICE-COVER CHANGES AND HARP SEAL MIGRATION IN THE WHITE SEA

An international team of researchers describes applications of radar imagery from the ERS-2 satellite in ice-cover monitoring in regions of whelping of the harp seal in the White Sea (February-March 1997). Among parameters relevant to the ecology of the harp seal that can be determined more effectively with radar imagery are ice age and continuity, position and condition of shore-ice edge, and direction of drift of ice fields. Examples of practical use of such imagery in regions of reproduction and migration of sea mammals are presented and comparisons with aerial imagery in visible and infrared wavelengths are made.