Key goals and objectives. The Russian scientific program includes multidisciplinary study of the lower atmosphere-sea ice-upper ocean system.

1. Scientific objectives include:

a) Oceanographic objectives:

• Determination of changes in the upper ocean physical characteristics depending on a season, weather pattern, phase and intensity of the barotropic tide, bottom configuration and drift region.
• Study of temperature, salinity and current vector distribution in the Arctic surface waters, halocline waters and Atlantic waters simultaneously in several regions of the Arctic Basin.
• Study of mineral silica, phosphate and nitrogen distribution in 0-300-m water column (weekly in summer and bi-weekly in winter) and in 0-1000 m water column (monthly). Integrated study in the contact layer (water-ice) in the period of intense melting of sea ice.

Oceanographic observations include:

• Measurement of CTD parameters and current vectors in the Arctic surface waters and halocline waters (0-100 m layer) to determine seasonal, synoptic and mesoscale space-time variability of the upper ocean.
• Measurement of CTD parameters and current vectors in the layer up to the upper bound of bottom waters (100-1500 m).
• Year-round measurement of CTD parameters and рН and dissolved oxygen in the contact layer ”water-ice” with the use of autonomous hydrophysical probes (developed by ”Granit” firm).
• Conduction of integrated hydrochemical analysis of biogenic elements of seawater in the 0-1000 m layer on standard depths in the area of study.
• Conduction of integrated hydrochemical analysis of biogenic elements in the contact layer ”water-ice”.

b) Sea ice objectives:

• Analysis of interannual and seasonal variability of main characteristics of ice cover in various regions of the Arctic Basin.
• Verification of satellite image data obtained during the station drift.
• Analysis of synoptic and hydrological conditions impact on redistribution of the Arctic Basin ice cover and its ice exchange between the Siberian shelf seas.
• Determination of the system ”atmospheric circulation ⁄ surface water circulation ⁄ ice drift ⁄ ice conditions” in the climatic aspect.
• Obtaining detailed ice drift fields based on additional installation of ARGOS buoys in the Arctic Basin.

For this purpose it is planned to do the following:

• Profile measurements of flat ice.
• Profile measurements of morphometric characteristics of ice ridges.
• Measurements of snow depth and density on flat and ridged ice;
• Measurements of mechanical-and-physical properties of ice.
• Measurements of flat, deformed and ridged ice thickness.
• Glacial and hydrological air survey of the Arctic Basin water area in the winter-spring period.

The measurements will be performed with an established frequency during the drift both for first-year (seasonal) and multi-year ice.

c) Snow-ice cover:

• Measurements of thermophysical and radiative properties of ice and snow, including man-made contamination of the surface with oil products, to develop new parameterizations of power exchange and evolution of ice-snow cover within sea ice climatic models of sea ice.
• Year-round measurement of morphometric and radiative parameters of meltwater pools to take into account them in calculations of winter ice accumulation.

The main task of the study of lower atmosphere is to study the air-sea boundary layer and transfer of substance flows. The main tasks of measurements of the air-sea boundary layer are as follows:

• Measurement of fine structure of near-water and near-ice atmosphere layer.
• Study of thermophysical properties of different surfaces in the Polar Regions.
• Study of small gas and aerosol atmospheric components in the Arctic.
• Study of seasonal cycle and interannual variability of carbon dioxide concentration and its modeling taking into account physical and biochemical processes.
• Study of atmospheric boundary layer dynamics over drifting ice and tundra taking into account its stratification and development of adequate parameterizations to calculate turbulent heat fluxes and pulse, and transfer of impurities.

Measurement program provides for a series of observations of underlying surface radiation balance in the area of study; gradient measurements of atmosphere parameters and observations of atmosphere transparency. Study of transfer of substance flows includes the following:

• System study of aerosols, snow and ice of the Arctic and assessment of their impact on climate, deposition of sediments and pollution of the central part of the Arctic Ocean.
• Assessment of iron transfer to the Arctic Ocean by eolian activity and with drifting ice and its impact on microalgae productivity

Measurement program includes the following:

• Study of snow: dissolved phase; insoluble particles (by the same methods as described for aerosols); flows of eolian particles with snow.
• Study of sea ice and sedimentary materials (”dirty ice”) – study of granulometric, mineral and chemical composition of sedimentary materials, microalgae composition and their debris. Study of ice cores.
• Study of vertical flows of sedimentary materials with the use of sediment traps (short term placement of small sediment traps and year-round placement of traps with replaceable cartridges).

d) Biological study includes sea ice biota and plankton studies:

During sea ice studies, a special attention should be given to year-round observations of physico-chemical parameters of under ice water-layer, surface water (0-30 m) and sea ice itself, as well as composition and structure of sea ice biological communities. Cryobiological studies include:

• Determination of species composition, indication of dominant species, vertical distribution of sea ice biota, and surface water biological communities.
• Measurement of primary production within the system”sea ice – upper ocean”.

The main priorities will be focused on phytoplankton distribution in the 0-30 m water layer in summer and zooplankton in the 0-1000 m water layer. It is planned:

• To collect Niskin bottle water samples in the 0-30 m mixed layer (from the lower ice surface to the upper bound of the density layer).
• To carry out zooplankton net collections in the 0-1000 m water column to study species composition, number and biomass of dominating species.

2. Logistics

The proposed variant of PAICEX is a combination of two base camps supported by aircrafts from the coastal airfields and 7-8 Ice Drifting Camps (IDC) at a distance of 400 km from the base camps operatively supported by helicopters.

The base camp includes an ice airfield with a landing strip capable of accommodating AN-12 type aircrafts with up to 55-t landing weight and a helicopter deck with two helicopters MI-8 providing air traffic with the IDCs. The base camp consists of residential modules for scientific staff and operating personnel, fuel storage facility and spare parts depot, energy unit, medical post, repair shops for all types of equipment and other rooms required for supporting scientific programs; bulldozers T-70 and snow vehicles. The base camp staff includes repair specialists and a physician who will be able to provide emergency medical assistance at an IDC or at the base camp medical post.

IDC personnel are 5 people including the rotating scientific staff and an operator responsible for the camp equipment operation and cooking. Each IDC has a helicopter deck, companion cabin with a diesel generator room and a shower, two-three two-bed residential modules combined with a research laboratory, residential module and shop for the technical engineer and a mobile module for hydrological observations, etc.

In the period of PAICEX implementation, the base camp and IDC scientific staff will be rotated according to a flexible schedule in compliance with the expedition research program. In spring (approximately from 25 March, 2007 to 10 May, 2007) and autumn-winter (approximately from 25 September, 2007 to 01 April, 2008), the scientific staff is transported to the base camps by aircrafts of AN-74 and AN-26 type and then to the ice drifting camps by helicopters.

In summer, from the beginning of May to the end of September 2007 the base camps will be supplied by research vessels participating in the IPY programs and icebreakers operating on the Northern Sea Route. If abnormal or emergency circumstances occur, heavy helicopters MI-26 will be used.

3. Project Management

The International Scientific Committee for the Project is planned to be established to develop the Project scientific program taking into consideration stakeholders' interests. The International Scientific Committee will consist of lead scientists of the representatives of the consortium participants and work pro bono. The International Scientific Committee will do the following:

• Develop and approve the Project scientific program based on the Project participants' proposals.
• Review and approve amendments and modifications to the Project.
• Develop and approve an experiment schedule and plan of personnel and equipment rotation.
• Review a question of the admission of new members.
• Hear the report and approve the Executive Directorate work results.

The Executive Directorate for the Project is planned to be established to prepare and implement the Project. The Executive Directorate for the Project is a legal entity. The Executive Directorate is composed on the base on the consortium participants' proposals and works on an ongoing basis till the completion of the Project. The Executive Directorate accumulates the consortium participants' funds on its account and performs practical work aimed at preparing and implementing the Project. The Executive Directorate is governed by resolutions of the International Scientific Committee and reports to the Committee on the Directorate work results

The Executive Directorate will establish the Operative Headquarters to carry out operative management of the Project implementation. To facilitate the Operative Headquarters operation, it will be permanently located in Longyearbyen, Spitzbergen Archipelago.