ACCESS NUMBER: TO45262

STUDY TITLE: Workshop on Hydrological Modeling of Freshwater Discharge from Alaska's

Arctic Coast

REPORT TITLE: Proceedings of a Workshop on Hydrological Modeling of Freshwater Discharge

from Alaska's Arctic Coast

CONTRACT NUMBER: 0102CA85294; TASK ORDER (TO): 35262

SPONSORING OCS REGION: Alaska

APPLICABLE PLANNING AREA: Beaufort Sea and Chukchi Sea

FISCAL YEAR OF PROJECT FUNDING: 2003

COMPLETION DATE OF REPORT: August 2005

COST: FY 2003: $77844; CUMULATIVE PROJECT COST: $77844

PROJECT MANAGER: Richard Prentki

AFFILIATION: University of Alaska Fairbanks

ADDRESS: International Arctic Research Center, University of Alaska Fairbanks, Fairbanks, AK

99775-7340

PRINCIPAL INVESTIGATOR *: Jia Wang

KEY WORDS: Hydrological cycle, freshwater runoff, digital elevation model (DEM), watershed,

land processes, atmospheric downscaling forcing, circulation, Iandfast ice zone, nearshore

Beaufort Sea

BACKGROUND:

The development of offshore oil exploration and production facilities on the inner

shelf of the Beaufort Sea might impact the nearshore biota and inhibit clean up of

spilled pollutants. This project (hydrological modeling workshop) was undertaken to

bring modelers and observationalists together to discuss strategies for state-of-theart hydrological modeling north of the Brooks Range. The workshop highlighted

approaches to medium-range, regional hydrological modeling that could be applied to

the North Slope region, which drains to the nearshore Beaufort and Chukchi seas,

affecting seasonal landfast ice, coastal circulation, and water mass properties.

This hydrological modeling workshop is directly related to the MMS framework issue TMModeling

studies of environmental, social, economic, or cultural processes related to OCS gas and oil

activities in order to improve scientific predictive capabilities" MMS is interested in freshwater

runoff because it is important locally in the coastal Beaufort Sea: it enhances breakup of

nearshore ice and affects release of spilled oil from landfast ice, water mass properties, and

density-driven currents of the nearshore shelf, such as coastal current along Alaska's Arctic

coast. Furthermore, changes in timing and amounts of river runoff to the arctic shelves may affect

the ocean circulation.

*Pls affiliation may be different than that listed for Project Manager(s).
ACCESS NUMBER: TO-35262

OBJECTIVES:

The objectives of this workshop were 1) to promote discussion of the following topics:

Climate variability and its impacts on hydrological cycle in the Arctic

Collection and archival of hydrological datasets in Alaska

Hydrological modeling approaches on the North Slope

Hydrology-related sea ice, oceanography, and geochemistry.

and 2) to produce recommendations, which are valuable for MMS needs and which may be used

as a guideline to arctic hydrological modeling and related research areas.

DESCRIPTION:

The workshop had three research themes: 1) Climate and variability and its impacts, 2)

Hydrological observations and modeling, and 3) Sea ice, oceanography, and geochemistry.

There were 28 participants (23 presentations). Each theme had a rapporteur to chair the

discussions and summarize the recommendations at the end of the workshop. The workshop

focused on precedents in data processing, hydrological modeling, and field observations:

including needs, scientific and economic issues, and possible solutions in this region. The

participants included scientists and managers from academic institutions, governmental

laboratories, the state and borough, and local communities.

SIGNIFICANT CONCLUSIONS:

The workshop made a series of detailed recommendations in the three research themes, and

proposed an interdisciplinary (hydrology, meteorology, oceanography, sea ice, and geochemistry)

integration/synthesis (IIS) study in the pan-North Slope (and Beaufort-Chukchi Seas) region, an

important research platform for oil and gas exploration and development. The proposed I/S in the

pan-North Slope region can be linked to IPY 2007-2008. The strategy of this I/S will combine

modeling (ice-ocean, hydrological, and downscaling of atmospheric forcing) with field

observations (river gauges, meteorological measurements, satellite measurements, etc.).

STUDY RESULTS:

Based on the working group recommendations, a concise summary is drawn as follows:

Theme 1: Climate variability and its impacts

Improve the basic data record by establishing observations (temperature, precipitation,

wind, etc.) for the following areas, in order of importance: a. The Brooks Range, b. The

interior regions of the North Slope, c. The Alaska Beaufort and Chukchi coasts linked to

the International Polar Year initiative.

Climate model data should be downscaled to improve utility for the terrestrial hydrological

modeling context.

Assess general circulation model output for the Alaska region, in terms of a) Internal

consistency (i.e., model to model), and b) Accuracy of representation (compared to

observational data)

Establish an Alaska data clearing house. There are observational data sets that do exist;

having them at one accessible portal would enhance future research efforts. Given the

unique nature of Alaska in the U.S. arctic system, perhaps the National Snow and Ice

Data Center (NSIDC) could be approached to add an "Alaska' search term to their data

sets.

Evaluate the potential of satellite-derived data for providing climate fields relevant to

hydrological modeling at the North Slope scale. Parameters could include surface and

near-surface air temperature, snow water equivalent, or soil moisture content.
ACCESS NUMBER: TO-35262

Theme 2: Hydrological Observation and Modeling

Development of a fine-resolution (1-5 km) DEM-based hydrological model covering the

entire North Slope from the Brooks Range to the coastal region. The scientific objections

are to understand i) thermokarst occurrence and potential for increase in sediment and

carbon fluxes, ii) Groundwater dynamics, aufeis fields and permafrost distribution.

Combine different methods (remote sensing, modeling, ground measurements). In addition,

an intefligent, physically-based scheme for downscaling course meteorology (e.g.

European Center for Medium Range Weather Forecasting [ECMWF]) or interpolating

station observations in data sparse regions should be developed.

Reestablish U.S. Geological Survey gages on the North Slope.

Establish a web site that provides links for data sets.

Theme 3: Sea Ice, Oceanography, and Geochemistry

High-resolution (1-5 km) ocean-sea ice models in the Chukchi-Beaufort Seas should be

developed under forcing of freshwater discharge (both point source/rivers and line

source) derived from a high-resolution pan-North Slope OEM-based hydrological model.

Improve/develop parameterizations of landlast ice in large scale ice-ocean models.

Coordinated field measurement and modeling studies: parallel efforts to maximize limited

resources, use model guidance to choose ideal' site for long-term/process studies, such

as focused process studies of landfast ice, coastal currents, fronts and density-driven

circulation, and measurements of freshwater flux through Bering Strait.

Determine relative importance of North Slope vs. Mackenzie runoff impact on local iceocean dynamics; modeling sensitivity studies of the ocean dynamics response to

freshwater inputs and pathways from the North Slope

Prediction of effects of severe/single storm on coastal erosion, sediment transport,

ecosystem variability, impact on humans, and pollutant dispersal, such as storm-induced

coastal upwelling, changes in vertical structures of T&S, and mixing.

Remotely sensed data on surface ocean thermal fronts for model validation/improvements,

landfast ice, and multi-year sea ice.

STUDY PRODUCTS:

Wang, J. 2005. Report on Workshop on Hydrological Modeling of Freshwater Discharge from

Alaska's Arctic Coast. MMS Information Transfer Meeting, April 2005, Anchorage.

Wang, J. 2005. Workshop on Hydrological Modeling of Freshwater Discharge from Alaska's

Arctic Coast. International Conference on Global Change: Connection to the Arctic (6).

Dec. 11-13, 2005. Miraikan, Koto-ku, Tokyo, Japan (poster).
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Figure 2. (Left upper) River networks in the North Slope region and outer continental

shelf in the Beaufort and Chukehi seas. (Right lower) Terrain distribution based on the

ETOPO5 (9.2 km) dataset, a much coarser resolution dataset than the (JTOPO3O (1 kni).

The Brooks Range divides the North Slope watershed from the Yukon River watershed

south of the Brooks Range. The Mackenzie River watershed in Canada is not showm

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Figure 1. Focus area for Beaufort Sea Nearshore Under-Ice Currents: Science, Analysis, and

Logistics.