Program for Arctic Regional Climate Assessment (PARCA)

Updated 2000-06-30

The Program for Arctic Regional Climate Assessment (PARCA) was formally initiated in 1995 by combining into one coordinated program various investigations associated with efforts, started in 1991, to assess whether airborne laser altimetry could be applied to measure ice-sheet thickness changes. It has the prime goal of measuring and understanding the mass balance of the Greenland ice sheet, with a view to assessing its present and possible future impact on sea level. It includes: · Airborne laser-altimetry surveys along precise repeat tracks across all major ice drainage basins, in order to measure changes in ice-surface elevation. · Ice thickness measurements along the same flight lines. · Shallow ice cores at many locations to infer snow-accumulation rates and their spatial and interannual variability, recent climate history, and atmospheric chemistry. · Estimating snow-accumulation rates from atmospheric model diagnosis of precipitation rates from winds and moisture amounts given by European Centre for Medium-Range Weather Forecasts (ECMWF) operational analyses. · Surface-based measurements of ice motion at 30-km intervals approximately along the 2000-m contour completely around the ice sheet, in order to calculate total ice discharge for comparison with total snow accumulation, and thus to infer the mass balance of most of the ice sheet. · Local measurements of ice thickness changes in shallow drill holes ("dh/dt" sites in Figure 1). · Investigations of individual glaciers and ice streams responsible for much of the outflow from the ice sheet. · Monitoring of surface characteristics of the ice sheet using satellite radar altimetry, Synthetic Aperture Radar (SAR), passive-microwave, scatterometer and visible and infrared data. · Investigations of surface energy balance and factors affecting snow accumulation and surface ablation. · Continuous monitoring of crustal motion using global positioning system (GPS) receivers at coastal sites.

This is not a National Implementation Plan (NIP) project
Comments and additional information:

A special issue of Journal of Geophysical Research is being devoted to the results of PARCA. This should be published by early 2001, if not sooner.

Time frame

Project time span
1991 -
Data collection
1993 - 1999
Data processing
1995 - 1999
Data reporting
1995 - 1999

Contact information

Contact person
Robert H. Thomas
EG&G Services NASA/Wallops Flight Facility Bldg. N-159 Wallops Island VA 23337 USA
+1 757-824-1405
+1 757-824-1036
Other project contacts
Waleed Abdalati, Goddard Space Flight Center

Parameters and Media

Parameter groups measured/observed/modelled
Climate change effects
Media sampled/studied/modelled
Additional information or further specification of types of data / information collected, species / tissues / organs sampled, etc.

Microwave signatures, internal and basal ice layers, snow pits and ice cores, surface radiation balance


Regions studied
Climate change effects

Data availability

Are data archived or planned to be archived at an AMAP Thematic Data Centre?
If no (or only part of data are reported to a TDC), where and how are (other) data stored?
Contact Robert Thomas for plans on data archiving and distribution. Some products already available from PARCA investigators.
References to key publications (or planned publications) and data reports
A special issue of Journal of Geophysical Research is being devoted to the results of PARCA. This should be published by early 2001, if not sooner.
Samples/specimens archived in specimen banks?

Methods & Procedures

Not specified

Additional Information

Is this a bi- AND multi-lateral project (i.e. a project involving cooperation between different countries)?
Other institutes involved in the project

Collaboration with University of Bristol, England, and University of Copnhagen, Denmark

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