Holocene Spatial and Temporal Patterns of Environmental Change in the Arctic

CAPE (Circum-Arctic PaleoEnvironments), was established as an organization within IGBP-PAGES following a planning meeting held in Copenhagen in September, 1995. CAPE has as its central mandate to link international and national Arctic paleo-programs, and to provide a forum for regional syntheses and modeling. The primary emphasis of CAPE is to facilitate scientific integration of paleoenvironmental research on terrestrial environments and adjacent continental margins covering the last 250,000 years of Earth history, particularly those tasks that cannot be easily achieved by individual investigators or even regionally-focused research teams. The primary mechanism by which CAPE will perform its role is through a series of tightly focused workshops that address specific topics identified by the community as key to our understanding of the role of the Arctic in the climate system.

The first task identified for CAPE was to define the spatial and temporal patterns of environmental change in the Arctic during the Holocene, the last 10,000 years of Earth history. The Holocene offers possibilities for paleoenvironmental reconstruction at a level of precision unavailable for earlier periods. There exists a rich and diverse set of proxy data in a continuous, or near-continuous time series, that offers the potential for high spatial and temporal resolution. The Holocene includes the interval of instrumental and written records, thus allowing a firmly-based calibration of proxy data in terms of climate variables, and it overlaps with the period of rapidly increasing CO2 content in the atmosphere, a significant feature to be evaluated when predicting future climate change. A key element of CAPE is to ensure that the syntheses are data-based, with full documentation of the sources, and archiving of the primary data in one of the international paleoenvironmental databases.

The CAPE Holocene Project

Planning

An organizational meeting for the CAPE Holocene Project was held in London, UK, in September, 1996. The meeting was attended by the CAPE Steering Committee and local Organizing Committee, who together established the primary objectives for the project. To synthesize the vast array of observational data, twelve regions were defined (Fig. 1). For each region, two individuals were identified and recruited, one each for the marine and terrestrial realms (Table 1). These individuals were to coordinate the regional compilations and to insure that the data were transcribed on to standardized forms. As dataforms were completed they were entered on to digital spreadsheets so that the regional syntheses could be compiled for the entire Arctic and compared to model simulations in real time during the meeting.

Strategy

A wide range of terrestrial and marine proxies exist as continuous times series for the Holocene. Our goal was to first characterize the Earth's surface at 1 ka time slices throughout this period. On land, reconstructions were based primarily on paleovegetation data (pollen and macrofossils) interpreted in terms of a limited number of vegetation types. Additional surface characteristics include the distribution of lakes and glacier ice, and paleoshorelines. Paleoenvironmental data are also available from ice cores, and diagnostic changes in isotope data in organic matter from lakes, aerial plankton, diatoms, and various other faunal and floral elements. Key marine characteristics are the seasonal and permanent sea ice distribution, sea surface temperature (SST), water mass type (e.g. Polar versus Atlantic/Pacific) and dominant currents.

Report of the CAPE Meeting in Lammi, Finland, 4-7 April, 1997.

Terrestrial Holocene Environmental Change Pages

Marine Holocene Environmental Change Pages

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