1.4 PAGES activities that are relevant to CLIVAR | |
| Because the Earth's environmental and ecological systems operate on a wide range of temporal and spatial scales, PAGES activities are global and encompass timescales varying from 1 to a few x10 5 years (Table 1). Part of this temporal focus is too long to be of use to CLIVAR. In addition, many sediment records of past environmental change are very long, but offer a temporal resolution that is too coarse to meet CLIVAR objectives. However, even though some aspects of PAGES are unlikely to be of use to CLIVAR, many PAGES activities are likely to yield significant contributions to meeting the objectives of all three CLIVAR components. Annually resolved tropical paleoclimatic reconstructions of the last two millennia are of direct relevance to understanding the longer period modulations of the ENSO and monsoon phenomena. In the tropical oceans, the development of multicentury, subseasonally resolved climate records from corals is a central PAGES activity, and should provide new information about the functioning of the tropical ocean-atmosphere system on the Stream I timescale. | In addition, corals and sediments from the western Atlantic and Caribbean regions provide an opportunity to obtain long records of variability in the Gulf Stream/Sargasso Sea region and its impact on the thermohaline circulation during the last millennium. Interhemispheric transfer of energy is primarily ensured by the oceanic thermohaline circulation and by atmospheric monsoon circulation. On the annual-to-century timescales, climatic conditions at the continental surface depend strongly on those of the ocean. In order to determine the response of continental climate to ocean changes, PAGES has established three major interhemispheric studies, the PEP (Pole-Equator-Pole) transects, to unravel the paleoclimatic evolution of both hemispheres along three longitudinal bands: one through the Americas (PEP I), a second over Asia and Australia (PEP 2), and the third through Europe and Africa (PEP 3). In addition, the PAGES ARTS, HIPP, and Paleomonsoons (Table 1) efforts will be directly relevant to CLIVAR. Paleoclimatic data with annual resolution should allow the documentation of how systems such as ENSO have influenced continental climate dynamics. PAGES will facilitate the recovery of the needed proxy records from the best sites, and will promote the international collaboration necessary to provide the required combination of climatological insight, local expertise, and logistical/analytical capability. |
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