Tree-ring records as indicators of air-sea interaction in the northeast Pacific sector

Climate conditions in land areas of the Pacific Northwest are strongly influenced by atmosphere/ocean variability, including fluctuations in the Aleutian Low, Pacific-North American (PNA) atmospheric circulation modes, and the El Niño-Southern Oscillation (ENSO). It thus seems likely that climatically sensitive tree-ring data from these coastal land areas would likewise reflect such climatic parameters. In this paper, tree-ring width and maximum lakewood density chronologies from northwestern Washington State and near Vancouver Island, British Columbia, are compared to surface air temperature and precipitation from nearby coastal and near-coastal land stations and to monthly sea surface temperature (SST) and sea level pressure (SLP) data from the northeast Pacific sector. Results show much promise for eventual reconstruction of these parameters, potentially extending available instrumental records for the northeastern Pacific by several hundred years or more.

Disturbance climate in the Columbia River Basin [abstract]

EXTRACT (SEE PDF FOR FULL ABSTRACT): Climatological events that disturb a landscape are important components in ecosystem processes. Modern ecosystem management plans now hope to incorporate knowledge of the spatial distribution and frequency of disturbance climate. The following describes a few analytic tools developed to help managers include disturbance climate in an ecosystem management plan for areas in the Columbia River Basin of the northwestern United States.

Structural features of geostrophic circulation in open region of the South China Sea

On the basis of observation data of water temperature and salinity the mean seasonal geostrophic circulation in open region of the South China Sea (SCS) was computed by the dynamic method relative to the 800 decibar reference surface. The results of computation let go to following notices: In both main monsoons (winter and summer) there are two main geostrophic eddies: the anticlockwise eddy in the northern and northwestern part, and the clockwise eddy in the southern part of the SCS with corresponding divergent and convergent zones. The main frontal zones go along the middle latitudes of the sea from the southern continental shelf of Vietnam to the area west of Luzon Island. The strength and stability of the current in winter are higher than in summer. The Kuroshio has an enough strong branch intruding into the SCS through Bashi Strait in winter creating in the sea the water structure similar to that of the Northwest Pacific subtropical and tropical regions. In summer the Kuroshio water can intrude directly only into the area southwest of Taiwan.