Palynological records from bay of islands, Newfoundland: Direct correlation of Holocene paleoceanographic and climatic changes
Palynological records from bay of islands, Newfoundland: Direct correlation of Holocene paleoceanographic and climatic changes
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纽芬兰岛湾的孢粉学记录：全新世古海洋与气候变化的直接相关性
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发表时间：
2003
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通讯作者：
E. Levac
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作者：
E. Levac
摘要利用纽芬兰岛西部岛屿湾的孢粉记录，研究了古海洋和古气候事件之间的时间差异，以及冷海表面温度（SST）间隔。海面条件重建从dinocyst代理数据和古生物气候转换函数。陆上-海上花粉记录的相关性被用来确定海洋-大气相互作用。在9.5和8.6 ka之间，寒冷和低盐度的海面条件和寒冷的气候可能是通过圣劳伦斯湾大量冰川融水涌入的结果。海洋最适温期在6.8 ka之前，SST比现在高5°C，与北方森林的扩张相吻合，这可能是气候改善的结果，而陆地高温期仅在6 ka左右开始，这可能是由于残留的冰盖对区域气候的影响。它与夏季SST比今天低相吻合。云杉和莎草的比例增加后3.7万年建议区域冷却的趋势，这是后来记录在海湾（800年前）的表面沃茨，并在此之前的间隔SST温暖比今天之间的4和1万年。这些结果表明，在海湾的海面条件控制的位置的主要电流和融水的涌入，而纽芬兰气候的影响下，劳伦潮汐冰盖，直到6万年，之后，它可能是由空气质量的位置，而不是在邻近的海面条件控制。
Abstract A palynological record from Bay of Islands (western Newfoundland) was used to investigate differences in timing between paleoceanographic and paleoclimatic events, and episodic cold sea surface temperature (SST) intervals. Sea surface conditions were reconstructed from dinocyst proxy‐data and paleobioclimatic transfer functions. Correlation of onshore‐offshore pollen records was used to determine ocean‐atmosphere interactions. Between 9.5 and 8.6 ka, cold and lower salinity sea surface conditions and a cold climate may be the result of a large influx of glacial meltwater through the Gulf of St. Lawrence. The marine optimum followed with SST up to 5°C warmer than today until 6.8 ka and coincides with an expansion of boreal forest trees, probably resulting from a climatic amelioration .The terrestrial hypsithermal started only around 6 ka, however, possibly due to the lingering effect of the remaining ice sheet on the regional climate. It coincides with lower summer SST than today. Increased proportions of spruce and sedge after 3.7 ka suggest a regional cooling trend, which was recorded later in the surface waters of the Bay (800 years ago) and was preceded by an interval of SST warmer than today between 4 and 1 ka. These results suggest that sea surface conditions in the bay are controlled by the position of the major currents and influx of meltwater, while Newfoundland climate remained under the influence of the Lauren tide ice sheet until 6 ka, after which it was probably controlled by the position of air masses rather than by conditions in the adjacent sea surface.