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加利福尼亚流是北太平洋环流的重要组成部分,它的变化对全球气候及碳循环有重要影响。对位于东北太平洋低纬区Baja California外海的PC14柱状样进行了有机地球化学分析,重建了过去14ka来这一地区百年尺度的海水表面温度及生产力变化,发现其存在明显的B/A(Bling-Aller)和YD(Younger Drays)事件,但B/A和YD事件温度变化幅度小于中纬度地区。与中纬度加利福尼亚流系早中全新世温度降低不同,PC14全新世温度无明显变化趋势。这些结果表明了东太平洋低纬地区对高纬地区的气候响应以及沿岸上升流和ENSO现象对加利福尼亚流系中纬和低纬地区的影响不同。从冰消期到全新世,PC14生产力呈现阶段上升趋势,指示了由E1 Ni?o气候向La Ni?a气候的转化以及沿岸上升流加强的总体趋势。在全新世中后期(6.5—3.8ka)生产力的降低,则可能是受ENSO加强的影响。在B/A暖期,PC14生产力增加不多,但氧最小层强度增加,这表明生产力变化不是东太平洋边缘海的氧最小层强化的控制因素。
The California stream is an important part of the North Pacific circulation and its changes have a significant impact on the global climate and the carbon cycle. Organic geochemical analysis of PC14 column located in the offshore of Baja California in the low latitude of the northeast Pacific rebuilt the surface temperature and productivity of the seawater over a century-old scale in the past 14 ka. It was found that there was a significant B / A (Bling- Aller and Yod (Younger Drays) events, but the B / A and YD events have less variation than the mid-latitudes. In contrast to the early-mid-Holocene temperature drop in the mid-latitude California fluvial system, there was no significant change in the temperature of the PC14 Holocene. These results show that the climate response to high latitudes in the low latitudes of the East Pacific and the effects of updrafts and ENSOs on the latitude latitudes and low latitudes of the California fluid system are different. From the time of ice expulsion to the Holocene, PC14 productivity showed an upward trend in stages indicating the transformation from the El Niño climate to the La Niña climate and the general trend of the coastal upwelling strengthening. The decrease in productivity in the mid and late Holocene (6.5-3.8 ka) may be due to the strengthening of ENSO. In the B / A warm season, the productivity of PC14 increased little, but the intensity of oxygen minimum layer increased, indicating that productivity change is not the controlling factor for the enhancement of oxygen minimum layer in the marginal seas of the eastern Pacific Ocean.