We investigated an alkenone-based sea surface temperature (SST) and the hydrographic change records of the subarctic Northwestern (NW) Pacific from the last glacial to interglacial. The core we investigated is a piston core (LV 63-41-2, 52.56° N, 160.00° E; water depth 1924 m) retrieved from the southern offshore east coast of the Kamchatka Peninsula, which is a location of high sedimentation rate, with highly dynamic interactions with the cold/warm water masses of the Bering Sea/the NW Pacific. Based on our alkenone analysis with a previously well-established chronology of the core, we found high glacial C_37:4 contents suggesting larger freshwater influences prior to the last deglacial in approximately 27–16 ka BP. The most significant features of what we found are alkenone indicative of “warming” intervals with minimum alkenone productions that occurred prior to the stadial Heinrich event 1 and the Younger Dryas. In contrast, for the interval corresponding to the Bølling–Allerød period, our alkenone analysis shows relatively “colder” but maximum alkenone productions. We conclude that this particular subarctic alkenone SST proxy record is mainly masked by non-thermal environmental influences, such as strong shifts of timing and duration of the sea ice retreat and/or salinity changes in surface water at this site, which could cause changes in water stratification that affect nutrient supplies of the upper ocean that modulate growth durations of phytoplankton/coccolithophore productions. Our studies suggest that this subarctic alkenone “SST” proxy record is indicative of the changes of seasonality that control the timing and duration of the blooming seasons of coccolithophores. The alkenone “SST” proxy is also dominantly driven by water stratification effects that, instead of SSTs, reflect most likely a combination of the following local to regional climate and ocean current patterns: (1) the amount of meltwater inputs from high mountain glaciers at Kamchatka; (2) less saline, nutrient-rich Alaskan Stream waters from the Cordilleran Ice Sheet in the Gulf of Alaska; (3) downwelling waters associated with the interactions between the southward Eastern Kamchatka Current and the spinning-up of the North Pacific Subarctic Gyre; and (4) the strength of the Kuroshio Current since the last glacial.

中文翻译：

---

自上次冰川以来北极亚西北太平洋的烯酮表面水文变化：代理局限性和非热环境影响的意义

我们调查了基于烯酮的海表温度（SST）和北极北极西北（NW）太平洋从最后一次冰期到中间冰期的水文变化记录。我们研究的岩心是从堪察加半岛南部近海东海岸取回的活塞岩心（LV 63-41-2，N。52.56°N，160.00°E；水深1924 m），该地区是沉积速率高的地方，与白令海/西北太平洋的冷/暖水团高度互动。根据我们对烯酮的分析以及以前确定的岩心年代，我们发现冰川高度C _37：4含量表明在大约27-16 ka BP末次冰期之前较大的淡水影响。我们发现的最重要的特征是烯酮，它指示“变暖”间隔，在体育场海因里希事件1和Younger Dryas发生之前，烯酮的产量最少。相反，对于与Bølling–Allerød时期相对应的时间间隔，我们的烯酮分析显示相对“冷”但烯酮产量最高。我们得出结论，该特定的北极亚烯酮SST代理记录主要被非热环境影响所掩盖，例如该地点冰海撤退的时间和持续时间的强烈变化和/或地表水的盐度变化，这可能会导致水分层变化，从而影响上层海洋的营养供应，从而调节浮游植物/球石藻产量的持续时间。我们的研究表明，这种北极亚烯酮“ SST”代理记录指示季节性变化，该季节性变化控制了球墨石藻开花季节的时间和持续时间。烯酮“ SST”替代物也主要由水分层效应驱动，这种分层效应代替了SST，最有可能反映以下局部到区域气候和洋流模式的组合：（1）来自高山冰川的融水输入量堪察加半岛 （2）来自阿拉斯加湾科迪勒拉冰原的盐分少，营养丰富的阿拉斯加溪流水；（3）与南部堪察加半岛东部海流和北太平洋亚北极环流的旋转相关的下行水域；（4）自上次冰川以来黑潮的强度。