Sedimentary changes during the Holocene in the Bohai Sea and its paleoenvironmental implication

Samples of two cores, Cores M5-5 and M7-4 in the Bohai Sea were analyzed in isotopes, grain size, heavy minerals, chemical compositions, and 14 C dating to reconstruct the sedimentation during the Holocene. Abrupt change in carbon and oxygen stable isotopes was recognized at Core M5-5 at about 6400 a BP, which was likely due to the intrusion of the Yellow Sea Warm Current (YSWC) extension into the Bohai Sea. At Core M7-4, sediments between 5900 and 6600 a BP (150-260 cm depth) became coarse-grained, containing rich garnet, high manganese content, and nil autogenic pyrite, indicating a very dynamic sedimentary event during which the ambience was transformed from reductive to oxidative, and sedimentation boosted. Meanwhile, the YSWC had invaded into the Bohai Sea indicated by rich planktonic foraminifera in this event. (c) 2008 Elsevier Ltd. All rights reserved.

Paleoenvironmental change in the middle Okinawa Trough since the last deglaciation: Evidence from the sedimentation rate and planktonic foraminiferal record

Well-dated, high-resolution records of planktonic foraminifera and oxygen isotopes from two sediment cores, A7 and E017, in the middle Okinawa Trough reveal strong and rapid millennial-scale climate changes since similar to 18 to 17 thousand years before present (kyr B.P.). Sedimentation rate shows a sudden drop at similar to 11.2 cal. kyr B.P. due to a rapid rise of sea level after the Younger Dryas (YD) and consequently submergence of the large continental shelf on the East China Sea (ECS) and the retreat of the estuary providing sediment to the basin. During the last deglaciation, the relative abundance of warm and cold species of planktonic foraminifera fluctuates strongly, consistent with the timing of sea surface temperature (SST) variations determined from Mg/Ca measurements of planktonic foraminifera from one of the two cores. These fluctuations are coeval with climate variation recorded in the Greenland ice cores and North Atlantic sediments, namely Heinrich event 1 (H1), Bolling-Allerod (B/A) and YD events. At about 9.4 kyr B.P., a sudden change in the relative abundance of shallow to deep planktonic species probably indicates a sudden strengthening of the Kuroshio Current in the Okinawa Trough, which was synchronous with a rapid sea-level rise at 9.5-9.2 kyr B.P. in the ECS, Yellow Sea (YS) and South China Sea (SCS). The abundance of planktonic foraminiferal species, together with Mg/Ca based SST, exhibits millennial-scale oscillations during the Holocene, with 7 cold events (at about 1.7, 2.3-4.6, 6.2, 7.3, 8.2, 9.6, 10.6 cal. kyr BP) superimposed on a Holocene warming trend. This Holocene trend, together with centennial-scale SST variations superimposed on the last deglacial trend, suggests that both high and low latitude influences affected the climatology of the Okinawa Trough. (c) 2006 Elsevier B.V. All rights reserved.

A preliminary study on fingerprinting approach in marine sediment dynamics with the rare earth elements

Locating the quantitized natural sediment fingerprints is an important work for marine sediment dynamics study. The total of 146 sediment samples were collected from the Shelf of the East China Sea and five rivers, including Huanghe (Yellow), Changjiang (Yangtze), Qiantang, Ou and Min River. The sediment grain size and the contents of rare earth elements (REEs) were measured with laser particle size analyzer and ICP-MS technology. The results show that absolute REE content (Sigma REE) and the concentration ratio of light REEs to heavy REEs (L/HREE) are different in the sediments among those rivers. There are higher REE contents in being less than 2 m and 2-31 mu m fractions in the Changjiang Estuary surface sediments. The REE contents of bulk sediment are dominated by the corresponding values of those leading size-fractions. Sigma REE of sediment is higher close to the estuaries and declines seaward on the inner shelf of the East China Sea (ECS). The L/HREE ratio has a tendency of increase southward from 28 degrees N. Hydrodynamic conditions plays a predominate role on spacial distributions of the surficial sediment's REE parameters. In some situations, the currents tend to remove the coarser light grains from initial populations, as well as the deposit of the finer heavy mineral grains. In other situations, the currents will change the ratio of sediment constituents, such as ratio between silts and clays in the sediments. As a result, the various values of Sigma REE or L/HREE ratio in different bulk sediments are more affected by the change of size-fractions than source location. Under the long-term stable hydrodynamic environment, i.e., the East China Sea Shelf, new sediment transport model based on the size and density gradation concept may help to understand the spatial distribution patterns of REE parameters.

Characteristics of clay minerals in the northern South China Sea and its implications for evolution of East Asian monsoon since Miocene

Clay mineral assemblages, crystallinity, chemistry, and micromorphology of clay particles in sediments from ODP Site 1146 in the northern South China Sea (SCS) were analyzed, and used to trace sediment sources and obtain proxy records of the past changes in the East Asian monsoon climate since the Miocene, based on a multi-approach, including X-ray diffraction (XRD) and scanning electron microscopy combined with energy dispersive X-ray spectrometry (SEM-EDS). Clay minerals consist mainly of illite and smectite, with associated chlorite and kaolinite. The illite at ODP Site 1146 has very well-to-well crystallinity, and smectite has moderate-to-poor crystallinity. In SEM the smectite particles at ODP Site 1146 often appear cauliflower-like, a typical micromorphology of volcanic smecites. The smectite at ODP Site 1146 is relatively rich in Si element, but poor in Fe, very similar to the smectite from the West Philippine Sea. In contrast, the chemical composition of illite at ODP Site 1146 has no obvious differences from those of the Loess plateau, Yellow River, Yangtze River, and Pearl River. A further study on sediment source indicates that smectite originates mainly from Luzon, kaolinite from the Pearl River, and illite and chlorite from the Pearl River, Taiwan and/or the Yangtze River. The clay mineral assemblages at ODP Site 1146 were not only controlled by continental eathering regimes surrounding the SCS, but also by the changing strength of the transport processes. The ratios of (illite+chlorite)/smectite at ODP Site 1146 were adopted as proxies for the East Asian monsoon evolution. Relatively higher ratios reflect strongly intensified winter monsoon relative to summer monsoon, in contrast, lower ratios indicate a strengthened summer monsoon relative to winter monsoon. The consistent variation of this clay proxy from those of Loess plateau, eolian deposition in the North Pacific, planktonic, benthic foraminifera, and black carbon in the SCS since 20 Ma shows that three profound shifts of the East Asian winter monsoon intensity, and aridity in the Asian inland and the intensity of winter monsoon relative to summer monsoon, occurred at about 15 Ma, 8 Ma, and the younger at about 3 Ma. The phased uplift of the Himalaya-Tibetan plateau may have played a significant role in strengthening the Asian monsoon at 15 Ma, 8 Ma, and 3 Ma.

Responses of summertime extreme wave heights to local climate variations in the East China Sea

We detected the responses of summertime extreme wave heights (H-top10, average of the highest 10% of significant wave heights in June, July and August) to local climate variations in the East China Sea by applying an empirical orthogonal function analysis to Htop10 derived from the WAVEWATCH- III wave model driven by 6 hourly sea surface wind fields from ERA-40 reanalysis over the period 1958-2002. Decreases in H-top10 in the northern East China Sea ( Yellow Sea) correspond to attenuation of the East Asian Summer Monsoon, while increases in the south are primarily due to enhancement of tropical cyclone activities in the western North Pacific.

Interbasin freshwater, heat and salt transport through the boundaries of the East and South China Seas from a variable-grid global ocean circulation model

The monthly and annual mean freshwater, heat and salt transport through the open boundaries of the South and East China Seas derived from a variable-grid global ocean circulation model is reported. The model has 1/6degrees resolution for the seas adjacent to China and 30 resolution for the global ocean. The model results are in fairly good agreement with the existing estimates based on measurements. The computation shows that the flows passing through the South China Sea contribute volume, heat and salt transport of 5.3 Sv, 0.57 PW and 184 Ggs(-1), respectively (about 1/4) to the Indonesian Throughflow, indicating that the South China Sea is an important pathway of the Pacific to Indian Ocean throughflow. The volume, heat and salt transport of the Kuroshio in the East China Sea is 25.6 Sv, 2.32 PW and 894 Ggs(-1), respectively. Less than 1/4 of this transport passes through the passage between Iriomote and Okinawa. The calculation of heat balance indicates that the South China Sea absorbs net heat flux from the sun and atmosphere with a rate of 0.08 PW, while the atmosphere gains net heat flux from the Baohai, Yellow and East China Seas with a rate of 0.05 PW.

Mean sea surface heights of the South and East China Seas from ocean circulation model and geodetic leveling

The mean sea surface heights (sea surface topography) of the South China, East China, Yellow and Bohai Seas are derived from an ocean general circulation model and surface air pressure. The circulation model covers the global oceans, with fine grid (1/6degrees) covering the East Asian marginal seas and coarse grid (31) covering the rest part of the global oceans. The result shows that the China 1985 National Altitude Datum is 24.7 cm above the me-an sea surface height of the world oceans. The mean sea surface in the coastal ocean adjacent to China is higher in the south than in the north. Intercomparison of the model results with the geodetic leveling measurements at 28 coastal tidal stations shows a standard deviation of 4.8 cm and a fitting coefficient of 95.3%. After correction through linear regression, the standard deviation is reduced to 4.5 cm. This indicates that the accuracy of model results is sufficient for practical application. Based on the model results, the mean sea surface heights for the study area with a resolution of 1/6 degree are given. This result also links the mean sea levels at islands with those on the mainland coast and gives the mean sea surface heights at tidal stations in the Taiwan Island, the Dongsha Islands, the Yisha Islands and the Nansha Islands relative to the China 1985 National Altitude Datum.

Analysis of the sea-level variability along the Chinese coast and estimation of the impact of a CO2-perturbed atmospheric circulation

The relationship between monthly sea-level data measured at stations located along the Chinese coast and concurrent large-scale atmospheric forcing in the period 1960-1990 is examined. It is found that sea-level varies quite coherently along the whole coast, despite the geographical extension of the station set. A canonical correlation analysis between sea-level and sea-level pressure (SLP) indicates that a great part of the sea-level variability can be explained by the action of the wind stress on the ocean surface. The relationship between sea-level and sea-level pressure is analyzed separately for the summer and winter half-years. In winter, one factor affecting sea-level variability at all stations is the SLP contrast between the continent and the Pacific Ocean, hence the intensity of the winter Monsoon circulation. Another factor that affects coherently all stations is the intensity of the zonal circulation at mid-latitudes. In the summer half year, on the other hand, the influence of SLP on sea-level is spatially less coherent: the stations in the Yellow Sea are affected by a more localized circulation anomaly pattern, whereas the rest of the stations is more directly connected to the intensity of the zonal circulation. Based on this analysis, statistical models (different for summer and winter) to hindcast coastal sealevel anomalies from the large-scale SLP field are formulated. These models have been tested by fitting their internal parameters in a test period and reproducing reasonably the sea-level evolution in an independent period. These statistical models are also used to estimate the contribution of the changes of the atmospheric circulation on sea-level along the Chinese coast in an altered climate. For this purpose the ouput of 150 year-long experiment with the coupled ocean-atmosphere model ECHAM1-LSG has been analyzed, in which the atmospheric concentration of greenhouse gases was continuously increased from 1940 until 2090, according to the Scenario A projection of the Intergovermental Panel on Climate Change. In this experiment the meridional (zonal) circulation relevant for sea-level tends to become weaker (stronger) in the winter half year and stronger (weaker) in summer. The estimated contribution of this atmospheric circulation changes to coastal sea-level is of the order of a few centimeters at the end of the integration, being in winter negative in the Yellow Sea and positive in the China Sea with opposite signs in the summer half-year.

Measurements of ocean wave and current field using dual polarized X-band radar

A new ocean wave and sea surface current monitoring system with horizontally-(HH) and vertically-(VV) polarized X-band radar was developed. Two experiments into the use of the radar system were carried out at two sites, respectively, for calibration process in Zhangzi Island of the Yellow Sea, and for validation in the Yellow Sea and South China Sea. Ocean wave parameters and sea surface current velocities were retrieved from the dual polarized radar image sequences based on an inverse method. The results obtained from dual-polarized radar data sets acquired in Zhangzi Island are compared with those from an ocean directional buoy. The results show that ocean wave parameters and sea surface current velocities retrieved from radar image sets are in a good agreement with those observed by the buoy. In particular, it has been found that the vertically-polarized radar is better than the horizontally-polarized radar in retrieving ocean wave parameters, especially in detecting the significant wave height below 1.0 m.

Numerical investigation of nutrient limitations in the Bohai Sea

River discharges are the important freshwater and nutrient sources for Bohai Sea (BS), and have a profound impact on the local marine environment. In this paper, the annual cycles of nutrient and phytoplankton dynamics in 1980s were reproduced using a coupled biogeochemical-physical model. Based on the validated simulations, the nutrient limitation characters were further investigated by running the model with the riverine nutrient altered, first enriching nitrogen and then phosphorus. It was found that although the riverine N:P ratios in Yellow and Haihe Rivers were much higher than the Redfield number, the nitrogen enrichment was still able to enhance the algae bloom in Laizhou and Bohai Bays. On the other hand, the response of algae growth to phosphorus enrichment was not thus obvious, which suggests that the local phytoplankton dynamics was characterized by the nitrogen limitation. Simulations also show that the nitrogen enrichment is generally accompanied by the phosphorus consumption, so a shift from nitrogen limitation to phosphorus limitation may occur if such a trend continues. (C) 2010 Elsevier Ltd. All rights reserved.

A new empirical model for retrieving sea surface salinity in L band

Sea surface salinity is a key physical parameter in ocean science. It is important in the ocean remote sensing to retrieve sea surface salinity by the microwave probe technology. Based on the in situ measurement data and remote sensing data of the Yellow Sea, we have built a new empirical model in this paper, which can be used to retrieve sea surface salinity of the Yellow Sea by means of the brightness temperature of the sea water at L-band. In this model, the influence of the roughness of the sea surface is considered, and the retrieved result is in good agreement with the in situ measurement data, where the mean absolute error of the retrieved sea surface salinity is about 0.288 psu. This result shows that our model has greater retrieval precision compared with similar models.

东黄海海洋蓝细菌（Svnechococcus）生态学研究

该文对中国黄海和东海的蓝细菌在春、秋两季的生态分布特点进行了研究和比较,对黄海蓝细胞从10月至次年6月的生态分布进行了研究.1.东黄海海区：在秋季（2000年10月19日至11月29日）和春季（2001年3月26日至4月24日）两个季节中蓝细菌丰度在0.19～7.84×10<'4>cell/ml之间,生物量在0.56～13.74μgC/L之间,整体水平上春季比秋季高（蓝细菌的丰充与生物量平均值春季分析为4.83×10<'4>cell/ml和7.25μgC/L;秋季分别为1.72×10<'4>cell/ml和5.07μgC/L）,东海比黄海高（蓝细菌生物量平均值春季黄海和东海分别为4.42μgC/L和5.52μgC/L;秋季黄海和东海分别为7.02μgC/L和7.45μgC/L）.2.黄海海区：黄海蓝细菌丰度与生物量随时间变化趋势为10月至12月降低（蓝细菌丰度分别为15×10<'4>cell/ml和1.19×10<'4>cell/ml,生物量分别为4.41μgC/L和3.49×10<'4>cell/ml）,4月（蓝细菌丰度与生物量分别为4.68×10<'4>cell/ml和7.02μgC/L）与12月相比有明显增高,蓝细菌丰度4月是12月的3.93倍,生物量4月是12月的2.01倍,4月至6月蓝细菌生物量大致稳定,略有增加（5月和6月蓝细菌丰度分别为5.23×10<'4>cell/ml和5.25×10<'4>cell/ml,生物量分别为7.85μgC/L和7.88μgC/L）.研究发现蓝细菌在水体中的垂直分布与温度变化比较一致.

古龙咀周围海区沉积物粒度特征及海底地形变化

对古龙咀周围浅海区沉积物的粒度进行了测试与分析，结合相关的地质水文资料，探讨了海岸形态对沉积物粒度的影响。研究区表层沉积物平均粒径在海湾浅海区呈带状由岸向海变细，中等水深和岬角处分布着细粒区，向外海粒径相对变粗；除险岛湾砂质区外，分选差；偏态多数为正偏或近正态；整体峰形极窄，峰型多样。底质类型以粘土质粉砂和砂质粉砂为主，由东北经古龙咀岬角向西南形成S形粘土质粉砂分布带，险岛湾地区沉积物呈带状由砂逐渐过渡到粉砂。潮汐和波浪是本区沉积物输运的主要水动力，岬角的存在影响了沉积物粒度的分布。粒度趋势分析表明沉积物整体有向岬角汇聚的输运趋势。 对收集到基于1954年、1969年、1982年测量绘成的地形图水深数据进行数字化，结合2005年测量的水深数据，分别建立各时期DEM图，在此基础上分析研究区的地形特征。四个时期海底DEM呈现出大体一致的趋势，在险岛湾及白沙口海湾内为浅水区，水深值在-1～-4 m之间，深水区主要分布在南黄岛南端至古龙咀连线以南区域，呈扇形展布，水深由南黄岛两侧向中间逐渐加深，水深值在-10～ -17 m之间。从整体上看，研究区海底地形呈NW-SE方向逐渐加深。 将数字化后的水深数据统一校正到1956黄海高程系，分别建立DEM，运用GIS的栅格计算分析得出冲淤变化图。相关结果表明：1954～1969年研究区整体近岸为冲（险岛湾除外），离岸海域为淤；1969～1982年研究区总体处于弱淤积状态；1982-2005研究区海域近岸为淤，外海以弱冲刷状态为主。

黄海纤毛虫的丰度和生物量

海洋浮游纤毛虫是在海洋中浮游生活的一类单细胞原生动物，主要是指寡毛类纤毛虫(Oligotrich ciliates)，隶属原生动物界(Protozoa)、纤毛门(Ciliophora)、寡毛纲(Oligotrichea)，分属于Oligotrichina 和Tintinnina两个亚纲。它们个体微小，粒径在5-200 µm之间，是微型浮游动物和海洋微食物环(Marine Microbial Food Web)的重要组成部分。 2006年4月至2007年12月，在黄海(包括胶州湾)采样分析海洋浮游纤毛虫的种类组成(砂壳纤毛虫)、丰度和生物量，分析纤毛虫在这一海区的季节变化和空间变化。 纤毛虫丰度和生物量的研究方法为：Rosette采水器(胶州湾用Niskin采水器)采集水样，取1 L水样，加Lugol’s试剂固定(终浓度1%)，Utermöhl方法100倍镜检。测量虫体的体长、体宽，按最接近的几何形状(圆柱体、球体和圆锥体)计算体积。生物量由体积乘转换系数(0.19 pgC/µm3)得到，砂壳纤毛虫的肉体体积按照壳体积的1/3近似。 本文的结果表明，胶州湾各站纤毛虫平均丰度于6月达到全年最高值6065 ind./L，12月为全年丰度最低值843 ind./L。平均生物量8月达全年最高值(18.5 µg C/L)，6月为全年最低值(0.6 µg C/L)。砂壳纤毛虫种丰富度于8月达到最高值，共发现25种砂壳纤毛虫，1月种类最少(6种)。湾内站位的纤毛虫平均丰度比湾外的高(6月和8月除外)。砂壳纤毛虫在纤毛虫总丰度中的比例较小，平均为25%，范围为8-57%，分别于1月和8月达到最低和最高值。 两次冷水团大面调查结果表明，4月表层纤毛虫平均丰度(1490 ind./L)要高于10月(972 ind./L)。10月表层纤毛虫生物量0.14-5.33 µg C/L，14194站、15694站和15894站生物量较高，为4.08-5.33 µg C/L。无壳纤毛虫优势种Laboea strobila在两个航次中均呈现斑块分布，4月航次丰度0-10000 ind./L，10月航次丰度11-350 ind./L；砂壳纤毛虫优势种Ptychocylis obtusa仅在4月航次发现，最大丰度2895 ind./L，10月航次未发现。4月航次砂壳纤毛虫有百乐拟铃虫(Tintinnopsis beroidea)，丰度为0-1920 ind./L；卡拉直克拟铃虫(Tintinnopsis karajacensis)，丰度很小(10-93 ind./L)。10月航次砂壳纤毛虫优势种Tintinnidium primitivum，丰度为35-700 ind./L；也出现了尖底类瓮虫(Amphorellopsis acuta)和网纹虫(Favella spp.)，但丰度不大(0-210 ind./L)；运动类铃虫(Codonellopsis mobilis)、筒状拟铃虫(Tintinnopsis tubulosoides)和Eutintinnus sp.丰度也较低(35-105 ind./L)；Craterella torulata丰度为0-120 ind./L，主要分布于15694站。10月航次已经出现了温跃层，位于30 m左右水层，纤毛虫主要分布于温跃层之上。 六次黄海断面航次表明：温跃层在5月已经出现，到12月消失。在有温跃层的5月、6月、8月、9月，纤毛虫主要分布于温跃层(30 m左右)之上。其中8月份航次纤毛虫丰度最高，表层平均丰度3103 ind./L。12月份纤毛虫丰度最低，表层平均丰度406 ind./L。纤毛虫生物量春夏季为0.02-5.5 µg C/L，冬季为0.04-1.99 µg C/L。小型无壳纤毛虫占优势，砂壳纤毛虫东方拟铃虫(Tintinnopsis orientalis)、筒状拟铃虫、运动类铃虫、Craterella torulata和Tintinnidium primitivum几乎在各个航次均有分布。

末次冰消期以来东亚季风演化：来自东海和北黄海沉积孢粉记录

本论文通过对冲绳海槽南部的MD05-2908孔、北黄海的B-U35、B-U41、B-L44孔和北黄海的299份表层样中的孢粉组成、堆积速率、有机碳氮同位素的综合研究，分析了北黄海的孢粉来源、传播动力和途径，并与其它古气候记录对比，重建了末次冰消期以来东亚季风的演化。 MD05-2908孔孢粉组合特征显示6800-3800a BP间气候温暖干燥，其间存在着两次明显的温度降低、湿度增加阶段，即6800-6600a BP和5800-4850a BP；3800a BP以后，气候变得比较寒冷湿润，中世纪暖期和小冰期分别位于990-480a BP和480-230a BP。 北黄海表层孢粉百分含量等值线图显示北黄海不同海域孢粉来源不同，北黄 海东部海域(123.5°E以东的陆架区域)孢粉主要来源于鸭绿江；北黄海中部海域(123.5°E-122.6°E的陆架区域)孢粉来源比较复杂，既有来自辽东半岛、沿海岛屿、山东半岛，还有由黄海暖流携带而来的；北黄海西部海域(122.6°E以西的陆架区域)孢粉以黄海沿岸流携带而来的黄河来源的为主。 北黄海表层孢粉百分含量等值线图还显示，北黄海东部海域孢粉分布主要受 鸭绿江冲淡水影响，波浪和潮汐的作用较弱；北黄海中部海域孢粉分布受黄海暖流和辽东沿岸流的分支共同影响；黄海暖流与黄海沿岸流在山东半岛东北部相遇，形成一逆时针方向的涡旋，该涡旋控制着北黄海西部海域孢粉的分布。 B-U35孔、B-U41和B-L44孔孢粉组合特征显示，12830-12350a BP时气候 寒冷干燥，植被以旱生草本植物为主，时间上可能对应YD事件；12350-10100a BP时植被以针叶林为主，林下生长着大量蕨类植物，气候寒冷湿润，可能对应着YD事件；10100-6600a BP时植被以落叶阔叶林为主，伴生大量旱生草本植物，气候温暖干燥；6600-5000a BP时植被以针叶-落叶阔叶混交林为主，旱生草本植物含量下降，相对上一阶段温度有所降低，但气候更湿润，可能对应全新世最佳期；5000-4000a BP时针叶林所占比例扩大，温度再次降低，湿度变化不明显；4000-500a BP旱生草本植物含量增加，气候寒冷干燥；500a BP-至今，受人类活动影响，植被遭到严重破坏。 B-U35孔和B-U41孔淡水水生植物花粉百分含量曲线显示11750a BP以来黄河河口地区沼泽湿地面积几经变化。10100-6600a BP时沼泽湿地范围在上一阶段的基础上进一步扩大；6600-2850a BP间沼泽湿地大面积缩小，水生植物属种式微；2850a BP之后黄河河口地区沼泽湿地面积再次扩大，水生植物重新繁盛。 MD05-2908孔蕨类孢子百分含量被用来作为中国东南部季风演化的代用指标。结果显示6800-3800a BP时夏季风较强，其间有两次夏季风减弱阶段，分别位于6800-6600a BP和5800-4850a BP，3800a BP以来，夏季风明显减弱，此期的夏季风减弱除受太阳辐射量的减少影响外，可能还与El Nino的频繁爆发有关。 B-U35孔和B-U41孔蒿属、藜科、麻黄科百分含量被用来作为中国中北部夏季风演化的代用指标。研究表明，11750a BP以来东亚夏季风强度在10100-6600a BP时，显著加强，6600a BP左右，夏季风开始减弱，4000a BP以后夏季风显著减弱。 将MD05-2908孔、B-U35孔和B-U41孔夏季风代用指标进行对比发现，中晚全新世以来中国南-北湿度变化特征正好相反，东亚夏季风强度变化以及由此引起的雨锋的南进北撤可能是导致中国不同区域中晚全新世以来降雨量不同的主要原因。