A Possible Role of Solar Radiation and Ocean in the Mid-Holocene East Asian Monsoon Climate

An atmospheric general circulation model (AGCM) and an oceanic general circulation model (OGCM) are asynchronously coupled to simulate the climate of the mid-Holocene period. The role of the solar radiation and ocean in the mid-Holocene East Asian monsoon climate is analyzed and some mechanisms are revealed. At the forcing of changed solar radiation induced by the changed orbital parameters and the changed SST simulated by the OGCM, compared with when there is orbital forcing alone, there is more precipitation and the monsoon is stronger in the summer of East Asia, and the winter temperature increases over China. These agree better with the reconstructed data. It is revealed that the change of solar radiation can displace northward the ITCZ and the East Asia subtropical jet, which bring more precipitation over the south of Tibet and North and Northeast China. By analyzing the summer meridional latent heat transport, it is found that the influence of solar radiation change is mainly to increase the convergence of atmosphere toward the land, and the influence of SST change is mainly to transport more moisture to the sea surface atmosphere. Their synergistic effect on East Asian precipitation is much stronger than the sum of their respective effects.

Revisiting Mid-Holocene Temperature over China Using PMIP3 Simulations

Using the simulations performed by 15 cli mate models under the latest protocol of the Paleoclimate Modeling Intercomparison Project(PMIP)Phase 3(PMIP3),the authors revisited the annual and seasona temperature changes over China during the mid-Holocene Similar to the previous results produced by PMIP Phase 1(PMIP1)and 2(PMIP2)models,14(15)of the 15 PMIP3models reproduced colder annual(boreal winter and spring)temperature in response to mid-Holocene insola tion changes,with an average cooling of 0.33 K(1.31 K and 1.58 K)over China.The mid-Holocene boreal sum mer(autumn)temperature increased in all(13)of the 15PMIP3 models,with an average warming of 1.02 K(0.61K)at the national scale.Those changes simulated by the PMIP3 models were similar to those from the PMIP2simulations but generally weaker than those from the PMIP1 models.A considerable mismatch still existed between the simulated cooling by the PMIP3 models and the reconstructed warming for annual and winter tem peratures over China during the mid-Holocene,as wa also the case between the previous PMIP1/2 simulation and proxy data.

Paleoclimate Simulations of the Mid-Holocene and Last Glacial Maximum by FGOALS

Paleoclimate simulations of the mid-Holocene （MH） and Last Glacial maximum （LGM） by the latest versions of the Flexible Global Ocean-Atmosphere-Land System model, Spectral Version 2 and Grid-point Version 2 （FGOALS-s2 and g2） are evaluated in this study. The MH is characterized by changes of insolation induced by orbital parameters, and the LGM is a glacial period with large changes in greenhouse gases, sea level and ice sheets. For the MH, both versions of FGOALS simulate reasonable responses to the changes of insolation, such as the enhanced summer monsoon in African-Asian regions. Model differences can be identified at regional and seasonal scales. The global annual mean surface air temperature （TAS） shows no significant change in FGOALS-s2, while FGOALS-g2 shows a global cooling of about 0.7~C that is related with a strong cooling during boreal winter. The amplitude of ENSO is weaker in FGOALS-g2, which agrees with proxy data. For the LGM, FGOALS-g2 captures the features of the cold and dry glacial climate, including a global cooling of 4.6℃ and a decrease in precipitation by 10%. The ENSO is weaker at the LGM, with a tendency of stronger ENSO cold events. Sensitivity analysis shows that the Equilibrium Climate Sensitivity （ECS） estimated for FGOALS ranges between 4.23℃ and 4.59℃. The sensitivity of precipitation to the changes of TAS is -2.3%℃-1, which agrees with previous studies. FGOALS-g2 shows better simulations of the Atlantic Meridional Overturning Circulation （AMOC） and African summer monsoon precipitation in the MH when compared with FGOALS-gl.0; however, it is hard to conclude any improvements for the LGM.

Mid-Holocene Ocean Feedback on Global Monsoon Area and Precipitation

Mid-Holocene ocean feedback on global monsoon area, global monsoon precipitation(GMP), and GMP intensity(GMPI) was investigated by a set of numerical experiments performed with the Community Climate System Model version 4. Results showed that ocean feedback induced an increase in land monsoon area for northern Africa but a decrease for Asia and North and South America, and led to an increase in ocean monsoon area for the western Indian Ocean and southeastern Pacific but a decrease for the eastern Indian Ocean, tropical western Pacific, and tropical West Atlantic between the mid-Holocene and pre-industrial period. Dynamic oceaninduced changes in GMP and GMPI were 10.9×109 m3 d-1and-0.11 mm d-1 between the two periods, respectively.Ocean feedback induced consistent change between the Northern and Southern Hemisphere land or ocean but opposite change between land and ocean in the Northern or Southern Hemisphere monsoon areas for monsoon precipitation. The mid-Holocene summer changes in meridional temperature gradient and land-sea thermal contrast were the underlying mechanisms.

A Possible Impact of Cooling over the Tibetan Plateau on the Mid-Holocene East Asian Monsoon Climate

By using a 9-level global atmospheric general circulation model developed at the Institute of Atmospheric Physics （IAP9L-AGCM） under the Chinese Academy of Sciences, the authors investigated the response of the East Asian monsoon climate to changes both in orbital forcing and the snow and glaciers over the Tibetan Plateau at the mid-Holocene, about 6000 calendar years before the present （6 kyr BP）. With the Earth＇s orbital parameters appropriate for the mid-Holocene, the IAP9L-AGCM computed warmer and wetter conditions in boreal summer than for the present day. Under the precondition of continental snow and glacier cover existing over part of the Tibetan Plateau at the mid-Holocene, the authors examined the regional climate response to the Tibetan Plateau cooling. The simulations indicated that climate changes in South Asia and parts of central Asia as well as in East Asia are sensitive to the Tibetan Plateau cooling at the mid-Holocene, showing a significant decrease in precipitation in northern India, northern China and southern Mongolia and an increase in Southeast Asia during boreal summer. The latter seems to correspond to the weakening, southeastward shift of the Asian summer monsoon system resulting from reduced heat contrast between the Eurasian continent and the Pacific and Indian Oceans when a cooling over the Tibetan Plateau was imposed. The simulation results suggest that the snow and glacier environment over the Tibetan Plateau is an important factor for mid-Holocene climate change in the areas highly influenced by the Asian monsoon.

The PMIP3 Simulated Climate Changes over Arid Central Asia during the Mid-Holocene and Last Glacial Maximum

In this study, the climate changes over Arid Central Asia(ACA) during the mid-Holocene(approximately 6,000 calendar years ago, MH) and the Last Glacial Maximum(approximately 21,000 calendar years ago, LGM) were investigated using multimodel simulations derived from the Paleoclimate Modelling Intercomparison Project Phase 3(PMIP3). During the MH, the multimodel median(MMM) shows that in the core region of ACA, the regionally averaged annual surface air temperature(SAT) decreases by 0.13°C and annual precipitation decreases by 3.45%, compared with the preindustrial(PI) climate. The MMM of the SAT increases by 1.67/0.13°C in summer/autumn, whereas it decreases by 1.23/1.11°C in spring/winter. The amplitude of the seasonal cycles of the SAT increases over ACA due to different MH orbital parameters. For precipitation, the regionally averaged MMM decreases by 5.77%/5.69%/0.39%/5.24% in spring/summer/autumn/winter, respectively. Based on the analysis of the aridity index(AI), compared with the PI, a drier climate appears in southern Central Asia and western Xinjiang due to decreasing precipitation. During the LGM, the MMM shows that the regionally averaged SAT decreases by 5.04/4.36/4.70/5.12/5.88°C and precipitation decreases by 27.78%/28.16%/31.56%/27.74%/23.29% annually and in the spring, summer, autumn, and winter, respectively. Robust drying occurs throughout almost the whole core area. Decreasing precipitation plays a dominant role in shaping the drier conditions, whereas strong cooling plays a secondary but opposite role. In response to the LGM external forcings, over Central Asia and Xinjiang, the seasonal cycle of precipitation has a smaller amplitude compared with that under the PI climate. In the model-data comparison, the simulated MH moisture changes over ACA are to some extent consistent with the reconstructions, further confirming that drier conditions occurred during that period than during the PI.

Contribution of Mountain River Materials to the Continental Shelf off Southeastern Hainan Island Since the Mid-Holocene

The concentrations of rare earth elements(REEs)in the bulk sediment of Core X2,which was collected from southeastern Hainan Island,were analyzed to investigate the relative contributions of various provenance regions since mid-Holocene.The results show that sediments in Core X2 were primarily derived from Hainan Island with lesser amounts from Taiwan and limited input from the Pearl River.Based on the application of quantitative inversion to model the REE data,the average contributions of river materials from southeastern Hainan Island and southwestern Taiwan to the study area were 68%and 32%,respectively.Furthermore,starting at 4.0 kyr BP,the transport of fluvial sediments from Taiwan to the study region increased due to enhanced hydrodynamics in South China Sea(SCS).These results indicate that the contributions of mountain river materials from Hainan Island and Taiwan to the continental shelf of northern SCS are non-negligible.Furthermore,these results demonstrate that mountain rivers can play an important role in the material cycle of continental margins and may feature a greater impact than large river systems in specific continental shelf areas.

Geochemical evidences of dry climate in the Mid-Holocene in Gonghe Basin, northeastern Qinghai-Tibetan Plateau

Previous research on climatic change in the Mid-Holocene in China indicates that it was a warm and humid period, accompanied by stronger summer monsoons, and it is defined as the Megatherrnal in the Holocene, or the Holocene Optimum period. However, this conclusion is mainly dh＇eeted at the monsoonal region in eastem China. In this research, we chose the Gonghe Basin in the northeastern Qinghai-Tibetan Plateau as the study area. Geochemical analysis of the profiles of paleosols and aeolian sand in the Santala area in the middle of the Gonghe Basin, along with OSL （optically stimulated luminescence） dating, indicates that the regional climate has experienced several warm-humid and cold-dry cycles since 11.8 ka. In particular, the Mid-Holocene （8.14.6 ka） was relatively cold and dry as evidenced by drastic fluctuations in chemical weathering degree and humidity, a higher aridity index, and sparse vegetation, accompanying increased winter monsoonal strength. In order to clarify whether this is an individual or local signal, we compared our geochemical analysis results with lake and peat records and aeolian de- posits of the monsoonal boundary region. The results indicate that the climate deteriorated widely, with declines in temperature and moisture, in the Mid-Holocene in the modem monsoonal boundary zone. Furthermore, the duration of climate deteriora- tion （relatively dry period） generally decreased from west to east in the aforementioned regions. Therefore, this dry phase in Gonghe Basin may be representative of dry events in Mid-Holocene in northem China. In addition, we discuss the reasons for this dry climate from several perspectives： （1） it probably can be attributed to a decline in summer monsoonal strength; （2） the regional evaporation loss （forced by high temperature） was not compensated by regional precipitation; （3） the thermal dynamic effect of the Qinghai-Tibetan Plateau.

Precipitation Pattern of the Mid-Holocene Simulated by a High-Resolution Regional Climate Model

Early proxy-based studies suggested that there potentially occurred a ＂southern drought/northern flood＂ （SDNF） over East China in the mid-Holocene （from roughly 7000 to 5000 years before present）.In this study,we used both global and regional atmospheric circulation models to demonstrate that the SDNF-namely,the precipitation increases over North China and decreases over the the lower reaches of the Yangtze River Valley--could have taken place in the mid-Holocene.We found that the SDNF in the mid-Holocene was likely caused by the lower SST in the Pacific.The lowered SST and the higher air temperature over China's Mainland increased the land-sea thermal contrast and,as a result,strengthened the East Asian summer monsoon and enhanced the precipitation over North China.

Late Olenekian Radiolarians from Bedded Chert of Ashio Terrane, Northeast Japan, and Faunal Turnovers in Western Panthalassa during Early Triassic

Late Olenekian assemblages in the western Panthalassa have been recovered from bedded radiolarian chert sequences of an accretionary complex, the Ashio belt. These faunas are documented and considered in terms of radiolarian diversity and faunal turnover during the latest Permian to Middle Triassic time. The fauna includes 30 radiolarians belonging to Spumellaria or Entactinaria, with two relicts from the Late Permian. This late Olenekian fauna is markedly different from Permian and Anisian faunas, respectively, and is herein named the Minowa fauna. Study of the literature indicates that radiolarian provinces were significantly disconnected between the western Panthalassa and eastern Tethys during late Olenekian time. Furthermore, 121 of 143 species disappeared during late Olenekian time, and in turn 118 new species appeared in the western Panthalassa around the Olenekian Anisian boundary. It is concluded that faunal turnover occurred at least three times between the latest Permian and Middle Triassic. The first turnover is the Paleozoic type radiolarian extinction at the Permian Triassic boundary, the second is the diversification of spheroidal Spumellaria and Entactinaria between early and late Olenekian time, and the third is a faunal turnover from the Minowa fauna to the true Mesozoic type radiolarian faunas that are characterized by multi segmented Nassellaria.

Revision to Kowalskia from the Houhecun Fauna and a New Discovery of Tscherskia(Cricetidae, Rodentia) from the Youhe Fauna of Weinan, Shaanxi Province, China

The fossil hamster(an isolated m1) from the early Early Pleistocene Houhecun fauna found in Dali, Weinan, Shaanxi, China, originally identified as Kowalskia dalinica, is reexamined. Its unique characters, including a high crown, very small degree of division of the anteroconid and relatively large size, is taken as evidence of its attribution to the genus Sinocricetus, instead of Kowalskia(junior synonym of Neocricetodon) suggested by the original author. Therefore, the specific name of the species established based on this m1 should be changed to S. dalinicus(Wang, 1988). S. dalinicus probably has a relatively close affinity with S. major Li, 2010, but there are still some obvious differences of characters between them. The discovery of S. dalinicus in the Houhecun fauna confirms that the genus indeed survived into the Pleistocene. A broken hamster mandible, which was found in Weinan, Shaanxi, China and belongs to the late Pliocene Youhe fauna, is also described here and identified as Tscherskia sp.. This specimen represents the earliest Tscherskia in Asia so far, but fails to refute the hypothesis that the genus originated in Europe during the early Pliocene.

A review on the eco-geography of soil fauna in China

This review summarizes main research findings in soil fauna eco-geography in China in the past 30 years. The subject areas and main results were overviewed including biodiversity and eco-geological distribution of soil fauna communities. Studies of ecological distributions of soil fauna and dynamic ranges in space from tropical, subtropical to temperate regions, and in categories from forest, grassland, desert, wetland, farmland to urban ecosystems, the responses and indications of soil fauna to soil environments. Effects of intensive disturbance such as fire, grazing, farming, fertilization on soil fauna include sensitive （e.g. nematode） and rare groups and community indexes. The functions of soil fauna were discussed including environmental construction, environmental purification, litter decomposition and elements cycling. Interactions between soil fauna and other biota in soil ecosystems and linking between aboveground and belowground diversity and the effects of global change on soil fauna community in China were also included. Finally, the authors pointed out common interests in soil fauna eco-geographical studies, which include application of molecule biology into soil fauna taxa; function and mechanism of soil fauna community diversity; interaction between aboveground and belowground ecosystems; effects of disturbance, pollution, biological invasion, and global change on soil fauna community and function. The review is to provide a scientific basis for promoting soil fauna eco-geographical studies in China.

Conodont Evidence for the Age of the Panxian Fauna,Guizhou,China

Detailed conodont analysis on the Yangjuan-Chupiwa section, Xinmin, Panxian County, Guizhou Province, revealed a conodont sequence including four Anisian conodont zones, viz. Nicoraella germanica Zone, Nc. kockeli Zone, Paragondolella bifurcata Zone and Neogondolella constricta Zone. These zones indicate that the upper Guanling Formation consists of strata from the Bithynian to the lllyrian of the Anisian. Appearance of Neogondolella constricta suggests that the Anisian/Ladinian boundary might be in the overlying Yangliujing Formation. The Panxian Fauna with well-preserved marine reptile and fish fossils is proved to belong to the lower part of the conodont Nc. kockeli Zone in the studied area. Thus, the age of the Panxian Fauna could be the early Pelsonian of the Anisian.

Biodiversity and Sequence of the Middle Triassic Panxian Marine Reptile Fauna,Guizhou Province,China

The Middle Triassic Panxian fauna is a physical marker and representative record of the rapid recovery of the Triassic marine ecosystem following the Early Triassic stagnant stage after the end-Permian mass extinction. Ten marine reptile taxa have been found from the 1.82-2.10 m-thick fossiliferous level in the Upper Member of the Guanling Formation, which can be subdivided into three marine reptile beds through the analysis on the stratigraphic distributions of fossil reptiles. The Lower Reptile Bed yields the sauropterygians Placodus inexpectatus Jiang et al., 2008 and Lariosaurus hongguoensis Jiang et al., 2006, the ichthyopterygians Xinminosaurus catactes Jiang et al., 2008 and Phalarodon cf. Phalarodon fraasi Merriam, 1910, associated with Mixosaurus panxianensis Jiang et al., 2006, representing a stage of predominance of durophagous taxa. In this bed, the large complete skeletons may reach up to 2.3 m in length, and lithofacies and chemostratigraphic analyses indicate a relatively deep carbonate platform with an oxic water environment near the bottom, as well as a rising sea level The Middle Reptile Bed yields the sauropterygian Nothosaurus yangjuanensis Jiang et al., 2006 and the archosaur Qianosuchus mixtus Li et al., 2006, associated with Mixosaurus panxianensis Jiang et al., 2006. The fossils in this bed are characterized by its pincering dentition and large overall body size, with the largest possibly exceeding 3 m in length. This bed might represent a time of deepest basin with relatively anoxic condition near the bottom. The Upper Reptile Bed yields the sauropterygians Wumengosaurus delicatomandibularis Jiang et al., 2008, Keichousaurus sp., the protorosaur Dinocephalosaurus orientalis Li, 2003, and the ichthyopterygian Mixosaurus panxianensis Jiang et al., 2006. In this bed, reptilian taxa characterized by suction feeding appeared, and most are less than 1 m long. This bed corresponds to a period of decreasing water depth.

New Vetulicoliids from the Lower Cambrian Guanshan Fauna, Kunming

The Guanshan Fauna, a soft-bodied fauna intermediate between the Chengjiang Fauna and the Kaili Fauna and also the Burgess Shale Fauna stratigraphically, consists of trilobites, trilobitoides, Tuzoia, Vetulicola, Paleoscolex, brachiopods and sponges. The discovery and research of this fauna is of great significance in understading the 'Cambrian Explosion' and the evolution of early life. The occurrence of vetulicoliids from the Guanshan Fauna not only adds new members to the taxonomic list, but also provides new information to the evolution of this animal group. This paper describe Vetulicola gantoucunensis Luo, Fu et Hu sp. nov. from the Lower Cambrian Wulongqing Formation in the Kunming area. Also presented are the amended description of Vetulicola and the comparisons with related genera within Vetulicoliids. The affinity, distribution, as well as evolution of vetulicoliids are discussed.

A New Vetulicolian from the Early Cambrian Chengjiang Fauna in Yunnan of China

The genus and species Yuyuanozoon magnificissimi gen. et sp. nov., a new fossil vetulicolian, is reported from the Early Cambrian Chengjiang Fauna in Yunnan of China. It has a bipartite body plan and five pairs of chain-formed gill sacs, showing the general characteristics of Ventulicolia. However, the exclusive 'atrial cavity' and external gill observed indicate that the new form is different from those previously described as vetulicolians, probably representing a lineage developed within deuterostomes and more primitive than urochordates.

Response of soil fauna to simulated nitrogen deposition: A nursery experiment in subtropical China

We studied the responses of soil fauna to a simulated nitrogen deposition in nursery experimental plots in Subtropical China. Dissolved NH4NO3 was applied to the soil by spraying twice per month for 16 months, starting January 2003 with treatments of 0, 5, 10, 15 and 30 gN/（m^2·a）. Soil fauna was sampled after 6, 9, 13 and 16 months of treatment in three soil depths （0-5 cm, 5-10 cm, 10-15 cm）. Soil available N increased in correspondence with the increasing N treatment, whereas soil pH decreased. Bacterial and fungal densities were elevated by the N treatment. Soil fauna increased in the lower nitrogen treatments but decreased in the higher N treatments, which might indicate that there was a threshold around 10 gN/（m^2·a） for the stimulating effects of N addition. The N effects were dependent on the soil depth and sampling time. The data also suggested that the effects of the different N treatments were related to the level of N saturation, especially the concentration of NO3^- in the soil.

A New Arthropod,Guangweicaris Luo,Fu et Hu gen. nov. from the Early Cambrian Guanshan Fauna,Kunming,China

The Guanshan Fauna is a soft-bodied fauna dominated by arthropods （including trilobites, trilobitoides, Tuzoia, Isoxys, and bradorids） in association with priapulids, brachiopods, anomalocaridids, vetulicoliids, sponges, chancellorids, and echinoderms. This paper reports and describes a new arthropod from the yellowish green mudstone at the lower part of the Wulongqing Formation, Canglangpuan Stage, Lower Cambrian in Kunming, Yunnan, China. The stratigraphic and geographic distribution, classification, fossil preservation, life style of this new arthropod and comparisons with other fossil arthropods are also discussed in details. The discovery and research of the non-mineralized arthropod, Guangweicaris Luo, Fu et Hu gen. nov. from the Guanshan Fauna adds new members to the taxonomic list and provides new information to the evolution of early arthropods. Furthermore, this study would shed new light into the ＂Cambrian Explosion＂ and the evolution of early life.

New Quaternary Mammalian Faunas and Cave Deposits in the Zhoukoudian Area,Beijing

From 1985 to 1987, four new localities with abundant fossil mammals were dis-covered by Cao, Tian and others in the Zhoukoudian (Choukoutien) area, Beijing. They are theEast, West, Shangdian and Donglingzi caves. The East Cave fauna consists of 28 speices ofmammals and its age is middle Early Pleistocene. The East Cave assemblage shows that a tem-perature-falling event took place at around 1.20 Ma B.P. at Zhoukoudian. Sixteen species ofmammals were collected from the West Cave, which are mainly forms of late Early Pleistoceneage. The West Cave fauna represents a transitional fauna from the East Cave fauna (dry-cold)to the fauna (warm) at locality 9. The Shangdian Cave fauna is composed of four forms, beingMiddle Pleistocene in age. The Donglingzi Cave fauna contains 21 Late Pleistocene forms. Inthe cave two fossil horizons may be distinguished. The age of the lower horizon is early LatePleistocene, which is equivalent to that of the New Cave fauna; while the fauna of the upper ho-rizon may be correlated with the Upper Cave fauna.

LATE EOCENE MAMMALIAN FAUNA OF HUANGZHUANG,QUFU,SHANDONG

This paper describes Mammalian fossils of 18 species discovered at Donghuangzhuang,about 15 km from NE of Qufu county,Shandong Province.The materials were collected bya farmer in 1984 and were sent to The Shandong Provincial Museum for studing.A short fieldinvestigation was made by Wang Jinwen,Sha Yesue(BGMRSD),Han Qingwen(SDM)andthe present author in same year.The age of the fauna is tentatively considered as the late Late Eocene,probably correlatedas the Heti Fauna(Yuanqu Basin).It represents the first occurrence of Late Eocene fossils inthis province.