Jiaju Zhao

• Ph. D
• The Institute of Earth Environment Chinese Academy of Sciences

Numerous studies have demonstrated that there are major differences in the timing of maximum Holocene precipitation between the monsoonal East Asia and westerly dominated Central Asia, but it is unclear if the moisture differences are also associated with corresponding temperature contrasts. Here we present the first alkenone-based paleotemperature...

Our recent study suggests that branched glycerol dialkyl glycerol tetraethers (brGDGTs) in ancient bones may have great potential for reconstructing in-situ paleoclimate conditions. However, one major problem with reconstructing past climate and environmental conditions using brGDGTs in ancient bones is the lack of calibrations specific to bones. H...

Branched glycerol dialkyl glycerol tetraethers (brGDGTs) are a class of ubiquitous, bacteria-derived lipid biomarkers in terrestrial and aquatic environments. Many studies have demonstrated the potential for brGDGTs as paelotemperature proxies, but the observed seasonal bias in brGDGT-inferred temperatures still remains poorly understood, particula...

Investigations of the evolution of naturally and anthropogenically driven hydrology in arid regions are of great significance for hydrological forecasts. Here, we built the past ∼500-year history of lake area and discharge of Lake Tuosu in the northeastern Qaidam Basin. We found that the lake area and inflow variations were sensitive to westerly-fo...

The influence of Holocene East Asian Summer Monsoon (EASM) rainfall on ecosystems over northern China remains controversial: delay or synchronization. Here we present Holocene quantitatively reconstructed temperature and salinity records based on alkenone proxies in the Dali Lake from northern China. Our data indicate that the Dali Lake was signifi...

Hydroclimatic change in the Asian interior plays a key role in regulating regional environmental sustainability, water security, and human-nature relationships. However, the influence of the summer monsoon and westerly circulation on the evolution of hydroclimate over the arid Asian interior remains controversial. Here we present newly collected hy...

Hydroclimatic change in the Asian interior plays a key role in regulating regional environmental sustainability, water security, and human-nature relationships. However, the influence of the summer monsoon and westerly circulation on the evolution of hydroclimate over the arid Asian interior remains controversial. Here we present newly collected hy...

Understanding the causes of abrupt hydrologic declines in the Asian summer monsoon region may help limit the adverse effects of such events on the region’s economy and ecology. Here, we provide a high-resolution record of hydrological evolution in the East Asian monsoon margin region since the last deglaciation. Our synthesis of hydrological record...

Despite extensive investigation, the nature and causes of the Mid-Pleistocene Transition remain enigmatic. In this work, we assess its linkage to asynchronous development of bipolar ice sheets by synthesizing Pleistocene mid- to high-latitude proxy records linked to hemispheric ice sheet evolution. Our results indicate substantial growth of the Ant...

The effect of plant type on n-alkane biomarker has been widely studied, but the influence of plant type on n-alkanoic acids (n-FAs) has received less attention. Understanding the effect of the distribution of n-FAs and their hydrogen isotope composition (δ 2 H FA) is critical for interpreting sedimentary δ 2 H FA values as proxies of hydroclimate a...

In saline lakes, the paleoenvironmental interpretation of long-chain alkenones (LCAs) is difficult due to the inputs of Isochrysidales Group 2i, which are ice-related bloomers. Here, we perform detailed analysis of LCAs and long-chain alkenoates in sediment cores from Lake Daihai in north China. During the late Holocene, alkenone-inferred temperatu...

The multi-proxy approach is becoming an effective means to reduce uncertainties and errors compared to the single proxy approach. In this study, we investigated leaf wax biomarker and brGDGTs in topsoils along a semiarid elevation transect on the Chinese Loess Plateau. We found that both leaf wax n-alkane d2Hwax values and brGDGTs-derived MBT0 5ME...

The Asian summer monsoon (ASM), including the intensity and range limits of it's associated rainfall belt, is relevant to ecosystems, agriculture, natural hazards and water availability for millions of people in this region. However, understanding of the pattern of dunefield changes near the northern limit of the East Asian summer monsoon (EASM) si...

Holocene evolution of the East Asian summer monsoon (EASM), which provides precipitation to 1.6 billion people and has played a key role in the development of Chinese civilizations, has been hypothesized to be driven directly by summer insolation changes. However, an insolation-driven early-Holocene EASM maximum has not been convincingly validated,...

Terrestrial leaf wax n-alkane biomarkers provide considerable insights into paleoenvironmental reconstruction. Over decades, a substantial number of field investigations were performed to constrain hydroclimatic factors that influence leaf wax n-alkane biomarkers to improve their utility for paleoenvironmental applications. However, a critical issu...

Understanding the response of mid-latitude Asian (MLA) biomes to Holocene climate fluctuations is important for the conservation of fragile dryland ecosystems under future climate warming. Here, we use fossil pollen records from two cores recovered from Balikun Lake, eastern Tien Shan, to reconstruct regional Holocene vegetation dynamics and enviro...

There are debates regarding whether a wet and warm climate or a dry and cold climate dominated Holocene fire activity in northern China on the millennial timescale, and when human activities overtook climate change as the dominant control on fire occurrence in the region. Here we present a high-resolution fire history for the past ∼15,500 years fro...

Lakes are one of the most important freshwater resources on Earth and they provide a wide range of ecosystem services. However, due to rapid economic development and the intensification of human activities, many lakes have become eutrophic, which may threaten their status as water resources. Human activities have played a significant role in lake e...

Alpine wetland ecosystems are of importance in water conservation and animal husbandry in the arid central Asian. However, there is limited research on their formation and relationship with climate. In this study, we evaluated the long-term interactions of vegetation, hydrology, and climate based on multiple proxies (lithology, grain size, loss-on-...

Understanding past climate and environmental evolutions is of great significance for predicting the future in the context of global warming in arid Central Asia. Here, we report new Holocene paleovegetation records based on the concentrations and distributions of leaf wax long chain (C28-C32) n-acids and stable carbon isotopes of leaf wax C28 n-aci...

Dust raised from Arid Central Asia (ACA) affects the global climate, global biogeochemical cycles, and human health. Studies on the ACA dust activities thus are crucial for understanding dust forcing mechanisms and the mitigation of hazardous storms. Located at the downwind margin of the ACA, the Lake Qinghai basin is an ideal trap for dust activit...

Long-chain alkenones (LCAs) produced by phylogenetically classified Groups 1 and 3 Isochrysidales are increasingly used for paleotemperature and/or paleosalinity reconstructions in oligohaline lakes and marine environments. However, there are considerable difficulties in the paleoenvironmental interpretation of LCAs from Group 2 Isochrysidales thri...

Volcanic eruptions can cause abrupt changes in surrounding environments, but detailed sediment records of such changes are rare. The very high sediment accumulation rate in Lake Wudalianchi, a volcanic-dammed freshwater lake in northeastern China, provides an excellent opportunity for reconstructing volcanic-induced environmental change. Here we us...

Earth's climate system has experienced substantial millennial‐scale oscillations characterized by abrupt changes superimposed on orbital‐scale changes. However, the dynamic connection between millennial and orbital timescales remains elusive. Here, we provide a summer monsoon precipitation δ¹⁸O record spanning from ∼8 to ∼60.5 ka based on the oxyge...

Lakes in the permafrost zone have been proposed to serve as key outlets for methane and carbon dioxide emissions. However, there has been no geological record of the hydrological and biogeochemical responses of lakes throughout the thawing of surrounding permafrost. We use multiple biomarker and isotopic proxies to reconstruct hydrological and biog...

Available online xxx Handling Editor: P Rioual Keywords: Daye lake Water depth reconstruction Precipitation pattern Little ice age %Cren a b s t r a c t Alpine lakes are natural rain gauges, and reconstructing changes in their water level is a key to understanding the regional hydrological environment, climate change and vegetation evolution. Preci...

Reconstructing the environmental and hydrological response to millennial‐scale fluctuations of climate‐sensitive areas of mid‐latitudes is crucial to understanding the Late Pleistocene climate in terrestrial inland regions. We use sedimentological and geochemical proxies (e.g. lithology, gain size, loss‐on‐ignition, soluble salts, X‐ray fluorescenc...

Plain Language Summary Arid central Asia (ACA), one of the largest arid zones in the world, suffers from water resource scarcity, which impacts the regional ecosystems and human civilizations. Reconstructions of lake water salinity in ACA can provide valuable information on past overall hydroclimatic changes, which is of crucial importance for our...

Branched glycerol dialkyl glycerol tetraethers (brGDGTs) are potentially valuable biomarkers for paleoclimatic and paleoenvironmental studies. However, multiple factors controlling their variations in lake sediments hamper the widespread application of brGDGT-based proxies. Here we investigate brGDGTs in water column suspended particulate matter (S...

The TEX86 index, based on the distribution of isoprenoid glycerol dialkyl glycerol tetraethers (iGDGTs), has been widely applied for reconstructing past sea surface temperature (SST). However, its successful application in lacustrine environments has been limited to certain large lakes in which aquatic Thaumarchaeota are thought be the dominant iGD...

There have been numerous attempts to use long-chain alkenones (LCAs) in saline lakes for paleotemperature and paleosalinity reconstructions. However, LCAs in saline lakes are often produced by multiple haptophyte species, which may confound data interpretations. Here we analyzed LCAs in a finely laminated, high sedimentation rate core from the hype...

Pollen data are useful palaeoecological archives for understanding vegetation and associated climatic changes. In this paper we present new pollen data and other proxies (lithology, grain size, loss-on-ignition (LOIorg at 550 °C)) obtained from a sediment core (BLK11A) from Balikun Lake, north-west China, to explore the vegetation and climate histo...

Study of meteoritic organic compounds offers a unique opportunity to understand the origins of the organic matter in the early Solar System. Meteoritic polycyclic aromatic hydrocarbons (PAHs) and heteropolycyclic aromatic compounds (HACs) have been studied for over fifty years, however; their hydrogen stable isotopic ratios (δD) have never been rep...

Mechanism of arid central Asia climate dynamics is still an open question even it has been studied for a long time. Interpreting climatic proxy data properly is crucial for better understanding the paleoclimate in such a sensitive area and its role in the earth system. According to the analysis of water stable isotope (δ18O and δD), Lake Barkol cat...

Marine Isotope Stage (MIS) 2 is mostly a cold period encompassing the Last Glacial Maximum (LGM), but the regional expression of MIS2 in arid areas of China is not well known. In this paper, we use highresolution lacustrine pollen and grain-size records from Balikun Lake to infer vegetation, lake evolution, and climate in arid western China during...

The chain length of long chain alkenones (LCAs) in ocean and lake sediments commonly ranges from C37 to C39. Alkenones > C40 are extremely rare: C41 and C42 alkenones have only been reported in a Cretaceous black shale (Cenomanian, ca. 95 Ma) from the Blake Bahama Basin, western North Atlantic (DSDP Leg 76, site 534). The significance of these exce...

Surface and fossil pollen samples were collected to reconstruct the vegetation and environment since 30.7 cal ka BP in the Lake Balikun Basin, northwest China. This record demonstrates that the region was occupied by four vegetation communities during the interval 30.7–9.0 cal ka BP, including desert steppe (30.7–25.1 cal ka BP), Amaranthaceae-Aste...

27 samples were collected from a north-south transect in the Small Yourdusi Basin in the Central Tianshan Mountains, Xinjiang Region, in order to reveal the relationship between sporo-pollen and vegetation zones and the sporopollen sources in the Meitiane Lake in the basin. It is found that sporopollen assemblages are mainly constitute of Picea, Co...

Grain-size distributions and detrital minerals were investigated for modern dust and for lacustrine sediment in Lake Barkol region, northwest China. Characteristics of the modern dust and lacustrine sediments, principle component analysis, and changes of quartz contents all suggest grain size 45–138μm in the core sediment is the dust sensitive comp...

A sediment core from Lake Barkol located in the eastern Xinjiang autonomous region, northwest China, provided a high-resolution record of environmental change covering the last ~8.6 cal ka BP. Three major climate stages, 8.6–7.1, 7.1–2.0 and from 2.0 cal ka BP to the present, were divided by grain size and the authigenic carbonate stable isotope of...

A high-resolution record of Holocene environmental and climatic change in the Balikun area was reconstructed from a sediment core from the Lake Balikun. Multiproxy data show that the climate was extremely arid during the early Holocene (before 8.6 cal. ka BP). Moisture began to increase after 8.6 cal. ka BP and the climate was humid between 7.9 and...

A long dust history established using geological archives from dust provenance areas is necessary to understand the role of atmospheric dust in the global climate system better. Core sediments from a closed-basin groundwater-recharged lake in arid Central Asia were investigated using a multi-proxy approach (e.g. 14C AMS dating, pollen, and grain si...

A high-resolution fossil pollen record from the sedimentary cores of Balikun Lake, northwestern China, combined with modern surface pollen data, is used to reconstruct the history of vegetation and climatic change since 16.7 cal. ka BP. Fossil pollen assemblages and lithology indicate that the study area was dominated by desert. The desert had extr...