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Atmospheric Warming Slowdown during 1998-2013 Associated with Increasing Ocean Heat Content

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Advances in Atmospheric Sciences 2019年第11期36卷 1188-1202,I0006,I0007,I0008,I0009,I0010,I0011页

作者： changyu li Jianping HUANG Yongli HE Dongdong li Lei DING Key Laboratory for Semi-Arid Climate Change of the Ministry of Education College of Atmospheric SciencesLanzhou University

Although atmospheric greenhouse gas concentrations continuously increased, there was relatively little change in global-averaged surface temperatures from 1998 to 2013, which is known as atmospheric warming slowdown. For further understanding the mechanism involved, we explored the energy redistribution between the atmosphere and ocean in different latitudes and depths by using data analysis as well as simulations of a coupled atmosphere–ocean box model. The results revealed that, compared with observational changes of ocean heat content (OHC) associated with rapid warming, the OHC changes related to warming slowdown are relatively larger in multiple ocean basins, particularly in the deeper layer of the Atlantic. The coupled box model also showed that there is a larger increasing trend of OHC under the warming slowdown scenario than the rapid warming scenario. Particularly, during the warming slowdown period, the heat storage in the deeper ocean increases faster than the ocean heat uptake in the surface ocean. The simulations indicated that the warming patterns under the two scenarios are accompanied by distinct outgoing longwave radiation and atmospheric meridional heat transport, as well as other related processes, thus leading to different characteristics of ocean heat uptake. Due to the global energy balance, we suggest this slowdown has a tight relationship with the accelerated heat transport into the global ocean.

关键词： warming slowdown ocean heat content box model heat transport

The global oxygen budget and its future projection

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Science Bulletin 2018年第18期63卷 1180-1186页

作者： Jianping Huang Jiping Huang Xiaoyue liu changyu li Lei Ding Haipeng Yu Key Laboratory for Semi-Arid Climate Change of the Ministry of Education Lanzhou University Lanzhou 730000 China Enlightening Bioscience Research Center Mississauga L4X 2X7 Canada

Atmospheric oxygen （02） is the most crucial element on earth for the aerobic organisms that depend on it to release energy from carbon-based macromolecules. This is the first study to systematically analyze the global O2 budget and its changes over the past 100 years. It is found that anthropogenic fossil fuel combustion is the largest contributor to the current O2 deficit, which consumed 2.0 Gt/a in 1900 and has increased to 38.2 Gt/a by 2015. Under the Representative Concentration Pathways （RCPs） RCP8,5 scenario, approximately 100Gt （gigatonnes） of O2 would be removed from the atmosphere per year until 2100, and the O2 concentration will decrease from its current level of 20.946% to 20.825%. Human activities have caused irreversible decline of atmospheric O2. It is time to take actions to promote O2 production and reduce O2 consumption.

关键词： Atmospheric oxygen Oxygen decline Oxygen budget Oxygen concentration

Estimation of Gridded Atmospheric Oxygen Consumption from 1975 to 2018

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Journal of Meteorological Research 2020年第3期34卷 646-658页

作者： Xiaoyue liU Jianping HUANG Jiping HUANG changyu li Lei DING Wenjun MENG Collaborative Innovation Center for Western Ecological Safety Lanzhou UniversityLanzhou 730000China Enlightening Bioscience Research Center Mississauga L4X 2X7Canada Laboratory for Earth Surface Processes College of Urban and Environmental SciencesPeking UniversityBeijing 100871China

Atmospheric Oxygen(O2)is one of the dominating features that allow the earth to be a habitable planet with advanced civilization and diverse ***,since the late 1980 s,observational data have indicated a steady decline in O2 content on the scale of parts-per-million *** current scientific consensus is that the decline is caused by the fossil-fuel combustion;however,few works have been done to quantitatively evaluate the response of O2 cycle under the anthropogenic impact,at both the global and regional *** paper manages to quantify the land O2 flux and makes the initial step to quantificationally describe the anthropogenic impacts on the global O2 *** estimation reveals that the global O2 consumption has experienced an increase from 33.69±1.11 to47.63±0.80 Gt(gigaton,109 t)O2yr^-1 between 2000 and 2018,while the land production of O2(totaling 11.34±13.48 Gt O2yr^-1 averaged over the same period)increased only *** 2018,the combustion of fossil-fuel and industrial activities(38.45±0.61 Gt O2yr^-1)contributed the most to consumption,followed by wildfires(4.97±0.48 Gt O2yr^-1)as well as livestock and human respiration processes(2.48±0.16 and 1.73±0.13 Gt O2yr^-1,respectively).Burning of fossil-fuel that causes large O2 fluxes occurs in East Asia,India,North America,and Europe,while wildfires that cause large fluxes in comparable magnitude are mainly distributed in central Africa.

关键词： oxygen(O2)cycle climate change anthropogenic activities

Variations in terrestrial oxygen sources under climate change

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Science China Earth Sciences 2022年第9期65卷 1810-1823页

作者： Lei DING Jianping HUANG changyu li Dongliang HAN Xiaoyue liU Haiyun li Yan BAI Jiping HUANG College of Atmospheric Sciences Lanzhou UniversityLanzhou 730000China Collaborative Innovation Center for Western Ecological Safety Lanzhou UniversityLanzhou 730000China Enlightening Bioscience Research Center Mississauga L4X 2X7Canada

The terrestrial ecosystem is an important source of atmospheric oxygen, and its changes are closely related to variations in atmospheric oxygen level. However, few studies have focused on the characteristics and driving forces behind terrestrial ecosystem oxygen sources. In this study, based on observations and net carbon flux simulations from the Sixth Coupled Model Intercomparison Project, we investigated temporal and spatial variations in terrestrial oxygen sources. As the largest source of atmospheric oxygen, the terrestrial ecosystem can produce approximately 7.10±0.38 gigatons of oxygen per year, and the tropics are the main oxygen producing regions. Notably, there are many “non-oxygen-producing lands”, where the lands no longer provide oxygen to the atmosphere, located in the high latitudes and around the deserts of Central Asia. Long-term analysis reveals that anthropogenic activities and climate change are responsible for the variations in terrestrial oxygen sources owing to land-use changes and competing effects between net photosynthesis and heterotrophic respiration. By 2100, more oxygen will be produced from the low-middle latitudes, while the high latitudes will serve as a larger oxygen sink due to extreme land-use type changes and drastic increases in soil respiration. Through this study, we supplement the understanding of the modern oxygen cycle and help provide better estimates for future variations in atmospheric oxygen level.

关键词： Oxygen cycle Terrestrial ecosystem CMIP6 Anthropogenic forcing Climate change

The oxygen cycle and a habitable Earth

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Science China Earth Sciences 2021年第4期64卷 511-528页

作者： Jianping HUANG Xiaoyue liU Yongsheng HE Shuzhong SHEN Zengqian HOU Shuguang li changyu li lijie YAO Jiping HUANG Collaborative Innovation Center for Western Ecological Safety College of Atmospheric SciencesLanzhou UniversityLanzhou 730000China CAS Center for Excellence in Tibetan Plateau Earth Sciences Chinese Academy of Sciences.Beijing 100101China State Key Laboratory of Geological Processes and Mineral Resources China University of Geosciences(Beijing)Beijing 100083China School of Earth Sciences and Engineering Nanjing UniversityNanjing 210023China LPS Nanjing Institute of Geology and Paleontology and Center for Excellence in Life and PaleoenvironmentChinese Academy of SciencesNanjing 210008China National Science Foundation of China Beijing 100085China

As an important contributor to the habitability of our planet, the oxygen cycle is interconnected with the emergence and evolution of complex life and is also the basis to establish Earth system science. Investigating the global oxygen cycle provides valuable information on the evolution of the Earth system, the habitability of our planet in the geologic past, and the future of human life. Numerous investigations have expanded our knowledge of the oxygen cycle in the fields of geology,geochemistry, geobiology, and atmospheric science. However, these studies were conducted separately, which has led to onesided understandings of this critical scientific issue and an incomplete synthesis of the interactions between the different spheres of the Earth system. This review presents a five-sphere coupled model of the Earth system and clarifies the core position of the oxygen cycle in Earth system science. Based on previous research, this review comprehensively summarizes the evolution of the oxygen cycle in geological time, with a special focus on the Great Oxidation Event(GOE) and the mass extinctions, as well as the possible connections between the oxygen content and biological evolution. The possible links between the oxygen cycle and biodiversity in geologic history have profound implications for exploring the habitability of Earth in history and guiding the future of humanity. Since the Anthropocene, anthropogenic activities have gradually steered the Earth system away from its established trajectory and had a powerful impact on the oxygen cycle. The human-induced disturbance of the global oxygen cycle, if not controlled, could greatly reduce the habitability of our planet.

关键词： Oxygen cycle Habitable earth Mass extinction Anthropocene

The Variability of Air-sea O_(2)Flux in CMIP6:Implications for Estimating Terrestrial and Oceanic Carbon Sinks

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Advances in Atmospheric Sciences 2022年第8期39卷 1271-1284,I0024-I0026页

作者： changyu li Jianping HUANG Lei DING Yu REN linli AN Xiaoyue liU Jiping HUANG College of Atmospheric Sciences Lanzhou UniversityLanzhou 730000China Collaborative Innovation Center for Western Ecological Safety Lanzhou UniversityLanzhou 730000China Enlightening Bioscience Research Center MississaugaL4X 2X7Canada

The measurement of atmospheric O_(2)concentrations and related oxygen budget have been used to estimate terrestrial and oceanic carbon ***,a discrepancy remains in assessments of O_(2)exchange between ocean and atmosphere(***-sea O_(2)flux),which is one of the major contributors to uncertainties in the O_(2)-based estimations of the carbon ***,we explore the variability of air-sea O_(2)flux with the use of outputs from Coupled Model Intercomparison Project phase 6(CMIP6).The simulated air-sea O_(2)flux exhibits an obvious warming-induced upward trend(~1.49 Tmol yr−2)since the mid-1980s,accompanied by a strong decadal variability dominated by oceanic climate *** subsequently revise the O_(2)-based carbon uptakes in response to this changing air-sea O_(2)*** results show that,for the 1990−2000 period,the averaged net ocean and land sinks are 2.10±0.43 and 1.14±0.52 GtC yr−1 respectively,overall consistent with estimates derived by the Global Carbon Project(GCP).An enhanced carbon uptake is found in both land and ocean after year 2000,reflecting the modification of carbon cycle under human *** derived from CMIP5 simulations also investigated in the study allow for comparisons from which we can see the vital importance of oxygen dataset on carbon uptake estimations.

关键词： air-sea O_(2)flux carbon budget land and ocean carbon sinks CMIP6

Drag reduction and shear resistance properties of ionomer and hydrogen bond systems based on lauryl methacrylate

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Petroleum Science 2011年第3期8卷 357-364页

作者： Yu Ping li changyu Zhang Changqiao Chen Shiwei Fang Shu Sun Hui School of Chemistry and Chemical Engineering Shandong University Jinan 250061 China

Based on molecular dynamics simulation results, a lauryl methacrylate polymer with drag reduction and shear resistance properties was designed, and synthesized by emulsion polymerization using 2-vinyl pyridine and methyl methacrylate as the polar polymerization monomer. After ionization of lauryl methacrylate polymer, an ion-dipole interaction based drag reduction agent （DRA） was obtained. The existence of ion-dipole interaction was proven through characterization of the drag-reducing agent from its infrared （IR） spectrum. The pilot-scale reaction yield of the DRA under optimum conditions was investigated, and the drag reduction and shear resistance properties were measured. The results show that： l） The ion-dipole or hydrogen bonding interaction can form ladder-shaped chains, therefore the synthesized DRA has shear resistance properties; 2） The larger the molecular weight （MW） and more concentrated the distribution of MW, the better the drag reduction efficiency and the performance of the ionomer system was superior to that of the hydrogen bonding system; 3） With increasing shear frequency, the drag-reduction rates of both the DRAs decreased, and the drag reduction rate of the ionomer system decreased more slowly than of the corresponding hydrogen bonding system. From the point of view of drag reduction rate and shear resistance property, the ionomer system is more promising than the hydrogen bonding system

关键词： Molecular design ion-dipole interaction hydrogen bonding drag reduction rate shearresistance property

Establishing a predictive model for fast online determination of relative density and refractive index of e-cigarette liquids using near-infrared spectroscopy

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烟草科技 2018年第A1期51卷 71-76页

作者： ZHANG Jianqiang li Jingjing liU Weijuan li changyu WU Shujiao YANG Yanmei Ruvian Technology Ltd. No.1699 Haiyuan North Road Kunming 650000 China Yunnan Reascend Tobacco Technology(Group) Co. Ltd. No.1699 Haiyuan North Road Kunming 650000China

Relative density and refractive index are two fundamental physical properties of e?cigarette liquids to indicate their uniformity and batch *** parameters are mainly determined by a density meter and refractometer respectively,which is tedious and the analysis results are not readily available for massive measurements.A rapid determination of the two parameters is important for quality inspection and control of cigarette liquids,and a lot efforts have been devoted to establishing a predictive model for these *** this study,a novel near-infrared spectroscopy(NIR)combined with particle swarm optimization-support vector regression(PSO-SVR)algorithm was applied to build a prediction *** experimental results showed that comparing with the traditional partial least squares regression(PLSR)model and the principal component regression(PCR)model,the PSO?SVR model had superior prediction performance.

关键词： E-cigarette liquid Relative density Refractive index NIR PSO-SVR

Normalized transfer function for characterizing conversion efficiency and harmonic distortion of all-optical sampling

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Chinese Science Bulletin 2011年第15期56卷 1633-1636页

作者： ZHANG ShangJian liN changyu li Xuan ZOU ZhiTai liU Yong liU YongZhi State Key Laboratory of Electronic Thin Film and Integrated Devices School of Optoelectronic Information University of Electronic Science &Technology of China Chengdu 610054 China

A novel method for characterizing the nonlinearity of all-optical sampling is proposed based on the normalized transfer *** results demonstrate the effectiveness of our ***,an all-optical sampling experiment is performed to verify our *** simulation and experiment show consistency between our method and the *** method only requires normalization and polynomial fitting of the transfer curve,and enables direct expression of the nonlinearity with the coefficients of the normalized transfer function.

关键词：非线性特征传递函数谐波失真转换效率采样全光归一化仿真结果