Article
Agronomy
Jia Bai, Helin Zhang, Rui Sun, Xing Li, Jingfeng Xiao, Yan Wang
Summary: Previous studies have shown that GPP and SIF have a strong linear relationship and exhibit similar spatial and temporal patterns. However, their responses to the environment may differ. To investigate the impact of the dynamics in GPP-SIF relationship on GPP estimation, two GPP models were established. Considering the variations of GPP-SIF relationship can improve GPP simulation to a certain extent, but the performance of one model is not as good as the other due to associated uncertainties.
AGRICULTURAL AND FOREST METEOROLOGY
(2022)
Article
Green & Sustainable Science & Technology
Haixiang Si, Ruiyan Wang, Ruhao Wang, Zixuan He
Summary: This study proposes a random-forest-based downscaling method to improve the spatial resolution of GOME-2 SIF data from 0.5 degrees to 0.05 degrees. The downscaled SIF data shows good accuracy and represents the structural and physiological information of the SIF well. However, the accuracy of using MODIS to downscale the GOME-2 SIF data is low in areas with grassland land cover type, temperate grassland climate region, alpine vegetation climate region of Qinghai-Tibet Plateau, and regions with high altitude and complex terrain.
Article
Engineering, Multidisciplinary
Sanjeevi Pandiyan, C. Navaneethan, R. Vijayan, G. Gunasekaran, K. Y. Khan, Ya Guo
Summary: This study compared the response of satellite solar-induced chlorophyll fluorescence (SIF) with soil moisture, precipitation, standardized precipitation evapotranspiration index, and evapotranspiration to monitor drought stress on crop growth. The results demonstrate that satellite SIF provides deep insight for drought detection, with SPEI and ET showing higher sensitivity and more constant decline in response to drought compared to SM and PPT.
Article
Biodiversity Conservation
Anping Chen, Jiafu Mao, Daniel Ricciuto, Dan Lu, Jingfeng Xiao, Xing Li, Peter E. Thornton, Alan K. Knapp
Summary: The study found strong seasonal variations in the relationship between satellite-derived sun-induced chlorophyll fluorescence (SIF) and gross primary production (GPP) across the Northern Hemisphere (NH), with a hump-shaped pattern of GPP/SIF ratio over northern latitudes. The seasonal amplitude of the GPP/SIF ratio decreased from high latitudes to drylands and the tropics, with different vegetation types exhibiting varying seasonal trends. In most parts of the NH, the lowest GPP/SIF values were observed in October or September, while the highest values were seen in June and July, indicating a distinct seasonal dynamic influenced by temperature and precipitation.
GLOBAL CHANGE BIOLOGY
(2021)
Article
Environmental Sciences
Yu Bai, Shunlin Liang, Wenping Yuan
Summary: Global estimates of monthly gross primary production (GPP) from 2001 to 2017 were calculated using the global OCO-2-based SIF product (GOSIF) and auxiliary data. A machine learning model was used to integrate and calibrate satellite GPP products, resulting in highly accurate GPP estimates with validated spatial and seasonal variations on a global scale.
Article
Environmental Sciences
Chuanhua Li, Lixiao Peng, Min Zhou, Yufei Wei, Lihui Liu, Liangliang Li, Yunfan Liu, Tianbao Dou, Jiahao Chen, Xiaodong Wu
Summary: Drought has a strong and widespread impact on terrestrial ecosystem Gross Primary Productivity (GPP). This study compared different indicators and analyzed the response of GPP to drought. The results showed that Sun-induced Chlorophyll fluorescence (SIF) is the most sensitive indicator and GPP estimated based on SIF data is more accurate. The study helps to understand the response of GPP to drought and provides scientific information for drought prediction and ecosystem management.
Article
Environmental Sciences
Genghong Wu, Chongya Jiang, Hyungsuk Kimm, Sheng Wang, Carl Bernacchi, Caitlin E. Moore, Andy Suyker, Xi Yang, Troy Magney, Christian Frankenberg, Youngryel Ryu, Benjamin Dechant, Kaiyu Guan
Summary: Recent advances in remotely sensed solar-induced chlorophyll fluorescence (SIF) have provided an exciting and promising opportunity for estimating gross primary production (GPP). However, the seasonal differences between SIF and GPP can weaken their correlation. The seasonal patterns of leaf area index, leaf chlorophyll content, and leaf angle distribution may affect the peak timing of SIF and GPP as well as their seasonal relationship.
REMOTE SENSING OF ENVIRONMENT
(2022)
Article
Biodiversity Conservation
Shiliu Chen, Yuefei Huang, Guangqian Wang
Summary: The study demonstrates that spaceborne sun-induced chlorophyll fluorescence (SIF) can be a reliable indicator of GPP, successfully characterizing temporal dynamics and spatial extents of GPP anomalies during drought events and accurately estimating drought-induced GPP losses. SIF, with a stronger correlation to plant physiological changes induced by droughts compared to enhanced vegetation index, shows potential in vegetation drought monitoring.
ECOLOGICAL INDICATORS
(2021)
Article
Agronomy
Linsheng Wu, Xiaokang Zhang, Micol Rossini, Yunfei Wu, Zhaoying Zhang, Yongguang Zhang
Summary: This study investigated the effects of relative altitude and slope on woody plant diversity in wetland communities, using continuous monitoring of parameters such as slope, forest type, and temperature and humidity of the same population. The results showed that relative altitude and slope were important factors affecting woody plant diversity in wetlands, and the community structure and species composition of wetland woody plant communities varied significantly under different altitudes and slopes.
AGRICULTURAL AND FOREST METEOROLOGY
(2022)
Article
Agronomy
XiangFen Cheng, MeiJun Hu, Yu Zhou, Feng Wang, LinQi Liu, Yao Wang, Hui Huang, JinSong Zhang
Summary: Observing solar-induced chlorophyll fluorescence (SIF) signals on a spaceborne platform provides a new approach for estimating and monitoring the gross primary production (GPP) of terrestrial ecosystems at a regional scale. By combining continuous ground tower-based SIF signals with GPP, the mechanical connection between them in different ecosystems can be explored. The study focuses on exploring the relationship between SIF and GPP in two temperate deciduous broadleaf plantations based on ground observations. The results show a nonlinear relationship between SIF and GPP on a 30 min timescale, which transforms into a linear correlation with aggregation. With increasing SIF, GPP gradually saturates and even declines in cork oak.
AGRICULTURAL AND FOREST METEOROLOGY
(2022)
Article
Biodiversity Conservation
Yanan Wang, Yuan Sun, Yanan Chen, Chaoyang Wu, Changping Huang, Cheng Li, Xuguang Tang
Summary: There is a non-linear relationship between solar-induced fluorescence (SIF) and terrestrial gross primary production (GPP) in subtropical evergreen forests. SIF peaks earlier than GPP and the relationship is stronger on cloudy days but weakens as vapor pressure deficit (VPD) increases.
ECOLOGICAL INDICATORS
(2023)
Article
Environmental Sciences
Rui Cheng, Troy S. Magney, Erica L. Orcutt, Zoe Pierrat, Philipp Kohler, David R. Bowling, M. Syndonia Bret-Harte, Eugenie S. Euskirchen, Martin Jung, Hideki Kobayashi, Adrian Rocha, Oliver Sonnentag, Jochen Stutz, Sophia Walther, Donatella Zona, Christian Frankenberg
Summary: Photosynthesis of terrestrial ecosystems in the Arctic-Boreal region is crucial for the global carbon cycle. However, using solar-induced chlorophyll fluorescence (SIF) as a proxy for photosynthesis in high latitudes presents challenges due to unique plant species and land cover types, as well as complex terrain and sub-pixel land cover. This study evaluates the empirical relationships between SIF and gross primary production (GPP) in the Arctic-Boreal region, revealing specific issues that need to be considered for accurate estimation of GPP and dealing with model-data uncertainties.
ENVIRONMENTAL RESEARCH LETTERS
(2022)
Article
Environmental Sciences
Weina Duan, Xinjie Liu, Jidai Chen, Shanshan Du, Liangyun Liu, Xia Jing
Summary: The results of the study indicate that canopy red SIF and far-red SIF are strongly correlated with GPP, with red SIF being more consistent during seasonal variations and having greater potential for monitoring the gross primary productivity of alpine meadow ecosystems.
Article
Geosciences, Multidisciplinary
Luis Guanter, Cedric Bacour, Andreas Schneider, Ilse Aben, Tim A. van Kempen, Fabienne Maignan, Christian Retscher, Philipp Kohler, Christian Frankenberg, Joanna Joiner, Yongguang Zhang
Summary: This work introduces a global SIF dataset produced from TROPOMI measurements within the TROPOSIF project funded by the European Space Agency, covering the period between May 2018 and April 2021. The high quality and dense spatial and temporal sampling of TROPOMI data promise to improve the application of global SIF datasets in small or fragmented ecosystems.
EARTH SYSTEM SCIENCE DATA
(2021)
Article
Environmental Sciences
Ying Huang, Cheng Zhou, Minghui Du, Pengfei Wu, Lin Yuan, Jianwu Tang
Summary: This study demonstrates that the correlation between SIF760 and GPP improves with increasing time scale in different phenological stages, and the canopy structure plays a crucial role in explaining their relationship. Tidal inundation significantly suppresses the strength of the correlation between SIF760 and GPP.
REMOTE SENSING OF ENVIRONMENT
(2022)
Article
Environmental Sciences
Liming He, H. Peter White, Wenjun Chen
Summary: Mining operations in the Arctic can cause fugitive dust, which can affect nearby communities and lead to early snowmelt. This study analyzed a 21-year MODIS time series snow cover product and found that dust decreased snow albedo and resulted in changes in land-atmosphere interactions, hydrology, and socioeconomic activities in the Arctic. The study also showed that early snowmelt can rapidly change when additional factors are introduced.
Article
Plant Sciences
Mauricio Tejera-Nieves, Michael Abraha, Jiquan Chen, Stephen K. Hamilton, G. Philip Robertson, Berkley Walker James
Summary: Leaf photosynthesis of perennial grasses declines from early to late summer, and water availability is associated with this decline. Despite reduced water availability, the photosynthetic decline is similar in grasses with and without rainfall exclusion, suggesting water deficit is not the sole driver of the decline. Rhizome starch accumulation and sink activity likely explain the observed photosynthetic declines towards the end of the growing season.
FRONTIERS IN PLANT SCIENCE
(2023)
Article
Environmental Sciences
Pei Zhou, Yang Wang, Jane Liu, Linglin Xu, Xiang Chen, Likun Zhang
Summary: This study investigated the difference between global and regional aerosol models and their impact on satellite AOD retrieval. It found that aerosols can be classified into five types with different optical and physical parameters. The regional aerosol model performed better than the global model in simulating air pollution events and AOD.
ATMOSPHERIC ENVIRONMENT
(2023)
Article
Environmental Sciences
Yihong Liu, Jing M. Chen, Liming He, Rong Wang, Nicholas G. Smith, Trevor F. Keenan, Cheryl Rogers, Wenyu Li, Jiye Leng
Summary: This study proposes a refined data assimilation scheme to retrieve daily Vcmax using remotely sensed solar-induced chlorophyll fluorescence (SIF) and leaf chlorophyll content (LCC) data. The spatial distribution of Vcmax depends on the spatial distribution of biomes, along with air temperature and absorbed photosynthetically active radiation (APAR). Vcmax25, which is more closely related to the Rubisco content, also has considerable spatiotemporal variations.
REMOTE SENSING OF ENVIRONMENT
(2023)
Article
Environmental Sciences
Huimin Chen, Bingliang Zhuang, Jane Liu, Yinan Zhou, Yaxin Hu, Yang Chen, Yiman Gao, Wen Wei, Huijuan Lin, Shu Li, Tijian Wang, Min Xie, Mengmeng Li
Summary: Absorbing aerosols significantly influence tropospheric photochemistry and regional climate change. A quantification of the direct radiative effects of absorbing aerosols at major AERONET sites in East Asia and their impacts on near-surface photochemical processes was conducted using a radiation transfer model. The annual average aerosol optical depth (AOD) of sites in China, Korea, and Japan was 1.15, 1.02, and 0.94, respectively, with absorbing aerosol optical depth (AAOD) proportions of 8.61%, 6.69%, and 6.49%, respectively. The influence of absorbing aerosol on ultraviolet (UV) radiation was mainly observed in the UV-A band (315-400 nm). The reduction in annual mean near-surface J[NO2] (J[(OD)-D-1]) due to absorbing aerosols was 16.95% (22.42%), 9.61% (13.55%), and 9.63% (13.79%) for China, Korea, and Japan, respectively. In the Beijing-Tianjin-Hebei (BTH) and Yangtze River Delta (YRD) regions, the annual average AOD was 1.48 and 1.29, and the AAOD was 0.14 and 0.13, respectively. The solar radiative forcing caused by black carbon (BC)-dominated aerosols on the surface was -3.19 and -2.98 W m(-2) for BTH and YRD, accounting for around 40% of the total aerosol radiative forcing. The reduction efficiency of BC-dominated aerosols on solar radiation was higher than that of other types of aerosols. The annual mean J[NO2] (J[(OD)-D-1]) decreased by 14.90% (20.53%) and 13.71% (18.20%) due to BC-dominated aerosols. The daily maximum photolysis rate usually occurred near noon due to the diurnal variation of solar zenith angle, resulting in a daily average photolysis rate decrease of 2-3% during 10:00-14:00.
Article
Environmental Sciences
Jihua Pan, Jane Liu, Mengmiao Yang, Rong Wang
Summary: Carbon-water (C-W) relationships vary across different time scales, vegetation types, and regions. This study investigated the C-W relationships in two subtropical forests in China during summer and found that daily water use efficiency (WUE) differed between the two forests, while the correlation coefficient (r) of hourly C-W coupling was similar. Both WUE and r were influenced by meteorological conditions, with vapor pressure deficit (VPD) playing a significant role.
Article
Multidisciplinary Sciences
Zhaoying Zhang, Alessandro Cescatti, Ying-Ping Wang, Pierre Gentine, Jingfeng Xiao, Luis Guanter, Alfredo R. Huete, Jin Wu, Jing M. Chen, Weimin Ju, Josep Penuelas, Yongguang Zhang
Summary: Photosynthesis and evapotranspiration in Amazonian forests have significant impacts on global carbon and water cycles. However, their diurnal patterns and responses to atmospheric warming and drying at regional scale are still not well understood. Using proxies from the International Space Station, we found a significant decrease in afternoon photosynthesis and evapotranspiration during the dry season, while morning photosynthesis showed a positive response to vapor pressure deficit (VPD) and afternoon photosynthesis showed a negative response. Furthermore, we projected that the decrease in afternoon photosynthesis will be compensated by an increase in the morning in future dry seasons. These findings provide new insights into the complex interplay between climate and carbon and water fluxes in Amazonian forests and improve the reliability of future projections.
Article
Agronomy
Mengmiao Yang, Jane Liu, Yong Wang, Jing M. Chen, Zeyu Cui, Zhanjie Zhang, Zhixiong Chen, Xugeng Cheng
Summary: Rainfall variations on a diurnal scale have significant impacts on ecosystem evapotranspiration and gross primary productivity. More daytime rainfall, especially occurring around noon, leads to decreased daily total evapotranspiration and gross primary productivity, while more unevenly distributed rainfall away from noon results in increased daily total evapotranspiration and gross primary productivity. Consideration of diurnal rainfall variations in observations and models is crucial for improving our understanding of atmosphere-biosphere interactions.
AGRICULTURAL AND FOREST METEOROLOGY
(2023)
Article
Environmental Sciences
Yongxian Su, Chaoqun Zhang, Philippe Ciais, Zhenzhong Zeng, Alessandro Cescatti, Jiali Shang, Jing Ming Chen, Jane Liu, Ying-Ping Wang, Wenping Yuan, Shushi Peng, Xuhui Lee, Zaichun Zhu, Lei Fan, Xiaoping Liu, Liyang Liu, Raffaele Lafortezza, Yan Li, Jiashun Ren, Xueqin Yang, Xiuzhi Chen
Summary: Changes in tree cover can affect surface temperatures due to asymmetric direct biophysical effects. The cooling effect of tree cover gain is greater in magnitude than the warming effect of tree cover loss in most forests. Neglecting this asymmetric temperature effect of fine-scale tree cover change ignores the fact that biophysical feedbacks continue to cause surface temperature changes even under net-zero tree cover changes. Thus, it is necessary to account for gross, rather than net, tree cover changes when quantifying the biophysical effects of forests.
NATURE CLIMATE CHANGE
(2023)
Article
Meteorology & Atmospheric Sciences
Xiaokang Chen, Min Wang, Tai-Long He, Zhe Jiang, Yuqiang Zhang, Li Zhou, Jane Liu, Hong Liao, Helen Worden, Dylan Jones, Dongyang Chen, Qinwen Tan, Yanan Shen
Summary: Urban air pollution continues to pose a significant health threat, despite regulations to control emissions. Comparative analysis of ozone responses to nitrogen oxide changes in China and the US reveals that data-based methods can accurately simulate urban air quality, with variations in O-3 responses across different regions.
JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES
(2023)
Article
Environmental Sciences
Xinyao Xie, Jing M. Chen, Wenping Yuan, Xiaobin Guan, Huaan Jin, Jiye Leng
Summary: Vegetation in mountainous areas contributes significantly to global gross primary productivity (GPP), but the effects of topography on radiation and water redistributions have been overlooked in existing global GPP data sets. This study developed a topographical correction index (TCI) based on simulated soil water redistribution, radiation redistribution, and redistribution of climate factors, and applied it to four GPP data sets. Results showed that integrating topography-induced interactions improved the accuracy of GPP estimation, with reduced mean-bias-error (MBE) and Root-Mean-Square-Error (RMSE). This study highlights the importance of considering topographical effects in GPP estimation to understand carbon budgets in mountain ecosystems.
JOURNAL OF GEOPHYSICAL RESEARCH-BIOGEOSCIENCES
(2023)
Article
Meteorology & Atmospheric Sciences
Zhixiong Chen, Jane Liu, Xugeng Cheng, Mengmiao Yang, Lei Shu
Summary: During the COVID-19 lockdown period in northern China, there was an unexpected increase in surface ozone despite vigorous emission reduction. A stratospheric intrusion event occurred during this period, contributing to up to 45% of the surface ozone over northern China. This event could explain up to 18% of the ozone increase in some cities and 5-10% over larger affected areas. Considering the nonnegligible stratospheric influences, natural ozone sources should be taken into account when analyzing the role of emission reduction and meteorological conditions during lockdown periods.
NPJ CLIMATE AND ATMOSPHERIC SCIENCE
(2023)
Article
Environmental Sciences
Danyang Ma, Tijian Wang, Hao Wu, Yawei Qu, Jian Liu, Jane Liu, Shu Li, Bingliang Zhuang, Mengmeng Li, Min Xie
Summary: Despite the implementation of the Clean Air Action Plan, increasing surface ozone (O-3) concentrations remain a significant environmental concern in China. This study used an improved regional climate-chemistry-ecology model to investigate the impact of anthropogenic emissions, meteorological factors, and CO2 changes on O-3 levels in China from 2008 to 2018. The results showed that anthropogenic emissions were the primary contributor to O-3 increase, but meteorological conditions and CO2 changes also played important roles.
ATMOSPHERIC CHEMISTRY AND PHYSICS
(2023)
Article
Environmental Sciences
Guoqiang Xu, Shizuo Fu, Jane Liu, Rong Shang, Yuanyuan Luo
Summary: This study investigates the effects of mountainous terrains on shallow convective clouds (SCCs) using Landsat-8 satellite data. The cloud size distributions (CSDs) are found to be described by double power laws controlled by two parameters. The number and size of clouds increase with elevation.
