Pub Date : 2024-09-15DOI: 10.1088/1748-9326/ad7043
Tonghui Huang, Rui Xia, Kai Zhang, Yan Chen, Yuanxin Ren, Jinxi Song, Yao Wang and Chengjian Liu
River eutrophication is difficult to diagnose and estimate quantitatively because of its complex degradation mechanism in large river systems. Conventional monitoring and modeling methods are limited to accurately revealing the evolution process and trends of river aquatic organisms. In the present study, based on HJ-1A/1B CCD sensor, combined with genetic algorithm (GA) and regression tree (GART), a remote sensing inversion prediction model was established; the model can estimate algal blooms in the Han River affected by China’s Middle Route of the South-to-North Water Diversion Project (SNWTP). During the outbreak of algal blooms, the near-infrared band reflectance evidently increased between 2009 and 2015, with increasing algal density. The algal density in the downstream of the Han River has a nearly synchronous positive change with the reflectance in the B4 (near-infrared) band and a nearly synchronous reverse change with the B1 (blue) band. B1 and B4 screened by GA reduced redundancy by 14%, leading to a good prediction performance (R2 = 0.88). According to GART and partial dependence analysis, the B4 band is a crucial characterization factor of algal blooms in the Han River. When the remote sensing band was in the range of B1 ⩾ 0.085 and B4 ⩽ 0.101, the algal density was lower than 0.15 × 107 cells l−1, indicating no algal bloom in the downstream of the Han River. When B4 was >0.103 and B1 ⩽ 0.076, algal density was higher than 1 × 107 cells l−1 and algal blooms were very likely to occur. These findings could provide a scientific reference for diagnosing and predicting large-scale water ecological degradation in similar watersheds.
{"title":"River algal blooms can be estimated by remote sensing reflectance","authors":"Tonghui Huang, Rui Xia, Kai Zhang, Yan Chen, Yuanxin Ren, Jinxi Song, Yao Wang and Chengjian Liu","doi":"10.1088/1748-9326/ad7043","DOIUrl":"https://doi.org/10.1088/1748-9326/ad7043","url":null,"abstract":"River eutrophication is difficult to diagnose and estimate quantitatively because of its complex degradation mechanism in large river systems. Conventional monitoring and modeling methods are limited to accurately revealing the evolution process and trends of river aquatic organisms. In the present study, based on HJ-1A/1B CCD sensor, combined with genetic algorithm (GA) and regression tree (GART), a remote sensing inversion prediction model was established; the model can estimate algal blooms in the Han River affected by China’s Middle Route of the South-to-North Water Diversion Project (SNWTP). During the outbreak of algal blooms, the near-infrared band reflectance evidently increased between 2009 and 2015, with increasing algal density. The algal density in the downstream of the Han River has a nearly synchronous positive change with the reflectance in the B4 (near-infrared) band and a nearly synchronous reverse change with the B1 (blue) band. B1 and B4 screened by GA reduced redundancy by 14%, leading to a good prediction performance (R2 = 0.88). According to GART and partial dependence analysis, the B4 band is a crucial characterization factor of algal blooms in the Han River. When the remote sensing band was in the range of B1 ⩾ 0.085 and B4 ⩽ 0.101, the algal density was lower than 0.15 × 107 cells l−1, indicating no algal bloom in the downstream of the Han River. When B4 was >0.103 and B1 ⩽ 0.076, algal density was higher than 1 × 107 cells l−1 and algal blooms were very likely to occur. These findings could provide a scientific reference for diagnosing and predicting large-scale water ecological degradation in similar watersheds.","PeriodicalId":11747,"journal":{"name":"Environmental Research Letters","volume":"102 1","pages":""},"PeriodicalIF":6.7,"publicationDate":"2024-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142257282","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-15DOI: 10.1088/1748-9326/ad7744
Mohammed Basheer, Khalid Siddig, Zuhal Elnour, Mosab Ahmed and Claudia Ringler
The Grand Ethiopian Renaissance Dam (GERD) on the Nile is expected to influence many ecosystem services, such as flood regulation, hydro-electricity production, food supply, and habitat provision, among others. Understanding these impacts (positive and negative) requires a comprehensive evaluation framework. This study develops and applies an integrated simulation framework for assessing the impacts of the GERD on Sudan, focusing on the simultaneous economywide effects of riverine flood hazards, irrigation water supply, hydropower generation, and floodplain-dependent industries, namely traditional fired clay brick production. The simulation framework incorporates three models: a river infrastructure system model, a flood model, and a Computable General Equilibrium Model. Results indicate positive impacts for hydropower generation and flood control, marginal benefits for water supply to existing irrigation, and negative consequences for brick production and the construction sector. Assuming that the GERD starts its long-term operation in 2025, we find an overall positive economic impact on Sudan’s Gross Domestic Product in 2025, with an increase of up to just over 0.1%, subject to river flow conditions. Recognizing the differences in impacts across sectors and income groups, the study emphasizes the need for interventions that ameliorate negative effects. While the study captures several impacts, other effects on the environment, recession agriculture, and soil fertility require further investigation. Still, our findings underscore the importance of adopting an integrated simulation approach to dam evaluation, acknowledging the interconnected nature of water and related sectors in national economies.
{"title":"Toward integrated dam assessment: evaluating multi-dimensional impacts of the Grand Ethiopian Renaissance Dam on Sudan","authors":"Mohammed Basheer, Khalid Siddig, Zuhal Elnour, Mosab Ahmed and Claudia Ringler","doi":"10.1088/1748-9326/ad7744","DOIUrl":"https://doi.org/10.1088/1748-9326/ad7744","url":null,"abstract":"The Grand Ethiopian Renaissance Dam (GERD) on the Nile is expected to influence many ecosystem services, such as flood regulation, hydro-electricity production, food supply, and habitat provision, among others. Understanding these impacts (positive and negative) requires a comprehensive evaluation framework. This study develops and applies an integrated simulation framework for assessing the impacts of the GERD on Sudan, focusing on the simultaneous economywide effects of riverine flood hazards, irrigation water supply, hydropower generation, and floodplain-dependent industries, namely traditional fired clay brick production. The simulation framework incorporates three models: a river infrastructure system model, a flood model, and a Computable General Equilibrium Model. Results indicate positive impacts for hydropower generation and flood control, marginal benefits for water supply to existing irrigation, and negative consequences for brick production and the construction sector. Assuming that the GERD starts its long-term operation in 2025, we find an overall positive economic impact on Sudan’s Gross Domestic Product in 2025, with an increase of up to just over 0.1%, subject to river flow conditions. Recognizing the differences in impacts across sectors and income groups, the study emphasizes the need for interventions that ameliorate negative effects. While the study captures several impacts, other effects on the environment, recession agriculture, and soil fertility require further investigation. Still, our findings underscore the importance of adopting an integrated simulation approach to dam evaluation, acknowledging the interconnected nature of water and related sectors in national economies.","PeriodicalId":11747,"journal":{"name":"Environmental Research Letters","volume":"31 1","pages":""},"PeriodicalIF":6.7,"publicationDate":"2024-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142257278","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-12DOI: 10.1088/1748-9326/ad747b
Vivek Vivek, Tapan Kar, Sesha Meka and Deepak Malghan
Marginal pricing has long been the instrument of choice to address water conservation challenges. More recently, non-price behavioral interventions have emerged as an alternative. However, there is limited data on the relative efficacies of price and non-price interventions. We report results from long-term field experiments studying unit-level water conservation responses to both price and non-price interventions in the same group of households (n = 64 186 household-days). Conservation habits, attitude-action gaps, principal-agent incongruities, and billing cycles help account for the heterogeneity in response between households, and across time. A non-price behavior modification intervention before the introduction of marginal pricing resulted in a large and significant effect on treated households (33%). The subsequent introduction of marginal volumetric pricing also reduced water use (8%, for previously untreated households). However, this average price effect masks how a large share (21%) of households increased water use, or how a mere 12% of the households accounted for all the aggregate reduction in water use. We investigated such heterogeneous responses as a systematic conservation maximization design question beyond statistical variance in individual responses. We used daily water consumption measurements across three years alongside a household survey to delineate structural and agentic barriers to conservation behavior. Our analysis reveals how combining price and non-price behavioral interventions could hold the key to achieving conservation effects that are both large and persistent.
{"title":"Combining price and non-price interventions for water conservation","authors":"Vivek Vivek, Tapan Kar, Sesha Meka and Deepak Malghan","doi":"10.1088/1748-9326/ad747b","DOIUrl":"https://doi.org/10.1088/1748-9326/ad747b","url":null,"abstract":"Marginal pricing has long been the instrument of choice to address water conservation challenges. More recently, non-price behavioral interventions have emerged as an alternative. However, there is limited data on the relative efficacies of price and non-price interventions. We report results from long-term field experiments studying unit-level water conservation responses to both price and non-price interventions in the same group of households (n = 64 186 household-days). Conservation habits, attitude-action gaps, principal-agent incongruities, and billing cycles help account for the heterogeneity in response between households, and across time. A non-price behavior modification intervention before the introduction of marginal pricing resulted in a large and significant effect on treated households (33%). The subsequent introduction of marginal volumetric pricing also reduced water use (8%, for previously untreated households). However, this average price effect masks how a large share (21%) of households increased water use, or how a mere 12% of the households accounted for all the aggregate reduction in water use. We investigated such heterogeneous responses as a systematic conservation maximization design question beyond statistical variance in individual responses. We used daily water consumption measurements across three years alongside a household survey to delineate structural and agentic barriers to conservation behavior. Our analysis reveals how combining price and non-price behavioral interventions could hold the key to achieving conservation effects that are both large and persistent.","PeriodicalId":11747,"journal":{"name":"Environmental Research Letters","volume":"24 1","pages":""},"PeriodicalIF":6.7,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142213449","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
As urbanization exposes wildlife to new challenging conditions and environmental pressures, species that exhibit a high degree of behavioral plasticity are considered potentially capable of colonizing and adapting to urban environments. However, differences in the behavior of populations that inhabit urban and suburban landscapes pose unprecedented challenges to traditional methods in wildlife management which often fail to consider a species’ needs or mitigate human–wildlife conflict due to changes in species behavior in response to intensive human interference. Here, we investigate differences in the home range, diel activity, movement, and diet of raccoon dogs (Nyctereutes procyonoides) between residential districts and forest park habitats in Shanghai, China. Using GPS tracking data from 22 individuals, we find that the home ranges of raccoon dogs in residential districts (10.4 ± 8.8 ha) was 91.26% smaller than those in forest parks (119.6 ± 135.4 ha). We also find that raccoon dogs in residential districts exhibited significantly lower nocturnal movement speeds (134.55 ± 50.68 m h−1) compared to their forest park counterparts (263.22 ± 84.972 m h−1). An analysis of 528 fecal samples showed a significantly higher intake of ingredients from human food in residential districts (χ2 = 4.691, P = 0.026), which indicates that urban raccoon dog foraging strategies differ from the forest park population due to the presence of discarded human food, cat food, and wet garbage in residential districts. Based on our findings, we propose a community-based wildlife management strategy and suggest modifying the current design of residential districts. Our results underscore the importance of mammal behavior studies in urban biodiversity management and provide a scientific basis for mitigating human–wildlife conflicts in urban environments in and beyond our study area.
由于城市化使野生动物面临新的挑战条件和环境压力，那些表现出高度行为可塑性的物种被认为有可能在城市中定居并适应城市环境。然而，栖息在城市和郊区景观中的种群行为差异给野生动物管理的传统方法带来了前所未有的挑战，因为传统方法往往无法考虑物种的需求，也无法缓解物种行为因人类的密集干预而发生变化所导致的人类与野生动物之间的冲突。在这里，我们研究了中国上海居民区和森林公园栖息地之间貉犬（Nyctereutes procyonoides）在家庭活动范围、日间活动、运动和饮食方面的差异。通过对22只貉的GPS追踪数据进行分析，我们发现住宅区貉的活动范围（10.4 ± 8.8公顷）比森林公园貉的活动范围（119.6 ± 135.4公顷）小91.26%。我们还发现，住宅区的浣熊犬夜间移动速度（134.55 ± 50.68 m h-1）明显低于森林公园的浣熊犬（263.22 ± 84.972 m h-1）。对528份粪便样本的分析表明，住宅区的浣熊从人类食物中摄取的成分显著较高(χ2 = 4.691, P = 0.026)，这表明城市浣熊犬的觅食策略与森林公园种群不同，因为住宅区存在废弃的人类食物、猫食和湿垃圾。根据我们的研究结果，我们提出了以社区为基础的野生动物管理策略，并建议修改目前的住宅区设计。我们的研究结果强调了哺乳动物行为研究在城市生物多样性管理中的重要性，并为缓解研究区域内外城市环境中的人类与野生动物冲突提供了科学依据。
{"title":"Behavioral plasticity of raccoon dogs (Nyctereutes procyonoides) provides new insights for urban wildlife management in metropolis Shanghai, China","authors":"Yihan Wang, Qianqian Zhao, Lishan Tang, Weiming Lin, Zhuojin Zhang, Yixin Diao, Yue Weng, Bojian Gu, Yidi Feng, Qing Zhao and Fang Wang","doi":"10.1088/1748-9326/ad7309","DOIUrl":"https://doi.org/10.1088/1748-9326/ad7309","url":null,"abstract":"As urbanization exposes wildlife to new challenging conditions and environmental pressures, species that exhibit a high degree of behavioral plasticity are considered potentially capable of colonizing and adapting to urban environments. However, differences in the behavior of populations that inhabit urban and suburban landscapes pose unprecedented challenges to traditional methods in wildlife management which often fail to consider a species’ needs or mitigate human–wildlife conflict due to changes in species behavior in response to intensive human interference. Here, we investigate differences in the home range, diel activity, movement, and diet of raccoon dogs (Nyctereutes procyonoides) between residential districts and forest park habitats in Shanghai, China. Using GPS tracking data from 22 individuals, we find that the home ranges of raccoon dogs in residential districts (10.4 ± 8.8 ha) was 91.26% smaller than those in forest parks (119.6 ± 135.4 ha). We also find that raccoon dogs in residential districts exhibited significantly lower nocturnal movement speeds (134.55 ± 50.68 m h−1) compared to their forest park counterparts (263.22 ± 84.972 m h−1). An analysis of 528 fecal samples showed a significantly higher intake of ingredients from human food in residential districts (χ2 = 4.691, P = 0.026), which indicates that urban raccoon dog foraging strategies differ from the forest park population due to the presence of discarded human food, cat food, and wet garbage in residential districts. Based on our findings, we propose a community-based wildlife management strategy and suggest modifying the current design of residential districts. Our results underscore the importance of mammal behavior studies in urban biodiversity management and provide a scientific basis for mitigating human–wildlife conflicts in urban environments in and beyond our study area.","PeriodicalId":11747,"journal":{"name":"Environmental Research Letters","volume":"8 1","pages":""},"PeriodicalIF":6.7,"publicationDate":"2024-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142213451","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
As one of the most densely populated and economically developed regions in China, Yangtze River Delta (YRD) has confronted with substantial land cover change (LCC) over the past several decades. This study investigates the impact of climate change and LCC on carbon dynamics in the YRD region for 1990–2019, taking advantage of a high-resolution vegetation model and two well-established LCC data in China. Simulated gross primary productivity increases from 0.52 ± 0.02 Pg[C] yr−1 in the 1990s to 0.57 ± 0.01 Pg[C] yr−1 in the 2010s with the major contribution by CO2 fertilization effect. The regional carbon sink, measured as net biospheric productivity (NBP), peaks at 0.03 Pg[C] yr−1 in the 2000s but remains stable or slightly decreases in the 2010s depending on the LCC datasets. Forests act as the main contributors to the enhancement of the regional carbon sink, with negative contributions from the loss of shrubland and grassland. The stable NBP during 2000–2019 suggests a potential slowdown in the efficacy of carbon sink as forests mature. While forest expansion significantly promotes NBP, the carbon released during the replacement of other vegetation types suggests that afforestation efforts need to be complemented with associated supportive measures to prevent newly forested areas from becoming net carbon sources.
{"title":"The effect of afforestation on a regional carbon sink: a case study in the Yangtze River Delta, China","authors":"Yuan Zhao, Xu Yue, Hao Zhou, Zhen Yu and Wenping Yuan","doi":"10.1088/1748-9326/ad6e08","DOIUrl":"https://doi.org/10.1088/1748-9326/ad6e08","url":null,"abstract":"As one of the most densely populated and economically developed regions in China, Yangtze River Delta (YRD) has confronted with substantial land cover change (LCC) over the past several decades. This study investigates the impact of climate change and LCC on carbon dynamics in the YRD region for 1990–2019, taking advantage of a high-resolution vegetation model and two well-established LCC data in China. Simulated gross primary productivity increases from 0.52 ± 0.02 Pg[C] yr−1 in the 1990s to 0.57 ± 0.01 Pg[C] yr−1 in the 2010s with the major contribution by CO2 fertilization effect. The regional carbon sink, measured as net biospheric productivity (NBP), peaks at 0.03 Pg[C] yr−1 in the 2000s but remains stable or slightly decreases in the 2010s depending on the LCC datasets. Forests act as the main contributors to the enhancement of the regional carbon sink, with negative contributions from the loss of shrubland and grassland. The stable NBP during 2000–2019 suggests a potential slowdown in the efficacy of carbon sink as forests mature. While forest expansion significantly promotes NBP, the carbon released during the replacement of other vegetation types suggests that afforestation efforts need to be complemented with associated supportive measures to prevent newly forested areas from becoming net carbon sources.","PeriodicalId":11747,"journal":{"name":"Environmental Research Letters","volume":"275 1","pages":""},"PeriodicalIF":6.7,"publicationDate":"2024-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142213450","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-11DOI: 10.1088/1748-9326/ad7745
Yuhang Zheng, Wei Wu, Minyang Wang, Yuhong Zhang and Yan Du
Near-inertial oscillations (NIOs) are widely observed dynamic motions in the global ocean, with a frequency related to earth’s rotation. Using a particle trajectory model, we found the combined influence of mesoscale eddies and NIOs could produce distinctive flower-like trajectories, which are a special case of near-inertial trajectories and were observed by surface drifters released within an anticyclone eddy in the South China Sea in 2021. The energy budget indicates that wind and geostrophic eddy currents are crucial in generating near-inertial energy during the flower-like trajectories. Furthermore, the particle trajectory model revealed variations in periods and widths of the near-inertial trajectory with latitudes. The width of near-inertial trajectories can exceed 8 km in the near-equatorial region and reach 3–6 km in the mid-latitude region (20°–50°). The ratios of near-inertial velocity to background velocity, defined as near-inertial trajectory shape index (NITSIs), lead to arc-shaped (0.5 < NITSI < 1.0), overlapping semi-circular (NITSI > 1.0), and near-circular trajectories (NITSI ≫ 1.0). Globally, approximately 1/3 of the drifters’ lifespan featured clear near-inertial trajectories, with a significant presence in most middle latitudes and the largest NITSI in the north Pacific westerly. These findings highlight the importance of NIOs and suggest their substantial impact on local surface matter distribution, trajectory prediction, and marine rescue operations.
{"title":"Different trajectory patterns of ocean surface drifters modulated by near-inertial oscillations","authors":"Yuhang Zheng, Wei Wu, Minyang Wang, Yuhong Zhang and Yan Du","doi":"10.1088/1748-9326/ad7745","DOIUrl":"https://doi.org/10.1088/1748-9326/ad7745","url":null,"abstract":"Near-inertial oscillations (NIOs) are widely observed dynamic motions in the global ocean, with a frequency related to earth’s rotation. Using a particle trajectory model, we found the combined influence of mesoscale eddies and NIOs could produce distinctive flower-like trajectories, which are a special case of near-inertial trajectories and were observed by surface drifters released within an anticyclone eddy in the South China Sea in 2021. The energy budget indicates that wind and geostrophic eddy currents are crucial in generating near-inertial energy during the flower-like trajectories. Furthermore, the particle trajectory model revealed variations in periods and widths of the near-inertial trajectory with latitudes. The width of near-inertial trajectories can exceed 8 km in the near-equatorial region and reach 3–6 km in the mid-latitude region (20°–50°). The ratios of near-inertial velocity to background velocity, defined as near-inertial trajectory shape index (NITSIs), lead to arc-shaped (0.5 < NITSI < 1.0), overlapping semi-circular (NITSI > 1.0), and near-circular trajectories (NITSI ≫ 1.0). Globally, approximately 1/3 of the drifters’ lifespan featured clear near-inertial trajectories, with a significant presence in most middle latitudes and the largest NITSI in the north Pacific westerly. These findings highlight the importance of NIOs and suggest their substantial impact on local surface matter distribution, trajectory prediction, and marine rescue operations.","PeriodicalId":11747,"journal":{"name":"Environmental Research Letters","volume":"94 1","pages":""},"PeriodicalIF":6.7,"publicationDate":"2024-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142213461","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-09DOI: 10.1088/1748-9326/ad747a
Jan Kretzschmar, Mira Pöhlker, Frank Stratmann, Heike Wex, Christian Wirth, Johannes Quaas
The ability of pollen to enable the glaciation of supercooled liquid water has been demonstrated in laboratory studies; however, the potential large-scale effect of plants and pollen on clouds, precipitation and climate is pressing knowledge to better understand and project clouds in the current and future climate. Combining ground-based measurements of pollen concentrations and satellite observations of cloud properties within the United States, we show that enhanced pollen concentrations during springtime lead to an increase in cloud ice fraction of up to 0.1 in the temperature regime where pollen are considered to act as INP (−15∘C and −25∘C ). We further establish the link from the pollen-induced increase in cloud ice to a higher precipitation frequency. In light of anthropogenic climate change, the extended and strengthened pollen season and future alterations in biodiversity can introduce a localized climate forcing and a modification of the precipitation frequency and intensity.
{"title":"From trees to rain: enhancement of cloud glaciation and precipitation by pollen","authors":"Jan Kretzschmar, Mira Pöhlker, Frank Stratmann, Heike Wex, Christian Wirth, Johannes Quaas","doi":"10.1088/1748-9326/ad747a","DOIUrl":"https://doi.org/10.1088/1748-9326/ad747a","url":null,"abstract":"The ability of pollen to enable the glaciation of supercooled liquid water has been demonstrated in laboratory studies; however, the potential large-scale effect of plants and pollen on clouds, precipitation and climate is pressing knowledge to better understand and project clouds in the current and future climate. Combining ground-based measurements of pollen concentrations and satellite observations of cloud properties within the United States, we show that enhanced pollen concentrations during springtime lead to an increase in cloud ice fraction of up to 0.1 in the temperature regime where pollen are considered to act as INP (−15<inline-formula>\u0000<tex-math><?CDATA $,^circ$?></tex-math><mml:math overflow=\"scroll\"><mml:mrow><mml:msup><mml:mstyle scriptlevel=\"0\"></mml:mstyle><mml:mo>∘</mml:mo></mml:msup></mml:mrow></mml:math><inline-graphic xlink:href=\"erlad747aieqn1.gif\"></inline-graphic></inline-formula>C and −25<inline-formula>\u0000<tex-math><?CDATA $,^circ$?></tex-math><mml:math overflow=\"scroll\"><mml:mrow><mml:msup><mml:mstyle scriptlevel=\"0\"></mml:mstyle><mml:mo>∘</mml:mo></mml:msup></mml:mrow></mml:math><inline-graphic xlink:href=\"erlad747aieqn2.gif\"></inline-graphic></inline-formula>C ). We further establish the link from the pollen-induced increase in cloud ice to a higher precipitation frequency. In light of anthropogenic climate change, the extended and strengthened pollen season and future alterations in biodiversity can introduce a localized climate forcing and a modification of the precipitation frequency and intensity.","PeriodicalId":11747,"journal":{"name":"Environmental Research Letters","volume":"21 1","pages":""},"PeriodicalIF":6.7,"publicationDate":"2024-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142213502","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Forecasting the Indian Ocean Dipole (IOD) is crucial because of its significant impact on regional and global climates. While traditional dynamic and empirical models suffer from systematic errors due to nonlinear processes, convolutional neural networks (CNN) are nonlinear in nature and have demonstrated remarkable El Niño Southern Oscillation (ENSO) and IOD forecasting skills based on oceanic predictors, particularly sea surface temperature and heat content. However, it is difficult to measure heat content and easily introduces uncertainties, prompting the need to explore atmospheric predictors for IOD forecasts. Based on sensitivity prediction experiments, we identified the sea level pressure (SLP) signal as a crucial predictor, which forecasts IOD at a 7 month lead. In addition, the CNN model improves monthly forecasting accuracy while reducing errors by 13.43%. Utilizing the heatmap analysis, we elucidated that the multi-seasonal predictability of the IOD primarily originates from mid-latitude climate variability. Besides ENSO signals in the Pacific Ocean, our study highlights the significant impact of remote climate forcing in the South Indian Ocean, tropical North Indian Ocean, and Northwest Pacific Ocean on IOD forecasts. By introducing the SLP precursor and extratropical zones into IOD forecasts, our study offers fresh insights into the underlying dynamics of IOD evolution.
{"title":"Indian Ocean Dipole (IOD) forecasts based on convolutional neural network with sea level pressure precursor","authors":"Yuqi Tao, Chunhua Qiu, Dongxiao Wang, Mingting Li, Guangli Zhang","doi":"10.1088/1748-9326/ad7522","DOIUrl":"https://doi.org/10.1088/1748-9326/ad7522","url":null,"abstract":"Forecasting the Indian Ocean Dipole (IOD) is crucial because of its significant impact on regional and global climates. While traditional dynamic and empirical models suffer from systematic errors due to nonlinear processes, convolutional neural networks (CNN) are nonlinear in nature and have demonstrated remarkable El Niño Southern Oscillation (ENSO) and IOD forecasting skills based on oceanic predictors, particularly sea surface temperature and heat content. However, it is difficult to measure heat content and easily introduces uncertainties, prompting the need to explore atmospheric predictors for IOD forecasts. Based on sensitivity prediction experiments, we identified the sea level pressure (SLP) signal as a crucial predictor, which forecasts IOD at a 7 month lead. In addition, the CNN model improves monthly forecasting accuracy while reducing errors by 13.43%. Utilizing the heatmap analysis, we elucidated that the multi-seasonal predictability of the IOD primarily originates from mid-latitude climate variability. Besides ENSO signals in the Pacific Ocean, our study highlights the significant impact of remote climate forcing in the South Indian Ocean, tropical North Indian Ocean, and Northwest Pacific Ocean on IOD forecasts. By introducing the SLP precursor and extratropical zones into IOD forecasts, our study offers fresh insights into the underlying dynamics of IOD evolution.","PeriodicalId":11747,"journal":{"name":"Environmental Research Letters","volume":"09 1","pages":""},"PeriodicalIF":6.7,"publicationDate":"2024-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142213503","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-09DOI: 10.1088/1748-9326/ad751e
Jianan Hu, Zhuotong Nan, Hailong Ji, Shuping Zhao, Minyue Ou
Climate warming poses complex challenges for alpine ecosystems on the Qinghai–Tibetan Plateau (QTP), further exacerbated by permafrost degradation. Quantifying the specific ecological impacts of permafrost thaw remains elusive, as ecological variations are also influenced by external climate factors. This study tackles this gap by employing the Noah-MP model to simultaneously simulate permafrost thermal–hydrological dynamics and net primary production (NPP) across the Three River Headwaters Region from 1989 to 2018. Model results were validated against observations. To isolate the ecological effects of permafrost thaw, we implemented a novel relative time transformation on the simulation results. Our analysis reveals a 7.5 × 104 km2 reduction in permafrost coverage during the study period, coinciding with a 1.09 g C m−2 yr−2 increase in NPP. While precipitation is the primary driver of NPP changes in most years, soil moisture emerges as a crucial factor during permafrost disappearance, when the ground transitions to seasonally frozen ground. Surprisingly, the NPP response to permafrost disappearance exhibited a transient effect, diminishing to negligible levels within five years post-thaw. These findings enhance our understanding of the intricate and dynamic responses of the QTP ecosystem to permafrost degradation under a warming climate.
气候变暖给青藏高原（QTP）的高寒生态系统带来了复杂的挑战，而永久冻土的退化又进一步加剧了这一挑战。由于生态变化也受到外部气候因素的影响，量化永久冻土融化对生态的具体影响仍是一个难题。本研究采用 Noah-MP 模型，同时模拟了 1989 年至 2018 年三江源地区的冻土热-水文动态和净初级生产力（NPP），从而弥补了这一空白。模型结果与观测结果进行了验证。为了分离永久冻土融化对生态的影响，我们对模拟结果进行了新颖的相对时间转换。我们的分析表明，在研究期间，永久冻土覆盖面积减少了 7.5 × 104 平方公里，同时净生产力增加了 1.09 g C m-2 yr-2。在大多数年份，降水是净生产力变化的主要驱动因素，而在永久冻土消失期间，土壤湿度则成为关键因素，此时地面会过渡到季节性冰冻地面。令人惊讶的是，永久冻土消失时的净吸水能力反应表现出一种瞬时效应，在解冻后五年内减少到可以忽略不计的水平。这些发现加深了我们对气候变暖条件下 QTP 生态系统对冻土退化的复杂动态响应的理解。
{"title":"Effect of permafrost degradation on grassland net primary productivity in Qinghai–Tibet Plateau","authors":"Jianan Hu, Zhuotong Nan, Hailong Ji, Shuping Zhao, Minyue Ou","doi":"10.1088/1748-9326/ad751e","DOIUrl":"https://doi.org/10.1088/1748-9326/ad751e","url":null,"abstract":"Climate warming poses complex challenges for alpine ecosystems on the Qinghai–Tibetan Plateau (QTP), further exacerbated by permafrost degradation. Quantifying the specific ecological impacts of permafrost thaw remains elusive, as ecological variations are also influenced by external climate factors. This study tackles this gap by employing the Noah-MP model to simultaneously simulate permafrost thermal–hydrological dynamics and net primary production (NPP) across the Three River Headwaters Region from 1989 to 2018. Model results were validated against observations. To isolate the ecological effects of permafrost thaw, we implemented a novel relative time transformation on the simulation results. Our analysis reveals a 7.5 × 10<sup>4</sup> km<sup>2</sup> reduction in permafrost coverage during the study period, coinciding with a 1.09 g C m<sup>−2</sup> yr<sup>−2</sup> increase in NPP. While precipitation is the primary driver of NPP changes in most years, soil moisture emerges as a crucial factor during permafrost disappearance, when the ground transitions to seasonally frozen ground. Surprisingly, the NPP response to permafrost disappearance exhibited a transient effect, diminishing to negligible levels within five years post-thaw. These findings enhance our understanding of the intricate and dynamic responses of the QTP ecosystem to permafrost degradation under a warming climate.","PeriodicalId":11747,"journal":{"name":"Environmental Research Letters","volume":"59 1","pages":""},"PeriodicalIF":6.7,"publicationDate":"2024-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142213542","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-09DOI: 10.1088/1748-9326/ad73ea
Yu Gao, Bin Zhao, Neil Saintilan, Jiquan Chen, Wanben Wu, Li Wen, Feng Zhao, Tao Zhang, Zhi Geng, Gang Yang, Chao Song, Ping Zhuang
The dynamics of lateral nutrient fluxes through hydrological movements are crucial for understanding ecological functions related to the flow of energy, materials, and organisms across various spatiotemporal scales. To investigate the connectivity of multiple spatial flow processes, we conducted a one-year field study to measure lateral hydrologic carbon (C) and nitrogen (N) fluxes across the continental shelf in the Yangtze estuary. We observed a significant correlation between the differences in remote sensing-based estimates of gross primary production (GPP) (ΔGPPMODIS) and the differences in eddy covariance (EC) tower-based GPP (ΔGPPEC) at both high-elevation and low-elevation sites. Our findings indicate that the saltmarsh acts as a net source of dissolved total C while serving as a net sink for dissolved total N. Furthermore, there was a significant correlation in the total dissolved stoichiometry of the C/N ratio between imports from and exports to adjacent aquatic systems. These findings highlight the importance of integrating ecological stoichiometric principles to improve our understanding of the complex relationships among physical, chemical, and ecological processes, particularly within the context of the meta-ecosystem framework. Additionally, when reciprocal hydrological lateral C and N flows are considered, a single ecosystem can function as both a source and sink within the meta-ecosystem framework.
通过水文运动的横向营养通量的动态变化对于理解与能量、物质和生物在不同时空尺度上的流动有关的生态功能至关重要。为了研究多种空间流动过程的连通性，我们开展了一项为期一年的野外研究，测量长江口大陆架横向水文碳（C）和氮（N）通量。我们观察到，在高海拔和低海拔地点，基于遥感估算的总初级生产力（GPP）差异（ΔGPPMODIS）与基于涡度协方差（EC）塔的总初级生产力差异（ΔGPPEC）之间存在明显的相关性。我们的研究结果表明，盐沼是溶解总 C 的净来源，同时也是溶解总 N 的净吸收汇。这些发现凸显了综合生态计量学原理的重要性，有助于我们更好地理解物理、化学和生态过程之间的复杂关系，尤其是在元生态系统框架下。此外，如果考虑到互惠的水文侧向碳流和氮流，在元生态系统框架内，单一生态系统既可以作为源，也可以作为汇。
{"title":"Rooting meta-ecosystems with reciprocal lateral carbon and nitrogen flows in a Yangtze coastal marsh","authors":"Yu Gao, Bin Zhao, Neil Saintilan, Jiquan Chen, Wanben Wu, Li Wen, Feng Zhao, Tao Zhang, Zhi Geng, Gang Yang, Chao Song, Ping Zhuang","doi":"10.1088/1748-9326/ad73ea","DOIUrl":"https://doi.org/10.1088/1748-9326/ad73ea","url":null,"abstract":"The dynamics of lateral nutrient fluxes through hydrological movements are crucial for understanding ecological functions related to the flow of energy, materials, and organisms across various spatiotemporal scales. To investigate the connectivity of multiple spatial flow processes, we conducted a one-year field study to measure lateral hydrologic carbon (C) and nitrogen (N) fluxes across the continental shelf in the Yangtze estuary. We observed a significant correlation between the differences in remote sensing-based estimates of gross primary production (GPP) (ΔGPP<sub>MODIS</sub>) and the differences in eddy covariance (EC) tower-based GPP (ΔGPP<sub>EC</sub>) at both high-elevation and low-elevation sites. Our findings indicate that the saltmarsh acts as a net source of dissolved total C while serving as a net sink for dissolved total N. Furthermore, there was a significant correlation in the total dissolved stoichiometry of the C/N ratio between imports from and exports to adjacent aquatic systems. These findings highlight the importance of integrating ecological stoichiometric principles to improve our understanding of the complex relationships among physical, chemical, and ecological processes, particularly within the context of the meta-ecosystem framework. Additionally, when reciprocal hydrological lateral C and N flows are considered, a single ecosystem can function as both a source and sink within the meta-ecosystem framework.","PeriodicalId":11747,"journal":{"name":"Environmental Research Letters","volume":"5 1","pages":""},"PeriodicalIF":6.7,"publicationDate":"2024-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142213498","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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