Pub Date : 2022-01-01DOI: 10.1525/elementa.2021.00074
Luisa von Albedyll, S. Hendricks, Raphael Grodofzig, T. Krumpen, Stefanie Arndt, H. J. Belter, G. Birnbaum, B. Cheng, M. Hoppmann, J. Hutchings, P. Itkin, R. Lei, M. Nicolaus, R. Ricker, J. Rohde, Mira Suhrhoff, A. Timofeeva, D. Watkins, M. Webster, C. Haas
Sea ice thickness is a key parameter in the polar climate and ecosystem. Thermodynamic and dynamic processes alter the sea ice thickness. The Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) expedition provided a unique opportunity to study seasonal sea ice thickness changes of the same sea ice. We analyzed 11 large-scale (∼50 km) airborne electromagnetic sea thickness and surface roughness surveys from October 2019 to September 2020. Data from ice mass balance and position buoys provided additional information. We found that thermodynamic growth and decay dominated the seasonal cycle with a total mean sea ice thickness increase of 1.4 m (October 2019 to June 2020) and decay of 1.2 m (June 2020 to September 2020). Ice dynamics and deformation-related processes, such as thin ice formation in leads and subsequent ridging, broadened the ice thickness distribution and contributed 30% to the increase in mean thickness. These processes caused a 1-month delay between maximum thermodynamic sea ice thickness and maximum mean ice thickness. The airborne EM measurements bridged the scales from local floe-scale measurements to Arctic-wide satellite observations and model grid cells. The spatial differences in mean sea ice thickness between the Central Observatory (<10 km) of MOSAiC and the Distributed Network (<50 km) were negligible in fall and only 0.2 m in late winter, but the relative abundance of thin and thick ice varied. One unexpected outcome was the large dynamic thickening in a regime where divergence prevailed on average in the western Nansen Basin in spring. We suggest that the large dynamic thickening was due to the mobile, unconsolidated sea ice pack and periodic, sub-daily motion. We demonstrate that this Lagrangian sea ice thickness data set is well suited for validating the existing redistribution theory in sea ice models. Our comprehensive description of seasonal changes of the sea ice thickness distribution is valuable for interpreting MOSAiC time series across disciplines and can be used as a reference to advance sea ice thickness modeling.
{"title":"Thermodynamic and dynamic contributions to seasonal Arctic sea ice thickness distributions from airborne observations","authors":"Luisa von Albedyll, S. Hendricks, Raphael Grodofzig, T. Krumpen, Stefanie Arndt, H. J. Belter, G. Birnbaum, B. Cheng, M. Hoppmann, J. Hutchings, P. Itkin, R. Lei, M. Nicolaus, R. Ricker, J. Rohde, Mira Suhrhoff, A. Timofeeva, D. Watkins, M. Webster, C. Haas","doi":"10.1525/elementa.2021.00074","DOIUrl":"https://doi.org/10.1525/elementa.2021.00074","url":null,"abstract":"Sea ice thickness is a key parameter in the polar climate and ecosystem. Thermodynamic and dynamic processes alter the sea ice thickness. The Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) expedition provided a unique opportunity to study seasonal sea ice thickness changes of the same sea ice. We analyzed 11 large-scale (∼50 km) airborne electromagnetic sea thickness and surface roughness surveys from October 2019 to September 2020. Data from ice mass balance and position buoys provided additional information. We found that thermodynamic growth and decay dominated the seasonal cycle with a total mean sea ice thickness increase of 1.4 m (October 2019 to June 2020) and decay of 1.2 m (June 2020 to September 2020). Ice dynamics and deformation-related processes, such as thin ice formation in leads and subsequent ridging, broadened the ice thickness distribution and contributed 30% to the increase in mean thickness. These processes caused a 1-month delay between maximum thermodynamic sea ice thickness and maximum mean ice thickness. The airborne EM measurements bridged the scales from local floe-scale measurements to Arctic-wide satellite observations and model grid cells. The spatial differences in mean sea ice thickness between the Central Observatory (<10 km) of MOSAiC and the Distributed Network (<50 km) were negligible in fall and only 0.2 m in late winter, but the relative abundance of thin and thick ice varied. One unexpected outcome was the large dynamic thickening in a regime where divergence prevailed on average in the western Nansen Basin in spring. We suggest that the large dynamic thickening was due to the mobile, unconsolidated sea ice pack and periodic, sub-daily motion. We demonstrate that this Lagrangian sea ice thickness data set is well suited for validating the existing redistribution theory in sea ice models. Our comprehensive description of seasonal changes of the sea ice thickness distribution is valuable for interpreting MOSAiC time series across disciplines and can be used as a reference to advance sea ice thickness modeling.","PeriodicalId":54279,"journal":{"name":"Elementa-Science of the Anthropocene","volume":"1 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66942161","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 : 2022-01-01DOI: 10.1525/elementa.2021.00099
S. Belmain, Y. Tembo, Angela G. Mkindi, Sarah E. J. Arnold, P. Stevenson
The development of large-scale monocropped agrisystems has facilitated increased problems with pests and diseases, perpetuating the reliance of farmers on synthetic pesticides. The economic success of synthetic inputs has, however, been achieved at a high cost to the environment through the loss of biodiversity, depletion of soil quality, greenhouse gas emissions, and disrupting the ecosystem services that can otherwise help mitigate losses caused by pests and diseases. Environmentally benign alternatives for pest and disease management are urgently needed and are now widely recognized as essential for sustainable food and agriculture. The Food and Agriculture Organization, for example, has published the 10 elements of agroecology as a framework for the transformation of agriculture. Agroecology combines ecological and social concepts and principles to develop sustainable food and agricultural systems by harnessing nature-based solutions that are tailored to farmers’ needs. Plant-based biopesticides, for example, offer an alternative to synthetic pesticides that are less harmful to the environment and nonpersistent, yet effective at managing pests and have a long tradition of use among farmers so are more socially acceptable. Here, we provide a critical assessment of how nature-based approaches to pest and disease management comply with the 10 elements of agroecology and show how they integrate with other ecosystem services through farmer participatory research. We conclude that the adoption of nature-based solutions for pest management addresses all 10 elements of agroecology and provides an entry point to promote sustainable farming practices among farmers more widely.
{"title":"Elements of agroecological pest and disease management","authors":"S. Belmain, Y. Tembo, Angela G. Mkindi, Sarah E. J. Arnold, P. Stevenson","doi":"10.1525/elementa.2021.00099","DOIUrl":"https://doi.org/10.1525/elementa.2021.00099","url":null,"abstract":"The development of large-scale monocropped agrisystems has facilitated increased problems with pests and diseases, perpetuating the reliance of farmers on synthetic pesticides. The economic success of synthetic inputs has, however, been achieved at a high cost to the environment through the loss of biodiversity, depletion of soil quality, greenhouse gas emissions, and disrupting the ecosystem services that can otherwise help mitigate losses caused by pests and diseases. Environmentally benign alternatives for pest and disease management are urgently needed and are now widely recognized as essential for sustainable food and agriculture. The Food and Agriculture Organization, for example, has published the 10 elements of agroecology as a framework for the transformation of agriculture. Agroecology combines ecological and social concepts and principles to develop sustainable food and agricultural systems by harnessing nature-based solutions that are tailored to farmers’ needs. Plant-based biopesticides, for example, offer an alternative to synthetic pesticides that are less harmful to the environment and nonpersistent, yet effective at managing pests and have a long tradition of use among farmers so are more socially acceptable. Here, we provide a critical assessment of how nature-based approaches to pest and disease management comply with the 10 elements of agroecology and show how they integrate with other ecosystem services through farmer participatory research. We conclude that the adoption of nature-based solutions for pest management addresses all 10 elements of agroecology and provides an entry point to promote sustainable farming practices among farmers more widely.","PeriodicalId":54279,"journal":{"name":"Elementa-Science of the Anthropocene","volume":"1 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66942333","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 : 2022-01-01DOI: 10.1525/elementa.2022.00018
Kenisha M. Shipley, T. Martz, P. Bresnahan, Taylor S. Wirth
A standing time series from autonomous sensors (pH, dissolved oxygen, salinity, temperature) in the Agua Hedionda Lagoon, Carlsbad, CA, captured the effects of a massive red tide occurring along the Southern and Baja California coast during the spring of 2020. Biogeochemical data (pH and dissolved oxygen) were examined using an open-source weighted regression model designed to filter out the influence of tides and estimate net ecosystem metabolism. Contemporaneous pH and dissolved oxygen observations allowed simultaneous, independent evaluations of production, respiration, and net ecosystem metabolism. Under normal conditions, the Agua Hedionda Lagoon tends toward net heterotrophy, averaging 10 mmol C m–2 d–1. During a 2-month period, centered around the peak of the event, trophic status in the lagoon shifted multiple times between net heterotrophic and net autotrophic, with a pronounced period of anoxia. Fueled by the intense local bloom, at its peak, respiration reached rates of 140 mmol C m–2d–1. We found that the co-location of pH and oxygen sensors affords independent assessment of metabolic rates, which often agree, as expected under baseline (oxic) conditions, but diverge during an extreme event. This observation allowed us to identify non-Redfieldian behavior and speculate on the source of anoxic reactions. Similar to many coastal environments, the Agua Hedionda Lagoon serves a multitude of functions (including a natural habitat for hundreds of marine and avian species, and several commercial and recreational activities), which makes characterizing the dominant mechanisms controlling the ecosystem state (such as metabolic rate) of great interest to scientists, stakeholders, decision-makers, and regulators alike.
来自加利福尼亚州卡尔斯巴德阿瓜赫迪昂达泻湖的自主传感器(pH值、溶解氧、盐度、温度)的长期时间序列捕捉到了2020年春季沿南加州和下加利福尼亚州海岸发生的大规模赤潮的影响。生物地球化学数据(pH和溶解氧)使用开源加权回归模型进行检验，该模型旨在过滤潮汐的影响并估计净生态系统代谢。同时进行的pH值和溶解氧观测允许同时、独立地评估产量、呼吸和净生态系统代谢。在正常条件下，Agua Hedionda泻湖倾向于净异养，平均为10 mmol C m-2 d-1。在2个月的时间里，以事件高峰期为中心，泻湖的营养状况在净异养和净自养之间多次转换，并伴有明显的缺氧期。在当地强烈的水华的推动下，呼吸速率达到140 mmol C m-2d-1。我们发现pH和氧传感器的共同位置提供了代谢率的独立评估，在基线(氧)条件下通常是一致的，但在极端事件中会出现分歧。这一观察结果使我们能够识别非雷德菲尔德行为，并推测缺氧反应的来源。与许多沿海环境类似，Agua Hedionda泻湖具有多种功能(包括数百种海洋和鸟类的自然栖息地，以及几种商业和娱乐活动)，这使得科学家、利益相关者、决策者和监管机构对控制生态系统状态(如代谢率)的主要机制非常感兴趣。
{"title":"Metabolic rates in the Agua Hedionda Lagoon during the 2020 Southern California red tide event","authors":"Kenisha M. Shipley, T. Martz, P. Bresnahan, Taylor S. Wirth","doi":"10.1525/elementa.2022.00018","DOIUrl":"https://doi.org/10.1525/elementa.2022.00018","url":null,"abstract":"A standing time series from autonomous sensors (pH, dissolved oxygen, salinity, temperature) in the Agua Hedionda Lagoon, Carlsbad, CA, captured the effects of a massive red tide occurring along the Southern and Baja California coast during the spring of 2020. Biogeochemical data (pH and dissolved oxygen) were examined using an open-source weighted regression model designed to filter out the influence of tides and estimate net ecosystem metabolism. Contemporaneous pH and dissolved oxygen observations allowed simultaneous, independent evaluations of production, respiration, and net ecosystem metabolism. Under normal conditions, the Agua Hedionda Lagoon tends toward net heterotrophy, averaging 10 mmol C m–2 d–1. During a 2-month period, centered around the peak of the event, trophic status in the lagoon shifted multiple times between net heterotrophic and net autotrophic, with a pronounced period of anoxia. Fueled by the intense local bloom, at its peak, respiration reached rates of 140 mmol C m–2d–1. We found that the co-location of pH and oxygen sensors affords independent assessment of metabolic rates, which often agree, as expected under baseline (oxic) conditions, but diverge during an extreme event. This observation allowed us to identify non-Redfieldian behavior and speculate on the source of anoxic reactions. Similar to many coastal environments, the Agua Hedionda Lagoon serves a multitude of functions (including a natural habitat for hundreds of marine and avian species, and several commercial and recreational activities), which makes characterizing the dominant mechanisms controlling the ecosystem state (such as metabolic rate) of great interest to scientists, stakeholders, decision-makers, and regulators alike.","PeriodicalId":54279,"journal":{"name":"Elementa-Science of the Anthropocene","volume":"1 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66943244","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 : 2022-01-01DOI: 10.1525/elementa.2022.00028
Jazel Ouled-Cheikh, M. Coll, L. Cardona, J. Steenbeek, F. Ramírez
Marine species are widely threatened by anthropogenic activities, including fishing and human-induced climate change. However, geographically broad and spatially explicit assessments of the simultaneous impacts of these major threats at regional scales are mostly lacking due to the practical challenges of surveying vast geographical areas and obtaining adequately resolved data. Yet, these assessments are key for identifying highly and cumulatively impacted areas and species that should be prioritized for conservation through knowledge-based management strategies. Here, we analysed a 26-year (1993–2018) time series of highly resolved remotely sensed environmental data to evaluate changes in optimal habitat availability (i.e., extent of marine areas encompassing optimal environmental conditions) for 15 species representative of small, medium and large pelagic fish inhabiting the Mediterranean Sea Large Marine Ecosystem. We then combined spatial and temporal data on fishing pressure and changes in optimal habitats to identify areas of high risk of cumulative impacts. Overall, results show how most of the studied Mediterranean pelagic species experienced a reduction in optimal habitat availability over the past decades. The few species that showed positive trends in optimal habitat availability expanded only to a small degree and hence were unlikely to compensate for the loss of key functional roles at the group level. Habitat loss concentrated in the western and central regions. Similarly, fishing pressure was found to be higher in these regions, thus overlapping with the areas experiencing a higher reduction of optimal habitat. Small and large pelagic fish were the most impacted groups, having a larger proportion of their distributions in highly, cumulative impacted areas. Redistributing fishing pressure and reducing it in highly impacted areas may alleviate the overall cumulative pressure on pelagic stocks, contributing to the necessary shift to sustainable and resilient fisheries that would ensure food security and a healthy ecosystem in this highly impacted basin.
{"title":"Fisheries-enhanced pressure on Mediterranean regions and pelagic species already impacted by climate change","authors":"Jazel Ouled-Cheikh, M. Coll, L. Cardona, J. Steenbeek, F. Ramírez","doi":"10.1525/elementa.2022.00028","DOIUrl":"https://doi.org/10.1525/elementa.2022.00028","url":null,"abstract":"Marine species are widely threatened by anthropogenic activities, including fishing and human-induced climate change. However, geographically broad and spatially explicit assessments of the simultaneous impacts of these major threats at regional scales are mostly lacking due to the practical challenges of surveying vast geographical areas and obtaining adequately resolved data. Yet, these assessments are key for identifying highly and cumulatively impacted areas and species that should be prioritized for conservation through knowledge-based management strategies. Here, we analysed a 26-year (1993–2018) time series of highly resolved remotely sensed environmental data to evaluate changes in optimal habitat availability (i.e., extent of marine areas encompassing optimal environmental conditions) for 15 species representative of small, medium and large pelagic fish inhabiting the Mediterranean Sea Large Marine Ecosystem. We then combined spatial and temporal data on fishing pressure and changes in optimal habitats to identify areas of high risk of cumulative impacts. Overall, results show how most of the studied Mediterranean pelagic species experienced a reduction in optimal habitat availability over the past decades. The few species that showed positive trends in optimal habitat availability expanded only to a small degree and hence were unlikely to compensate for the loss of key functional roles at the group level. Habitat loss concentrated in the western and central regions. Similarly, fishing pressure was found to be higher in these regions, thus overlapping with the areas experiencing a higher reduction of optimal habitat. Small and large pelagic fish were the most impacted groups, having a larger proportion of their distributions in highly, cumulative impacted areas. Redistributing fishing pressure and reducing it in highly impacted areas may alleviate the overall cumulative pressure on pelagic stocks, contributing to the necessary shift to sustainable and resilient fisheries that would ensure food security and a healthy ecosystem in this highly impacted basin.","PeriodicalId":54279,"journal":{"name":"Elementa-Science of the Anthropocene","volume":"1 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66943483","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}
Environmental, social, and governance (ESG) disclosure plays a critical role in promoting corporations’ abilities to achieve sustainable development. Previous research has focused on the concept, antecedents, and consequences of ESG disclosure, ignoring that there are significant differences in ESG disclosure strategies of corporations and providing even less understanding of how corporations adopt ESG disclosure strategies. Therefore, we identify the factors and mechanisms of ESG disclosure strategy adoption in context of stakeholders. Using new institutional theory (NIT) and resource dependence theory (RDT), we suggest that goals compatibility and resources dependence are the 2 critical factors that affect a corporation’s ESG disclosure strategy adoption. Accordingly, we construct a framework of corporations’ ESG disclosure strategies adoption. We address the gaps in understanding of ESG disclosure strategies adoption of corporations, expand NIT and RDT, and provide rich practical guidance to promote the healthy development of ESG disclosure strategies.
{"title":"Stakeholders and ESG disclosure strategies adoption: The role of goals compatibility and resources dependence","authors":"Zhiyang Liu, Ruoyu Zheng, Zhenyu Qiu, Xiaodong Jiang","doi":"10.1525/elementa.2022.00044","DOIUrl":"https://doi.org/10.1525/elementa.2022.00044","url":null,"abstract":"Environmental, social, and governance (ESG) disclosure plays a critical role in promoting corporations’ abilities to achieve sustainable development. Previous research has focused on the concept, antecedents, and consequences of ESG disclosure, ignoring that there are significant differences in ESG disclosure strategies of corporations and providing even less understanding of how corporations adopt ESG disclosure strategies. Therefore, we identify the factors and mechanisms of ESG disclosure strategy adoption in context of stakeholders. Using new institutional theory (NIT) and resource dependence theory (RDT), we suggest that goals compatibility and resources dependence are the 2 critical factors that affect a corporation’s ESG disclosure strategy adoption. Accordingly, we construct a framework of corporations’ ESG disclosure strategies adoption. We address the gaps in understanding of ESG disclosure strategies adoption of corporations, expand NIT and RDT, and provide rich practical guidance to promote the healthy development of ESG disclosure strategies.","PeriodicalId":54279,"journal":{"name":"Elementa-Science of the Anthropocene","volume":"1 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66944049","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 : 2022-01-01DOI: 10.1525/elementa.2022.00030
Hyeonmin Kim, R. Park, Saewung Kim, W. Brune, G. Diskin, A. Fried, S. Hall, A. Weinheimer, P. Wennberg, A. Wisthaler, D. Blake, K. Ullmann
We present a holistic examination of tropospheric OH reactivity (OHR) in South Korea using comprehensive NASA DC-8 airborne measurements collected during the Korea–United States Air Quality field study and chemical transport models. The observed total OHR (tOHR) averaged in the planetary boundary layer (PBL, <2.0 km) and free troposphere was 5.2 s−1 and 2.0 s−1 during the campaign, respectively. These values were higher than the calculated OHR (cOHR, 3.4 s−1, 1.0 s−1) derived from trace-gas observations, indicating missing OHR fractions in the PBL and free troposphere of 35% and 50%, respectively. Incorporating nonobserved secondary species from the observationally constrained box model increased cOHR to 4.0 s−1 in the PBL and 1.3 s−1 in the free troposphere. Simulated OHR (sOHR, 2.7 s−1, 0.8 s−1) was substantially lower than both tOHR and cOHR by as much as 60%. This underestimate was substantial in the free troposphere and marine boundary layer of the marginal sea (Yellow Sea). We then discuss the potential causes of unaccounted OHR. First, we suggest improving the accuracy of tropospheric reaction kinetics, which vary significantly in the available literature. Second, underestimated emissions of anthropogenic CO and oxygenated volatile organic compounds in East Asia contributed to the discrepancy between tOHR and sOHR. In addition, oxygenated and biogenic volatile organic compounds emitted from the marginal sea may contribute substantially to the regional OHR. Typical chemical transport models underestimate these sources, leading to a large missing OHR fraction. Despite this discrepancy, we found that simulated OH concentrations were comparable with those observed during the campaign because of slow OH recycling rates in the models; therefore, the models predicted less formation of photochemical oxidation products such as ozone.
{"title":"Observed versus simulated OH reactivity during KORUS-AQ campaign: Implications for emission inventory and chemical environment in East Asia","authors":"Hyeonmin Kim, R. Park, Saewung Kim, W. Brune, G. Diskin, A. Fried, S. Hall, A. Weinheimer, P. Wennberg, A. Wisthaler, D. Blake, K. Ullmann","doi":"10.1525/elementa.2022.00030","DOIUrl":"https://doi.org/10.1525/elementa.2022.00030","url":null,"abstract":"We present a holistic examination of tropospheric OH reactivity (OHR) in South Korea using comprehensive NASA DC-8 airborne measurements collected during the Korea–United States Air Quality field study and chemical transport models. The observed total OHR (tOHR) averaged in the planetary boundary layer (PBL, <2.0 km) and free troposphere was 5.2 s−1 and 2.0 s−1 during the campaign, respectively. These values were higher than the calculated OHR (cOHR, 3.4 s−1, 1.0 s−1) derived from trace-gas observations, indicating missing OHR fractions in the PBL and free troposphere of 35% and 50%, respectively. Incorporating nonobserved secondary species from the observationally constrained box model increased cOHR to 4.0 s−1 in the PBL and 1.3 s−1 in the free troposphere. Simulated OHR (sOHR, 2.7 s−1, 0.8 s−1) was substantially lower than both tOHR and cOHR by as much as 60%. This underestimate was substantial in the free troposphere and marine boundary layer of the marginal sea (Yellow Sea). We then discuss the potential causes of unaccounted OHR. First, we suggest improving the accuracy of tropospheric reaction kinetics, which vary significantly in the available literature. Second, underestimated emissions of anthropogenic CO and oxygenated volatile organic compounds in East Asia contributed to the discrepancy between tOHR and sOHR. In addition, oxygenated and biogenic volatile organic compounds emitted from the marginal sea may contribute substantially to the regional OHR. Typical chemical transport models underestimate these sources, leading to a large missing OHR fraction. Despite this discrepancy, we found that simulated OH concentrations were comparable with those observed during the campaign because of slow OH recycling rates in the models; therefore, the models predicted less formation of photochemical oxidation products such as ozone.","PeriodicalId":54279,"journal":{"name":"Elementa-Science of the Anthropocene","volume":"1 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66944179","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 : 2022-01-01DOI: 10.1525/elementa.2022.00055
K. Sobocinski, C. Harvell, Natalie J. K. Baloy, Ginny Broadhurst, M. Dethier, A. Flower, J. Delaney
Coastal seas and estuaries are among the most productive ecosystems on Earth and have long attracted human activity. Yet, urbanization pressures are intense and are compounded by accelerating climate stresses. Urban seas are now hotspots of stress in the Anthropocene ocean. The Salish Sea stands out as one of a few highly functioning urban seas in the world, boasting ecological riches and thriving coastal communities and industries, including tourism. For over 10,000 years the region has supported Indigenous peoples; now it is home to a growing population of almost nine million people, concentrated in and near the major cities of Seattle, Washington, and Vancouver, British Columbia. Increasing urbanization combined with intensifying climate stress is degrading the Salish Sea and acutely affecting communities already experiencing marginalization. Current environmental impacts include acidifying waters, hypoxia, and intense heat waves, all of which have had measurable impacts within the ecosystem. A recent synthesis of this system identified key domains for solutions, which we generalize here for invoking positive change in global urban seas: 1) innovation in data collection, curation, and integration using a systems approach in science and management; 2) sharing place-based knowledge to sustain community-based action; and 3) aligning science and policy with ecosystem boundaries. The differing governance and socio-political settings across two countries and numerous Indigenous nations creates a complex challenge in ecosystem management. Developing actionable solutions for people and the biota of the Salish Sea can create a global example of a sustainably managed urban sea with transferable insights to other urban seas in need of revitalization around the world.
{"title":"Urban seas as hotspots of stress in the Anthropocene ocean: The Salish Sea example","authors":"K. Sobocinski, C. Harvell, Natalie J. K. Baloy, Ginny Broadhurst, M. Dethier, A. Flower, J. Delaney","doi":"10.1525/elementa.2022.00055","DOIUrl":"https://doi.org/10.1525/elementa.2022.00055","url":null,"abstract":"Coastal seas and estuaries are among the most productive ecosystems on Earth and have long attracted human activity. Yet, urbanization pressures are intense and are compounded by accelerating climate stresses. Urban seas are now hotspots of stress in the Anthropocene ocean. The Salish Sea stands out as one of a few highly functioning urban seas in the world, boasting ecological riches and thriving coastal communities and industries, including tourism. For over 10,000 years the region has supported Indigenous peoples; now it is home to a growing population of almost nine million people, concentrated in and near the major cities of Seattle, Washington, and Vancouver, British Columbia. Increasing urbanization combined with intensifying climate stress is degrading the Salish Sea and acutely affecting communities already experiencing marginalization. Current environmental impacts include acidifying waters, hypoxia, and intense heat waves, all of which have had measurable impacts within the ecosystem. A recent synthesis of this system identified key domains for solutions, which we generalize here for invoking positive change in global urban seas: 1) innovation in data collection, curation, and integration using a systems approach in science and management; 2) sharing place-based knowledge to sustain community-based action; and 3) aligning science and policy with ecosystem boundaries. The differing governance and socio-political settings across two countries and numerous Indigenous nations creates a complex challenge in ecosystem management. Developing actionable solutions for people and the biota of the Salish Sea can create a global example of a sustainably managed urban sea with transferable insights to other urban seas in need of revitalization around the world.","PeriodicalId":54279,"journal":{"name":"Elementa-Science of the Anthropocene","volume":"1 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66944494","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 : 2022-01-01DOI: 10.1525/elementa.2021.00065
A. Romero-Olivares, C. Davie-Martin, M. Kramshøj, R. Rinnan, S. Frey
Biogenic volatile organic compounds (VOCs) play crucial roles in ecosystems at multiple scales, ranging from mediating soil microbial interactions to contributing to atmospheric chemistry. However, soil VOCs and how they respond to environmental change remains understudied. We aimed to assess how 2 abiotic global change drivers, soil warming and simulated nitrogen (N) deposition, impact soil VOC emissions over time in a temperate forest. We characterized the effect of warming, N deposition, and their interaction on the composition and emissions of soil VOCs during the growing season of 2 consecutive years. We found that chronic warming and N deposition enhanced total VOC emissions at certain times of the year (as high as 332.78 µg m–2 h–1), but that overall VOC composition was not strongly affected by these global change treatments. However, certain compounds, particularly sesquiterpenoids and alkanes, were sensitive to these treatments, with their emissions increasing under both chronic warming and N deposition. Moreover, specific signature VOCs—α-pinene, β-thujone, β-caryophyllene, and 2,4-dimethylheptane—were consistently found under chronic warming and N deposition. This suggests that emissions of specific VOC classes/compounds may increase under global change.
{"title":"Soil volatile organic compound emissions in response to soil warming and nitrogen deposition","authors":"A. Romero-Olivares, C. Davie-Martin, M. Kramshøj, R. Rinnan, S. Frey","doi":"10.1525/elementa.2021.00065","DOIUrl":"https://doi.org/10.1525/elementa.2021.00065","url":null,"abstract":"Biogenic volatile organic compounds (VOCs) play crucial roles in ecosystems at multiple scales, ranging from mediating soil microbial interactions to contributing to atmospheric chemistry. However, soil VOCs and how they respond to environmental change remains understudied. We aimed to assess how 2 abiotic global change drivers, soil warming and simulated nitrogen (N) deposition, impact soil VOC emissions over time in a temperate forest. We characterized the effect of warming, N deposition, and their interaction on the composition and emissions of soil VOCs during the growing season of 2 consecutive years. We found that chronic warming and N deposition enhanced total VOC emissions at certain times of the year (as high as 332.78 µg m–2 h–1), but that overall VOC composition was not strongly affected by these global change treatments. However, certain compounds, particularly sesquiterpenoids and alkanes, were sensitive to these treatments, with their emissions increasing under both chronic warming and N deposition. Moreover, specific signature VOCs—α-pinene, β-thujone, β-caryophyllene, and 2,4-dimethylheptane—were consistently found under chronic warming and N deposition. This suggests that emissions of specific VOC classes/compounds may increase under global change.","PeriodicalId":54279,"journal":{"name":"Elementa-Science of the Anthropocene","volume":"1 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66941427","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 : 2022-01-01DOI: 10.1525/elementa.2022.00024
Vanessa Engelhardt, T. Perez, L. Donoso, T. Müller, A. Wiedensohler
Atmospheric aerosols play an important role in atmospheric processes and human health. Characterizing atmospheric aerosols and identifying their sources in large cities is relevant to propose site-specific air pollution mitigation strategies. In this study, we measured the mass concentration of atmospheric aerosols with an aerodynamic diameter smaller than 2.5 µm (PM2.5) in the city of Caracas (urban) and in a tropical montane cloud forest (suburban site, located in a mountainous area 11 km far from Caracas) between June 2018 and October 2019. We also measured equivalent black carbon (eBC) mass concentration in PM2.5 in Caracas during the same period. Our goal is to assess PM2.5 and eBC temporal variation and identify their major sources in the area. eBC showed a pronounced diurnal cycle in the urban site, mainly modulated by traffic circulation and the diurnal changes of the mixing layer height. In contrast, PM2.5 showed stable median values during the day with slight variations like that of eBC. In the forest site, PM2.5 values were higher in the afternoons due to the convective transport of aerosols from Caracas and other surrounding urban areas located in adjacent valleys. The annual median for eBC and PM2.5 was 1.6 and 9.2 µg m–3, respectively, in the urban site, while PM2.5 in the forest site was 6.6 µg m–3. To our knowledge, these are the first measurements of this type in the northernmost area of South America. eBC and PM2.5 sources identification during wet and dry seasons was obtained by percentiles of the conditional bivariate probability function (CBPF). CBPF showed seasonal variations of eBC and PM2.5 sources and that their contributions are higher during the dry season. Biomass burning events are a relevant contributing source of aerosols for both sites of measurements inferred by fire pixels from satellite data, the national fire department’s statistics data, and backward trajectories. Our results indicate that biomass burning might affect the atmosphere on a regional scale, contribute to regional warming, and have implications for local and regional air quality and, therefore, human health.
{"title":"Black carbon and particulate matter mass concentrations in the Metropolitan District of Caracas, Venezuela: An assessment of temporal variation and contributing sources","authors":"Vanessa Engelhardt, T. Perez, L. Donoso, T. Müller, A. Wiedensohler","doi":"10.1525/elementa.2022.00024","DOIUrl":"https://doi.org/10.1525/elementa.2022.00024","url":null,"abstract":"Atmospheric aerosols play an important role in atmospheric processes and human health. Characterizing atmospheric aerosols and identifying their sources in large cities is relevant to propose site-specific air pollution mitigation strategies. In this study, we measured the mass concentration of atmospheric aerosols with an aerodynamic diameter smaller than 2.5 µm (PM2.5) in the city of Caracas (urban) and in a tropical montane cloud forest (suburban site, located in a mountainous area 11 km far from Caracas) between June 2018 and October 2019. We also measured equivalent black carbon (eBC) mass concentration in PM2.5 in Caracas during the same period. Our goal is to assess PM2.5 and eBC temporal variation and identify their major sources in the area. eBC showed a pronounced diurnal cycle in the urban site, mainly modulated by traffic circulation and the diurnal changes of the mixing layer height. In contrast, PM2.5 showed stable median values during the day with slight variations like that of eBC. In the forest site, PM2.5 values were higher in the afternoons due to the convective transport of aerosols from Caracas and other surrounding urban areas located in adjacent valleys. The annual median for eBC and PM2.5 was 1.6 and 9.2 µg m–3, respectively, in the urban site, while PM2.5 in the forest site was 6.6 µg m–3. To our knowledge, these are the first measurements of this type in the northernmost area of South America. eBC and PM2.5 sources identification during wet and dry seasons was obtained by percentiles of the conditional bivariate probability function (CBPF). CBPF showed seasonal variations of eBC and PM2.5 sources and that their contributions are higher during the dry season. Biomass burning events are a relevant contributing source of aerosols for both sites of measurements inferred by fire pixels from satellite data, the national fire department’s statistics data, and backward trajectories. Our results indicate that biomass burning might affect the atmosphere on a regional scale, contribute to regional warming, and have implications for local and regional air quality and, therefore, human health.","PeriodicalId":54279,"journal":{"name":"Elementa-Science of the Anthropocene","volume":"57 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66943411","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 : 2022-01-01DOI: 10.1525/elementa.2022.00045
Shanru Tian, K. Smits, Younki Cho, S. Riddick, D. Zimmerle, Aidan Duggan
Methane (CH4) leakage from natural gas (NG) pipelines poses an environmental, safety, and economic threat to the public. While previous leak detection and quantification studies focus on the aboveground infrastructure, the analysis of underground NG pipeline leak scenarios is scarce. Furthermore, no data from controlled release experiments have been published on the accuracy of methods used to (1) quantify emissions from an area source and (2) use these emissions to quantify the size of a subsurface leak. This proof-of-concept work uses CH4 mole fraction, as measured by a single gas sensor, as an input to a simple dispersion-based model (WindTrax) under ideal conditions (i.e., in a field) and compares the calculated emissions to the known controlled NG release rates. The aboveground and surface CH4 mole fractions were measured for 5 days at a field testbed using controlled underground release rates ranging from 0.08 to 0.52 kg hr–1 (3.83–24.94 ft3 hr–1). Results confirmed that the mean normalized CH4 mole fraction increases as the atmosphere transitions from the Pasquill–Gifford (PG) stability class A (extremely unstable) to G (extremely stable). The estimated surface CH4 emissions showed large temporal variability, and for the emission rates tested, at least 6 h of data are needed to have a representative estimate from subsurface pipeline leaks (±27% of the controlled release rate on average). The probability that the emission estimate is within ±50% of the controlled release rate (P±50%) is approximately 50% when 1 h of data is collected; the probability approaches 100% with 3–4 h of data. Findings demonstrate the importance of providing enough data over time for accurate estimation of belowground leak scenarios. By adopting the estimation method described in this study, operators can better estimate leakage rates and identify and repair the largest leaks, thereby optimizing annual greenhouse gas emissions reductions and improving public safety.
天然气(NG)管道泄漏的甲烷(CH4)对公众造成了环境、安全和经济威胁。以往的泄漏检测和量化研究主要集中在地上基础设施上，而对地下天然气管道泄漏情景的分析很少。此外，关于(1)量化区域源排放和(2)使用这些排放来量化地下泄漏大小的方法的准确性，尚未发表来自控制释放实验的数据。这项概念验证工作使用单个气体传感器测量的CH4摩尔分数作为理想条件下(即在野外)的简单分散型模型(WindTrax)的输入，并将计算的排放量与已知的受控NG释放率进行比较。在一个现场试验台上，使用控制的地下释放速率为0.08至0.52 kg hr-1 (3.83-24.94 ft3 hr-1)，测量了5天的地上和地表CH4摩尔分数。结果证实，当大气从Pasquill-Gifford (PG)稳定等级A(极不稳定)过渡到G(极稳定)时，平均归一化CH4摩尔分数增加。估算的地表甲烷排放量表现出较大的时间变异性，对于测试的排放率，至少需要6小时的数据才能从地下管道泄漏中获得具有代表性的估计(平均为控制释放率的±27%)。当收集1 h的数据时，排放估计值在控制释放率(P±50%)的±50%以内的概率约为50%;3-4小时的数据，概率接近100%。研究结果表明，随着时间的推移，提供足够的数据对于准确估计地下泄漏情景的重要性。通过采用本研究的估算方法，运营商可以更好地估算泄漏率，识别和修复最大的泄漏，从而优化年度温室气体减排，提高公共安全。
{"title":"Estimating methane emissions from underground natural gas pipelines using an atmospheric dispersion-based method","authors":"Shanru Tian, K. Smits, Younki Cho, S. Riddick, D. Zimmerle, Aidan Duggan","doi":"10.1525/elementa.2022.00045","DOIUrl":"https://doi.org/10.1525/elementa.2022.00045","url":null,"abstract":"Methane (CH4) leakage from natural gas (NG) pipelines poses an environmental, safety, and economic threat to the public. While previous leak detection and quantification studies focus on the aboveground infrastructure, the analysis of underground NG pipeline leak scenarios is scarce. Furthermore, no data from controlled release experiments have been published on the accuracy of methods used to (1) quantify emissions from an area source and (2) use these emissions to quantify the size of a subsurface leak. This proof-of-concept work uses CH4 mole fraction, as measured by a single gas sensor, as an input to a simple dispersion-based model (WindTrax) under ideal conditions (i.e., in a field) and compares the calculated emissions to the known controlled NG release rates. The aboveground and surface CH4 mole fractions were measured for 5 days at a field testbed using controlled underground release rates ranging from 0.08 to 0.52 kg hr–1 (3.83–24.94 ft3 hr–1). Results confirmed that the mean normalized CH4 mole fraction increases as the atmosphere transitions from the Pasquill–Gifford (PG) stability class A (extremely unstable) to G (extremely stable). The estimated surface CH4 emissions showed large temporal variability, and for the emission rates tested, at least 6 h of data are needed to have a representative estimate from subsurface pipeline leaks (±27% of the controlled release rate on average). The probability that the emission estimate is within ±50% of the controlled release rate (P±50%) is approximately 50% when 1 h of data is collected; the probability approaches 100% with 3–4 h of data. Findings demonstrate the importance of providing enough data over time for accurate estimation of belowground leak scenarios. By adopting the estimation method described in this study, operators can better estimate leakage rates and identify and repair the largest leaks, thereby optimizing annual greenhouse gas emissions reductions and improving public safety.","PeriodicalId":54279,"journal":{"name":"Elementa-Science of the Anthropocene","volume":"1 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66943732","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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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