Camille Pagniello, J. Butler, Annie Rosen, Addison Sherwood, P. Roberts, E. Parnell, J. Jaffe, A. Sirovic
S1. DEPLOYMENT AND UNDERWATER OPERATION The optical imaging system (OIS) was deployed in the kelp forests on the northern edge of the South La Jolla State Marine Reserve (SMR; 32.8263°N, 117.2901°W) in approximately 14 m water depth from July 10 to 23, 2018 (Figure S1a). It captured 24 images every 12 minutes between 05:00 and 21:00 (i.e., at least one hour before sunrise and after sunset) to ensure that no potentially usable light conditions were missed for image acquisition. Images were captured under aperture priority mode (aperture: f2.8) as uncompressed, raw image files with a 16:9 aspect ratio. The focusing distance of the lens was set at 0.3 m in air so that a fish one meter away from the camera in water would be in focus. This was determined using equations in Jenkins and White (2001) to compute the focusing distance for thick lenses, and we have included a MATLAB R2016b (MathWorks, Natick, MA) script to calculate this in the GitHub repository (https://github.com/cpagniel/FishOASIS/blob/master/hardware/FishOASIS_lens_ focusing_dist_code.m). The ISO (International Standards Organization) sensitivity of each image was automatically set by the camera between 50 and 409,600. The white balance was also automatically set by the camera. The OIS was mounted by divers to an L-bracket (for landscape images) on a 1 m tall u-post set in a 50 × 50 × 10 cm concrete block (Figure S1b). It could also be mounted directly to the stand for portrait images. The battery pack was placed on the concrete block and cable-tied to two eyebolts set in the concrete block. A HOBO Pendant temperature/light 8K data logger (Onset Computer Corporation, Bourne, MA) was attached to the camera housing to measure seawater temperature (in °C) and ambient light (in lux). To correct for the ambient light spectra, a DGK Color Tools WDKK Waterproof Color Chart was deployed in the field of view of the camera at a distance of 2 m. To approximate the distance of fishes from the camera, distances to various stationary objects always visible in the images (e.g., rocks, kelp holdfasts, cinderblocks) from the camera were measured using a transect tape. To demonstrate the OIS’s ability to synchronize its clock with that of a passive acoustic recorder, the OIS was deployed alongside a SoundTrap ST4300 (Ocean Instruments, Auckland, NZ) four-channel acoustic recorder equipped An Optical Imaging System for Capturing Images in Low-Light Aquatic Habitats Using Only Ambient Light
{"title":"An Optical Imaging System for Capturing Images in Low-Light Aquatic Habitats Using Only Ambient Light.","authors":"Camille Pagniello, J. Butler, Annie Rosen, Addison Sherwood, P. Roberts, E. Parnell, J. Jaffe, A. Sirovic","doi":"10.25607/OBP-1552","DOIUrl":"https://doi.org/10.25607/OBP-1552","url":null,"abstract":"S1. DEPLOYMENT AND UNDERWATER OPERATION The optical imaging system (OIS) was deployed in the kelp forests on the northern edge of the South La Jolla State Marine Reserve (SMR; 32.8263°N, 117.2901°W) in approximately 14 m water depth from July 10 to 23, 2018 (Figure S1a). It captured 24 images every 12 minutes between 05:00 and 21:00 (i.e., at least one hour before sunrise and after sunset) to ensure that no potentially usable light conditions were missed for image acquisition. Images were captured under aperture priority mode (aperture: f2.8) as uncompressed, raw image files with a 16:9 aspect ratio. The focusing distance of the lens was set at 0.3 m in air so that a fish one meter away from the camera in water would be in focus. This was determined using equations in Jenkins and White (2001) to compute the focusing distance for thick lenses, and we have included a MATLAB R2016b (MathWorks, Natick, MA) script to calculate this in the GitHub repository (https://github.com/cpagniel/FishOASIS/blob/master/hardware/FishOASIS_lens_ focusing_dist_code.m). The ISO (International Standards Organization) sensitivity of each image was automatically set by the camera between 50 and 409,600. The white balance was also automatically set by the camera. The OIS was mounted by divers to an L-bracket (for landscape images) on a 1 m tall u-post set in a 50 × 50 × 10 cm concrete block (Figure S1b). It could also be mounted directly to the stand for portrait images. The battery pack was placed on the concrete block and cable-tied to two eyebolts set in the concrete block. A HOBO Pendant temperature/light 8K data logger (Onset Computer Corporation, Bourne, MA) was attached to the camera housing to measure seawater temperature (in °C) and ambient light (in lux). To correct for the ambient light spectra, a DGK Color Tools WDKK Waterproof Color Chart was deployed in the field of view of the camera at a distance of 2 m. To approximate the distance of fishes from the camera, distances to various stationary objects always visible in the images (e.g., rocks, kelp holdfasts, cinderblocks) from the camera were measured using a transect tape. To demonstrate the OIS’s ability to synchronize its clock with that of a passive acoustic recorder, the OIS was deployed alongside a SoundTrap ST4300 (Ocean Instruments, Auckland, NZ) four-channel acoustic recorder equipped An Optical Imaging System for Capturing Images in Low-Light Aquatic Habitats Using Only Ambient Light","PeriodicalId":54695,"journal":{"name":"Oceanography","volume":" ","pages":""},"PeriodicalIF":2.8,"publicationDate":"2021-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43590988","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-09-01DOI: 10.5670/OCEANOG.2021.317
Elizabeth B. Cerny-Chipman
{"title":"CAREER PROFILES • OPTIONS AND INSIGHTS: Elizabeth Cerny-Chipman","authors":"Elizabeth B. Cerny-Chipman","doi":"10.5670/OCEANOG.2021.317","DOIUrl":"https://doi.org/10.5670/OCEANOG.2021.317","url":null,"abstract":"","PeriodicalId":54695,"journal":{"name":"Oceanography","volume":"34 1","pages":"90-91"},"PeriodicalIF":2.8,"publicationDate":"2021-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41836440","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-09-01DOI: 10.5670/OCEANOG.2021.315
A. Pershing, D. Pendleton
{"title":"Can Right Whales Out-Swim Climate Change? Can We?","authors":"A. Pershing, D. Pendleton","doi":"10.5670/OCEANOG.2021.315","DOIUrl":"https://doi.org/10.5670/OCEANOG.2021.315","url":null,"abstract":"","PeriodicalId":54695,"journal":{"name":"Oceanography","volume":"34 1","pages":"19-21"},"PeriodicalIF":2.8,"publicationDate":"2021-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47676798","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-09-01DOI: 10.5670/OCEANOG.2021.307
M. Behl, S. Cooper, C. Garza, S. Kolesar, S. Legg, Jonathan C. Lewis, L. White, Brandon Jones
INTRODUCTION Over the past few years, abundant news articles reporting violence against communities of color in America have spurred members of the geoscience community to pay much-needed attention to promoting belonging, accessibility, justice, equity, diversity, and inclusion in our disciplines, including in the coastal, ocean, and marine sciences (e.g., see antiracism initiatives No Time for Silence, Call for a Robust Anti-Racism Plan for The Geosciences, Unlearning Racism in Geoscience, and Black in Marine Science, among others). For years, many wellintentioned programs have invested time and resources to attract students from historically excluded groups into the coastal, ocean, and marine (COM) science workforce, with limited retention success. It has become increasingly clear that recruitment is not enough. What is urgently needed is a change in the culture that includes systematic eradication of existing paradigms and models that have perpetuated racism, inequities, and injustices in higher education. Bold new paradigms and models are needed to create working and learning climates where all can thrive, both personally and professionally. To truly take an all-hands-on-deck approach to solving the enormous environmental problems humanity now faces, the COM science enterprise needs to critically examine and evaluate the effectiveness of its traditional working and learning practices. Why would anyone want to stay in a discipline that is disrespectful, toxic, and unwelcoming? How do we expect to retain people if they don’t see others with similar backgrounds and experiences in positions of leadership and power? How can people pursue science in environments that perpetuate harassment, discrimination, and misconduct? We will all benefit by creating a scientific and professional culture that offers its workforce exciting, financially viable, REGULAR ISSUE FEATURE
{"title":"Changing the Culture of Coastal, Ocean, and Marine Sciences: Strategies for Individual and Collective Actions","authors":"M. Behl, S. Cooper, C. Garza, S. Kolesar, S. Legg, Jonathan C. Lewis, L. White, Brandon Jones","doi":"10.5670/OCEANOG.2021.307","DOIUrl":"https://doi.org/10.5670/OCEANOG.2021.307","url":null,"abstract":"INTRODUCTION Over the past few years, abundant news articles reporting violence against communities of color in America have spurred members of the geoscience community to pay much-needed attention to promoting belonging, accessibility, justice, equity, diversity, and inclusion in our disciplines, including in the coastal, ocean, and marine sciences (e.g., see antiracism initiatives No Time for Silence, Call for a Robust Anti-Racism Plan for The Geosciences, Unlearning Racism in Geoscience, and Black in Marine Science, among others). For years, many wellintentioned programs have invested time and resources to attract students from historically excluded groups into the coastal, ocean, and marine (COM) science workforce, with limited retention success. It has become increasingly clear that recruitment is not enough. What is urgently needed is a change in the culture that includes systematic eradication of existing paradigms and models that have perpetuated racism, inequities, and injustices in higher education. Bold new paradigms and models are needed to create working and learning climates where all can thrive, both personally and professionally. To truly take an all-hands-on-deck approach to solving the enormous environmental problems humanity now faces, the COM science enterprise needs to critically examine and evaluate the effectiveness of its traditional working and learning practices. Why would anyone want to stay in a discipline that is disrespectful, toxic, and unwelcoming? How do we expect to retain people if they don’t see others with similar backgrounds and experiences in positions of leadership and power? How can people pursue science in environments that perpetuate harassment, discrimination, and misconduct? We will all benefit by creating a scientific and professional culture that offers its workforce exciting, financially viable, REGULAR ISSUE FEATURE","PeriodicalId":54695,"journal":{"name":"Oceanography","volume":" ","pages":""},"PeriodicalIF":2.8,"publicationDate":"2021-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45308899","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-09-01DOI: 10.5670/OCEANOG.2021.313
Bob Friel
{"title":"Tangled Up in Blue","authors":"Bob Friel","doi":"10.5670/OCEANOG.2021.313","DOIUrl":"https://doi.org/10.5670/OCEANOG.2021.313","url":null,"abstract":"","PeriodicalId":54695,"journal":{"name":"Oceanography","volume":"34 1","pages":"12-15"},"PeriodicalIF":2.8,"publicationDate":"2021-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43465424","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-09-01DOI: 10.5670/OCEANOG.2021.316
Peter J. S. Franks
{"title":"Envisioning and Writing a Thesis Proposal","authors":"Peter J. S. Franks","doi":"10.5670/OCEANOG.2021.316","DOIUrl":"https://doi.org/10.5670/OCEANOG.2021.316","url":null,"abstract":"","PeriodicalId":54695,"journal":{"name":"Oceanography","volume":"34 1","pages":"82-87"},"PeriodicalIF":2.8,"publicationDate":"2021-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48650770","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-09-01DOI: 10.5670/OCEANOG.2021.314
N. Record
16 IF YOU COULD somehow ask a North Atlantic right whale what she thinks the future holds, what would she say? Right whales must, in some way, think about the future in order to make survival decisions. As an ocean science community, our eyes are trained increasingly on the future as well. The twin global environmental crises of climate change and biodiversity loss have elevated the science of real-world prediction to one of urgent interest. At timescales ranging from hours to decades, society is asking ocean science for actionable predictions, projections, and forecasts, with the hope of mitigating and adapting to the changing ocean. Meeting this challenge requires more than the ability to predict ocean dynamics. For highly endangered species like the North Atlantic right whale (Eubalaena glacialis), better foresight might have prepared us for the changes that recently led to a catastrophic unusual mortality event (UME). Predictable oceanographic changes in turn drove changes in right whale migration and calving, reversing what had been a recovery of the species. Now, fewer than 400 of them remain alive. For many of us working in right whale science, policy, and management, we are haunted by questions of how the UME might have been anticipated and prevented and how we might prevent something similar in the future. The oceanography itself, while crucial, is only half of the equation. As Meyer-Gutbrod et al. (2021, in this issue) detail in their analysis, the oceanographic mechanisms behind the recent changes are well understood by the oceanographic community. Warming has led to shifts in ocean currents like the Gulf Stream, which influence the source of deep-water supply to the Gulf of Maine (Neto et al., 2021). Changes in deepwater conditions alter the availability of right whales’ primary prey, Calanus finmarchicus (Record et al., 2019). Without a reliable supply of prey, foraging patterns have changed, broadening the range outside of protected areas, leading to higher mortality (Davies and Brillant, 2019) and reduced calving, and thus putting the species at significant risk of extinction (Meyer-Gutbrod et al., 2021, in this issue). PERSPECTIVE
16如果你能问北大西洋露脊鲸她认为未来会怎样，她会怎么说？露脊鲸必须以某种方式思考未来，才能做出生存决定。作为一个海洋科学界，我们的眼睛也越来越关注未来。气候变化和生物多样性丧失这两大全球环境危机使现实世界预测科学成为人们迫切关注的问题之一。在从几个小时到几十年的时间尺度上，社会要求海洋科学提供可操作的预测、预测和预测，以期缓解和适应不断变化的海洋。应对这一挑战需要的不仅仅是预测海洋动力学的能力。对于北大西洋露脊鲸（Eubalaena glacialis）等高度濒危物种来说，更好的远见可能会让我们为最近导致灾难性异常死亡事件（UME）的变化做好准备。可预测的海洋学变化反过来推动了露脊鲸迁徙和产仔的变化，扭转了该物种的复苏。现在，他们中只有不到400人还活着。对于我们许多从事露脊鲸科学、政策和管理工作的人来说，我们一直被如何预测和预防UME以及我们如何在未来防止类似的事情的问题所困扰。海洋学本身虽然至关重要，但只是等式的一半。正如Meyer Gutbrod等人（2021，本期）在他们的分析中详细描述的那样，海洋学界对最近变化背后的海洋学机制有着深刻的理解。变暖导致了墨西哥湾流等洋流的变化，这影响了缅因湾深水供应的来源（Neto等人，2021）。深水条件的变化改变了露脊鲸主要猎物Calanus finmarchicus的可用性（Record等人，2019）。在没有可靠猎物供应的情况下，觅食模式发生了变化，扩大了保护区以外的范围，导致更高的死亡率（Davies和Brillant，2019）和产仔减少，从而使该物种面临重大灭绝风险（Meyer Gutbrod et al.，2021，在本期中）。透视
{"title":"The Intertwined Futures of Whales and Humans","authors":"N. Record","doi":"10.5670/OCEANOG.2021.314","DOIUrl":"https://doi.org/10.5670/OCEANOG.2021.314","url":null,"abstract":"16 IF YOU COULD somehow ask a North Atlantic right whale what she thinks the future holds, what would she say? Right whales must, in some way, think about the future in order to make survival decisions. As an ocean science community, our eyes are trained increasingly on the future as well. The twin global environmental crises of climate change and biodiversity loss have elevated the science of real-world prediction to one of urgent interest. At timescales ranging from hours to decades, society is asking ocean science for actionable predictions, projections, and forecasts, with the hope of mitigating and adapting to the changing ocean. Meeting this challenge requires more than the ability to predict ocean dynamics. For highly endangered species like the North Atlantic right whale (Eubalaena glacialis), better foresight might have prepared us for the changes that recently led to a catastrophic unusual mortality event (UME). Predictable oceanographic changes in turn drove changes in right whale migration and calving, reversing what had been a recovery of the species. Now, fewer than 400 of them remain alive. For many of us working in right whale science, policy, and management, we are haunted by questions of how the UME might have been anticipated and prevented and how we might prevent something similar in the future. The oceanography itself, while crucial, is only half of the equation. As Meyer-Gutbrod et al. (2021, in this issue) detail in their analysis, the oceanographic mechanisms behind the recent changes are well understood by the oceanographic community. Warming has led to shifts in ocean currents like the Gulf Stream, which influence the source of deep-water supply to the Gulf of Maine (Neto et al., 2021). Changes in deepwater conditions alter the availability of right whales’ primary prey, Calanus finmarchicus (Record et al., 2019). Without a reliable supply of prey, foraging patterns have changed, broadening the range outside of protected areas, leading to higher mortality (Davies and Brillant, 2019) and reduced calving, and thus putting the species at significant risk of extinction (Meyer-Gutbrod et al., 2021, in this issue). PERSPECTIVE","PeriodicalId":54695,"journal":{"name":"Oceanography","volume":"34 1","pages":"16-18"},"PeriodicalIF":2.8,"publicationDate":"2021-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44728242","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-06-01DOI: 10.5670/oceanog.2021.220
A. Benson, T. Murray, G. Canonico, E. Montes, F. Muller‐Karger, M. Kavanaugh, J. Trinanes, L. Dewitt
Assessing the current state of and predicting change in the ocean’s biological and ecosystem resources requires observations and research to safeguard these valuable public assets. The Marine Biodiversity Observation Network (MBON) partnered with the Global Ocean Observing System Biology and Ecosystems Panel and the Ocean Biodiversity Information System to address these needs through collaboration, data standardization, and data sharing. Here, we describe the generalized MBON data processing flow, which includes several steps to ensure that data are findable, accessible, interoperable, and reusable. By following this flow, data collected and managed by MBON have contributed to our understanding of the Global Ocean Observing System Essential Ocean Variables and demonstrated the value of web-based, interactive tools to explore and better understand environmental change. Although the MBON’s generalized data processing flow is already in practice, work remains in building ontologies for biological concepts, improving processing scripts for data standardization, and speeding up the data collection-to-sharing timeframe.
{"title":"Data Management and Interactive Visualizations for the Evolving Marine Biodiversity Observation Network","authors":"A. Benson, T. Murray, G. Canonico, E. Montes, F. Muller‐Karger, M. Kavanaugh, J. Trinanes, L. Dewitt","doi":"10.5670/oceanog.2021.220","DOIUrl":"https://doi.org/10.5670/oceanog.2021.220","url":null,"abstract":"Assessing the current state of and predicting change in the ocean’s biological and ecosystem resources requires observations and research to safeguard these valuable public assets. The Marine Biodiversity Observation Network (MBON) partnered with the Global Ocean Observing System Biology and Ecosystems Panel and the Ocean Biodiversity Information System to address these needs through collaboration, data standardization, and data sharing. Here, we describe the generalized MBON data processing flow, which includes several steps to ensure that data are findable, accessible, interoperable, and reusable. By following this flow, data collected and managed by MBON have contributed to our understanding of the Global Ocean Observing System Essential Ocean Variables and demonstrated the value of web-based, interactive tools to explore and better understand environmental change. Although the MBON’s generalized data processing flow is already in practice, work remains in building ontologies for biological concepts, improving processing scripts for data standardization, and speeding up the data collection-to-sharing timeframe.","PeriodicalId":54695,"journal":{"name":"Oceanography","volume":" ","pages":""},"PeriodicalIF":2.8,"publicationDate":"2021-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48678287","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-06-01DOI: 10.5670/OCEANOG.2021.203
J. M. Magalhães, W. Alpers, A. M. Santos-Ferreira, Jose Machado da Silva
Breaking surface waves play a key role in the exchange of momentum, heat, and gases between the atmosphere and the ocean. Waves break at the ocean’s surface at high or medium wind speeds or in the absence of wind due to shoaling of the seafloor. However, surface waves also break due to interactions with internal solitary waves (ISWs). In this paper, we revisit surface wave breaking caused by ISWs and how ISWs are manifested in synthetic aperture radar (SAR) images acquired by the TerraSAR-X and Sentinel-1 satellites and in high-resolution radar altimeter data acquired by the SAR altimeter (SRAL) onboard the Sentinel-3A satellite. X-band TerraSAR-X images acquired at low wind speeds suggest that meter-scale surface breaking waves resulting from large-scale ISWs are associated with large modulations in backscatter at HH and VV polarizations that cannot be explained by present theories. Furthermore, Sentinel-1 C-band SAR satellite images acquired at moderate to high wind speeds also exhibit large radar signatures from surface wave breaking at VV and VH cross-polarizations. Finally, new observations from the Sentinel-3 SRAL altimeter show clear evidence of significant wave height (SWH) variations along the propagation paths of ISWs. The SWH signatures are unique in showing that the surface wave energy does not return to its unperturbed level after an ISW passes, most likely because intense meter-scale wave breaking results in surface wave energy dissipation. In summary, these results show that surface wave breaking contributes significantly to radar remote sensing of ISWs.
{"title":"Surface Wave Breaking Caused by Internal Solitary Waves: Effects on Radar Backscattering Measured by SAR and Radar Altimeter","authors":"J. M. Magalhães, W. Alpers, A. M. Santos-Ferreira, Jose Machado da Silva","doi":"10.5670/OCEANOG.2021.203","DOIUrl":"https://doi.org/10.5670/OCEANOG.2021.203","url":null,"abstract":"Breaking surface waves play a key role in the exchange of momentum, heat, and gases between the atmosphere and the ocean. Waves break at the ocean’s surface at high or medium wind speeds or in the absence of wind due to shoaling of the seafloor. However, surface waves also break due to interactions with internal solitary waves (ISWs). In this paper, we revisit surface wave breaking caused by ISWs and how ISWs are manifested in synthetic aperture radar (SAR) images acquired by the TerraSAR-X and Sentinel-1 satellites and in high-resolution radar altimeter data acquired by the SAR altimeter (SRAL) onboard the Sentinel-3A satellite. X-band TerraSAR-X images acquired at low wind speeds suggest that meter-scale surface breaking waves resulting from large-scale ISWs are associated with large modulations in backscatter at HH and VV polarizations that cannot be explained by present theories. Furthermore, Sentinel-1 C-band SAR satellite images acquired at moderate to high wind speeds also exhibit large radar signatures from surface wave breaking at VV and VH cross-polarizations. Finally, new observations from the Sentinel-3 SRAL altimeter show clear evidence of significant wave height (SWH) variations along the propagation paths of ISWs. The SWH signatures are unique in showing that the surface wave energy does not return to its unperturbed level after an ISW passes, most likely because intense meter-scale wave breaking results in surface wave energy dissipation. In summary, these results show that surface wave breaking contributes significantly to radar remote sensing of ISWs.","PeriodicalId":54695,"journal":{"name":"Oceanography","volume":" ","pages":""},"PeriodicalIF":2.8,"publicationDate":"2021-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47280706","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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