Evaluation of ocean chlorophyll-a remote sensing algorithms using in situ fluorescence data in Southern Brazilian Coastal Waters

Silva, Gabriel Serrato de Mendonça; Garcia, Carlos Alberto Eiras

doi:10.1590/2675-2824069.20-014gsdms

Cited by 7 publications

(4 citation statements)

References 55 publications

(58 reference statements)

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“…Another initiative of SiMCosta's team is to offer ocean color products (i.e., chlorophyll-a concentration, total suspended solids concentration, turbidity, etc.) to the ocean community daily (Ávila et al, 2021;Silva and Garcia, 2021). The increased number of satellite sensors in recent years has considerably improved our spatial and temporal resolution for coastal studies.…”

Section: Brazilian Coastal Observing and Modeling Systemsmentioning

confidence: 99%

Coastal Ocean Observing and Modeling Systems in Brazil: Initiatives and Future Perspectives

et al. 2021

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Coastal ocean observing and modeling systems (coastal observatories), connected with regional and global ocean systems, improve the quality of information and forecasts for effective management of safe and sustainable maritime activities. The public availability of systematic and long-term information of the ocean is an engine for the Blue Economy, boosting economic growth, employment, and innovation. An overview of some Brazilian initiatives is presented in this paper, involving universities, private companies, federal and state agencies, covering institutions from south to north of Brazil. Although these initiatives focus mainly on ocean physics, integrated efforts can extend the scope to include biogeochemistry and marine biodiversity, helping to address interdisciplinary problems. Existing initiatives can be connected, and new ones fostered, to fill in the gaps of temporal and spatial coverage of ocean monitoring in the vast oceanic area under Brazilian jurisdiction (nationally referred to as the Blue Amazon, in reference to the similar richness of the Amazon Forest). The alignment among national and regional initiatives, as well as with international programs, can be promoted if coordinated by a national-level organization, maximizing the return of public investment and socioeconomic benefits. In light of international examples, possible future institutional arrangements are discussed, leveraging from existing national public policies and international cooperation that Brazil is taking part. The United Nations Decade of Ocean Science for Sustainable Development is a timely opportunity to encourage an institutional arrangement to support and articulate an integrated network of coastal observatories in Brazil.

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Section: Brazilian Coastal Observing and Modeling Systemsmentioning

confidence: 99%

Coastal Ocean Observing and Modeling Systems in Brazil: Initiatives and Future Perspectives

et al. 2021

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“…To overcome this temporal limitation, alternative technologies that present real-time data acquisition have been proposed (Loisa et al 2015;Cremella et al 2018;Shin et al 2018;Garrido et al 2019;Panchenko et al 2020;Silva and Garcia 2021). Fluorescence optical sensors stand out among diverse technologies.…”

Section: Introductionmentioning

confidence: 99%

Fluorescence in the estimation of chlorophyll-a in public water reservoirs in the Brazilian cerrado

Souza de Barros,

de Almeida,

Moraes Soares

et al. 2024

Mar. Freshw. Res.

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Context The usual strategy for monitoring of eutrophication process is the use of traditional limnological methods, based on laboratory analysis. These procedures involve costly and time-consuming analyses, usually with in vitro methodologies, which can still have limitations in terms of sensitivity and reliability, if poorly managed. Phytoplankton pigments, such as chlorophyll-a (Chl-a), are highly fluorescent and can provide the environmental status of water bodies. Aims This study aims to analyse, compare and evaluate an estimation of Chl-a through fluorescence in public water sources in the Brazilian cerrado. Exploratory statistical analyses were conducted by using absolute fluorescence units (AFU) and relative fluorescence units (RFU) compared with traditional laboratory data (standard procedure for the determination of Chl-a by spectroscopic methods) to evaluate the significance of differences in estimating Chl-a concentration. Subsequently, empirical models, based on spectral band combinations, were generated to convert fluorescence measurement in Chl-a concentration, by linear regression. Key results The generated model found a strong correlation and coefficient of determination (r = 0.88; R2 = 0.78). The efficiency of the model was also confirmed by statistical indicators (RMSE = 1.27, MAPE = 26.72 and BIAS = −6.32). Conclusions We concluded that the estimate of Chl-a through RFU was better than through AFU. Implications Therefore, based on the results of this study, it is recommended that RFU be used to obtain more precise and accurate estimates of Chl-a concentration through empirical models based on linear regression.

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“…In attempting to achieve an accurate understanding of ocean information, ocean remote sensing encounters the following challenges: the ocean reflection signal is weak and the spectral difference between phenomena is small, and ocean remote sensing requires sensors with high temporal resolutions and high spectral resolutions. The vast ocean is a body of water that is in motion all the time; for example, the sea surface wind field, wave field, current field, tides, and eddies are all simultaneously changing elements in the ocean's dynamic environment [11][12][13][14]. Therefore, the timedomain characteristics of ocean remote sensing are very important.…”

Section: Introductionmentioning

confidence: 99%

A High-Performance Thin-Film Sensor in 6G for Remote Sensing of the Sea Surface

Song

et al. 2023

Remote Sensing

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Functional devices in the THz band will provide a highly important technical guarantee for the promotion and application of 6G technology. We sought to design a high-performance sensor with a large area, high responsiveness, and low equivalent noise power, which is stable at room temperature for long periods and still usable under high humidity; it is suitable for the environment of marine remote sensing technology and has the potential for mass production. We prepared a Te film with high stability and studied its crystallization method by comparing the sensing and detection effects of THz waves at different annealing temperatures. It is proposed that the best crystallization and detection effect is achieved by annealing at 100 °C for 60 min, with a sensitivity of up to 19.8 A/W and an equivalent noise power (NEP) of 2.8 pW Hz−1/2. The effective detection area of the detector can reach the centimeter level, and this level is maintained for more than 2 months in a humid environment at 30 °C with 70–80% humidity and without encapsulation. Considering its advantages of stability, detection performance, large effective area, and easy mass preparation, our Te thin film is an ideal sensor for 6G ocean remote sensing technology.

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Evaluation of ocean chlorophyll-a remote sensing algorithms using in situ fluorescence data in Southern Brazilian Coastal Waters

Cited by 7 publications

References 55 publications

Coastal Ocean Observing and Modeling Systems in Brazil: Initiatives and Future Perspectives

Coastal Ocean Observing and Modeling Systems in Brazil: Initiatives and Future Perspectives

Fluorescence in the estimation of chlorophyll-a in public water reservoirs in the Brazilian cerrado

A High-Performance Thin-Film Sensor in 6G for Remote Sensing of the Sea Surface

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