Computed Relationships Between the Inherent and Apparent Optical Properties of a Flat Homogeneous Ocean

Gordon, Howard R.; Brown, Otis B.; Jacobs, Michael M.

doi:10.1364/ao.14.000417

Cited by 649 publications

(329 citation statements)

References 9 publications

Supporting

Mentioning

319

Contrasting

Unclassified

Order By: Relevance

“…[11] Method 3 involves the concept that the apparent optical properties of the ocean are determined by the inherent optical properties of seawater and boundary conditions (such as solar zenith angle and sea state) through radiative transfer theory [Gordon et al, 1975]. In this strategy, the values of the absorption, a, and backscattering, b b , coefficients are most essential to the determination of both apparent optical properties of interest to our study, R rs and K d (wavelength notation suppressed).…”

Section: Methods 3: Semianalytical Approachmentioning

confidence: 99%

Diffuse attenuation coefficient of downwelling irradiance: An evaluation of remote sensing methods

et al. 2005

View full text Add to dashboard Cite

[1] The propagation of downwelling irradiance at wavelength l from surface to a depth (z) in the ocean is governed by the diffuse attenuation coefficient, K d (l). There are two standard methods for the derivation of K d (l) in remote sensing, which both are based on empirical relationships involving the blue-to-green ratio of ocean color. Recently, a semianalytical method to derive K d (l) from reflectance has also been developed. In this study, using K d (490) and K d (443) as examples, we compare the K d (l) values derived from the three methods using data collected in three different regions that cover oceanic and coastal waters, with K d (490) ranging from $0.04 to 4.0 m À1 . The derived values are compared with the data calculated from in situ measurements of the vertical profiles of downwelling irradiance. The comparisons show that the two standard methods produced satisfactory estimates of K d (l) in oceanic waters where attenuation is relatively low but resulted in significant errors in coastal waters. The newly developed semianalytical method appears to have no such limitation as it performed well for both oceanic and coastal waters. For all data in this study the average of absolute percentage difference between the in situ measured and the semianalytically derived K d is $14% for l = 490 nm and $11% for l = 443 nm.

show abstract

Section: Methods 3: Semianalytical Approachmentioning

confidence: 99%

Diffuse attenuation coefficient of downwelling irradiance: An evaluation of remote sensing methods

et al. 2005

View full text Add to dashboard Cite

show abstract

“…Rrs w, through the formula Rrs w = f/Qb bw /(a w + b bw ) from [51,52], depends on the pure seawater inherent properties (absorption (a w ) and backscattering (b bw ) coefficients), on the Sun and viewing angles through the ratio f/Q which also accounts for bidirectional and reflexion-refraction effects at the air-water interface [51,52]. Relationships for the three sensors were computed for different intercepts calculated for different Rrs w values corresponding to solar and sensor zenith angles varying from 0˝to 75˝.…”

Section: Best In Situ Based Rrs Vs Spm Regional Relationships For Olmentioning

confidence: 99%

Potential of High Spatial and Temporal Ocean Color Satellite Data to Study the Dynamics of Suspended Particles in a Micro-Tidal River Plume

et al. 2016

View full text Add to dashboard Cite

Ocean color satellite sensors are powerful tools to study and monitor the dynamics of suspended particulate matter (SPM) discharged by rivers in coastal waters. In this study, we test the capabilities of Landsat-8/Operational Land Imager (OLI), AQUA&TERRA/Moderate Resolution Imaging Spectroradiometer (MODIS) and MSG-3/Spinning Enhanced Visible and Infrared Imager (SEVIRI) sensors in terms of spectral, spatial and temporal resolutions to (i) estimate the seawater reflectance signal and then SPM concentrations and (ii) monitor the dynamics of SPM in the Rhône River plume characterized by moderately turbid surface waters in a micro-tidal sea. Consistent remote-sensing reflectance (Rrs) values are retrieved in the red spectral bands of these four satellite sensors (median relative difference less than~16% in turbid waters). By applying a regional algorithm developed from in situ data, these Rrs are used to estimate SPM concentrations in the Rhône river plume. The spatial resolution of OLI provides a detailed mapping of the SPM concentration from the downstream part of the river itself to the plume offshore limits with well defined small-scale turbidity features. Despite the low temporal resolution of OLI, this should allow to better understand the transport of terrestrial particles from rivers to the coastal ocean. These details are partly lost using MODIS coarser resolutions data but SPM concentration estimations are consistent, with an accuracy of about 1 to 3 g¨m´3 in the river mouth and plume for spatial resolutions from 250 m to 1 km. The MODIS temporal resolution (2 images per day) allows to capture the daily to monthly dynamics of the river plume. However, despite its micro-tidal environment, the Rhône River plume shows significant short-term (hourly) variations, mainly controlled by wind and regional circulation, that MODIS temporal resolution failed to capture. On the contrary, the high temporal resolution of SEVIRI makes it a powerful tool to study this hourly river plume dynamics. However, its coarse resolution prevents the monitoring of SPM concentration variations in the river mouth where SPM concentration variability can reach 20 g¨m´3 inside the SEVIRI pixel. Its spatial resolution is nevertheless sufficient to reproduce the plume shape and retrieve SPM concentrations in a valid range, taking into account an underestimation of about 15%-20% based on comparisons with other sensors and in situ data. Finally, the capabilities, advantages and limits of these satellite sensors are discussed in the light of the spatial and temporal resolution improvements provided by the new and future generation

show abstract

“…wheref is an empirical factor averaging about 0.32-0.33 [Gordon et al, 1975;Morel and Prieur, 1977;Jerome et al, 1988;Kirk, 1991], t is the transmittance of the air-sea interface, Q(3.) is the upwelling irradiance-to-radiance ratio Eu(3.)/Lu(3.…”

Section: Theoretical Basismentioning

confidence: 99%

Semianalytic Moderate‐Resolution Imaging Spectrometer algorithms for chlorophyll a and absorption with bio‐optical domains based on nitrate‐depletion temperatures

Carder¹,

Chen²,

Lee³

et al. 1999

J. Geophys. Res.

504

321

View full text Add to dashboard Cite

(1) high photoprotective pigment to chlorophyll ratio and low self-shading, which for brevity, we designate as "unpackaged"; (2) low photoprotective pigment to chlorophyll ratio and high selfshading, which we designate as "packaged"; and (3) a transitional or global-average type. These domains can be identified from space by comparing sea-surface temperature to nitrogendepletion temperatures for each domain. Algorithm errors of more than 45 % are reduced to errors of less than 30 % with this approach, with the greatest effect occurring at the eastern and polar boundaries of the basins.

show abstract

Computed Relationships Between the Inherent and Apparent Optical Properties of a Flat Homogeneous Ocean

Cited by 649 publications

References 9 publications

Diffuse attenuation coefficient of downwelling irradiance: An evaluation of remote sensing methods

Diffuse attenuation coefficient of downwelling irradiance: An evaluation of remote sensing methods

Potential of High Spatial and Temporal Ocean Color Satellite Data to Study the Dynamics of Suspended Particles in a Micro-Tidal River Plume

Semianalytic Moderate‐Resolution Imaging Spectrometer algorithms for chlorophyll a and absorption with bio‐optical domains based on nitrate‐depletion temperatures

Contact Info

Product

Resources

About