Charles R. Mcclain

• National Aeronautics and Space Administration

The Ocean Color Instrument (OCI) is the primary payload on NASA’s Plankton, Aerosol, Cloud, ocean Ecosystem (PACE) mission. Its primary purpose is to enable new scientific studies of ocean biology, aerosols, and clouds. This paper describes the design of the instrument and its radiometric performance as measured during the prelaunch characterizatio...

We recount, based on our involvements in NASA ocean color flight projects, the chronology of technical challenges, lessons learned, and key developments over the past 40 + years of NASA satellite ocean color, beginning with the Nimbus-7/Coastal Zone Color Scanner, that have led to the upcoming Plankton, Aerosol, Cloud, ocean Ecosystem (PACE) missio...

The Plankton, Aerosol, Cloud, Ocean Ecosystem (PACE) mission represents the National Aeronautics and Space Administration’s (NASA) next investment in satellite ocean color and the study of Earth’s ocean–atmosphere system, enabling new insights into oceanographic and atmospheric responses to Earth’s changing climate. PACE objectives include extendin...

The Plankton, Aerosol, Cloud, ocean Ecosystem (PACE; https://pace.gsfc.nasa.gov) mission represents NASA’s next great investment in satellite ocean color and the combined study of Earth’s oceanatmosphere system.

A 16-year (1998–2013) analysis of trends and seasonal patterns was conducted for the 5 subtropical ocean gyres using chlorophyll-a (Chl-a) retrievals from ocean color satellite data, sea surface temperature (SST) obtained from optimally interpolated Advanced Very High Resolution Radiometer (AVHRR) data, and sea-level anomaly (SLA) from Aviso multi-...

The NASA VIIRS Ocean Science Team (VOST) has developed two independent calibrations of the SNPP VIIRS moderate resolution reflective solar bands using solar diffuser and lunar observations through June 2013. Fits to the solar calibration time series show mean residuals per band of 0.078–0.10%. There are apparent residual lunar libration correlation...

Photosynthetic production of organic matter by microscopic oceanic phytoplankton fuels ocean ecosystems and contributes roughly half of the Earth's net primary production. For 13 years, the Sea-viewing Wide Field-of-view Sensor (SeaWiFS) mission provided the first consistent, synoptic observations of global ocean ecosystems. Changes in the surface...

The mid-shelf front (MSF) of the Buenos Aires province continental shelf in the Southwestern Atlantic Ocean plays a central role in the pelagic ecosystem of the region acting as the main spring reproductive area for the northern population of the Argentine anchovy Engraulis anchoita and supporting high concentrations of chlorophyll as well as zoopl...

Photosynthetic production of organic matter by microscopic oceanic phytoplankton fuels ocean ecosystems and contributes roughly half of the Earth's net primary production. For 13 years, the Sea-viewing Wide Field-of-view Sensor (SeaWiFS) mission provided the first consistent, synoptic observations of global ocean ecosystems. Changes in the surface...

VIIRS is being used by NOAA to routinely generate measurements of the Earth’s surface and atmosphere, which are referred to as Environment Data Records (EDR). The ocean color EDR includes normalized water-leaving radiance (a measure of surface reflectance at 410, 443, 486, 551, and 671 nm), inherent optical properties (absorption and phytoplankton...

Ocean color climate data records (CDRs) require water-leaving radiances with 5% absolute and 1% relative accuracies as input. Because of the amplification of any sensor calibration errors by the atmospheric correction, the 1% relative accuracy requirement translates into a 0.1% long-term radiometric stability requirement for top-of-the-atmosphere (...

A satellite multi-sensor approach is used to analyse the biological response of open ocean regions of the subtropical gyres to changes in physical forcing. Thirteen years (1998–2010) of Sea-viewing Wide Field-of-view Sensor (SeaWiFS) chlorophyll-a (chl-a) data, combined with concurrent satellite records of sea-surface temperature (SST) and sea leve...

The NASA VIIRS Ocean Science Team (VOST) has the task of evaluating Suomi NPP VIIRS ocean color data for the continuity of the NASA ocean color climate data records. The generation of science quality ocean color data products requires an instrument calibration that is stable over time. Since the VIIRS NIR Degradation Anomaly directly impacts the ba...

Following the launch of the Visible Infrared Imaging Radiometer Suite (VIIRS) aboard the Suomi National Polar-orbiting Partnership (NPP) spacecraft, the NASA NPP VIIRS Ocean Science Team (VOST) began an evaluation of ocean color data products to determine whether they could continue the existing NASA ocean color climate data record (CDR). The VOST...

Sensor design and mission planning for satellite ocean color measurements requires careful consideration of the signal dynamic range and sensitivity (specifically here signal-to-noise ratio or SNR) so that small changes of ocean properties (e.g., surface chlorophyll-a concentrations or Chl) can be quantified while most measurements are not saturate...

We developed an ecosystem/biogeochemical model system, which includes multiple phytoplankton functional groups and carbon cycle dynamics, and applied it to investigate physical-biological interactions in Icelandic waters. Satellite and in situ data were used to evaluate the model. Surface seasonal cycle amplitudes and biases of key parameters (DIC,...

The National Aeronautics and Space Administration ocean color products of Sea-viewing Wide Field-of-view Sensor (SeaWiFS) and Moderate Resolution Imaging Spectroradiometer (MODIS) Aqua have been reprocessed in 2009. This paper describes the changes to the calibration approach for MODIS Aqua. Due to a significant downward trend in the operational MO...

This document suggests requirements for an advanced ocean radiometer, such as e.g. the ACE (Aerosol/Cloud/Ecosystem) ocean radiometer. The ACE ocean biology mission objectives have been defined in the ACE Ocean Biology white paper. The general requirements presented therein were chosen as the basis for the requirements provided in this document, wh...

Ocean color climate data records require water-leaving radiances with 5% absolute and 1% relative accuracies as input. Because of the amplification of any sensor calibration errors by the atmospheric correction, the 1% relative accuracy requirement translates into a 0.1% long-term radiometric stability requirement for top-of-the-atmosphere radiance...

For several years, the NASA/Goddard Space Flight Center (GSFC) NPP VIIRS Ocean Science Team (VOST) provided substantial scientific input to the NPP project regarding the use of Visible Infrared Imaging Radiometer Suite (VIIRS) to create science quality ocean color data products. This work has culminated into an assessment of the NPP project and the...

The Ocean Radiometer for Carbon Assessment (ORCA) is a new design for the next generation remote sensing of ocean biology and biogeochemistry. ORCA is configured to meet all the measurement requirements of the Decadal Survey Aerosol, Cloud, and Ecology (ACE ), the Ocean Ecosystem (OES) radiometer and the Pre-ACE climate data continuity mission (PAC...

The VIIRS Ocean Science Team (VOST) has been developing an Ocean Data Simulator to create realistic VIIRS SDR datasets based on MODIS water-leaving radiances. The simulator is helping to assess instrument performance and scientific processing algorithms. Several changes were made in the last two years to complete the simulator and broaden its usefu...

The Ocean Radiometer for Carbon Assessment (ORCA) is a new design for the next generation remote sensing of oceans biology and biogeochemistry satellite. ORCA is configured to meet the requirements of the Decadal Survey recommended Aerosol, Cloud, and Ecology (ACE ), the Ocean Ecosystem (OES) radiometer and the Pre-ACE climate data continuity missi...

The relationship between the Secchi depth (ZSD) and the diffuse attenuation coefficient for photosynthetically active radiation (Kd(PAR)), and in particular the product of the two, ZSD · Kd(PAR), is governed primarily by the ratio of light scattering to absorption. We analyzed measurements of ZSD and Kd(PAR) at main stem stations in Chesapeake Bay...

We use an ecosystem/biogeochemical model, which includes multiple phytoplankton functional groups and carbon cycle dynamics, to investigate physical-biological interactions in Icelandic waters. Satellite and in situ data were used to validate the model. The seasonality of the coccolithophore and "other phytoplankton" (diatoms and dinoflagellates) b...

Table 3 of Appl. Opt. 49, 5455 (2010)APOPAI0003-6935 is corrected in this publisher’s note.

Observations of the Moon provide a primary technique for the on-orbit cross calibration of Earth remote sensing instruments. Monthly lunar observations are major components of the on-orbit calibration strategies of SeaWiFS and MODIS. SeaWiFS has collected more than 132 low phase angle and 59 high phase angle lunar observations over 12 years, Terra...

The Moderate Resolution Imaging Spectroradiometer (MODIS) on the Aqua platform has nine spectral bands with center wavelengths from 412 to 870 nm that are used to produce the standard ocean color data products. Ocean scenes usually contain high contrast due to the presence of bright clouds over dark water. About half of the MODIS Aqua ocean pixels...

We describe the development of a new suite of aerosol models for the retrieval of atmospheric and oceanic optical properties from the SeaWiFS and MODIS sensors, including aerosol optical thickness (τ), angstrom coefficient (α), and water-leaving radiance ( L w ). The new aerosol models are derived from Aerosol Robotic Network (AERONET) observations...

The NASA ocean color products of SeaWiFS and MODIS Aqua have been reprocessed in 2009 and 2010, respectively. This paper describes the changes to the calibration approach for MODIS Aqua. Due to a significant downward trend in the operational MODIS Aqua water-leaving radiances at 412nm, the previous calibration approach was no longer sufficient. The...

Continental shelves are believed to play a major role in carbon cycling due to their high productivity. To improve our understanding of carbon dynamics on continental margins, a dissolved organic matter (DOM) model was developed and imbedded within an existing coupled ocean circulation-biogeochemical model of the U.S. East coast. A model simulation...

Imagers and Sounders for Low Earth Orbit (LEO) provide fundamental global daily observations of the Earth System for scientists, researchers, and operational weather agencies. The imager provides the nominal 1-2 km spatial resolution images with global coverage in multiple spectral bands for a wide range of uses including ocean color, vegetation in...

We, the guest editors of this special issue of Advances in Meteorology (AMET), are grateful to all of the authors, reviewers, and AMET stuff. We hope that the papers in this issue will stimulate further development and confidence building for improved characterization of this extremely complex topic.

Contemporaneous satellite ocean colour data from the Sea-viewing Wide Field-of-view Sensor (SeaWiFS), the Moderate Resolution Imaging Spectroradiometer (MODIS) Terra and MODIS Aqua instruments are consistently calibrated and uniformly processed using equivalent code and algorithms. These sensors cover the globe at different times of a local day. Co...

Observations of the Moon provide one technique for the cross calibration of Earth remote sensing instruments. Monthly lunar observations are major components of the on-orbit calibration strategies of the SeaWiFS and MODIS instruments. SeaWiFS has collected more than 132 low phase angle and 59 high phase angle lunar observations over 12 years, while...

MODIS has 20 reflective solar bands (RSB), covering the VIS, NIR, and SWIR spectral regions. They are calibrated on-orbit using a solar diffuser (SD) panel, made of space-grade Spectralon. The SD bi-directional reflectance factor (BRF) was characterized pre-launch by the instrument vendor with reference to the NIST reflectance standard. Its on-orbi...

Scanning radiometers on earth-orbiting satellites are used to measure the chlorophyll content of the oceans via analysis of the water-leaving radiances. These radiances are very sensitive to the atmospheric correction process, which in turn is polarization dependent. The image created by a scanning radiometer is usually com-posed of successive scan...

The SIMBIOS (Sensor Intercomparison and Merger for Biological and Interdisciplinary Oceanic Studies) Program was conceived as a result of a NASA management review of the agency's strategy for monitoring the bio-optical properties of the global ocean through space-based ocean color remote sensing. SIMBIOS Radiometric Intercomparisons (SIMRICs) were...

Scanning radiometers on earth-orbiting satellites are used to measure the chlorophyll content of the oceans via analysis of the water-leaving radiances. These radiances are very sensitive to the atmospheric correction process. In the standard atmospheric correction algorithms, two bands in the NIR wavelength region are used to determine the radianc...

One of the roles of the VIIRS Ocean Science Team (VOST) is to assess the performance of the instrument and scientific processing software that generates ocean color parameters such as normalized water-leaving radiances and chlorophyll. A VIIRS data simulator is being developed to help aid in this work. The simulator will create a sufficient set of...

The Ocean Radiometer for Carbon Assessment (ORCA) is a new design concept for the next generation ocean biology and biogeochemistry satellite sensor. The wavelength range will be from the near UV, through the visible and to the Short Wave infrared. The challenge in this design is to remove the polarization effects from the optical performance of th...

This paper addresses the uncertainties of global sea-air CO2 flux estimated on the basis of the sea-air pCO2 differences and sea-air CO2 gas transfer rate. Uncertainties in the global sea-air flux estimates are identified from different gas transfer algorithms and monthly wind speeds (NCEP-2 and SSM/I). The net global sea-air flux estimates for the...

We provide an analysis of the seasonal change of the physical forcing factors and their impact on the timing and intensity of phytoplankton blooms in the Barents Sea, with emphasis on the different functional groups that can be distinguished (coccolithophores and other phytoplankton groups) using satellite remote sensing algorithms. Our analyses ar...

Author Posting. © American Geophysical Union, 2009. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research 114 (2009): D06204, doi:10.1029/2008JD011257. The paper presents the current status of the Maritime Aerosol Netw...

Phytoplankton photosynthesis links global ocean biology and climate-driven fluctuations in the physical environment. These interactions are largely expressed through changes in phytoplankton physiology, but physiological status has proven extremely challenging to characterize globally. Phytoplankton fluorescence does provide a rich source of physio...

Concentrations of the phytoplankton pigment chlorophyll-a (Ca) provide indicators of nutrient over-enrichment that has negatively affected Chesapeake Bay, U.S.A. Ca time-series from the National Aeronautics and Space Administration (NASA) Sea-viewing Wide Field-of-view Sensor (SeaWiFS) and Moderate Resolution Imaging Spectroradiometer aboard the Aq...

Ocean-color applications require maximum uncertainties in blue-wavelength water-leaving radiances in oligotrophic ocean of approximately 5%. Water-leaving radiances from Moderate Resolution Imaging Spectroradiometer (MODIS) on the Terra satellite, however, exhibit temporal drift of the order of 15% as well as sensor changes in response versus scan...

The Barents Sea is characterized by significant calcification rates during summer promoted by intense coccolithophore blooms that peak during August. Coccolithophores, among which Emiliania huxleyi (E. huxleyi) is the most abundant and widespread species, are considered to be the most productive calcifying organisms on Earth. They inhabit the surfa...

After the successful Coastal Zone Color Scanner (CZCS, 1978-1986) demonstration that quantitative estimations of geophysical variables such as chlorophyll a and diffuse attenuation coefficient could be derived from top of the atmosphere radiances, a number of international missions with ocean color capabilities were launched beginning in the late 1...

Coccolithophores, among which Emiliania huxleyi (E. huxleyi) is the most abundant and widespread species, are considered to be the most productive calcifying organisms on Earth. They inhabit the surface layer (MLD ~20m) in highly stratified waters where light intensity is high. E. huxleyi often forms massive blooms in temperate and sub-polar oceans...

Phytoplankton photosynthesis links global ocean biology and climate-driven fluctuations in the physical environment. These interactions are largely expressed through changes in phytoplankton physiology, but physiological status has proven extremely challenging to characterize globally. Phytoplankton fluorescence does provide a rich source of physio...

The Moon plays an important role in the radiometric stability monitoring of the NASA Earth Observing System's (EOS) remote sensors. The MODIS and SeaWIFS are two of the key instruments for NASA's EOS missions. The MODIS Protoflight Model (PFM) on-board the Terra spacecraft and the MODIS Flight Model 1 (FM1) on-board the Aqua spacecraft were launche...

The Moderate Resolution Imaging Spectroradiometer (MODIS) on the Earth Observing System (EOS) Aqua platform has 9 spectral bands with center wavelengths from 412nm to 870nm that are used to produce the standard ocean color data products. Ocean color products require a stability of the radiometric calibration on the order of 0.2%, which surpasses th...

The NASA Ocean Biology Processing Group's Calibration and Validation Team uses SeaWiFS on-orbit lunar calibrations to monitor the radiometric response of the instrument over time. With almost eleven years of lunar measurements (more than 124 monthly observations) available for this analysis, the Cal/Val Team has undertaken an investigation of the o...

The Moderate Resolution Imaging Spectroradiometer (MODIS) on the Earth Observing System (EOS) Aqua platform has 9 spectral bands with center wavelengths from 412nm to 870nm that are used to produce the standard ocean color data products. Ocean scenes usually contain high contrast due to the presence of bright clouds over dark water. The MODIS has b...

The Moderate Resolution Imaging Spectroradiometer (MODIS) is currently flying on both the Terra and Aqua satellite platforms. The Ocean Biology Processing Group (OBPG) at NASA Goddard Space Flight Center is producing operational ocean color products from the MODIS-Aqua sensor; however, documented uncertainties and instabilities in the prelaunch and...

The shelf-break front formed between Argentinean shelf waters and the Malvinas Current (MC) flow shows a conspicuous band of high phytoplankton biomass throughout spring and summer, detected by ocean color sensors. That area is the feeding and spawning ground of several commercial species of fish and squid and is thought to play an important role i...

The primary seasonal phytoplankton bloom in the equatorial Atlantic occurs in boreal summer in response to seasonal strengthening of zonal winds. However, the equatorial Atlantic also has a secondary bloom in late fall - early winter. This secondary bloom is weaker than the primary bloom by a factor of two, but is subject to year-to-year variabilit...

Presently, a suite of 12 aerosol models are used for atmospheric correction purposes to retrieve normalized water-leaving radiances in the visible bands of the SeaWiFS and MODIS sensors. These aerosol models are based on Shettle and Fenn's models (1979) of tropospheric and oceanic aerosols. Over most of the open oceans of the world (case 1 water),...

The Gulf Stream western front (GSF) follows the shelf slope topography for a great extent of the South Atlantic Bight (SAB). Sub-surface intrusions of the Gulf Stream are known to provide nutrient-rich waters to the outer shelf regions of the SAB and, consequently, promote phytoplankton growth. These intrusions are much more frequent during summer...

The NASA Ocean Biology Processing Group's Calibration and Validation Team has analyzed the mission-long Sea-Viewing Wide Field-of-View Sensor (SeaWiFS) on-orbit gain and detector calibration time series to verify that lunar calibrations, obtained at nonstandard gains and radiance ranges, are valid for Earth data collected at standard gains and typi...

The NASA Ocean Biology Processing Group's Calibration and Validation (Cal/Val) Team has used SeaWiFS on- orbit lunar and gain calibration data, in conjunction with mission-long trends of global ocean color data products, to diagnose and correct recently emergent residual drifts in the radiometric response of the instrument. An anomaly analysis of t...

The MODIS (Moderate Resolution Imaging Spectroradiometer) scanner makes subframe measurements in some of its bands to increase the spatial resolution from its standard 1km resolution to 500m or 250m. This is achieved by sampling a detector of a high resolution band at twice (or four times) the sampling rate of the 1km bands. This paper shows that a...

The absorption by atmospheric nitrogen dioxide ( NO 2 ) gas in the visible has been traditionally neglected in the retrieval of oceanic parameters from satellite measurements. Recent measurements of NO 2 from spaceborne sensors show that over the Eastern United States the NO 2 column amount often exceeds 1 Dobson Unit ( ∼ 2.69 × 10 16 molecules / c...

Recent advances in global biogeochemical research demonstrate a critical need for long-term ocean color satellite data records of consistent high quality. To achieve that quality, spaceborne instruments require on-orbit vicarious calibration, where the integrated instrument and atmospheric correction system is adjusted using in situ normalized wate...

The retrieval of ocean color radiometry from space-based sensors requires on-orbit vicarious calibration to achieve the level of accuracy desired for quantitative oceanographic applications. The approach developed by the NASA Ocean Biology Processing Group (OBPG) adjusts the integrated instrument and atmospheric correction system to retrieve normal...

We suggest the establishment of the Oceanic Aerosol Network as a new component of the Aerosol Robotic Network (AERONET) that adheres to AERONET calibration and processing. Climate change studies, atmospheric correction of the satellite data, satellite data validation, and aerosol modeling creates a strong demand for new data acquisition. Ship-based...

The NASA Ocean Biology Processing Group's Calibration and Validation (Cal∕Val) team has undertaken an analysis of the mission-long Sea-Viewing Wide Field-of-View Sensor (SeaWiFS) solar calibration time series to assess the long-term degradation of the solar diffuser reflectance over 9 years on orbit. The SeaWiFS diffuser is an aluminum plate coated...

The Moderate Resolution Imaging Spectroradiometer (MODIS) is currently flying on both the Terra and Aqua satellite platforms. The Ocean Biology Processing Group (OBPG) at NASA Goddard Space Flight Center is producing operational ocean color products from the MODIS-Aqua sensor; however, documented uncertainties and instabilities in the prelaunch and...

Contributing roughly half of the biosphere's net primary production (NPP), photosynthesis by oceanic phytoplankton is a vital link in the cycling of carbon between living and inorganic stocks. Each day, more than a hundred million tons of carbon in the form of CO2 are fixed into organic material by these ubiquitous, microscopic plants of the upper...

Historically aerosol optical properties of the maritime atmosphere were not well studied. Being expensive, time and labor consuming, those measurements were by no means systematic, vastly depending on "opportunity" rather than "necessity". Several island sites established by the Aerosol Robotic Network (AERONET) allowed routine data collection, but...

Presently, a suite of 12 aerosol models are used for atmospheric correction purposes to retrieve water-leaving radiances in the visible and near IR spectral bands of the SeaWiFS and MODIS sensors. These models are based on Shettle and Fenn's (1979) aerosol models of tropospheric and oceanic aerosols. As a part of the atmospheric correction effort,...

The Ocean Biology Processing Group (OBPG) at NASA's Goddard Space Flight Center provides the global processing and distribution of ocean color products from MODIS (Esaias et al. 1998), SeaWiFS (McClain et al. 1998), and other ocean color capable sensors. The fundamental measurement in ocean color remote sensing is the spectral distribution of radia...

The NASA Ocean Biology Processing Group's Calibration and Validation Team has used monthly lunar calibrations of SeaWiFS to establish and maintain the on-orbit radiometric stability of instrument at the 0.1% level over its 9-year mission. The Cal/Val Team has compared the SeaWiFS lunar observations with the USGS ROLO photometric model of the Moon t...

The NASA Ocean Biology Processing Group's Calibration and Validation (Cal/Val) Team implemented daily solar calibrations of SeaWiFS to look for step-function changes in the instrument response and has used these calibrations to supplement the monthly lunar calibrations in monitoring the radiometric stability of SeaWiFS during its first year of on-o...

The characterization of the polarization sensitivity of a remote sensing sensor can have a large impact on the data quality of the top-of-atmosphere radiances measured by optical sensors on earth-orbiting satellites. This paper describes an algorithm to improve the polarization characterization of certain elements of an imaging sensor (e.g. detecto...

The timing and duration of coccolithophore blooms along the Patagonian shelf break, as well as insights on the mechanisms that drive and maintain these blooms, were analyzed using time series of chlorophyll chl a, calcite, and sea-surface temperature (SST) derived from remote sensing data (SeaWiFS and AVHRR) and historic hydrographic data. The seas...