Earth Observing System AM1 mission to Earth

An empirical model based on the regression between daily PM 2.5 (particles with aerodynamic diameters of less than 2.5 µm) concentrations and aerosol optical thickness (AOT) measurements from the multiangle imaging spectroradiometer (MISR) was developed and tested using data from the eastern United States during the period of 2001. Overall, the empirical model explained 48% of the variability in PM 2.5 concentrations. The root-meansquare error of the model was 6.2 µg/m 3 with a corresponding average PM 2.5 concentration of 13.8 µg/m 3 . When PM 2.5 concentrations greater than 40 µg/m 3 were removed, model results were shown to be unbiased estimators of observations. Several factors, such as planetary boundary layer height, relative humidity, season, and other geographical attributes of monitoring sites, were found to influence the association between PM 2.5 and AOT. The findings of this study illustrate the strong potential of satellite remote sensing in regional ambient air quality monitoring as an extension to ground networks. With the continual advancement of remote sensing technology and global data assimilation systems, AOT measurements derived from satellite remote sensors may provide a cost-effective approach as a supplemental source of information for determining ground-level particle concentrations.

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“…The PM2. 5 (b) Regression Analysis. The empirical model described in eq 4 was fitted using the model dataset.…”

Section: Resultsmentioning

confidence: 99%

“…In December 1999, the National Aeronautics and Space Administration (NASA) launched its Terra Earth Observing Satellite (5). The multiangle imaging spectroradiometer (MISR) aboard Terra employs nine cameras pointed at different fixed angles to simultaneously observe reflected and scattered sunlight in four wavelength bands.…”

Section: Introductionmentioning

confidence: 99%

Estimating Ground-Level PM_2.5 in the Eastern United States Using Satellite Remote Sensing

Liu

Sarnat

Kilaru

et al. 2005

Environ. Sci. Technol.

427

283

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“…The spatial resolution of band 1-2 is 250 m at nadir, 500 m for bands 3-7, and 1 km for the remaining 29 bands (Kaufman et al, 1998;Barnes et al, 1998).…”

Section: Modis Lai/fpar Products (Mod15a2)mentioning

confidence: 99%

Improved global simulations of gross primary product based on a new definition of water stress factor and a separate treatment of C3 and C4 plants

Yan

Wang

Billesbach

et al. 2015

Ecological Modelling

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A B S T R A C TAccurate simulation of terrestrial gross primary production (GPP), the largest global carbon flux, benefits our understanding of carbon cycle and its source of variation. This paper presents a novel light use efficiency-based GPP model called the terrestrial ecosystem carbon flux model (TEC) driven by MODIS FPAR and climate data coupled with a precipitation-driven evapotranspiration (E) model (Yan et al., 2012). TEC incorporated a new water stress factor, defined as the ratio of actual E to Priestley and Taylor (1972) potential evaporation (E PT ). A maximum light use efficiency (e*) of 1.8 gC MJ À1 and 2.76 gC MJ À1 was applied to C3 and C4 ecosystems, respectively. An evaluation at 18 eddy covariance flux towers representing various ecosystem types under various climates indicates that the TEC model predicted monthly average GPP for all sites with overall statistics of r = 0.85, RMSE = 2.20 gC m À2 day À1 , and bias = À0.05 gC m À2 day À1 . For comparison the MODIS GPP products (MOD17A2) had overall statistics of r = 0.73, RMSE = 2.82 gC m À2 day À1 , and bias = À0.31 gC m À2 day À1 for this same set of data. In this case, the TEC model performed better than MOD17A2 products, especially for C4 plants. We obtained an estimate of global mean annual GPP flux at 128.2 AE 1.5 Pg C yr À1 from monthly MODIS FPAR and European Centre for Medium-Range Weather Forecasts (ECMWF) ERA reanalysis data at a 1.0 spatial resolution over 11 year period from 2000 to 2010. This falls in the range of published land GPP estimates that consider the effect of C4 and C3 species. The TEC model with its new definition of water stress factor and its parameterization of C4 and C3 plants should help better understand the coupled climate-carbon cycle processes.

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“…To assess the climatic impact of aerosol on a global scale, a variety of instruments designed for measuring different aerosol properties are now and/or will soon be flying on spacecraft (cf. Kaufman et al [1997aKaufman et al [ , 1998] for a more detailed review).…”

Section: Introductionmentioning

confidence: 99%

Path radiance technique for retrieving aerosol optical thickness over land

Wen¹,

Tsay²,

Cahalan³

et al. 1999

J. Geophys. Res.

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Abstract. The key issue in retrieving aerosol optical thickness over land from shortwave satellite radiances is to identify and separate the signal due to scattering by a largely transparent aerosol layer from the noise due to reflection by the background surface, where the signal is relatively uniform compared to the highly inhomogeneous surface contribution. Sensitivity studies in aerosol optical thickness retrievals reveal that the apparent reflectance at the top of the atmosphere is very susceptible to the surface reflectance, especially when aerosol optical thickness is small. Uncertainties associated with surface reflectance estimation can greatly amplify the error of the aerosol optical thickness retrieval. To reduce these uncertainties, we have developed a "path radiance" method to retrieve aerosol optical thickness over land by extending the traditional technique that uses the "dark object" approach to extract the aerosol signal. This method uses the signature of the correlation of visible and middle-IR reflectance at the surface and couples the correlation with the atmospheric effect. suggested a "dark object" approach to retrieve aerosol optical thickness in regions where the surface is covered with dense vegetation or forest. One advantage of the dark object approach is that the surface reflectance is small, so that the error in retrieved aerosol optical thickness is also relatively small compared to errors over bright surfaces. Another advantage of using the dark object approach is that there are correlations between the middle-IR band at 2.2/am and visible (blue and 31,321

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Earth Observing System AM1 mission to Earth

Cited by 108 publications

References 45 publications

Estimating Ground-Level PM_2.5 in the Eastern United States Using Satellite Remote Sensing

Estimating Ground-Level PM_2.5 in the Eastern United States Using Satellite Remote Sensing

Improved global simulations of gross primary product based on a new definition of water stress factor and a separate treatment of C3 and C4 plants

Path radiance technique for retrieving aerosol optical thickness over land

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Earth Observing System AM1 mission to Earth

Cited by 108 publications

References 45 publications

Estimating Ground-Level PM2.5 in the Eastern United States Using Satellite Remote Sensing

Estimating Ground-Level PM2.5 in the Eastern United States Using Satellite Remote Sensing

Improved global simulations of gross primary product based on a new definition of water stress factor and a separate treatment of C3 and C4 plants

Path radiance technique for retrieving aerosol optical thickness over land

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Product

Resources

About

Estimating Ground-Level PM_2.5 in the Eastern United States Using Satellite Remote Sensing

Estimating Ground-Level PM_2.5 in the Eastern United States Using Satellite Remote Sensing