Development of a high spectral resolution surface albedo product for the ARM Southern Great Plains central facility

Abstract. We present a method for identifying dominant surface type and estimating high spectral resolution surface albedo at the Atmospheric Radiation Measurement (ARM) facility at the Southern Great Plains (SGP) site in Oklahoma for use in radiative transfer calculations. Given a set of 6-channel narrowband visible and near-infrared irradiance measurements from upward and downward looking multi-filter radiometers (MFRs), four different surface types (snow-covered, green vegetation, partial vegetation, non-vegetated) can be identified. A normalized difference vegetation index (NDVI) is used to distinguish between vegetated and non-vegetated surfaces, and a scaled NDVI index is used to estimate the percentage of green vegetation in partially vegetated surfaces. Based on libraries of spectral albedo measurements, a piecewise continuous function is developed to estimate the high spectral resolution surface albedo for each surface type given the MFR albedo values as input. For partially vegetated surfaces, the albedo is estimated as a linear combination of the green vegetation and non-vegetated surface albedo values. The estimated albedo values are evaluated through comparison to high spectral resolution albedo measurements taken during several Intensive Observational Periods (IOPs) and through comparison of the integrated spectral albedo values to observed broadband albedo measurements. The estimated spectral albedo values agree well with observations for the visible wavelengths constrained by the MFR measurements, but have larger biases and variability at longer wavelengths. Additional MFR channels at 1100 nm and/or 1600 nm would help constrain the high resolution spectral albedo in the near infrared region.

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Development of a high spectral resolution surface albedo product for the ARM Southern Great Plains central facility

Atmospheric Measurement Techniques ◽

10.5194/amt-4-1713-2011 ◽

2011 ◽

Vol 4 (9) ◽

pp. 1713-1733 ◽

Cited By ~ 12

Author(s):

S. A. McFarlane ◽

K. L. Gaustad ◽

E. J. Mlawer ◽

C. N. Long ◽

J. Delamere

Keyword(s):

Great Plains ◽

Spectral Resolution ◽

Surface Albedo ◽

Vegetation Index ◽

Near Infrared ◽

High Spectral Resolution ◽

Surface Type ◽

Southern Great Plains ◽

Green Vegetation ◽

Visible Wavelengths

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Broadband Albedo Observations in the Southern Great Plains

Journal of Applied Meteorology and Climatology ◽

10.1175/jam2317.1 ◽

2006 ◽

Vol 45 (1) ◽

pp. 210-235 ◽

Cited By ~ 7

Author(s):

Claude E. Duchon ◽

Kenneth G. Hamm

Keyword(s):

Time Series ◽

Great Plains ◽

Surface Albedo ◽

Vegetation Index ◽

Normalized Difference Vegetation Index ◽

Geographic Location ◽

Bare Soil ◽

Southern Great Plains ◽

Oklahoma Mesonet ◽

The One

Abstract Time series of daily broadband surface albedo for 1998 and 1999 have been analyzed from six locations in the network of 22 Atmospheric Radiation Measurement Program Solar–Infrared Radiation Stations distributed from central Kansas to central Oklahoma. Two of the stations are in Kansas, and four are in Oklahoma; together they reasonably encompass the variation in geography in the southern Great Plains. Daily precipitation totals locally measured or obtained from nearby Oklahoma Mesonet stations and time series of biweekly maximum normalized difference vegetation index obtained from NOAA’s Advanced Very High Resolution Radiometer were used to determine linkages between surface albedo and amount of precipitation and degree of green vegetation. As part of this determination, daily albedo was categorized according to sky condition, that is, clear, partly cloudy, or overcast, with appropriate boundaries for each category. The more notable results are the following: 1) 2-yr mean annual albedos varied by more than 20% among the six sites, the lowest albedo being 0.18 and the highest albedo being 0.22; 2) the numerical difference was about 4 times the maximum interannual mean difference among the six stations, indicating the importance of geographic location; 3) for sites with a large amount of bare soil, a systematic decrease in albedo in response to rainfall events and a systematic increase in albedo as the soil dried were observed; 4) at the one site with total vegetation cover, that is, no bare soil, albedo response to precipitation events was suppressed; 5) no relation was found between mean annual albedo and annual precipitation; 6) whether days were classified as clear or partly cloudy had little influence on daily albedo, but overcast days typically reduced albedo, sometimes substantially; and 7) the main contributor to low albedos on overcast days with rain was the wet surface; the contribution by the overcast sky was secondary.

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Filling-in of near-infrared solar lines by terrestrial fluorescence and other geophysical effects: simulations and space-based observations from SCIAMACHY and GOSAT

Atmospheric Measurement Techniques ◽

10.5194/amt-5-809-2012 ◽

2012 ◽

Vol 5 (4) ◽

pp. 809-829 ◽

Cited By ~ 109

Author(s):

J. Joiner ◽

Y. Yoshida ◽

A. P. Vasilkov ◽

E. M. Middleton ◽

P. K. E. Campbell ◽

...

Keyword(s):

Spectral Resolution ◽

Vegetation Index ◽

Near Infrared ◽

Fluorescence Emission ◽

Temporal Variations ◽

High Spectral Resolution ◽

Emission Region ◽

Terrestrial Vegetation ◽

Satellite Measurements ◽

The Impact

Abstract. Global mapping of terrestrial vegetation fluorescence from space has recently been accomplished with high spectral resolution (ν/Δν > 35 000) measurements from the Japanese Greenhouse gases Observing SATellite (GOSAT). These data are of interest because they can potentially provide global information on the functional status of vegetation including light-use efficiency and global primary productivity that can be used for global carbon cycle modeling. Quantifying the impact of fluorescence on the O2-A band is important as this band is used for photon pathlength characterization in cloud- and aerosol-contaminated pixels for trace-gas retrievals including CO2. Here, we examine whether fluorescence information can be derived from space using potentially lower-cost hyperspectral instrumentation, i.e., more than an order of magnitude less spectral resolution (ν/Δν ~ 1600) than GOSAT, with a relatively simple algorithm. We discuss laboratory measurements of fluorescence near one of the few wide and deep solar Fraunhofer lines in the long-wave tail of the fluorescence emission region, the calcium (Ca) II line at 866 nm that is observable with a spectral resolution of ~0.5 nm. The filling-in of the Ca II line due to additive signals from various atmospheric and terrestrial effects, including fluorescence, is simulated. We then examine filling-in of this line using the SCanning Imaging Absorption spectroMeter for Atmospheric CHartographY (SCIAMACHY) satellite instrument. In order to interpret the satellite measurements, we developed a general approach to correct for various instrumental artifacts that produce false filling-in of solar lines in satellite measurements. The approach is applied to SCIAMACHY at the 866 nm Ca II line and to GOSAT at 758 and 770 nm on the shoulders of the O2-A feature where there are several strong solar Fraunhofer lines that are filled in primarily by vegetation fluorescence. Finally, we compare temporal and spatial variations of SCIAMACHY additive signals with those of GOSAT and the Enhanced Vegetation Index (EVI) from the MODerate-resolution Imaging Spectroradiometer (MODIS). Although the derived additive signals from SCIAMACHY are extremely weak at 866 nm, their spatial and temporal variations are consistent with chlorophyll a fluorescence or another vegetation-related source. We also show that filling-in occurs at 866 nm over some barren areas, possibly originating from luminescent minerals in rock and soil.

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Filling-in of far-red and near-Infrared solar lines by terrestrial and atmospheric effects: simulations and space-based observations from SCIAMACHY and GOSAT

Atmospheric Measurement Techniques Discussions ◽

10.5194/amtd-5-163-2012 ◽

2012 ◽

Vol 5 (1) ◽

pp. 163-210 ◽

Cited By ~ 7

Author(s):

J. Joiner ◽

Y. Yoshida ◽

A. P. Vasilkov ◽

E. M. Middleton ◽

P. K. E. Campbell ◽

...

Keyword(s):

Spectral Resolution ◽

Vegetation Index ◽

Near Infrared ◽

Fluorescence Emission ◽

High Spectral Resolution ◽

Emission Region ◽

Atmospheric Effects ◽

Terrestrial Vegetation ◽

Spatial And Temporal Patterns ◽

The Impact

Abstract. Global mapping of terrestrial vegetation fluorescence from space has recently been accomplished with high spectral resolution (ν/Δν>35 000) measurements from the Japanese Greenhouse gases Observing SATellite (GOSAT). These data are of interest because they can potentially provide global information on the functional status of vegetation including light use efficiency and global primary productivity that can be used for global carbon cycle modeling. Quantifying the impact of fluorescence on the O2-A band is important as this band is used for cloud- and aerosol-characterization for other trace-gas retrievals including CO2. Here, we explore whether fluorescence information can be derived from space using potentially lower-cost hyperspectral instrumentation, i.e., more than an order of magnitude less spectral resolution (ν/Δν ∼1600) than GOSAT, with a relatively simple algorithm. We simulate the filling-in, from various atmospheric and terrestrial effects, of one of the few wide and deep solar Fraunhofer lines in the long-wave tail of the fluorescence emission region, the calcium (Ca) II line near 866 nm. We then examine filling-in of this line using the SCanning Imaging Absorption spectroMeter for Atmospheric CHartographY (SCIAMACHY) satellite instrument. We develop and apply methodology to correct for various instrumental artifacts that produce false filling-in of solar lines in satellite radiance measurements. We then compare the derived additive near-InfraRed (NIR) signal at 866 nm, that fills in the Ca II line, with larger signals retrieved at 758 and 770 nm on the shoulders of the O2-A feature from GOSAT that are presumably due primarily to vegetation fluorescence. Finally, we compare temporal and spatial variations of GOSAT and SCIAMACHY additive signals with those of the Enhanced Vegetation Index (EVI) from the MODerate-resolution Imaging Spectroradiometer (MODIS). Although the observed filling-in signal from SCIAMACHY is extremely weak at 866 nm, the spatial and temporal patterns of the derived additive signal are consistent with a vegetation source, chlorophyll-a fluorescence being a plausible candidate. We also show that filling-in occurs at 866 nm over some barren areas, possibly originating from luminescent minerals in rock and soil.

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Description of derivative-based high-spectral-resolution (AVIRIS) green vegetation index

10.1117/12.157068 ◽

1993 ◽

Cited By ~ 8

Author(s):

Zhikang Chen ◽

Christopher D. Elvidge ◽

Wally T. Jansen

Keyword(s):

Spectral Resolution ◽

Vegetation Index ◽

High Spectral Resolution ◽

Green Vegetation

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Influence of local surface albedo variability and ice crystal shape on passive remote sensing of thin cirrus

Atmospheric Chemistry and Physics ◽

10.5194/acp-14-1943-2014 ◽

2014 ◽

Vol 14 (4) ◽

pp. 1943-1958 ◽

Cited By ~ 12

Author(s):

C. Fricke ◽

A. Ehrlich ◽

E. Jäkel ◽

B. Bohn ◽

M. Wirth ◽

...

Keyword(s):

Optical Thickness ◽

Surface Albedo ◽

Near Infrared ◽

Effective Radius ◽

High Spectral Resolution ◽

Spectral Radiance ◽

Crystal Shape ◽

Frequency Distributions ◽

Airborne Measurements ◽

Moderate Resolution Imaging Spectroradiometer

Abstract. Airborne measurements of solar spectral radiance reflected by cirrus are performed with the HALO-Solar Radiation (HALO-SR) instrument onboard the High Altitude and Long Range Research Aircraft (HALO) in November 2010. The data are used to quantify the influence of surface albedo variability on the retrieval of cirrus optical thickness and crystal effective radius. The applied retrieval of cirrus optical properties is based on a standard two-wavelength approach utilizing measured and simulated reflected radiance in the visible and near-infrared spectral region. Frequency distributions of the surface albedos from Moderate resolution Imaging Spectroradiometer (MODIS) satellite observations are used to compile surface-albedo-dependent lookup tables of reflected radiance. For each assumed surface albedo the cirrus optical thickness and effective crystal radius are retrieved as a function of the assumed surface albedo. The results for the cirrus optical thickness are compared to measurements from the High Spectral Resolution Lidar (HSRL). The uncertainty in cirrus optical thickness due to local variability of surface albedo in the specific case study investigated here is below 0.1 and thus less than that caused by the measurement uncertainty of both instruments. It is concluded that for the retrieval of cirrus optical thickness the surface albedo variability is negligible. However, for the retrieval of crystal effective radius, the surface albedo variability is of major importance, introducing uncertainties up to 50%. Furthermore, the influence of the bidirectional reflectance distribution function (BRDF) on the retrieval of crystal effective radius was investigated and quantified with uncertainties below 10%, which ranges below the uncertainty caused by the surface albedo variability. The comparison with the independent lidar data allowed for investigation of the role of the crystal shape in the retrieval. It is found that if assuming aggregate ice crystals, the HSRL observations fit best with the retrieved optical thickness from HALO-SR.

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Spectrum Filter Performance Analysis on Near-Infrared High-Spectral-Resolution Lidar

Chinese Journal of Lasers ◽

10.3788/cjl201643.0414004 ◽

2016 ◽

Vol 43 (4) ◽

pp. 0414004

Author(s):

张与鹏 Zhang Yupeng ◽

刘东 Liu Dong ◽

杨甬英 Yang Yongying ◽

罗敬 Luo Jing ◽

成中涛 Cheng Zhongtao ◽

...

Keyword(s):

Performance Analysis ◽

Spectral Resolution ◽

Near Infrared ◽

High Spectral Resolution ◽

Filter Performance ◽

High Spectral Resolution Lidar

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Global monitoring of terrestrial chlorophyll fluorescence from moderate spectral resolution near-infrared satellite measurements: methodology, simulations, and application to GOME-2

Atmospheric Measurement Techniques Discussions ◽

10.5194/amtd-6-3883-2013 ◽

2013 ◽

Vol 6 (2) ◽

pp. 3883-3930 ◽

Cited By ~ 42

Author(s):

J. Joiner ◽

L. Guanter ◽

R. Lindstrot ◽

M. Voigt ◽

A. P. Vasilkov ◽

...

Keyword(s):

Chlorophyll Fluorescence ◽

Spectral Resolution ◽

Near Infrared ◽

High Spectral Resolution ◽

High Signal ◽

Good Precision ◽

Atmospheric Absorption ◽

Red Fluorescence ◽

Fluorescence Measurements ◽

Global Mapping

Abstract. Globally mapped terrestrial chlorophyll fluorescence retrievals are of high interest because they can provide information on the functional status of vegetation including light-use efficiency and global primary productivity that can be used for global carbon cycle modeling and agricultural applications. In addition, fluorescence can contaminate photon path estimates from the O2 A-band that has become an integral part of missions to accurately measure greenhouse gas concentrations. Global mapping of far-red (~ 755–770 nm) terrestrial vegetation solar-induced fluorescence from space has been accomplished using the high spectral resolution (ν/Δ ν > 35 000) interferometer on the Japanese Greenhouse gases Observing SATellite (GOSAT). These satellite retrievals of fluorescence rely solely upon the filling-in of solar Fraunhofer lines that are not significantly affected by atmospheric absorption. Although these measurements provide near global coverage on a monthly basis, they suffer from relatively low precision and sparse spatial sampling. Here, we describe a new methodology to retrieve global far-red fluorescence information; we use hyperspectral data to disentangle the spectral signatures of three basic components in and surrounding the O2 A-band: atmospheric absorption, surface reflectance, and fluorescence radiance. Through detailed simulations, we demonstrate the feasibility of the approach and show that moderate spectral resolution measurements with a relatively high signal-to-noise ratio within and outside the O2 A-band can be used to retrieve far-red fluorescence information with good precision and accuracy. The method is then applied to data from the Global Ozone Monitoring Instrument 2 (GOME-2). The GOME-2 fluorescence retrievals display similar spatial structure as compared with GOSAT. GOME-2 enables global mapping of far-red fluorescence with higher precision over smaller spatial and temporal scales than is possible with GOSAT. It should be noted that both GOME-2 and GOSAT were designed to make atmospheric trace gas measurements and were not optimized for fluorescence measurements. Our approach can be applied to other existing and future space-based instruments that provide moderate spectral resolution observations in the near-infrared region.

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