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| Titel |
Development of a high spectral resolution surface albedo product for the ARM Southern Great Plains central facility |
| VerfasserIn |
S. A. McFarlane, K. L. Gaustad, E. J. Mlawer, C. N. Long, J. Delamere |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1867-1381
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| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Measurement Techniques ; 4, no. 9 ; Nr. 4, no. 9 (2011-09-01), S.1713-1733 |
| Datensatznummer |
250002086
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| Publikation (Nr.) |
 copernicus.org/amt-4-1713-2011.pdf |
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| Zusammenfassung |
| 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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