Min Figure 1

Figure 1. The comparison of measured and synthesized spectra at the ARM SGP Site.

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Figure 2. The statistics of optical depth of aerosol, thin clouds, and overcast clouds over Harvard Forest during the growing season of 1998.

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Figure 3. The statistics of direct and diffuse PAR of Chlorophyll-a against optical depths of aerosol and cloud under three categories of clear-sky, thin clouds, and thick overcast clouds for different solar airmasses or solar zenith angles

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Figure 4. Intercomparison of the "True PAR" (MFRSR), PAR (LICOR), and PAR (GOES) during the growing season of 1998 at Harvard Forest site.

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Figure 5. Scattergrams of direct (d), diffuse (f), and effective dose (t) vs. measured CO2 uptake and water use efficiency (WUE) under aerosols, partial or thin clouds, and overcast clouds.