A time history of the calibration coefficients for channels 1 and 2 of the Advanced Very High Resolution Radiometer (AVHRR) on the NOAA-12 and NOAA-15 spacecraft is presented. The history is based on reflectances observed for the interior zones of the Antarctic and Greenland ice sheets previously obtained with the...
Studies using International Satellite Cloud Climatology Project (ISCCP) data have reported decreases in cloud optical depth with increasing temperature, thereby suggesting a positive feedback in cloud optical depth as climate warms. The negative cloud optical depth and temperature relationships are questioned because ISCCP employs threshold assumptions to identify cloudy pixels...
One-kilometer Advanced Very High Resolution Radiometer (AVHRR) observations of the effects of ships on
low-level clouds off the west coast of the United States are used to derive limits for the degree to which clouds
might be altered by increases in anthropogenic aerosols. As ships pass beneath low-level clouds, particles...
Simple threshold scene identification methods are developed to reduce the effects of errors in scene identifications on the anisotropy of reflected and emitted radiances inferred from Earth Radiation Budget Experiment (ERBE) scanner observations. The ERBE maximum likelihood estimate (MLE) scene identification is assumed to be accurate for nadir fields of...
Visible and near infrared reflectances from NOAA-14 Advanced Very High Resolution Radiometer (AVHRR) daytime passes are used to derive optical depths at 0.55 μm, an index of aerosol type, continental or marine, and the direct effect of the aerosol on the top of the atmosphere and surface solar radiative fluxes...
Retrievals of cloud properties from satellite imagery often invoke the assumption that the fields of view are overcast when cloud-contaminated, even though a significant fraction are only partially cloud-covered. The overcast assumption leads to biases in the retrieved cloud properties: cloud amounts and droplet effective radii are typically overestimated, while...
Ship tracks appearing in both the morning and afternoon Moderate Resolution Imaging Spectroradiometer (MODIS) imagery for the Pacific Ocean off the west coast of the United States were used to study the morning-to-afternoon evolution of marine stratus polluted by underlying ships and nearby uncontaminated stratus. Analyzed 925-hPa winds were used...
Many investigations using satellite data have determined that aerosol optical depth and cloud cover are correlated and some have interpreted the correlation as evidence of an aerosol indirect effect on clouds. This study uses in situ aircraft observations taken during the Indian Ocean Experiment (INDOEX), February–March 1999, and mostly over...
Observations of sunlight reflected from regions of sun glint are used to check the relative calibration of spectral radiances obtained with imaging radiometers. Reflectances at different wavelengths for sun-glint regions are linearly related. Provided that the atmosphere is reasonably transparent at the wavelengths, the aerosol burden is reasonably light, 0.64-μm...
A scheme is presented for retrieving aerosol properties for ocean regions from reflected sunlight at both the visible and near infrared wavelengths measured by the NOAA advanced very high resolution radiometer (AVHRR). For the Indian Ocean Experiment (INDOEX), aerosols were presumed to be a mixture of a continental haze that...