Global Aerosol Climatology Project


Peter Pilewskie, Warren Gore, and Larry Pezzolo

The Puerto Rico Dust Experiment

In June and July, 2000, the Ames Atmospheric Radiation Group participated in the Puerto Rico Dust Experiment (PRIDE), a multi-agency field study of the radiative, microphysical, and transport properties of Saharan dust. There were two primary objectives: 1) determine the extent to which the properties of dust particles and the spectral surface reflectance of the ocean surface need to be known before remote sensing systems can accurately determine optical depth and flux; and 2) evaluate/validate the skill with which the Naval Research Laboratory's Aerosol Analysis and Prediction System (NAAPS) predicts the long-range transport and vertical distribution of African dust.

The results of these efforts will support Navy and NASA applied science objectives on satellite validation and the prediction of dust-induced visibility degradation. In addition, secondary efforts of PRIDE will address in-situ issues of coarse mode particles and basic research issues on climate forcing, geochemical cycles, and meteorology.

Our specific contributions to PRIDE were to provide measurements and analyses of solar spectral fluxes. The Ames Solar Spectral Flux Radiometer (SSFR) was deployed on the Space and Naval Warfare Systems Command (SPAWAR) Navajo, measuring upwelling and downwelling spectral irradiance between 300 and 1700 nm. A similar SSFR was deployed at a ground site to obtain downwelling irradiance at the surface. The data will be used to determine the net solar radiative forcing of dust (and other) aerosols, to quantify the solar spectral radiative energy budget in the presence of elevated aerosol loading, to support satellite algorithm validation, and to provide tests of closure with in-situ measurements.

The South African Regional Science Initiative 2000

In August/September 2000 we participated in the South African Regional Science Initiative (SAFARI 2000), an international science initiative aimed at developing a better understanding of the southern African earth-atmosphere-human system. The goal of SAFARI 2000 is to identify and understand the relationships between the physical, chemical, biological and anthropogenic processes that underlie the biogeophysical and biogeochemical systems of southern Africa. Particular emphasis will be placed upon biogenic, pyrogenic and anthropogenic emissions, their characterization and quantification, their transport and transformations in the atmosphere, their influence on regional climate and meteorology, their eventual deposition, and the effects of this deposition on ecosystems.

During SAFARI 2000 the Ames Atmospheric Radiation Group deployed the SSFR on the NASA ER-2, the University of Washington CV-580, and at a ground site in Kruger National Park. Data will be used to characterize the spectrally dependence of cloud and aerosol radiative forcing.

Collaborators: Maura Rabbette and John Pommier, Bay Area Environmental Research Institute; Steve Howard, Symtech Corporation


Point of Contact: Peter Pilewskie, 650/604-0746,