ENVIRONMENTAL MEASUREMENTS FROM DIRECT SOLAR RADIATION: TRANSPARENT VS. TRANSLUCENT ATMOSPHERE, STEAMBOAT SPRINGS, COLORADO

This research introduces the effects of the Arizona wildfires of June 2011 as observed at Storm Peak Lab (SPL) in Steamboat Springs, Colorado. Current field research was possible through a summer internship provided by GRASP*. The purpose of this study is to compare the direct solar radiation on a “clear day,” one without smoke particles overhead SPL, to a “smoke day,” with smoke particles overhead SPL. The direct solar radiation can be derived from subtracting the diffuse solar radiation from total solar radiation. The investigation variables used to proceed with the study were restricted to the month of June 2011. The variables consist of radiometric data such as shadowband UV irradiance, shadowband visible irradiance, total optical depth, and satellite visible imagery data from Moderate Resolution Imaging Spectroradiometer (MODIS) and Geostationary Operational Environmental Satellite West (GOES-W). The Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) was employed to track the smoke direction from the wildfire in Arizona. The HYSPLIT data for the 5th of June 2011 were correlated with MODIS and GOES-W images for the same day; as both images displayed smoke overhead SPL which presumably believed to have originated from the Arizona wildfire. On a clear day, the total visible irradiance plot of watts per meter sq. against time, produced a high symmetrical curve with an expected peak at solar noon. A nearly equal symmetrical curve was also derived for direct solar irradiance, with the diffuse solar irradiance plot producing a very low symmetrical curve. In contrast, the same plot on the 5th of June 2011, showed a jagged symmetrical curve with relatively less total irradiance. The anomaly for the 5th of June 2011 at SPL explains how smoke from one location not only distributes trace gases like carbon monoxide and aerosols into the atmosphere, but also impedes incoming solar radiation at a different location.

* GRASP (Geoscience Research at Storm Peak) is a year-long program providing exceptional field research experiences for a diverse group of undergraduate students and authors greatly acknowledge their logistical and financial support for this research.