An Evaluation of Cloud Cover, Cloud Effect, and Surface Radiation Budgets at the Tropical Western Pacific Darwin

• Main Authors: C. N. Long, K. Gaustad
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Subjects: Pacific; north slope; Alaska
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.176.6121; http://www.arm.gov/publications/proceedings/conf16/extended_abs/long_cn2.pdf

The Shortwave Flux Analysis (SWFA) Value-Added Product (VAP) was developed originally for daily fitting of coefficients (Long and Ackerman 2000). However, daily fitting calls for at least 110 oneminute clear data/day as minimum requirement. As shown in Figure 1 (top left), the ARM Climate Research Facility’s (ACRF’s) Southern Great Plains (SGP) and North Slope of Alaska (not shown) site climates easily meet the minimum daily fitting requirements. For the ARM equatorial tropical sites, persistent cloudiness precludes daily fitting (top right), and a composite fitting approach was developed (Long and Gaustad 2004). For Manus and Nauru, an 8-month running composite fit is used for the clear-sky total downwelling shortwave (SW), with fit coefficients for the clear-sky ratio of diffuse over total SW adjusted in a final pass through the data. The monsoon climate of Darwin (bottom), however, requires daily fitting for the dry season, but composite fitting for the wet. The switch between the two fitting methodologies as appropriate requires a knowledgeable decision. It is proposed that Darwin ARM data be manually processed for the SWFA VAP submission to ARM Archive.