Ozone and Aerosol Influence on Ultraviolet Radiation on the East Coast of the Brazilian Northeast

Abstract

The purpose of this research is to determine the influence of Total Ozone and Aerosols about variability of Ultraviolet Radiation (UV) in the east coast of the Northeastern region of Brazil through measures from multispectral sensor GUV (Ground-based Ultraviolet Radiometer). The methodology consisted of descriptive study and cluster analyses using data of UV in channels UVB (305 nm) and UVA (320 nm, 340 nm and 380 nm) and data of UV index, Total Ozone, Aerosol, Global Solar Radiation, Cloudiness and Wind. The results for city of Natal indicated that an annual event occurs in September/October which stabilizes the UV or UV Index when Total Ozone levels reach their annual maximum. This event is influenced by marine Aerosol that is found on mainland at a higher concentration in September due to greater Wind intensity and their southeasterly direction (sea for land). The cluster analysis using the variables above allowed us to detect three different groups: the first group is formed by Natal, Recife and João Pessoa and so determined that this event occurs in these three cities; the second group is formed by Maceió, Aracaju and Salvador and the third group includes only Fortaleza and had different results.

UV Index Modeling by Autoregressive Distributed Lag (ADL Model)

“…The annual variability of the UV Index in city of Natal has a stabilization/reduction in September e October as associated with a higher ozone concentration [28]. This feature was observed in this data series, as shown in Figure 1. …”

“…The annual variability has a characteristic in September and October that consists of stabilization and reduction in UV Index because of highest concentration of Total Ozone and increased presence of marine aerosols [28]. The annual UV Index average observed for the period was 11 (±1.0).…”