The Evolution of Temporal and Spatial Patterns of Carbon Monoxide Concentrations in the Metropolitan Area of Sao Paulo, Brazil

Author(s)

Dutra Ribeiro, Flavia Noronha ; Paiva Salinas, Delhi Teresa ; Soares, Jacyra ; de Oliveira, Amauri Pereira ; de Miranda, Regina Maura ; Tolentino Souza, Luana Antunes

• Document type: Journal article
• Source: ADVANCES IN METEOROLOGY; v. 2016, p. 13-pg., 2016-01-01.

Abstract

The Environmental Agency of Sao Paulo has a large dataset of carbonmonoxide measurements: 20 years of records in 18 automatic stations inside the metropolitan area. However, a thorough investigation on the time evolution of CO concentration tendency and cycles also considering spatial variability is lacking. The investigation consists of a trend line analysis, a periodogram analysis, a correlation between CO concentration and meteorological variables, and spatial distribution of CO concentration. Local and federal policies helped in decreasing CO concentrations and the highest decreasing rate was 0.7% per month. This tendency is lately stabilizing, since the vehicles fleet is increasing. CO most relevant cycles are annual and diurnal and a few series indicate a weekly cycle. Diurnal cycle shows two peaks, morning and evening rush hours, 1.2 and 1.1 ppm, respectively, in 2012. However, lately there is an extended evening peak (20 h to 23 h), related to changes in emission patterns. The spatial analysis showed that CO concentration has high spatial variability and is influenced by proximity to heavy traffic and vegetated areas. The present work indicates that several processes affect CO concentration and these results forma valuable basis for other studies involving air quality modeling, mitigation, and urban planning. (AU)

• FAPESP's process: 14/04372-2 - Influence of the sea breeze circulation on the development of the PBL and implications to the air quality at the MRSP
• Grantee: Flávia Noronha Dutra Ribeiro
• Support Opportunities: Regular Research Grants