Emissions from sugar cane fires in the Central & Western State of São Paulo and aerosol layers over metropolitan São Paulo observed by IPEN's lidar: Is there a connection?

Sep 8, 2026

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The central and western parts of the State of São Paulo are well known for extensive sugar cane plantations, where harvesting traditionally includes burning about 12 hours before manual cutting, releasing aerosols and a range of gases. These emissions are detected by IPMet radar systems in Bauru and Presidente Prudente on days with no or little rain and, depending on plume distance, can be observed up to at least 5 km amsl. During the dry winter season of 2008, radar observations from 10–21 July 2008 and IPEN Elastic Backscatter Lidar measurements over metropolitan São Paulo were compared using Flextra 3.3 trajectory modeling. Results for 14–15 July 2008 show strong agreement between radar-detected plume sources on 11 July 2008 and lidar observations on 14 July 2008 in forward and backward trajectories, including transport duration of about 70 hours.

LanguageEnglish

CategoryResearch & Report

FormatPDF

Pages9

Reading Time23 min

AccessFree to download

Introduction

Background and emissions source

Radar detection conditions and transport

2008 dry season observations

Trajectory modeling with Flextra 3.3

Results comparison: radar sources vs lidar layers

Ó[PTICA PURA YAPLICADA. www.sedoptica.es](PTICA PURA YAPLICADA. www.sedoptica.es) Sección Especial / Special Section: V Workshop on Lidar Measurements in Latin America Emissions from sugar cane fires in the Central & Western State ofSão Paulo and aerosol layers over metropolitan São Paulo observed by IPEN´s lidar: Is there a connection? Gerhard Held(1,*), Eduardo Landulfo(2), Fabio J. S. Lopes(2), Joaquim Arteta(3,4), Virginie Marecal(3) and José Marcio Bassan(1) 1. Instituto de Pesquisas Meteorológicas, Universidade Estadual Paulista, Bauru, S.P., Brazil. 2. Instituto de Pesquisas Energéticas e Nucleares, Universidade São Paulo, São Paulo, Brazil. 3. Laboratoire de Physique et Chimie de l’Environnement et de l’Espace, CNRS, Université d’Orleans, France. 4. Current affiliation: CNRM/GAME/CARMA, Meteo‐France, Toulouse, France. (*) [Email: gerhard@ipmet.unesp.br](Email: gerhard@ipmet.unesp.br) S: miembro de SEDOPTICA / SEDOPTICA member Recibido / Received: 16/11/2010. Versión revisada / revised versión: 01/03/2011. Aceptado / Accepted: 02/03/2011 ABSTRACT: The central and western parts of the State of São Paulo are well‐known for vast sugar cane plantations, which during the harvest time are traditionally burnt about 12 hours before manual cutting. This procedure causes the release of large quantities of aerosols and a variety of gases, which can be observed by IPMet’s radars, located in Bauru and Presidente Prudente, on days with no or little rain. Depending on the distance of these plumes from the radar, they can be detected up to 5 km amsl or more, and are subsequently being transported by winds to other regions. During the dry winter season of 2008, such plumes, attributed to cane fires, were frequently observed by IPMet’s radars and documented in terms of radar reflectivity, time and location during the period 10th – 21st July 2008. At the same time, IPEN’s Elastic Backscatter Lidar in São Paulo observed layers of aerosols of variable strength and heights above the city. The most significant days, viz. 14 and 15 July 2008 had been selected for calculating backward, as well as forward trajectories, deploying the European Flextra 3.3 Trajectory Model, which was initiated with ECMWF historic data with a 0,25º ×0,25º grid spacing. The results presented here show an excellent match between the radar‐detected sources of the plumes on 11th July 2008 in the central parts of the State and the observations by IPEN’s Lidar over Metropolitan São Paulo on 14th July 2008, both in terms of forward and backward trajectories, as well as their heights, with a transport duration of approximately 70 hours under the prevailing meteorological conditions. Key words: Sugar Cane Fires, Radar Observations, Elastic Backscatter Lidar, Aerosol Trajectories, Flextra 3.3 Trajectory Model, State of São Paulo, Brazil.. REFERENCES AND LINKS [1] A. Stohl,“The FLEXTRA Trajectory Model, Version 3.0: User Guide”. Lehrstuhl für Bioklimatologie und Immissionsforschung, University of Munich, Freising, Germany (1999) . Available from: [http://www.forst.uni‐muenchen.de/LST/METEOR/stohl/flextra.htm](http://www.forst.uni‐muenchen.de/LST/METEOR/stohl/flextra.htm). [2] G. Held, A. M. Gomes, R. V. Calheiros, Instituto de Pesquisas Meteorológicas (IPMet): Serviços para a Sociedade no Estado de São Paulo. Boletim da SBMET, 32, n.1, 27‐33,(2008) . [3] E. Landulfo, A. Papayannis, P. Artaxo, A.D.A. Castanho, A.Z. de Freitas, R.F. Souza, N.D. Vieira Junior, M. P. M. P. Jorge, O. R. Sánchez‐Ccoyllo, D. S. Moreira, “Synergetic measurements of aerosols over São Paulo, Brazil using LIDAR, sunphotometer and satellite data during the dry season”, Atmos. Chem. Phys. 3, 1523‐1539 (2003) . [4] A. Stohl, G. Wotawa, P. Seibert, H. Kromp‐Kolb, “Interpolation errors in wind fields as a function of spatial and temporal resolution and their impact on different types of kinematic trajectories”, J. Appl. Meteorol. 34, 2149‐2165 (1995) . Opt. Pura Apl. 44 (1)

FAQs

What emissions are associated with sugar cane burning in São Paulo, and how are they detected?

Burning before manual cutting releases aerosols and gases. IPMet radars in Bauru and Presidente Prudente detect these plumes on days with no or little rain, depending on distance and atmospheric conditions.

How were aerosol transport pathways analyzed for the 2008 dry winter season?

The study used the European Flextra 3.3 Trajectory Model with ECMWF historic data (0.25° × 0.25° grid). Backward and forward trajectories were calculated for selected significant days (14–15 July 2008) to link plume sources and observed aerosol layers.

What relationship did the study find between radar-detected sources and lidar observations?

An excellent match was reported between radar-detected plume sources in central São Paulo on 11 July 2008 and IPEN lidar observations over metropolitan São Paulo on 14 July 2008, consistent with both forward and backward trajectories and heights. The transport duration was about 70 hours under prevailing conditions.

Sep 8, 2026

Uploaded by Cipher