Abstract. Generoso et al. (2003) suggest a method for improving current inventories of aerosol emission from biomass burning based on the Along Track Scanning Radiometer (ATSR) nighttime hot spot product. In order to show the validity and representative of the nighttime burning product for such applications, Genoroso et al. (2003) compared the ATSR nighttime products to the daily fire products from TRMM, AVHRR etc. in nine selected regions. Their analyses demonstrate that in most cases, the nighttime products show a seasonal cycle that is consistent with the daily observations. However, they noticed significant discrepancies in biomass seasonality between ATSR nighttime product and TRMM daily product in Sahel region. In a commentary paper, Giglio and Kendall (2003) clarify that the origin of TRMM fire data used in Generoso et al. (2003) is from TRMM Science Data and Information System (Ji and Stocker, 2002). We thank Giglio and Kendall for such clarifications that provide an opportunity for us to clarify several issues on the applications of TSDIS fire data.