Remote sensing was employed for the first time to measure nitric oxide (NO) levels of on-road light-duty motor vehicles of the Metropolitan Area of Mexico City (MAMC). The sensor placed at 12 different sites also measured the concentration of CO2, CO, and total hydrocarbons (THC) in the exhaust emissions. A database was compiled containing 122 800 readings, of which 84 650 (69%) records were valid emissions measurements. CO, HC, and NO valid readings were 68.9, 63.4, and 62.9%, respectively, of the total attempted measurements. Furthermore, 42 822 vehicles were number-plate-matched to model year with the information provided by the Inspection/Maintenance Program. The mean emissions of total valid readings for CO, HC, and NO were determined to be 1.31 vol %, 440 ppm (propane), and 914 ppm, respectively. In 1991 and 1994, remote sensing measurements of CO and HC tailpipe emissions were performed in the MAMC in five different locations (30 000 valid readings). Large drops in both pollutants were observed for the intervening years, but sufficient vehicle information was not available at that time to fully explain the observed trends. Compared with those reports, our results point out to a steady decrease in CO and HC exhaust emissions with vehicle model year. The fleet emissions measured exhibit a gamma-distribution, with 10% of the most polluting fleet studied being responsible for 45%, 25%, and 29% of the CO, HC, and NO emissions, respectively. NO emissions in taxis are the highest among the vintage of vehicles, a matter of concern since according to the distance traveled per year, they represent 22% of the total activity in the MAMC.

A remote sensing study was conducted in year 2006 in four locations of the Metropolitan Area of Mexico City (MAMC). Two of the sites were the same studied back by us in year 2000 and by others in year 1994. A database was compiled containing 11,289 valid measurements for the carbon monoxide (CO), total hydrocarbons (THC), and nitric oxide (NO) exhaust vehicles emissions. Valid measurements were binned for each pollutant by the vehicle specific power (between -5 and 20 kW tonne(-1)) for the 2000 and 2006 databases. The mean average CO, THC, and NO emissions for year 2006 were determined to be 1.10 +/- 0.18 vol.%, 299 +/- 88.4 ppm, and 610 +/- 115.0 ppm, respectively. Matching the vehicle driving patterns of the fleet measured in year 2000 with the emissions factors obtained in this work, allows estimating the trends in the exhaust emissions of vehicles in the MAMC. The adjusted results of the remote sensing study performed in year 2006 shows that the fleet has decrease 22% in CO and 17% in NO emissions, with small change in total hydrocarbons emissions. The improvements could be related with the introduction in year 2001 of vehicles that met tighter emissions standards, particularly for nitrogen oxides.

The Latin American Giant Observatory (LAGO) is an extensive network of water Cherenkov detectors spread across Latin America, functioning as an astroparticle observatory. With its broad range of altitudes and geomagnetic rigidity cut-offs, the primary focus of LAGO's scientific program is to study space weather, climate phenomena, and high-energy astrophysical transients from ground level. To bolster these programs, the comprehensive simulation framework of ARTI and onedataSim was developed. This framework enables the calculation of the total secondary particle flux and the corresponding signals expected in various types of detectors operating anywhere in the world. It also incorporates the effects of real-time atmospheric and geomagnetic conditions, both secular and disturbed. These tools harness the expanding computational capabilities of highperformance computing facilities and cloud-based computing environments. By integrating these tools and infrastructures, we have managed to extend the total integration times of the background flux and the energy range of atmospheric neutrons. In this contribution, we illustrate how this intricate simulation sequence aids in achieving LAGO's scientific objectives. We also explore other applications, such as estimating the expected dose on board commercial flights, simulating the muon flux for muography studies, determining the distribution of neutrons in nuclear and medical facilities, and estimating the rate of errors produced by atmospheric neutrons in the upcoming generation of exascale supercomputing centers worldwide.