## 3 Materials and Methods
### Feature Vector Construction  
Feature vector construction is a critical step in the machine learning pipeline that has a profound impact on every subsequent step, from model training and evaluation to the interpretability of the results. It involves not just selecting the right features but also appropriately processing and engineering these features to best represent the problem space for the learning algorithm, hence the importance of understanding the variables within our research domain and their relationships in order to extract patterns from our data and enhance the precision of our predictions. Next, we will delve into the various factors and their influence on ozone concentrations. The concentration of tropospheric ozone (\(O_{3}\)) is influenced by various atmospheric and meteorological factors, as mentioned in the research in Table 1, including temperature, humidity, wind direction, and wind speed. Next, we present a general overview of how each of these factors can impact ozone concentration:  
1. Temperature: * Photochemical Reactions: Ozone formation in the troposphere is a result of photochemical reactions. Higher temperatures generally increase the rate of these reactions, leading to a faster and more efficient production of ozone. * Stability of the Atmosphere: On hot days, especially under high-pressure systems, the atmosphere can become more stable, trapping pollutants, including ozone and its precursors, close to the ground and increasing concentrations. * Volatile Organic Compound (VOC) Emissions: Higher temperatures can also lead to increased emissions of VOCs from vegetation and certain human-made sources, further promoting ozone formation. 2. Humidity: * \(OH\) Radical Production: Water vapor can contribute to the formation of hydroxyl radicals (\(OH\)), which play a crucial role in oxidizing VOCs and other pollutants, leading to the production of ozone. However, the exact relationship between humidity and ozone production can be complex and might vary depending on other prevailing conditions. * Dilution: On the other hand, extremely high humidity levels can lead to condensation and cloud formation, which may reduce solar radiation, slowing down photochemical reactions. Figure 1: Location of measurement sites. Red diamonds belong to CONAGUA’s Automatic Weather Stations, black diamonds belong to the SIMAT monitoring network of the Mexico City Environmental Secretariat. 3. Wind Direction: * Transport of Precursors: The direction of the wind can transport ozone precursors (like \(NO_{x}\) and VOCs) from their sources to other areas. For instance, if a city has major industrial zones on its eastern side and the wind is blowing from east to west, areas downwind can experience elevated ozone levels due to the transported pollutants. * Clean Air Advection: Conversely, winds from rural or oceanic directions can bring cleaner air, reducing ozone concentrations. 4. Wind Speed: * Dispersion: Faster wind speeds can help disperse pollutants, diluting their concentration. This can decrease the buildup of ozone precursors in a particular area and reduce localized ozone formation. * Vertical Mixing: Strong winds, especially when accompanied by turbulence, can enhance the vertical mixing of the atmosphere, distributing ozone and its precursors over a larger vertical layer. This can lead to a decrease in ground-level ozone concentrations.