## 2 Materials and Methods
### Data Collection
#### 2.2.2 Sensor Data for Soil Moisture and Climate Monitoring  
To validate satellite-derived soil moisture data from ERA5 against in situ field measurements collected at various depths within the avocado orchard, the soil moisture was measured using Watermark sensors installed at depths of 30 cm, 60 cm, and 120 cm along the planting beds in representative locations within the avocado orchard. The soil moisture sensors were strategically deployed across representative orchard blocks, with each sensor coded according to its location and depth. The sensor naming convention included a block identifier (e.g., \"A\", \"B\") and depth indicators (e.g., \"S1-30\" for a 30 cm depth sensor) representing the three soil depth categories: 30 cm, 60 cm, and 120 cm (Figure 3). This deployment design enabled comprehensive soil moisture monitoring at both horizontal and vertical scales, which is crucial for evaluating the spatial and temporal accuracy of satellite-derived moisture estimates. Figure 3: Three-dimensional spatial distribution of sensors in the field. The horizontal plane (X and Y coordinates) represents the layout of the field, where the distances in meters are illustrative and do not reflect the actual distance between sensors. In contrast, the vertical axis (Z coordinate) corresponds to the sensor placement depth in centimeters. These sensors were installed during the study period. Raw field sensor readings were recorded in centibars and converted to volumetric soil moisture contents (m\({}^{3}\)/m\({}^{3}\)) to ensure comparability with satellite data. This conversion was based on a calibration table that linked tension values to soil-specific moisture states, including the field capacity (FC) and permanent wilting point (PWP). These transformations provided a consistent framework for comparing field and satellite data, strengthening the analysis. Pearson correlation coefficients (r) and \(p\)-values were calculated to evaluate the agreement between the field measurements and ERA5 soil moisture estimates, quantifying the accuracy of the satellite data. These calculations were performed separately for each sensor, grouped by depth and growing season (2021 and 2022). The resulting correlations provided valuable insights into the performance of the field sensors and satellite estimates, allowing for a clear understanding of the spatial variability and the temporal dynamics of soil moisture. Seasonal analyses were conducted yearly to evaluate the interannual variability in the correlation results. Meteorological data were collected using an agro-meteorological station operated by a local commercial entity adjacent to the orchard. The station provided high-resolution hourly recordings of air temperature (\({}^{\circ}\)C), relative humidity (%), and solar radiation (MJ/m\({}^{2}\)). These air temperature data were critical for understanding the thermal conditions affecting evapotranspiration rates and crop physiological responses. Relative humidity measurements enabled the calculation of the vapor pressure deficit (VPD), a key indicator of atmospheric water demand, using saturation and actual vapor pressures derived from recorded temperature and humidity values. Solar radiation data quantified the incoming energy available for evapotranspiration and photosynthesis, while the VPD provided a comprehensive measure of the atmospheric potential to induce plant water stress. The meteorological data were aggregated into daily averages to match the temporal resolution of the satellite data. These aggregated datasets were aligned with the soil moisture and vegetation index data, ensuring temporal consistency for integrated analyses. The meteorological station was strategically located adjacent to the study orchard to capture representative environmental data influencing the crop's water dynamics. While microclimatic variations may exist due to differences in vegetation cover or terrain within the orchard, previous observational studies and field measurements indicated relatively uniform conditions across the orchard blocks.