The impact of temporal aggregation of land surface temperature data for surface urban heat island (SUHI) monitoring

• SUHI values are more enhanced in the daytime than the nighttime after aggregation.
• The larger composite periods lead to higher SUHI values.
• The impact on spring and summer are larger than autumn and winter for the daytime.
• The higher SUHI regions are likely to have a larger gap between two composite scales.
• The different spatial patterns from aggregation are related to cloud distributions.

The remotely sensed land surface temperature (LST) is widely used in studying the surface urban heat island (SUHI). Due to the influence of clouds, composite products usually are preferred; however, exactly what the impact of temporal aggregation is on LST and SUHI is still unknown. In this paper, we quantify this impact focusing on Houston, Texas and its surroundings using MODIS LST products from 2000 to 2010. The results show that 1) the SUHI values are more notably enhanced in the daytime than nighttime with an increasing trend with larger composite periods. 2) The influences of aggregation in the spring and summer are larger than autumn and winter for the daytime. 3) The temporal aggregation impacts the spatial pattern of the SUHI implying that the higher SUHI regions are more likely to have a larger gap between two composite scales and this is related to the amount and distribution of clouds.