Validation of Landsat 8 high resolution Sea Surface Temperature using surfers

Nearshore coastal waters are highly dynamic in both space and time. They can be difficult to sample using conventional methods due their shallow depth, tidal variability, the presence of strong currents breaking waves. High resolution satellite sensors used provide synoptic views Surface Temperature (ST), but performance such ST products nearshore zone is poorly understood. Close shoreline, pixels influenced by mixed composition water land, as a result sensor’s spatial resolution. This cause thermal adjacency effects different diurnal temperature cycles bodies land. Previously, data collected during surfing sessions has been proposed for validation moderate (1 km pixel size) products. In this paper we use validate three high (100 m resampled 30 derived from Thermal InfraRed Sensor (TIRS) on board Landsat 8 (L8). was Collection 1 2 Level (C1L1 C2L1) Atmospheric Correction Tool (TACT), obtained standard product (USGS C2L2). study represents one first evaluations new C2 products, L1 L2, released USGS at end 2020. Using automated matchup image quality control, 88 matchups between L8/TIRS surfers were identified, distributed across North-Western semihemisphere. The unbiased Root Mean Squared Difference (uRMSD) situ measurements generally ¡ K, with warm biases (Mean Average Difference, MAD) 1.7 K C2L2), 1.3 (TACT C1L1) 0.8 C2L1). Large interquartile ranges 5 × around location found several images, especially summer Californian coast. By filtering target stability number reduced 31, which halved uRMSD (to 1.1K), MAD much lower, i.e. 1.1 0.6 C1L1), 0.2 larger C2L2 compared TACT C2L1 caused of: (1) lower emissivity value targets C2L2, (2) differences atmospheric parameter retrieval, mainly upwelling radiance transmittance retrieved C2L2. Additionally, tiling artefacts present product, originate coarser correction process. Overall, compares well made while surfing, best performing processed TACT.