Validation of AVHRR Land Surface Temperature with MODIS and In Situ LST—A TIMELINE Thematic Processor

Philipp Reiners,Claudia Kuenzer,Jose Sobrino,Martin Bachmann,Stefanie Holzwarth,Sarah Asam,Corinne Frey,Frank-M Göttsche,Jörg Bendix

doi:10.3390/rs13173473

Abstract

Land Surface Temperature (LST) is an important parameter for tracing the impact of changing climatic conditions on our environment. Describing the interface between long- and shortwave radiation fluxes, as well as between turbulent heat fluxes and the ground heat flux, LST plays a crucial role in the global heat balance. Satellite-derived LST is an indispensable tool for monitoring these changes consistently over large areas and for long time periods. Data from the AVHRR (Advanced Very High-Resolution Radiometer) sensors have been available since the early 1980s. In the TIMELINE project, LST is derived for the entire operating period of AVHRR sensors over Europe at a 1 km spatial resolution. In this study, we present the validation results for the TIMELINE AVHRR daytime LST. The validation approach consists of an assessment of the temporal consistency of the AVHRR LST time series, an inter-comparison between AVHRR LST and in situ LST, and a comparison of the AVHRR LST product with concurrent MODIS (Moderate Resolution Imaging Spectroradiometer) LST. The results indicate the successful derivation of stable LST time series from multi-decadal AVHRR data. The validation results were investigated regarding different LST, TCWV and VA, as well as land cover classes. The comparisons between the TIMELINE LST product and the reference datasets show seasonal and land cover-related patterns. The LST level was found to be the most determinative factor of the error. On average, an absolute deviation of the AVHRR LST by 1.83 K from in situ LST, as well as a difference of 2.34 K from the MODIS product, was observed.

Highlights

IntroductionLand Surface Temperature (LST) is an important quantity for tracing the impact of changing climatic conditions on our environment from the local to the global scale
The comparison with in situ Land Surface Temperature (LST) comprises TIMELINE LST from the years 2010–2013 derived from National Oceanic and Atmospheric Administration (NOAA)-15, 16, 18 and 19 data
The analysis showed a high impact of the emissivity difference on the difference between TIMELINE and MODIS LST

Summary

Introduction

LST is an important quantity for tracing the impact of changing climatic conditions on our environment from the local to the global scale. As a key parameter in the energy exchange at the Earth’s surface, LST describes the interface between long- and shortwave radiation fluxes on one side, and turbulent heat fluxes and the ground heat flux on the other side. LST is recognized as one of the Essential Climate Variables (ECVs) by the World Meteorological Organization [1]. As it represents the temperature of the surface and is strongly linked to the near-surface air temperature, it can be directly used for monitoring the global warming taking place on our planet in the last few decades. As it represents the temperature of the surface and is strongly linked to the near-surface air temperature, it can be directly used for monitoring the global warming taking place on our planet in the last few decades. 4.0/).

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