Abstract

A long time-series land surface temperature (LST) product is useful for ecological and environmental studies. However, current LST products cannot provide a global coverage at a fine spatial resolution (∼100 m) over a long period (>30 years). Landsat series satellites that have been launched since 1972 provide a unique opportunity to fill the gap. Here, we proposed a single-channel framework for producing global long time-series Landsat LST retrievals on a Google earth engine (GEE) cloud computing platform. This framework unifies the LST, land surface emissivity (LSE) and atmospheric water vapor (AWV) estimation algorithms, as well as the emissivity and atmospheric input data for the Landsat LST retrievals from the entire Landsat thermal infrared image archive. In situ LST measurements and the MODIS LST products were employed to evaluate Landsat LST retrievals using the proposed framework over land and water surfaces, respectively. In total, 1317 clear-sky LST samples were collected from the Landsat 5–8 series after spatiotemporal registration with seven sites, and the average bias and root-mean-square error (RMSE) were 0.33 and 2.01 K, respectively. Intercomparison between Landsat and MODIS LST retrievals based on 100 clear-sky scenes over 12 inland lakes showed an average bias of 0.17 K and RMSE of 1.11 K. We conclude that the proposed single-channel framework can produce Landsat LST with high accuracy following a simple yet robust way. Implementation of the single-channel method on GEE shows promise in providing the community with freely accessible and global long time-series (>30 years) LST data.

Highlights

  • LAND surface temperature (LST) is a key parameter in understanding and analyzing environmental condition and global climate, and it has been widely used in surface evapotranspiration estimation[1, 2], surface energy balance[37], vegetation phenology[8, 9], agricultural drought[10] and urban heat island monitoring[11,12,13,14,15]

  • The performance of the proposed framework is assessed using the in situ LST derived from radiation measurements from SURFRAD, Baseline Surface Radiation Network (BSRN) and Heihe Watershed Allied Telemetry Experimental Research (HiWATER) stations, which provide continuous measurement of components of surface radiation budget, e.g. upwelling and downwelling longwave radiation, which can support the validation of LST retrieval [5052]

  • Many studies validated the LST retrieved from Landsat, VIIRS and Moderate Resolution Imaging Spectroradiometer (MODIS) data using the SURFRAD data[3, 52,53,54,55,56], BSRN data[44] and HiWATER data[57,58,59]

Read more

Summary

Introduction

LAND surface temperature (LST) is a key parameter in understanding and analyzing environmental condition and global climate, and it has been widely used in surface evapotranspiration estimation[1, 2], surface energy balance[37], vegetation phenology[8, 9], agricultural drought[10] and urban heat island monitoring[11,12,13,14,15]. Landsat series satellites have provided long-term observations of the Earth since 1972 [17]. There are currently more than 4 million Landsat thermal infrared (TIR) images dating back to Landsat 4 launched in 1982. These observations present a unique opportunity to provide long-term LST retrievals at a fine spatial resolution (~100 m) [18]. Landsat LST estimation encompasses three components: developing LST estimation algorithm, acquiring information of atmospheric conditions (i.e. atmospheric profiles or atmospheric parameters) and estimating land surface emissivity (LSE) [19]

Objectives
Methods
Results
Discussion
Conclusion
Full Text
Published version (Free)

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call