Zhanzhang Cai
Postdoc
Modelling daily gross primary productivity with sentinel-2 data in the nordic region–comparison with data from modis
Författare
Summary, in English
The high-resolution Sentinel-2 data potentially enable the estimation of gross primary productivity (GPP) at finer spatial resolution by better capturing the spatial variation in a heterogeneous landscapes. This study investigates the potential of 10 m resolution reflectance from the Sentinel-2 Multispectral Instrument to improve the accuracy of GPP estimation across Nordic vegetation types, compared with the 250 m and 500 m resolution reflectance from the Moderate Resolution Imaging Spectroradiometer (MODIS). We applied linear regression models with inputs of two-band enhanced vegetation index (EVI2) derived from Sentinel-2 and MODIS reflectance, respectively, together with various environmental drivers to estimate daily GPP at eight Nordic eddy covariance (EC) flux tower sites. Compared with the GPP from EC measurements, the accuracies of modelled GPP were generally high (R2 = 0.84 for Sentinel-2; R2 = 0.83 for MODIS), and the differences between Sentinel-2 and MODIS were minimal. This demonstrates the general consistency in GPP estimates based on the two satellite sensor systems at the Nordic regional scale. On the other hand, the model accuracy did not improve by using the higher spatial-resolution Sentinel-2 data. More analyses of different model formulations, more tests of remotely sensed indices and biophysical parameters, and analyses across a wider range of geographical locations and times will be required to achieve improved GPP estimations from Sentinel-2 satellite data.
Avdelning/ar
- Institutionen för naturgeografi och ekosystemvetenskap
- ICOS Sweden
- MERGE: ModElling the Regional and Global Earth system
Publiceringsår
2021
Språk
Engelska
Publikation/Tidskrift/Serie
Remote Sensing
Volym
13
Issue
3
Dokumenttyp
Artikel i tidskrift
Förlag
MDPI AG
Ämne
- Physical Geography
Nyckelord
- EVI2
- Gross primary productivity
- MODIS
- Nordic region
- Sentinel-2 MSI
Aktiv
Published
Projekt
- Upscaling carbon fluxes to a landscape
ISBN/ISSN/Övrigt
- ISSN: 2072-4292