Upscaling Northern Peatland CO2 Fluxes Using Satellite Remote Sensing Data

Research output: Contribution to journalArticle

Abstract

Peatlands play an important role in the global carbon cycle as they contain a large soil carbon stock. However, current climate change could potentially shift peatlands from being carbon sinks to carbon sources. Remote sensing methods provide an opportunity to monitor carbon dioxide (CO2) exchange in peatland ecosystems at large scales under these changing conditions. In this study, we developed empirical models of the CO2 balance (net ecosystem exchange, NEE), gross primary production (GPP), and ecosystem respiration (ER) that could be used for upscaling CO2 fluxes with remotely sensed data. Two to three years of eddy covariance (EC) data from five peatlands in Sweden and Finland were compared to modelled NEE, GPP and ER based on vegetation indices from 10 m resolution Sentinel-2 MSI and land surface temperature from 1 km resolution MODIS data. To ensure a precise match between the EC data and the Sentinel-2 observations, a footprint model was applied to derive footprint-weighted daily means of the vegetation indices. Average model parameters for all sites were acquired with a leave-one-out-cross-validation procedure. Both the GPP and the ER models gave high agreement with the EC-derived fluxes (R2 = 0.70 and 0.56, NRMSE = 14% and 15%, respectively). The performance of the NEE model was weaker (average R2 = 0.36 and NRMSE = 13%). Our findings demonstrate that using optical and thermal satellite sensor data is a feasible method for upscaling the GPP and ER of northern boreal peatlands, although further studies are needed to investigate the sources of the unexplained spatial and temporal variation of the CO2 fluxes

Details

Authors
Organisations
External organisations
  • University of Gothenburg
  • Finnish Meteorological Institute
  • Swedish University of Agricultural Sciences
  • University of Eastern Finland
  • University of Helsinki
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Physical Geography

Keywords

  • Ecosystem respiration (ER), Footprint analysis, Gross primary production (GPP), Net ecosystem exchange (NEE), Peatland, Sentinel-2, Upscaling
Original languageEnglish
Article number818
Number of pages23
JournalRemote Sensing
Volume13
Issue number4
Publication statusPublished - 2021 Feb 23
Publication categoryResearch
Peer-reviewedYes

Related projects

Lars Eklundh, Jonas Ardö, Leif Klemedtsson, Natascha Kljun, Johan Lindström & Mats B. Nilsson

FORMAS, a Swedish research council for sustainable development

2017/01/012019/12/31

Project: Research

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