Model development for estimating carbon dioxide exchange in Nordic forests and peatlands with MODIS time series data
(2011)- Abstract
- The ongoing increase in atmospheric greenhouse gas concentrations causes an increase in the global mean air temperature. One important moderator of the atmospheric carbon dioxide (CO2) concentration is the gas exchange between the atmosphere and the biosphere; photosynthesis extracts and respiration releases CO2, resulting in a net exchange. A variety of methods are used to improve our understanding of the temporal and spatial distribution of this exchange. Since satellite sensors provide data with a continuous coverage throughout the landscape, such data are suitable for regional or global estimations of CO2 exchange across time. In this project, satellite sensor-derived data have been used in models for the gross primary productivity... (More)
- The ongoing increase in atmospheric greenhouse gas concentrations causes an increase in the global mean air temperature. One important moderator of the atmospheric carbon dioxide (CO2) concentration is the gas exchange between the atmosphere and the biosphere; photosynthesis extracts and respiration releases CO2, resulting in a net exchange. A variety of methods are used to improve our understanding of the temporal and spatial distribution of this exchange. Since satellite sensors provide data with a continuous coverage throughout the landscape, such data are suitable for regional or global estimations of CO2 exchange across time. In this project, satellite sensor-derived data have been used in models for the gross primary productivity (GPP), ecosystem respiration (ER), and net ecosystem exchange (NEE) at sixteen Nordic forest and peatland sites. The light use efficiency (LUE) model was used as the theoretical basis for the development of empirical models where data from the Moderate Resolution Imaging Spectroradiometer (MODIS) were combined with modeled radiation data. All models were tested, calibrated, and validated with eddy covariance measurements of CO2 exchange. The results show that the GPP, ER, and NEE in forests and peatlands can be modeled with the MODIS enhanced vegetation index (EVI), MODIS two-band enhanced vegetation index (EVI2), MODIS land surface temperature (LST), and modeled incoming photosynthetic photon flux density (PPFD). It was also shown that there are nutrient-induced changes in the light use efficiency by which the vegetation converts light into biomass. In addition, near-ground sensors for spectral measurements were installed at five forest and peatland sites. This sensor network adds representative data for estimating ecosystem processes related to vegetation phenology that will aid the calibration of satellite sensor-derived data. Such knowledge will contribute to further improvements of the suggested models for the CO2 fluxes. The project has shown that the CO2 fluxes can be modeled with satellite sensor-derived data and that near-ground spectral measurements provide useful information for further model developments. (Less)
- Abstract (Swedish)
- Popular Abstract in Swedish
Den pågående ökningen av växthusgaser i atmosfären orsakar en ökning av den globala medeltemperaturen. En viktig påverkande faktor för koncentrationen koldioxid (CO2) i atmosfären är utbytet mellan atmosfären och biosfären; fotosyntesen tar upp CO2 och respirationen släpper ut CO2, vilket resulterar i ett nettoutbyte. För att öka vår förståelse av den spatiala och temporala distributionen av detta utbyte så har olika metodologier utvecklats. Eftersom satellitsensorer tillhandahåller data som sammanhängande täcker landskapet är satellitdata lämpliga för regionala och globala skattningar av CO2-utbytet över tiden. Inom detta projekt har satellitdata använts i modeller för uppskattning av... (More) - Popular Abstract in Swedish
Den pågående ökningen av växthusgaser i atmosfären orsakar en ökning av den globala medeltemperaturen. En viktig påverkande faktor för koncentrationen koldioxid (CO2) i atmosfären är utbytet mellan atmosfären och biosfären; fotosyntesen tar upp CO2 och respirationen släpper ut CO2, vilket resulterar i ett nettoutbyte. För att öka vår förståelse av den spatiala och temporala distributionen av detta utbyte så har olika metodologier utvecklats. Eftersom satellitsensorer tillhandahåller data som sammanhängande täcker landskapet är satellitdata lämpliga för regionala och globala skattningar av CO2-utbytet över tiden. Inom detta projekt har satellitdata använts i modeller för uppskattning av bruttoprimärutbyte, ekosystemrespiration och nettoutbyte av CO2 på sexton nordiska skogs- och torvmarkslokaler. En modell för växternas effektivitet att assimilera ljus användes som teoretisk bas för att utveckla empiriska modeller där data från satellitsensorn Moderate Resolution Imaging Spectroradiometer (MODIS) kombinerades med strålningsdata. Alla modeller testades, kalibrerades och validerades med eddy kovarians-uppmätt nettoutbyte av CO2. I skogar och torvmarker modellerades bruttoprimärutbytet, ekosystemrespirationen och nettoutbytet av CO2 framgångsrikt med MODIS vegetationsindex, MODIS-uppskattad temperatur på markytan och modellerad inkommande fotosyntetiskt aktiv strålning. Det visade sig också att tillgänglig näringsmängd i torvmarker påverkar växternas effektivitet att omvandla ljus till biomassa. Utöver dessa studier installerades sensorer för markbaserade spektrala mätningar på fem skogs- och torvmarkslokaler. Nätverket av sensorer bidrar med representativa data för ekosystemfunktionen som är relaterade till vegetationsfenologi och som kan användas vid kalibrering av satellitdata. Sådan kunskap kommer att bidra till den fortsatta utvecklingen av föreslagna modeller för uppskattning av CO2-utbyte. Projektet har visat att CO2-utbyte kan modelleras med satellitdata och att markbaserade spektrala mätningar är lovande för fortsatt modellutveckling. (Less)
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/record/2174785
- author
- Schubert, Per LU
- supervisor
-
- Lars Eklundh LU
- opponent
-
- Professor Huete, Alfredo, University of Technology, Sydney, Australia
- organization
- publishing date
- 2011
- type
- Thesis
- publication status
- published
- subject
- publisher
- Department of Physical Geography and Ecosystem Science, Lund University
- defense location
- Lecture room Världen, Geocentrum II, Sölvegatan 12, Lund
- defense date
- 2011-06-17 10:15:00
- external identifiers
-
- scopus:80053519448
- ISBN
- 978-91-85793-20-4
- language
- English
- LU publication?
- yes
- id
- d3ffe772-1e98-48e1-a54e-d292d03f1318 (old id 2174785)
- date added to LUP
- 2016-04-04 10:08:46
- date last changed
- 2022-01-29 19:53:37
@phdthesis{d3ffe772-1e98-48e1-a54e-d292d03f1318,
abstract = {{The ongoing increase in atmospheric greenhouse gas concentrations causes an increase in the global mean air temperature. One important moderator of the atmospheric carbon dioxide (CO2) concentration is the gas exchange between the atmosphere and the biosphere; photosynthesis extracts and respiration releases CO2, resulting in a net exchange. A variety of methods are used to improve our understanding of the temporal and spatial distribution of this exchange. Since satellite sensors provide data with a continuous coverage throughout the landscape, such data are suitable for regional or global estimations of CO2 exchange across time. In this project, satellite sensor-derived data have been used in models for the gross primary productivity (GPP), ecosystem respiration (ER), and net ecosystem exchange (NEE) at sixteen Nordic forest and peatland sites. The light use efficiency (LUE) model was used as the theoretical basis for the development of empirical models where data from the Moderate Resolution Imaging Spectroradiometer (MODIS) were combined with modeled radiation data. All models were tested, calibrated, and validated with eddy covariance measurements of CO2 exchange. The results show that the GPP, ER, and NEE in forests and peatlands can be modeled with the MODIS enhanced vegetation index (EVI), MODIS two-band enhanced vegetation index (EVI2), MODIS land surface temperature (LST), and modeled incoming photosynthetic photon flux density (PPFD). It was also shown that there are nutrient-induced changes in the light use efficiency by which the vegetation converts light into biomass. In addition, near-ground sensors for spectral measurements were installed at five forest and peatland sites. This sensor network adds representative data for estimating ecosystem processes related to vegetation phenology that will aid the calibration of satellite sensor-derived data. Such knowledge will contribute to further improvements of the suggested models for the CO2 fluxes. The project has shown that the CO2 fluxes can be modeled with satellite sensor-derived data and that near-ground spectral measurements provide useful information for further model developments.}},
author = {{Schubert, Per}},
isbn = {{978-91-85793-20-4}},
language = {{eng}},
publisher = {{Department of Physical Geography and Ecosystem Science, Lund University}},
school = {{Lund University}},
title = {{Model development for estimating carbon dioxide exchange in Nordic forests and peatlands with MODIS time series data}},
year = {{2011}},
}