@InProceedings{MottusAABHMMNORS:2018:ImDiCh,
               author = "Mottus, Matti and Aalto, Juho and Arag{\~a}o, Luiz Eduardo 
                         Oliveira e Cruz de and Back, Jaana and Hern{\'a}ndez-Clemente, 
                         Roc{\'{\i}}o and Maeda, Eduardo Eiji and Markiet, Vincent and 
                         Nichol, Caroline J. and Oliveira J{\'u}nior, Raimundo Cosme and 
                         Restrepo, Coupe-Natalia and Saleska, Scott R.",
          affiliation = "{VTT Technical Research Centre of Finland Ltd} and {University of 
                         Helsinki} and {Instituto Nacional de Pesquisas Espaciais (INPE)} 
                         and {University of Helsinki} and {University of Swansea} and 
                         {University of Helsinki} and {VTT Technical Research Centre of 
                         Finland Ltd} and {University of Edinburgh} and {Brazilian 
                         Agricultural Research Corporation} and {University of Arizona} and 
                         {University of Arizona}",
                title = "Implications of diurnal changes in leaf pri on remote measurements 
                         of light use efficiency",
            booktitle = "Proceedings...",
                 year = "2018",
         organization = "International Geoscience and Remote Sensing Symposium (IGARSS)",
             keywords = "Photochemical Reflectance Index, Light Use Efficiency, Boreal 
                         forest, Amazon rainforest, Pinus sylvestris, Betula Pendula, 
                         Manilkara elata1.",
             abstract = "The spectral properties of plant leaves reflect the state of their 
                         photosynthetic apparatus and the surrounding environment. A 
                         well-known mechanism of photosynthetic downregulation, active on 
                         the time scale from minutes to hours, is caused by reversible 
                         changes in the xanthophyll cycle pigments. These changes affect 
                         leaf spectral absorption and are frequently quantified using the 
                         Photochemical Reflectance Index (PRI). This index can thus be used 
                         to monitor the photosynthetic status of the vegetation canopy, 
                         potentially from a large distance, and allows for a global 
                         satellite-based monitoring of photosynthesis. Such Earth 
                         observation satellites in nearpolar orbits usually cover the same 
                         geographical location at the same local solar time at regular 
                         intervals. To facilitate the interpretation of these instantaneous 
                         remote PRI measurements and scale them to longer timescales, we 
                         measured the daily course of leaf PRI in two evergreen biomes: 
                         European boreal forest and Amazon rainforest. The daily course of 
                         PRI was different for the two locations. In Amazon, PRI was driven 
                         by incident Photosynthetic Photon Flux Density (PPFD). In the 
                         boreal location, PRI and PPFD were decoupled and PRI indicated 
                         downregulation only in the afternoon. This downregulation was 
                         confirmed with carbon exchange measurements. The study 
                         demonstrates the utility of biome-specific daily PRI curves for 
                         scaling instantaneous remote measurements to daily values and 
                         comparing data acquired at different times of day.",
  conference-location = "Valencia",
      conference-year = "23-27 jul.",
             language = "en",
        urlaccessdate = "27 abr. 2024"
}