B006-0017
Modeling the Magnitude and Direction of SIF and GPP in Response to Light Conditions Across Evergreen Forests

Monday, 7 December 2020
Poster
Nicholas Parazoo1, Troy Magney2, Alexander Norton3, Brett M Raczka4, Cédric Bacour5, Fabienne Maignan6, Ian T Baker7, Yongguang Zhang8, Mingjie Shi1, Natasha Macbean9, David R Bowling4, Sean P Burns10, Peter Blanken11, Jochen Stutz12, Katja Grossmann13, Christian Frankenberg1, Zoe Pierrat14, Stephanie Grace Stettz15 and A. Anthony Bloom15, (1)NASA Jet Propulsion Laboratory, Pasadena, CA, United States, (2)University of California Davis, Plant Sciences, Davis, CA, United States, (3)Jet Propulsion Laboratory, Pasadena, United States, (4)University of Utah, School of Biological Sciences, Salt Lake City, UT, United States, (5)Noveltis, Labège, France, (6)CEA Saclay DSM / LSCE, Gif sur Yvette, France, (7)Colorado State University, Atmospheric Sciences, Fort Collins, CO, United States, (8)Freie Univ Berlin, Berlin, Germany, (9)Indiana University Bloomington, Bloomington, IN, United States, (10)University of Colorado and National Center for Atmospheric Research, Boulder, CO, United States, (11)University of Colorado, Boulder, Geography, Boulder, CO, United States, (12)University of California Los Angeles, Department of Atmospheric and Oceanic Sciences, Los Angeles, CA, United States, (13)Heidelberg University, Institute of Environmental Physics, Heidelberg, Germany, (14)University of California Los Angeles, Los Angeles, CA, United States, (15)Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, United States
Abstract:
Recent successes in passive remote sensing of far-red solar induced chlorophyll fluorescence (SIF) have spurred development and integration of canopy-level fluorescence models in global terrestrial biosphere models (TBMs) for climate and carbon cycle research. The interaction of fluorescence with photochemistry at the leaf- and canopy- scale provides opportunities to diagnose and constrain model simulations of photosynthesis and related processes, through direct comparison to and assimilation of tower, airborne, and satellite data. TBMs describe key processes related to absorption of sunlight, leaf-level fluorescence emission, scattering and reabsorption throughout the canopy. Here, we analyze simulations from an ensemble of process-based TBM-SIF models (SiB3, SiB4, CLM4.5, CLM5.0, BETHY, ORCHIDEE, BEPS, CARDAMOM) and the SCOPE canopy radiation and vegetation model at high-altitude (Niwot Ridge, Colorado) and high-latitude (Old Black Spruce, Saskatchewan and Delta Junction, Alaska) evergreen needleleaf forests in North America. These models are forced with local meteorology and analyzed against tower-based continuous far-red SIF and gross primary productivity (GPP) partitioned eddy covariance data during the growing season. Our primary objective is to summarize the site-level state of the art in TBM-SIF modeling at diurnal, synoptic, and seasonal time scales, setting the stage for regional-scale analyses across the ABoVE domain. Early results at Niwot Ridge suggest these models are generally well constrained in simulating photosynthetic yield, but show strongly divergent patterns in the simulation of absorbed photosynthetic active radiation (PAR), absolute GPP and fluorescence, quantum yields, and light response at leaf and canopy scale. The Niwot Ridge study highlights the need for mechanistic modeling of non-photochemical quenching in stressed and unstressed environments, and improved representation of light absorption (APAR), distribution of sunlit and shaded light, and radiative transfer from leaf to canopy scale.

Parazoo, N.C., T. Magney, A. Norton, B. Raczka, C. Bacour et al., 2020: Wide discrepancies in the magnitude and direction of modeled solar-induced chlorophyll fluorescence in response to light conditions, Biogeosciences, 17(13), 3733-3755.

<< Previous Abstract | Next Abstract >>