scholarly journals The Evaluation of Meteorological Inputs retrieved from MODIS for Estimation of Gross Primary Productivity in the US Corn Belt Region

2011 ◽  
Vol 27 (4) ◽  
pp. 481-494 ◽  
Author(s):  
Ji-Hye Lee ◽  
Sin-Kyu Kang ◽  
Keun-Chang Jang ◽  
Jong-Han Ko ◽  
Suk-Young Hong
2020 ◽  
Author(s):  
Alexander Turner ◽  
Philipp Köhler ◽  
Troy Magney ◽  
Christian Frankenberg ◽  
Inez Fung ◽  
...  

2021 ◽  
Author(s):  
Alexander J. Turner ◽  
Philipp Köhler ◽  
Troy S. Magney ◽  
Christian Frankenberg ◽  
Inez Fung ◽  
...  

Abstract. Solar-Induced chlorophyll Fluorescence (SIF) has previously been shown to strongly correlate with gross primary productivity (GPP), however this relationship has not yet been quantified for the recently launched TROPOspheric Monitoring Instrument (TROPOMI). Here we use a Gaussian mixture model to develop a parsimonious relationship between SIF from TROPOMI and GPP from flux towers across the conterminous United States (CONUS). The mixture model indicates the SIF-GPP relationship can be characterized by a linear model with two terms. We then estimate GPP across CONUS at 500-m spatial resolution over a 16-day moving window. We find that CONUS GPP varies by less than 4 % between 2018 and 2019. However, we observe four extreme precipitation events that induce regional GPP anomalies: drought in west Texas, flooding in the midwestern US, drought in South Dakota, and drought in California. Taken together, these events account for 28 % of the year-to-year GPP differences across CONUS.


2021 ◽  
Author(s):  
Alexander J. Turner ◽  
Philipp Köhler ◽  
Troy S. Magney ◽  
Christian Frankenberg ◽  
Inez Fung ◽  
...  

2013 ◽  
Vol 13 (12) ◽  
pp. 31563-31605
Author(s):  
X. Yue ◽  
N. Unger

Abstract. We apply an off-line process-based vegetation model to assess the impacts of ozone (O3) vegetation damage on gross primary productivity (GPP) in the United States (US) during the past decade (1998–2007). The model's GPP simulation is evaluated at 40 sites of the North American Carbon Program (NACP) synthesis. The ecosystem-scale model version reproduces interannual variability and seasonality of GPP at most sites, especially in croplands. Inclusion of the O3 damage impact decreases biases of simulated GPP at most of the NACP sites. The simulation with the O3 damage effect reproduces 64% of the observed variance in summer GPP and 45% on the annual average. Based on a regional gridded simulation over the US, summertime average O3-free GPP is 5.9 g C m−2 day−1 (9.1 g C m−2 day−1 in the East of 95° W and 3.7 g C m−2 day−1 in the West). O3 damage decreases GPP by 3–7% on average in the eastern US and leads to significant decreases of 13–17% in east coast hotspots. Sensitivity simulations show that a reduction of 25% in surface O3 concentration alleviates the average GPP damages to 1–3%, suggesting a promising prospect for ecosystem health following the emission control.


2021 ◽  
Vol 18 (24) ◽  
pp. 6579-6588
Author(s):  
Alexander J. Turner ◽  
Philipp Köhler ◽  
Troy S. Magney ◽  
Christian Frankenberg ◽  
Inez Fung ◽  
...  

Abstract. Solar-induced chlorophyll fluorescence (SIF) has previously been shown to strongly correlate with gross primary productivity (GPP); however this relationship has not yet been quantified for the recently launched TROPOspheric Monitoring Instrument (TROPOMI). Here we use a Gaussian mixture model to develop a parsimonious relationship between SIF from TROPOMI and GPP from flux towers across the conterminous United States (CONUS). The mixture model indicates the SIF–GPP relationship can be characterized by a linear model with two terms. We then estimate GPP across CONUS at 500 m spatial resolution over a 16 d moving window. We observe four extreme precipitation events that induce regional GPP anomalies: drought in western Texas, flooding in the midwestern US, drought in South Dakota, and drought in California. Taken together, these events account for 28 % of the year-to-year GPP differences across CONUS. Despite these large regional anomalies, we find that CONUS GPP varies by less than 4 % between 2018 and 2019.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Alan Willse ◽  
Lex Flagel ◽  
Graham Head

Abstract Following the discovery of western corn rootworm (WCR; Diabrotica virgifera virgifera) populations resistant to the Bacillus thuringiensis (Bt) protein Cry3Bb1, resistance was genetically mapped to a single locus on WCR chromosome 8 and linked SNP markers were shown to correlate with the frequency of resistance among field-collected populations from the US Corn Belt. The purpose of this paper is to further investigate the relationship between one of these resistance-linked markers and the causal resistance locus. Using data from laboratory bioassays and field experiments, we show that one allele of the resistance-linked marker increased in frequency in response to selection, but was not perfectly linked to the causal resistance allele. By coupling the response to selection data with a genetic model of the linkage between the marker and the causal allele, we developed a model that allowed marker allele frequencies to be mapped to causal allele frequencies. We then used this model to estimate the resistance allele frequency distribution in the US Corn Belt based on collections from 40 populations. These estimates suggest that chromosome 8 Cry3Bb1 resistance allele frequency was generally low (<10%) for 65% of the landscape, though an estimated 13% of landscape has relatively high (>25%) resistance allele frequency.


2021 ◽  
Vol 307 ◽  
pp. 108456
Author(s):  
Marcelo Sacardi Biudes ◽  
George Louis Vourlitis ◽  
Maísa Caldas Souza Velasque ◽  
Nadja Gomes Machado ◽  
Victor Hugo de Morais Danelichen ◽  
...  

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