scholarly journals Observation of vertical profiles of NO, O3, and VOCs to estimate their sources and sinks by inverse modeling in a Japanese larch forest

2020 ◽  
Vol 76 (1) ◽  
pp. 1-10
Author(s):  
Ryuichi WADA ◽  
Masahito UEYAMA ◽  
Akira TANI ◽  
Tomoki MOCHIZUKI ◽  
Yuzo MIYAZAKI ◽  
...  
Keyword(s):  
Inverse Modeling ◽  
Japanese Larch ◽  
Larch Forest ◽  
Vertical Profiles ◽  
Sources And Sinks

Estimating contributions of sources of soil CO2 at the shallower layer in a Japanese larch forest area

2006 ◽  
Vol 25 (S1) ◽  
pp. 198-198
Author(s):  
Wei Liu ◽  
Jun Moriizumi ◽  
Hiromi Yamazawa ◽  
Takao Iida
Keyword(s):  
Forest Area ◽  
Japanese Larch ◽  
Larch Forest ◽  
Soil Co2

scholarly journals Data reduction for inverse modeling: an adaptive approach v1.0

2021 ◽  
Vol 14 (7) ◽  
pp. 4683-4696
Author(s):  
Xiaoling Liu ◽  
August L. Weinbren ◽  
He Chang ◽  
Jovan M. Tadić ◽  
Marikate E. Mountain ◽  
...  
Keyword(s):  
Case Studies ◽  
Data Reduction ◽  
Inverse Modeling ◽  
Co2 Flux ◽  
Real Data ◽  
Single Observation ◽  
Adaptive Approach ◽  
Sources And Sinks ◽  
Guiding Principle ◽  
Inverse Models

Abstract. The number of greenhouse gas (GHG) observing satellites has greatly expanded in recent years, and these new datasets provide an unprecedented constraint on global GHG sources and sinks. However, a continuing challenge for inverse models that are used to estimate these sources and sinks is the sheer number of satellite observations, sometimes in the millions per day. These massive datasets often make it prohibitive to implement inverse modeling calculations and/or assimilate the observations using many types of atmospheric models. Although these satellite datasets are very large, the information content of any single observation is often modest and non-exclusive due to redundancy with neighboring observations and due to measurement noise. In this study, we develop an adaptive approach to reduce the size of satellite datasets using geostatistics. A guiding principle is to reduce the data more in regions with little variability in the observations and less in regions with high variability. We subsequently tune and evaluate the approach using synthetic and real data case studies for North America from NASA's Orbiting Carbon Observatory-2 (OCO-2) satellite. The proposed approach to data reduction yields more accurate CO2 flux estimates than the commonly used method of binning and averaging the satellite data. We further develop a metric for choosing a level of data reduction; we can reduce the satellite dataset to an average of one observation per ∼ 80–140 km for the specific case studies here without substantially compromising the flux estimate, but we find that reducing the data further quickly degrades the accuracy of the estimated fluxes. Overall, the approach developed here could be applied to a range of inverse problems that use very large trace gas datasets.

scholarly journals Data reduction for inverse modeling: an adaptive approach v1.0

2020 ◽  
Author(s):  
Xiaoling Liu ◽  
August L. Weinbren ◽  
He Chang ◽  
Jovan Tadić ◽  
Marikate E. Mountain ◽  
...  
Keyword(s):  
Case Studies ◽  
Data Reduction ◽  
Inverse Modeling ◽  
Co2 Flux ◽  
Real Data ◽  
Single Observation ◽  
Adaptive Approach ◽  
Sources And Sinks ◽  
Guiding Principle ◽  
Inverse Models

Abstract. The number of greenhouse gas (GHG) observing satellites has greatly expanded in recent years, and these new datasets provide an unprecedented constraint on global GHG sources and sinks. However, a continuing challenge for inverse models that are used to estimate these sources and sinks is the sheer number of satellite observations, sometimes in the millions per day. These massive datasets often make it prohibitive to implement inverse modeling calculations and/or assimilate the observations using many types of atmospheric models. Although these satellite datasets are very large, the information content of any single observation is often modest and non-exclusive due to redundancy with neighboring observations and due to measurement noise. In this study, we develop an adaptive approach to reduce the size of satellite datasets using geostatistics. A guiding principle is to reduce the data more in regions with little variability in the observations and less in regions with high variability. We subsequently tune and evaluate the approach using synthetic and real data case studies for North America from NASA's Orbiting Carbon Observatory-2 (OCO-2) satellite. The proposed approach to data reduction yields more accurate CO2 flux estimates than the commonly-used method of binning and averaging the satellite data. We further develop a metric for choosing a level of data reduction; we can reduce the satellite dataset to an average of one observation per ~80–140 km for the specific case studies here without substantially compromising the flux estimate, but we find that reducing the data further quickly degrades the accuracy of the estimated fluxes. Overall, the approach developed here could be applied to a range of inverse problems that use very large trace gas datasets.

Canopy photosynthetic production in a Japanese larch forest. II. Estimation of the canopy photosynthetic production

1993 ◽  
Vol 8 (3) ◽  
pp. 349-361 ◽  
Author(s):  
Nahoko Kurachi ◽  
Akio Hagihara ◽  
Kazuo Hozumi
Keyword(s):  
Japanese Larch ◽  
Larch Forest ◽  
Photosynthetic Production

scholarly journals Tropospheric sources and sinks of gas-phase acids in the Colorado Front Range

2018 ◽  
Vol 18 (16) ◽  
pp. 12315-12327 ◽  
Author(s):  
James M. Mattila ◽  
Patrick Brophy ◽  
Jeffrey Kirkland ◽  
Samuel Hall ◽  
Kirk Ullmann ◽  
...  
Keyword(s):  
Gas Phase ◽  
Pyruvic Acid ◽  
Photochemical Reactions ◽  
Ionization Mass ◽  
Vertical Profiles ◽  
Front Range ◽  
Alkanoic Acid ◽  
Surface Level ◽  
Sources And Sinks ◽  
Alkanoic Acids

Abstract. We measured organic and inorganic gas-phase acids in the Front Range of Colorado to better understand their tropospheric sources and sinks using a high-resolution time-of-flight chemical ionization mass spectrometer. Measurements were conducted from 4 to 13 August 2014 at the Boulder Atmospheric Observatory during the Front Range Air Pollution and Photochemistry Éxperiment. Diurnal increases in mixing ratios are consistent with photochemical sources of HNO3, HNCO, formic, propionic, butyric, valeric, and pyruvic acid. Vertical profiles taken on the 300 m tower demonstrate net surface-level emissions of alkanoic acids, but net surface deposition of HNO3 and pyruvic acid. The surface-level alkanoic acid source persists through both day and night, and is thus not solely photochemical. Reactions between O3 and organic surfaces may contribute to the surface-level alkanoic acid source. Nearby traffic emissions and agricultural activity are a primary source of propionic, butyric, and valeric acids, and likely contribute photochemical precursors to HNO3 and HNCO. The combined diel and vertical profiles of the alkanoic acids and HNCO are inconsistent with dry deposition and photochemical losses being the only sinks, suggesting additional loss mechanisms.

scholarly journals Global inverse modeling of CH<sub>4</sub> sources and sinks: An overview of methods

2016 ◽  
Author(s):  
Sander Houweling ◽  
Peter Bergamaschi ◽  
Frederic Chevallier ◽  
Martin Heimann ◽  
Thomas Kaminski ◽  
...  
Keyword(s):  
Inverse Modeling ◽  
Process Model ◽  
Atmospheric Transport ◽  
Regional Scale ◽  
Data Uncertainty ◽  
Grand Challenge ◽  
Sources And Sinks ◽  
Multiple Data ◽  
Methodological Aspects ◽  
Atmospheric Transport Modeling

Abstract. The aim of this paper is to present an overview of inverse modeling methods that have been developed over the years for estimating the global sources and sinks of CH4. It provides insight into how techniques and estimates have evolved over time, and what the remaining shortcomings are. As such, it serves a didactical purpose of introducing apprentices to the field, but it also takes stock of the developments so far and reflects on promising new directions. The main focus is on methodological aspects that are particularly relevant for CH4, such as its atmospheric oxidation, the use of methane isotopologues, and specific challenges in atmospheric transport modeling of CH4. The use of satellite retrievals receives special attention, as it is an active field of methodological development, with special requirements on the sampling of the model and the treatment of data uncertainty. Regional scale flux estimation and attribution is still a grand challenge, which calls for new methods capable of combining information from multiple data streams of different measured parameters. A process model representation of sources and sinks in atmospheric transport inversion schemes allows the integrated use of such data. These new developments are needed not only to improve our understanding of the main processes driving the observed global trend, but also to support international efforts to reduce greenhouse gas emissions.

scholarly journals Tropospheric sources and sinks of gas-phase acids in the Colorado Front Range

2018 ◽  
Author(s):  
James M. Mattila ◽  
Patrick Brophy ◽  
Jeffrey Kirkland ◽  
Samuel Hall ◽  
Kirk Ullmann ◽  
...  
Keyword(s):  
Gas Phase ◽  
Pyruvic Acid ◽  
Photochemical Reactions ◽  
Ionization Mass ◽  
Vertical Profiles ◽  
Front Range ◽  
Alkanoic Acid ◽  
Surface Level ◽  
Sources And Sinks ◽  
Alkanoic Acids

Abstract. We measured organic and inorganic gas-phase acids in the Front Range of Colorado to better understand their tropospheric sources and sinks using a high-resolution time-of-flight chemical ionization mass spectrometer. Measurements were conducted from 4 to 13 August 2014 at the Boulder Atmospheric Observatory during the Front Range Air Pollution and Photochemistry Éxperiment. Diurnal increases in mixing ratios are consistent with photochemical sources of HNO3, HNCO, formic, propionic, butyric, valeric, and pyruvic acid. Vertical profiles taken on the 300 m tower demonstrate net surface-level emissions of alkanoic acids, but net surface deposition of HNO3 and pyruvic acid. The surface-level alkanoic acid source persists through both day and night, and is thus not solely photochemical. Reactions between O3 and organic surfaces may contribute to the surface-level alkanoic acid source. Nearby traffic emissions and agricultural activity are a primary source of propionic, butyric, and valeric acid, and likely contribute photochemical precursors to HNO3 and HNCO. The combined diel and vertical profiles of the alkanoic acids and HNCO are inconsistent with dry deposition and photochemical losses being the only sinks, suggesting additional loss mechanisms.

The train millipede (Parafontaria laminata) mediates soil aggregation and N dynamics in a Japanese larch forest

Geoderma ◽  
2010 ◽  
Vol 159 (1-2) ◽  
pp. 216-220 ◽  
Author(s):  
Reiji Fujimaki ◽  
Yui Sato ◽  
Naoyuki Okai ◽  
Nobuhiro Kaneko
Keyword(s):  
Soil Aggregation ◽  
Japanese Larch ◽  
Larch Forest ◽  
N Dynamics

scholarly journals Global inverse modeling of CH<sub>4</sub> sources and sinks: an overview of methods

2017 ◽  
Vol 17 (1) ◽  
pp. 235-256 ◽  
Author(s):  
Sander Houweling ◽  
Peter Bergamaschi ◽  
Frederic Chevallier ◽  
Martin Heimann ◽  
Thomas Kaminski ◽  
...  
Keyword(s):  
Inverse Modeling ◽  
Process Model ◽  
Atmospheric Transport ◽  
Regional Scale ◽  
Data Uncertainty ◽  
Grand Challenge ◽  
Sources And Sinks ◽  
Multiple Data ◽  
Methodological Aspects ◽  
Atmospheric Transport Modeling

Abstract. The aim of this paper is to present an overview of inverse modeling methods that have been developed over the years for estimating the global sources and sinks of CH4. It provides insight into how techniques and estimates have evolved over time and what the remaining shortcomings are. As such, it serves a didactical purpose of introducing apprentices to the field, but it also takes stock of developments so far and reflects on promising new directions. The main focus is on methodological aspects that are particularly relevant for CH4, such as its atmospheric oxidation, the use of methane isotopologues, and specific challenges in atmospheric transport modeling of CH4. The use of satellite retrievals receives special attention as it is an active field of methodological development, with special requirements on the sampling of the model and the treatment of data uncertainty. Regional scale flux estimation and attribution is still a grand challenge, which calls for new methods capable of combining information from multiple data streams of different measured parameters. A process model representation of sources and sinks in atmospheric transport inversion schemes allows the integrated use of such data. These new developments are needed not only to improve our understanding of the main processes driving the observed global trend but also to support international efforts to reduce greenhouse gas emissions.

scholarly journals Closing the Mediterranean Marine Floating Plastic Mass Budget: Inverse Modeling of Sources and Sinks

2020 ◽  
Vol 54 (19) ◽  
pp. 11980-11989
Author(s):  
Mikael L. A. Kaandorp ◽  
Henk A. Dijkstra ◽  
Erik van Sebille
Keyword(s):  
Inverse Modeling ◽  
Mass Budget ◽  
Sources And Sinks ◽  
Plastic Mass ◽  
The Mediterranean
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