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

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

scholarly journals Oxidation processes in the Eastern Mediterranean atmosphere: Evidence from the Modelling of HO<sub>x</sub> Measurements over Cyprus

2018 ◽  
Author(s):  
Chinmay Mallik ◽  
Laura Tomsche ◽  
Efstratios Bourtsoukidis ◽  
John N. Crowley ◽  
Bettina Derstroff ◽  
...  
Keyword(s):  
Eastern Mediterranean ◽  
Air Masses ◽  
North West ◽  
Sources And Sinks ◽  
Oxidation Processes ◽  
The North ◽  
Range Transport ◽  
The Mediterranean ◽  
Marine Air ◽  
Measurement Location

Abstract. The Mediterranean is a climatically sensitive region located at the crossroads of air masses from three continents: Europe, Africa and Asia. The chemical processing of air masses over this region has implications not only for the air quality, but also for the long-range transport of air pollution. To obtain a comprehensive understanding of oxidation processes over the Mediterranean, atmospheric concentrations of the hydroxyl radical (OH) and the hydroperoxyl radical (HO2) were measured during an intensive field campaign (CYprus PHotochemistry EXperiment, CYPHEX-2014) in the north-west of Cyprus in the summer of 2014. Very low local anthropogenic and biogenic emissions around the measurement location provided a vantage point to study the contrasts in atmospheric oxidation pathways under highly processed marine air masses and those influenced by relatively fresh emissions from mainland Europe. The CYPHEX measurements were used to evaluate OH and HO2 simulations using a photochemical box model (CAABA/MECCA) constrained with CYPHEX observations of O3, CO, NOx, hydrocarbons, peroxides and other major HOx (OH + HO2) sources and sinks in a low NOx environment (

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.

Mass budget and dynamics of polycyclic aromatic hydrocarbons in the Mediterranean Sea

1997 ◽  
Vol 44 (3-4) ◽  
pp. 881-905 ◽  
Author(s):  
E. Lipiatou ◽  
I. Tolosa ◽  
R. Simó ◽  
I. Bouloubassi ◽  
J. Dachs ◽  
...  
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Mediterranean Sea ◽  
Aromatic Hydrocarbons ◽  
Mass Budget ◽  
Polycyclic Aromatic ◽  
The Mediterranean

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 Origin and transport of Mediterranean moisture and air

2009 ◽  
Vol 9 (5) ◽  
pp. 21425-21461
Author(s):  
I. Schicker ◽  
S. Radanovics ◽  
P. Seibert
Keyword(s):  
Mediterranean Basin ◽  
Trade Wind ◽  
Trajectory Data ◽  
Data Set ◽  
Sources And Sinks ◽  
Four Seasons ◽  
Mediterranean Regions ◽  
Diagnosis Method ◽  
The Mediterranean ◽  
The Mediterranean Basin

Abstract. Considering the Mediterranean as a region of high evaporation and low precipitation, evaluations of the moisture and precipitation sources and sinks in the Mediterranean basin have been carried out within the frame of the CIRCE project. In addition, residence time and stagnation/ventilation have been analysed to investigate transport to and from the Mediterranean basin and in the basin itself. A Lagrangian moisture diagnosis method calculating budgets of evaporation minus precipitation was applied to a 5.5 year (October 1999–April 2005) trajectory data set and evaluated for eight Mediterranean regions of interest. The Mediterranean basin has been identified as a major source of moisture and precipitation to the surrounding land area and to the basin itself. Regions of stagnation have been identified through the analysis of the average 24-hour and 5-day displacements for the four seasons, and the Po basin was identified as being strongly affected by stagnation. Evaluation of the transport to and from the basin shows that the Mediterranean is a crossroad of airstreams where air enters mainly from the northwest and continues in two separate airstreams: one turns towards southwest, passing over North Africa into the trade wind zone while the other one continues northeastwards through Central Asia.

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.

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