Carbon dioxide dynamics in an agricultural headwater stream driven by hydrology and primary production

Abstract. Headwater streams are known to be hotspots for carbon dioxide (CO2) emissions to the atmosphere and are hence important components in landscape carbon balances. However, surprisingly little is known about stream CO2 dynamics and emissions in agricultural settings, a land use type that globally covers ca. 40 % of the continental area. Here we present hourly measured in situ stream CO2 concentration data from a 11.3 km2 temperate agricultural headwater catchment covering more than 1 year (in total 339 d excluding periods of ice and snow cover). The stream CO2 concentrations during the entire study period were generally high (median 3.44 mg C L−1, corresponding to partial pressures (pCO2) of 4778 µatm) but were also highly variable (IQR = 3.26 mg C L−1). The CO2 concentration dynamics covered a variety of different timescales from seasonal to hourly, with an interplay of hydrological and biological controls. The hydrological control was strong (although with both positive and negative influences dependent on season), and CO2 concentrations changed rapidly in response to rainfall and snowmelt events. However, during growing-season base flow and receding flow conditions, aquatic primary production seemed to control the stream CO2 dynamics, resulting in elevated diel patterns. During the dry summer period, rapid rewetting following precipitation events generated high CO2 pulses exceeding the overall median level of stream CO2 (up to 3 times higher) observed during the whole study period. This finding highlights the importance of stream intermittency and its effect on stream CO2 dynamics. Given the observed high levels of CO2 and its temporally variable nature, agricultural streams clearly need more attention in order to understand and incorporate these considerable dynamics in large-scale extrapolations.

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Carbon dioxide dynamics in an agricultural headwater stream driven by hydrology and primary production

10.5194/bg-2019-486 ◽

2020 ◽

Author(s):

Marcus B. Wallin ◽

Joachim Audet ◽

Mike Peacock ◽

Erik Sahlée ◽

Mattias Winterdahl

Keyword(s):

Carbon Dioxide ◽

Primary Production ◽

Large Scale ◽

Co2 Concentration ◽

Headwater Stream ◽

Concentration Data ◽

Entire Study ◽

Co2 Concentrations ◽

Variable Nature ◽

Co2 Dynamics

Abstract. Headwater streams are known to be hotspots for carbon dioxide (CO2) emissions to the atmosphere and are hence important components in landscape carbon balances. However, surprisingly little is known about stream CO2 dynamics and emissions in agricultural settings, a land-use type that globally cover ca 40 % of the continental area. Here we present continuously measured in-situ CO2 concentration data from a temperate agricultural headwater stream covering more than one year of open-water season. The stream CO2 concentrations during the entire study period were generally high (median 3.44 mg C L−1, corresponding to partial pressures (pCO2) of 4778 µatm) but were also highly variable (IQR = 3.26 mg C L−1). The CO2 concentration dynamics covered a variety of different time-scales from seasonal to hourly, and with an interplay of hydrological and biological controls. The hydrological control was strong (although with both positive as well as negative influences dependent on season) and CO2 concentrations changed rapidly in response to rainfall and snowmelt events. However, during growing-season baseflow and receding flow conditions, aquatic primary production seemed to control the stream CO2 dynamics resulting in elevated diel patterns. Given the observed high levels of CO2 and its temporally variable nature, agricultural streams clearly need more attention in order to understand and incorporate these considerable dynamics in large scale extrapolations.

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Effect of elevated carbon dioxide on biology and morphometric parameters of yellow stem borer, Scirpophaga incertulas infesting rice (Oryza sativa)

Journal of Agrometeorology ◽

10.54386/jam.v24i1.778 ◽

2022 ◽

Vol 24 (1) ◽

Author(s):

GOURI SHANKAR GIRI ◽

S. V. S. RAJU ◽

S. D. MOHAPATRA ◽

MUNMUN MOHAPATRA

Keyword(s):

Carbon Dioxide ◽

Larval Instar ◽

Co2 Concentration ◽

Elevated Carbon Dioxide ◽

Stem Borer ◽

Developmental Period ◽

Morphometric Parameters ◽

Scirpophaga Incertulas ◽

Yellow Stem Borer ◽

Co2 Concentrations

An experiment was conducted at Research Farm, National Rice Research Institute, Cuttack, Odisha, India to quantify the effect of elevated carbon dioxide (CO2) concentrations on the biology and morphometric parameters of yellow stem borer (Scirpophaga incertulas, Pyralidae, Lepidoptera). Yellow stem borer is one of the major pest of rice in the whole rice growing regions of South East Asia. The effect of three carbon dioxide concentrations i.e. 410 ppm (ambient), 550 ppm and 700 ppm on the duration of the developmental period as well as morphometric parameters of each stage of the lifecycle of the pest was analysed. It was found that, there was an increase in the duration of the developmental period of each stage of life cycle as the concentration of CO2 increases. However, the life span of the adult moth was significantly lower under the elevated CO2 concentrations when compared with ambient CO2 concentration. Morphometric parameters viz., mean length, width and weight of each larval instar, pupa and adult were found to be significantly higher in elevated concentrations of CO2 as compared to ambient concentration.

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Explicit silicate cycling in the Kiel Marine Biogeochemistry Model, version 3 (KMBM3) embedded in the UVic ESCM version 2.9

10.5194/gmd-2020-235 ◽

2020 ◽

Author(s):

Karin Kvale ◽

David P. Keller ◽

Wolfgang Koeve ◽

Katrin J. Meissner ◽

Chris Somes ◽

...

Keyword(s):

Southern Ocean ◽

Primary Production ◽

Large Scale ◽

Climate Model ◽

Net Primary Production ◽

Coupled Model ◽

Co2 Concentration ◽

Ecosystem Model ◽

New Model ◽

Fully Coupled

Abstract. We describe and test a new model of biological marine silicate cycling, implemented in the University of Victoria Earth System Climate Model (UVic ESCM) version 2.9. This new model adds diatoms, which are a key aspect of the biological carbon pump, to an existing ecosystem model. The new model performs well against important ocean biogeochemical indicators and captures the large-scale features of the marine silica cycle. Furthermore it is computationally efficient, allowing both fully-coupled, long-timescale transient simulations, as well as "offline" transport matrix spinups. We assess the fully-coupled model against modern ocean observations, the historical record since 1960, and a business-as-usual atmospheric CO2 forcing to the year 2300. The model simulates a global decline in net primary production (NPP) of 1.3 % having occurred since the 1960s, with the strongest declines in the tropics, northern mid-latitudes, and Southern Ocean. The simulated global decline in NPP reverses after the year 2100 (forced by the extended RCP CO2 concentration scenario), and NPP returns to pre-industrial rates by 2300. This recovery is dominated by increasing primary production in the Southern Ocean, mostly by calcifying phytoplankton. Large increases in calcifying phytoplankton in the Southern Ocean offset a decline in the low latitudes, producing a global net calcite export in 2300 that varies only slightly from pre-industrial rates. Diatoms migrate southward in our simulations, following the receding Antarctic ice front, but are out-competed by calcifiers across most of their pre-industrial Southern Ocean habitat. Global opal export production thus drops to 50 % of its pre-industrial value by 2300. Model nutrients phosphate, silicate, and nitrate build up along the Southern Ocean particle export pathway, but dissolved iron (for which ocean sources are held constant) increases in the upper ocean. This different behaviour of iron is attributed to a reduction of low-latitude NPP (and consequently, a reduction in both uptake and export and particle, including calcite, scavenging), an increase in seawater temperatures (raising the solubility of particle forms), and stratification that "traps" the iron near the surface. These results are meant to serve as a baseline for sensitivity assessments to be undertaken with this model in the future.

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Carbon dioxide, COVID-19 and the importance of restaurant ventilation: a case study from Spain approaching Christmas 2021

10.1101/2021.12.17.21267987 ◽

2021 ◽

Author(s):

Teresa Moreno ◽

Wes Gibbons

Keyword(s):

Co2 Concentration ◽

Infection Risk ◽

Concentration Data ◽

Co2 Concentrations ◽

Restaurant Managers ◽

Co2 Levels ◽

Run Up ◽

Poor Ventilation ◽

Airborne Disease

Restaurants present an especial challenge in the prevention of the spread of COVID-19 via exhalatory bioaerosols because customers are unprotected by facemasks while eating, so that ventilation protocols in such establishments become especial important. However, despite the fact that this pandemic airborne disease has been with us for two full years, many restaurants are still not successfully prioritising air renovation as a key tool for reducing infection risk. We demonstrate this in the run-up to the 2021 Christmas celebrations by reporting on CO2 concentration data obtained from a hotel breakfast room and restaurants during the 5-day Spanish holiday period of 4th-8th December. In the case of the breakfast room, poor ventilation resulted in average CO2 levels ranging from 868 to 1237 on five consecutive days, with the highest levels coinciding with highest occupancy numbers. Inside the five restaurants, three of these were well ventilated, maintaining stable average CO2 concentrations below 700ppm. In contrast, two restaurants failed to keep average CO2 levels below 1000ppm, despite sporadic, but ineffective, attempts by one of them to ventilate the establishment. More effort needs to be made to foster in both restaurant managers and the general public an improved awareness of the value of CO2 concentrations as an infection risk proxy and the relevance of ventilation issues to the propagation of respiratory diseases.

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Carbon Dioxide Footprint and Its Impacts: A Case of Academic Buildings

Sustainability ◽

10.3390/su13147847 ◽

2021 ◽

Vol 13 (14) ◽

pp. 7847

Author(s):

Muhammad Aashed Khan Abbasi ◽

Shabir Hussain Khahro ◽

Yasir Javed

Keyword(s):

Carbon Dioxide ◽

Carbon Emissions ◽

Co2 Concentration ◽

Automated System ◽

Rapid Urbanization ◽

Suggested Approach ◽

Humidity Level ◽

Co2 Concentrations ◽

Academic Buildings ◽

Academic Building

Carbon emissions have been considered a major reason behind climate change and global warming. Various studies report that rapid urbanization and the changing demands of 21st century life have resulted in higher carbon emissions. This study aims to examine the carbon footprints in an academic building to observe the carbon dioxide (CO2) levels at crucial landmarks and offices. A sensor-based automated system was designed and implemented for the collection of CO2 concentrations at selected locations. In the final stage, a CO2 footprint map was generated to highlight the vulnerable areas of CO2 in the academic building. It was concluded that offices have higher CO2 concentrations at both intervals (morning and afternoon), followed by the laboratory, corridors, and praying area. The CO2 concentration did not exceed 500 ppm at any location. Thus, all locations other than offices had normal CO2 concentration levels. Similarly, the humidity level was also satisfactory. The average humidity level was below 50%, which is below the permissible value of 65%. The recommended range for temperature values as per ASHRAE standards is 22.5 °C to 25.5 °C, except for prayer places. It was concluded that the selected academic institute is providing a good environment to the users of the building, but that may change once the academic institute becomes fully functional after COVID-19. This study assists the stakeholders in making guidelines and necessary actions to reduce CO2 concentration in academic buildings, as it is expected to rise once the human load increases in the next academic year. The suggested approach can be used in any other country and the results will vary based on the building type, building energy type, and building ventilation design.

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Correlation of Respiratory Aerosols and Metabolic Carbon Dioxide

Sustainability ◽

10.3390/su132112203 ◽

2021 ◽

Vol 13 (21) ◽

pp. 12203

Author(s):

Niklas Kappelt ◽

Hugo Savill Russell ◽

Szymon Kwiatkowski ◽

Alireza Afshari ◽

Matthew Stanley Johnson

Keyword(s):

Carbon Dioxide ◽

Oral Fluid ◽

Low Cost ◽

Co2 Concentration ◽

Transmission Route ◽

Viral Loads ◽

Co2 Concentrations ◽

Carbon Dioxide Co2 ◽

The Individual ◽

Metabolic Carbon

Respiratory aerosols from breathing and talking are an important transmission route for viruses, including severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Previous studies have found that particles with diameters ranging from 10 nm to 145 μm are produced from different regions in the respiratory system and especially smaller particles can remain airborne for long periods while carrying viral RNA. We present the first study in which respiratory aerosols have been simultaneously measured with carbon dioxide (CO2) to establish the correlation between the two concentrations. CO2 concentrations are easily available through low-cost sensors and could be used to estimate viral exposure through this correlation, whereas source-specific aerosol measurements are complicated and not possible with low-cost sensors. The increase in both respiratory aerosols and CO2 was linear over ten minutes in a 2 m3 chamber for all participants, suggesting a strong correlation. On average, talking released more particles than breathing, with 14,600 ± 16,800 min−1 (one-σ standard deviation) and 6210 ± 5630 min−1 on average, respectively, while CO2 increased with 139 ± 33 ppm min−1 during talking and 143 ± 29 ppm min−1 during breathing. Assuming a typical viral load of 7×106 RNA copies per mL of oral fluid, ten minutes of talking and breathing are estimated to produce 1 and 16 suspended RNA copies, respectively, correlating to a CO2 concentration of around 1800 ppm in a 2 m3 chamber. However, viral loads can vary by several orders of magnitude depending on the stage of the disease and the individual. It was therefore concluded that, by measuring CO2 concentrations, only the number and volume concentrations of released particles can be estimated with reasonable certainty, while the number of suspended RNA copies cannot.

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Effect of Carbon dioxide (CO2) on mortality and reproduction of Anagasta kuehniella (Zeller 1879), in mass rearing, aiming at the production of Trichogramma spp.

Anais da Academia Brasileira de Ciências ◽

10.1590/s0001-37652013000200021 ◽

2013 ◽

Vol 85 (2) ◽

pp. 823-831 ◽

Cited By ~ 5

Author(s):

ALOISIO COELHO JUNIOR ◽

JOSE R.P. PARRA

Keyword(s):

Carbon Dioxide ◽

Egg Production ◽

Co2 Concentration ◽

Mass Rearing ◽

High Density ◽

Biological Parameters ◽

Anagasta Kuehniella ◽

Co2 Concentrations ◽

Carbon Dioxide Co2

Eggs of Anagasta kuehniella (Zeller 1879) are widely used for mass rearing of Trichogramma spp. and other parasitoids and predators, largely commercialized in many countries. The aim of this study is to evaluate the effect of carbon dioxide (CO2) originated from larval metabolism on the biological parameters of A. kuehniella. For that purpose, we assess the production of carbon dioxide (CO2) per rearing tray of A. kuehniella and the effect of CO2 on the viability of egg-to-adult period and oviposition of A. kuehniella. Results allow to estimate that a rearing tray, containing 10,000 larvae between the 4th and 5th instars, produces an average of 30.67 mL of CO2 per hour. The highest egg production of A. kuehniella was obtained when the larvae were kept in rooms with lower concentration of CO2 (1,200 parts per million - ppm), producing 23% more eggs than in rooms with higher CO2 concentrations. In rooms with high density of trays (70 trays/room), CO2 concentration exceeded 4,400 ppm. The viability of the egg-to-adult period was not influenced by carbon dioxide.

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Correlation of Respiratory Aerosols with Metabolic Carbon Dioxide

10.21203/rs.3.rs-490702/v1 ◽

2021 ◽

Author(s):

Niklas Kappelt ◽

Hugo S. Russell ◽

Szymon Kwiatkowski ◽

Alireza Afshari ◽

Matthew S. Johnson

Keyword(s):

Carbon Dioxide ◽

Low Cost ◽

Co2 Concentration ◽

Strong Argument ◽

Wide Acceptance ◽

Co2 Concentrations ◽

Chamber Study ◽

Carbon Dioxide Co2 ◽

Indoor Spaces ◽

Metabolic Carbon

Abstract Respiratory Aerosols from breathing and talking have found wide acceptance as a transmission route for viruses such as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Previous studies have found particles with diameters ranging from 10 nm to 145 µm, exhibited from different regions in the respiratory system. We present the first chamber study, in which respiratory aerosols have been simultaneously measured with carbon dioxide (CO2) to establish the correlation between the two concentrations. CO2 concentrations are easily available through low-cost sensors and could be used to estimate viral exposure through this correlation, whereas source-specific aerosol measurements are complicated and not possible with low cost sensors. The increase in both PM10 and CO2 was linear over ten minutes in a 2 m3 chamber for all participants, suggesting a strong correlation. On average, talking released more particles than breathing, with 14,600 ± 16,800 min-1 (one-σ standard deviation) and 6,210 ± 5,630 min-1 on average, respectively, while CO2 increased with 139 ± 33 ppm min-1 during talking and 143 ± 29 ppm min-1 during breathing. Assuming a typical viral load of 7 × 106 RNA copies per ml of oral fluid, ten minutes of talking and breathing are estimated to produce 7 and 16 suspended RNA copies, respectively, correlating to a CO2 concentration of around 1.800 ppm in a 2 m3 chamber. This provides a strong argument for keeping indoor spaces well ventilated and shows how CO2 concentrations, measured with low-cost sensors, could be used as a proxy for viral exposure.

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The measurements of total carbon dioxide in dilute tropical waters

Marine and Freshwater Research ◽

10.1071/mf9650273 ◽

1965 ◽

Vol 16 (3) ◽

pp. 273 ◽

Cited By ~ 3

Author(s):

DV Subba Rao

Keyword(s):

Carbon Dioxide ◽

Primary Production ◽

Standard Error ◽

Co2 Concentration ◽

Total Carbon ◽

Gulf Of Thailand ◽

Tropical Water ◽

Single Determination ◽

The Gulf Of Thailand ◽

The Individual

A shipboard conductivity technique to measure the total carbon dioxide in dilute tropical water is described. The standard error of a single determination in the range 40-100 mg CO2/I is 6.0 mg/l. There were 41-102 mg CO2/l in waters of the Gulf of Thailand. In these waters, primary production determined with the usually assumed value of 90 mg CO2 gave errors ranging from 11 to 120% for the individual depth samples and from 6 to 92 % for column values as compared to the values obtained using the measured CO2 concentration.

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Improved simulation of regional CO<sub>2</sub> surface concentrations using GEOS-Chem and fluxes from VEGAS

Atmospheric Chemistry and Physics ◽

10.5194/acp-13-7607-2013 ◽

2013 ◽

Vol 13 (15) ◽

pp. 7607-7618 ◽

Cited By ~ 4

Author(s):

Z. H. Chen ◽

J. Zhu ◽

N. Zeng

Keyword(s):

North American ◽

Large Scale ◽

Transport Model ◽

Co2 Concentration ◽

Regional Model ◽

Surface Fluxes ◽

Persistent Problem ◽

Model Simulations ◽

Co2 Concentrations ◽

Single Station

Abstract. CO2 measurements have been combined with simulated CO2 distributions from a transport model in order to produce the optimal estimates of CO2 surface fluxes in inverse modeling. However, one persistent problem in using model–observation comparisons for this goal relates to the issue of compatibility. Observations at a single station reflect all underlying processes of various scales. These processes usually cannot be fully resolved by model simulations at the grid points nearest the station due to lack of spatial or temporal resolution or missing processes in the model. In this study the stations in one region were grouped based on the amplitude and phase of the seasonal cycle at each station. The regionally averaged CO2 at all stations in one region represents the regional CO2 concentration of this region. The regional CO2 concentrations from model simulations and observations were used to evaluate the regional model results. The difference of the regional CO2 concentration between observation and modeled results reflects the uncertainty of the large-scale flux in the region where the grouped stations are. We compared the regional CO2 concentrations between model results with biospheric fluxes from the Carnegie-Ames-Stanford Approach (CASA) and VEgetation-Global-Atmosphere-Soil (VEGAS) models, and used observations from GLOBALVIEW-CO2 to evaluate the regional model results. The results show the largest difference of the regionally averaged values between simulations with fluxes from VEGAS and observations is less than 5 ppm for North American boreal, North American temperate, Eurasian boreal, Eurasian temperate and Europe, which is smaller than the largest difference between CASA simulations and observations (more than 5 ppm). There is still a large difference between two model results and observations for the regional CO2 concentration in the North Atlantic, Indian Ocean, and South Pacific tropics. The regionally averaged CO2 concentrations will be helpful for comparing CO2 concentrations from modeled results and observations and evaluating regional surface fluxes from different methods.

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