Methane fluxes but not respiratory carbon dioxide fluxes altered under Si amendment during drying – rewetting cycles in fen peat mesocosms

Eddy covariance measurements of the net turbulent methane flux in the city centre – results of 2 years campaign in Łódź, Poland

10.5194/acp-2015-979 ◽

2016 ◽

Author(s):

W. Pawlak ◽

K. Fortuniak

Keyword(s):

Carbon Dioxide ◽

Eddy Covariance ◽

Vertical Component ◽

Ground Level ◽

Methane Flux ◽

City Centre ◽

Carbon Dioxide Fluxes ◽

Methane Fluxes ◽

Eddy Covariance Measurements ◽

The City

Abstract. In the period between July 2013 and August 2015, continuous measurements of turbulent methane exchange between an urbanised area and the atmosphere were carried out in Łódź. Such long, continuous measurement series of turbulent methane exchange between the city and the atmosphere are still a rarity. The measurement station was located in the centre of the city, where fluxes of energy (sensible and latent heat) and fluxes of mass (carbon dioxide) have been continuously measured since 2000 and 2007, respectively. In the immediate vicinity of the measurement station there are potential sources of methane, such as streets with vehicle traffic or dense sewerage and natural gas networks. To determine the fluxes, the eddy covariance technique was used; the measurement station was equipped with instruments for recording fluctuations in the vertical component of the wind speed (an ultrasonic 3D anemometer, RM Young 81000, RM Young, USA) as well as the concentration of methane in the air (an open path Li 7700 CH4 Analyser, Li-cor, USA). The devices were mounted on a mast at a height of 37 metres above ground level and, on average, 20 metres over the roofs of the surrounding buildings. The results were therefore averaged for an area with a diameter of approximately 1 kilometre. Our aim was to investigate the temporal variability of the turbulent exchange of methane in the city-atmosphere system. The results show in the first place that positive methane fluxes (turbulent gas transport from the surface to the atmosphere) definitely dominate compared with negative fluxes. This indicates that the study area of the centre of Łódź is a net source of methane to the troposphere. The measurements also indicated the existence of a clear annual rhythm of the turbulent flux of methane in the centre of Łódź (on average, the values observed in winter amounted to ~40–60 nmol m−2 s−1 and were significantly larger than in summer). The daily variability of the flux of CH4 (FCH4) is faintly visible throughout the year. The studied area of the centre of Łódź is also characterised by a cycle of methane exchange – the values measured on working days were higher by 6.6 % (winter) to 5.6 % (summer) than those observed at weekends. The largest monthly exchange was characteristic of winter months (from 2.0 to 2.7 g m−2 month−1) and the lowest occurred in summer (from 0.8 to 1.0 g m−2 month−1). The mean daily patterns of FCH4 in consecutive months were used to determine the cumulative annual exchange. In 2014, the centre of Łódź emitted a net quantity of almost 18 g m−2. Furthermore, the study analyses the covariability of methane and carbon dioxide fluxes.

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Carbon dioxide fluxes from contrasting ecosystems in the Sudanian Savanna in West Africa

Carbon Balance and Management ◽

10.1186/s13021-014-0011-4 ◽

2015 ◽

Vol 10 (1) ◽

Cited By ~ 21

Author(s):

Emmanuel Quansah ◽

Matthias Mauder ◽

Ahmed A Balogun ◽

Leonard K Amekudzi ◽

Luitpold Hingerl ◽

...

Keyword(s):

Carbon Dioxide ◽

West Africa ◽

Carbon Dioxide Fluxes

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Resolving space and time variation of lake-atmosphere carbon dioxide fluxes using multiple methods

10.1002/essoar.10501554.1 ◽

2020 ◽

Author(s):

Angela K Baldocchi ◽

David E Reed ◽

Luke C Loken ◽

Emily H. Stanley ◽

Hayley Huerd ◽

...

Keyword(s):

Carbon Dioxide ◽

Time Variation ◽

Multiple Methods ◽

Carbon Dioxide Fluxes ◽

Space And Time

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Soil carbon dioxide fluxes to atmosphere: the role of rainfall over CO2 transport

Applied Geochemistry ◽

10.1016/j.apgeochem.2020.104854 ◽

2020 ◽

pp. 104854

Author(s):

Isabelle Delsarte ◽

Grégory Cohen ◽

Marian Momtbrun ◽

Patrick Höhener ◽

Olivier Atteia

Keyword(s):

Carbon Dioxide ◽

Soil Carbon ◽

Carbon Dioxide Fluxes ◽

Soil Carbon Dioxide ◽

Co2 Transport

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Carbon dioxide fluxes increase from day to night across European streams

Communications Earth & Environment ◽

10.1038/s43247-021-00192-w ◽

2021 ◽

Vol 2 (1) ◽

Author(s):

Katrin Attermeyer ◽

Joan Pere Casas-Ruiz ◽

Thomas Fuss ◽

Ada Pastor ◽

Sophie Cauvy-Fraunié ◽

...

Keyword(s):

Carbon Dioxide ◽

Carbon Dioxide Emissions ◽

Large Scale ◽

Carbon Dioxide Flux ◽

Time Of Day ◽

Night Time ◽

Carbon Dioxide Fluxes ◽

Large Scale Assessment ◽

Air Interface ◽

Flux Variability

AbstractGlobally, inland waters emit over 2 Pg of carbon per year as carbon dioxide, of which the majority originates from streams and rivers. Despite the global significance of fluvial carbon dioxide emissions, little is known about their diel dynamics. Here we present a large-scale assessment of day- and night-time carbon dioxide fluxes at the water-air interface across 34 European streams. We directly measured fluxes four times between October 2016 and July 2017 using drifting chambers. Median fluxes are 1.4 and 2.1 mmol m−2 h−1 at midday and midnight, respectively, with night fluxes exceeding those during the day by 39%. We attribute diel carbon dioxide flux variability mainly to changes in the water partial pressure of carbon dioxide. However, no consistent drivers could be identified across sites. Our findings highlight widespread day-night changes in fluvial carbon dioxide fluxes and suggest that the time of day greatly influences measured carbon dioxide fluxes across European streams.

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The growing season greenhouse gas balance of a continental tundra site in the Indigirka lowlands, NE Siberia

Biogeosciences ◽

10.5194/bg-4-985-2007 ◽

2007 ◽

Vol 4 (6) ◽

pp. 985-1003 ◽

Cited By ~ 84

Author(s):

M. K. van der Molen ◽

J. van Huissteden ◽

F. J. W. Parmentier ◽

A. M. R. Petrescu ◽

A. J. Dolman ◽

...

Keyword(s):

Carbon Dioxide ◽

Soil Temperature ◽

Greenhouse Gas ◽

Growing Season ◽

Light Limitation ◽

Greenhouse Gas Balance ◽

Area Index ◽

North East ◽

Methane Fluxes ◽

Gas Balance

Abstract. Carbon dioxide and methane fluxes were measured at a tundra site near Chokurdakh, in the lowlands of the Indigirka river in north-east Siberia. This site is one of the few stations on Russian tundra and it is different from most other tundra flux stations in its continentality. A suite of methods was applied to determine the fluxes of NEE, GPP, Reco and methane, including eddy covariance, chambers and leaf cuvettes. Net carbon dioxide fluxes were high compared with other tundra sites, with NEE=−92 g C m−2 yr−1, which is composed of an Reco=+141 g C m−2 yr−1 and GPP=−232 g C m−2 yr−1. This large carbon dioxide sink may be explained by the continental climate, that is reflected in low winter soil temperatures (−14°C), reducing the respiration rates, and short, relatively warm summers, stimulating high photosynthesis rates. Interannual variability in GPP was dominated by the frequency of light limitation (Rg<200 W m−2), whereas Reco depends most directly on soil temperature and time in the growing season, which serves as a proxy of the combined effects of active layer depth, leaf area index, soil moisture and substrate availability. The methane flux, in units of global warming potential, was +28 g C-CO2e m−2 yr−1, so that the greenhouse gas balance was −64 g C-CO2e m−2 yr−1. Methane fluxes depended only slightly on soil temperature and were highly sensitive to hydrological conditions and vegetation composition.

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