Towards inferring the variability in oceanic CO2 fluxes at high latitudes using atmospheric O2 observations

2021 ◽  
Author(s):  
Nicolas Mayot ◽  
Corinne Le Quéré ◽  
Andrew Manning ◽  
Ralph Keeling ◽  
Christian Rödenbeck
Keyword(s):  
Time Series ◽  
Climate Variability ◽  
Transport Model ◽  
Atmospheric Transport ◽  
Southern Annular Mode ◽  
Global Ocean ◽  
Inversion Method ◽  
High Latitudes ◽  
Ocean Biogeochemistry ◽  
The One

<p>The oceanic CO<sub>2</sub> sink displays year-to-year to decadal variabilities which are not fully reproduced by global ocean biogeochemistry models, especially in the high-latitude oceans. Oceanic CO<sub>2</sub> is influenced by the same climate variability and the same ecosystem processes as oceanic oxygen (O<sub>2</sub>), although in different proportions. Unlike for CO<sub>2</sub>, oceanic O<sub>2</sub> flux is not influenced directly by the rise in atmospheric CO<sub>2</sub>, and therefore its variability reflects purely climatic and biogeochemical variability and trends. Therefore, natural climate variability and changes in oceanic processes controlling air-sea exchanges of CO<sub>2</sub> can be studied by focusing on oxygen (O<sub>2</sub>), where the signal is unencumbered by direct anthropogenic influence. A global time series of oceanic O<sub>2</sub> flux was obtained by building a global O<sub>2</sub> budget, with an approach similar to the one used for the global carbon budget. The global O<sub>2</sub> budget is based on atmospheric O<sub>2</sub> observations and fossil fuel statistics, and infers the partitioning of the land and ocean fluxes using constant C:O<sub>2</sub> ratios for land processes. One key result of this analysis is that air-sea O<sub>2</sub> exchange induced significant year-to-year variability in observed atmospheric O<sub>2</sub>. Estimates of regional oceanic O<sub>2</sub> fluxes were obtained from an atmospheric transport inversion analysis that inferred air-sea O<sub>2</sub> exchange based on global atmospheric O<sub>2</sub> observations and a global atmospheric transport model. For the Southern Ocean, a comparison was made between time series of winter oceanic O<sub>2</sub> fluxes from this inversion method and winter mixed layer depths from Argo floats. Results from this comparison confirmed the previously suggested relationship between the winter ocean mixing and air-sea O<sub>2</sub> exchange, which might be controlled by the climate variability induced by the Southern Annular Mode. Finally, these global and regional air-sea O<sub>2</sub> fluxes were compared with outputs from six global ocean biogeochemistry models to examine their current skills in simulating O<sub>2</sub> variability. Preliminary results suggested that all models underestimated the interannual variability in oceanic O<sub>2</sub> fluxes, however they were able to simulate some of the observed multi-annual variability in O<sub>2</sub> fluxes at high latitudes. We discuss the implications for the model’s representation of the variability in CO<sub>2</sub> fluxes.</p>

scholarly journals TransCom N<sub>2</sub>O model inter-comparison, Part II: Atmospheric inversion estimates of N<sub>2</sub>O emissions

2014 ◽  
Vol 14 (4) ◽  
pp. 5271-5321 ◽  
Author(s):  
R. L. Thompson ◽  
K. Ishijima ◽  
E. Saikawa ◽  
M. Corazza ◽  
U. Karstens ◽  
...  
Keyword(s):  
Transport Model ◽  
Atmospheric Transport ◽  
Meteorological Data ◽  
N2o Emission ◽  
Inversion Method ◽  
N2o Emissions ◽  
High Latitudes ◽  
The Mean ◽  
The Tropics ◽  
Atmospheric Inversion

Abstract. This study examines N2O emission estimates from 5 different atmospheric inversion frameworks. The 5 frameworks differ in the choice of atmospheric transport model, meteorological data, prior uncertainties and inversion method but use the same prior emissions and observation dataset. The mean emissions for 2006 to 2008 are compared in terms of the spatial distribution and seasonality. Overall, there is a good agreement among the inversions for the mean global total emission, which ranges from 16.1 to 18.7 Tg N yr−1 and is consistent with previous estimates. Ocean emissions represent between 31% and 38% of the global total compared to widely varying previous estimates of 24% to 38%. Emissions from the northern mid to high latitudes are likely to be more important, with a consistent shift in emissions from the tropics and subtropics to the mid to high latitudes in the Northern Hemisphere; the emission ratio for 0–30° N to 30–90° N ranges from 1.5 to 1.9 compared with 2.9 to 3.0 in previous estimates. The largest discrepancies across inversions are seen for the regions of South and East Asia and for tropical and South America owing to the poor observational constraint for these areas and to considerable differences in the modelled transport, especially inter-hemispheric exchange rates and tropical convection. Estimates of the seasonal cycle in N2O emissions are also sensitive to errors in modelled stratosphere-to-troposphere transport in the tropics and southern extra-tropics. Overall, the results show a convergence in the global and regional emissions compared to previous independent studies.

The Argo Project: Global Ocean Observations for Understanding and Prediction of Climate Variability

2002 ◽  
Author(s):  
Dean H. Roemmich ◽  
Russ E. Davis ◽  
Stephen C. Riser ◽  
W. B. Owens ◽  
Robert L. Molinari ◽  
...  
Keyword(s):  
Climate Variability ◽  
Global Ocean ◽  
Ocean Observations ◽  
Argo Project

scholarly journals Scenario Analyses of Exhaust Emissions Reduction through the Introduction of Electric Vehicles into the City

Energies ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 2030
Author(s):  
Marianna Jacyna ◽  
Renata Żochowska ◽  
Aleksander Sobota ◽  
Mariusz Wasiak
Keyword(s):  
Inner City ◽  
Electric Vehicles ◽  
Transport Model ◽  
Exhaust Emissions ◽  
Scenario Analyses ◽  
High Emission ◽  
Clean Air ◽  
The One ◽  
The City

In recent years, policymakers of urban agglomerations in various regions of the world have been striving to reduce environmental pollution from harmful exhaust and noise emissions. Restrictions on conventional vehicles entering the inner city are being introduced and the introduction of low-emission measures, including electric ones, is being promoted. This paper presents a method for scenario analysis applied to study the reduction of exhaust emissions by introducing electric vehicles in a selected city. The original scenario analyses relating to real problems faced by contemporary metropolitan areas are based on the VISUM tool (PTV Headquarters for Europe: PTV Planung Transport Verkehr AG, 76131 Karlsruhe, Germany). For the case study, the transport model of the city of Bielsko-Biala (Poland) was used to conduct experiments with different forms of participation of electric vehicles on the one hand and traffic restrictions for high emission vehicles on the other hand. Scenario analyses were conducted for various constraint options including inbound, outbound, and through traffic. Travel time for specific transport relations and the volume of harmful emissions were used as criteria for evaluating scenarios of limited accessibility to city zones for selected types of vehicles. The comparative analyses carried out showed that the introduction of electric vehicles in the inner city resulted in a significant reduction in the emission of harmful exhaust compounds and, consequently, in an increase in the area of clean air in the city. The case study and its results provide some valuable insights and may guide decision-makers in their actions to introduce both driving ban restrictions for high-emission vehicles and incentives for the use of electric vehicles for city residents.

scholarly journals The Environmental Effects of the April 2020 Wildfires and the Cs-137 Re-Suspension in the Chernobyl Exclusion Zone: A Multi-Hazard Threat

Atmosphere ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 467
Author(s):  
Rocío Baró ◽  
Christian Maurer ◽  
Jerome Brioude ◽  
Delia Arnold ◽  
Marcus Hirtl
Keyword(s):  
Air Quality ◽  
Nuclear Power ◽  
Transport Model ◽  
Atmospheric Transport ◽  
Point Of View ◽  
Plume Dispersion ◽  
Exclusion Zone ◽  
Fire Plume ◽  
Mean Values ◽  
The Impact

This paper demonstrates the environmental impacts of the wildfires occurring at the beginning of April 2020 in and around the highly contaminated Chernobyl Exclusion Zone (CEZ). Due to the critical fire location, concerns arose about secondary radioactive contamination potentially spreading over Europe. The impact of the fire was assessed through the evaluation of fire plume dispersion and re-suspension of the radionuclide Cs-137, whereas, to assess the smoke plume effect, a WRF-Chem simulation was performed and compared to Tropospheric Monitoring Instrument (TROPOMI) satellite columns. The results show agreement of the simulated black carbon and carbon monoxide plumes with the plumes as observed by TROPOMI, where pollutants were also transported to Belarus. From an air quality and health perspective, the wildfires caused extremely bad air quality over Kiev, where the WRF-Chem model simulated mean values of PM2.5 up to 300 µg/m3 (during the first fire outbreak) over CEZ. The re-suspension of Cs-137 was assessed by a Bayesian inverse modelling approach using FLEXPART as the atmospheric transport model and Ukraine observations, yielding a total release of 600 ± 200 GBq. The increase in both smoke and Cs-137 emissions was only well correlated on the 9 April, likely related to a shift of the focus area of the fires. From a radiological point of view even the highest Cs-137 values (average measured or modelled air concentrations and modelled deposition) at the measurement site closest to the Chernobyl Nuclear Power Plant, i.e., Kiev, posed no health risk.

scholarly journals Landslide geometry and activity in Villa de la Independencia (Bolivia) revealed by InSAR and seismic noise measurements

Landslides ◽  
2021 ◽  
Author(s):  
Chuang Song ◽  
Chen Yu ◽  
Zhenhong Li ◽  
Veronica Pazzi ◽  
Matteo Del Soldato ◽  
...  
Keyword(s):  
Time Series ◽  
Seismic Noise ◽  
Slip Surface ◽  
Inversion Method ◽  
Subsurface Structures ◽  
Slip Surfaces ◽  
Landslide Volume ◽  
Noise Measurements ◽  
Landslide Body

AbstractInterferometric Synthetic Aperture Radar (InSAR) enables detailed investigation of surface landslide movements, but it cannot provide information about subsurface structures. In this work, InSAR measurements were integrated with seismic noise in situ measurements to analyse both the surface and subsurface characteristics of a complex slow-moving landslide exhibiting multiple failure surfaces. The landslide body involves a town of around 6000 inhabitants, Villa de la Independencia (Bolivia), where extensive damages to buildings have been observed. To investigate the spatial-temporal characteristics of the landslide motion, Sentinel-1 displacement time series from October 2014 to December 2019 were produced. A new geometric inversion method is proposed to determine the best-fit sliding direction and inclination of the landslide. Our results indicate that the landslide is featured by a compound movement where three different blocks slide. This is further evidenced by seismic noise measurements which identified that the different dynamic characteristics of the three sub-blocks were possibly due to the different properties of shallow and deep slip surfaces. Determination of the slip surface depths allows for estimating the overall landslide volume (9.18 · 107 m3). Furthermore, Sentinel-1 time series show that the landslide movements manifest substantial accelerations in early 2018 and 2019, coinciding with increased precipitations in the late rainy season which are identified as the most likely triggers of the observed accelerations. This study showcases  the potential of integrating InSAR and seismic noise techniques to understand the landslide mechanism from ground to subsurface.

DISTRIBUTIONS OF LOCAL MANDELBROT-HURST EXPONENTS: MOTOR ACTIVITY IN FETAL RATS OF COCAINIZED MOTHERS AND MANIC-DEPRESSIVE PATIENTS

Fractals ◽  
1995 ◽  
Vol 03 (04) ◽  
pp. 893-904 ◽  
Author(s):  
KAREN A. SELZ ◽  
ARNOLD J. MANDELL ◽  
CARL M. ANDERSON ◽  
WILLIAM P. SMOTHERMAN ◽  
MARTIN H. TEICHER
Keyword(s):  
Time Series ◽  
Motor Activity ◽  
Motor Behavior ◽  
Pregnant Rats ◽  
Behavioral Systems ◽  
Statistical Indices ◽  
Manic Depressive ◽  
The One ◽  
Depressive Patients ◽  
Hurst Exponents

Intermittency, in which the normalized weight of large fluctuations grows for increasingly longer statistical samples, is seen as irregular bursting activity in time and is characteristic of the behavior of many brain and behavioral systems. This pattern has been related to the brain-stabilizing interplay of the general mechanisms of silence-evoked sensitization and activity-evoked desensitization, which can be found at most levels of neurobiological function and which vary more smoothly and at much longer times than the phasic observables. We use both the global Mandelbrot-Hurst exponent and the distribution of local Mandelbrot-Hurst exponents, in combination with dynamical entropies, to quantitate the property of nonuniform persistence which we treat as both deterministically expansive and statistically diffusive. For example, varying the parameter of the one-dimensional, Manneville-Pomeau intermittency map generated time series which demonstrated systematic changes in these statistical indices of persistence. Relatively small doses of cocaine administered to pregnant rats increased statistical indices of expansiveness and persistence in fetal motor behavior. These techniques also model and characterize a breakdown of statistical scaling in 72-hour time series of the amount of motor activity in some hospitalized manic-depressive patients.

scholarly journals Atmospheric 14C Variability Recorded in Tree Rings from Peninsular India: Implications for Fossil Fuel CO2 Emission and Atmospheric Transport

Radiocarbon ◽  
2008 ◽  
Vol 50 (3) ◽  
pp. 321-330 ◽  
Author(s):  
Supriyo Chakraborty ◽  
Koushik Dutta ◽  
Amalava Bhattacharyya ◽  
Mohit Nigam ◽  
Edward A G Schuur ◽  
...  
Keyword(s):  
Time Series ◽  
Fossil Fuel ◽  
Atmospheric Transport ◽  
Central India ◽  
Tectona Grandis ◽  
Peninsular India ◽  
Local Emission ◽  
Teak Tree ◽  
C Value ◽  
Peak Value

Radiocarbon analysis in annual rings of a teak tree (Tectona grandis) is reported in comparison with previously published results. Samples (disks) were collected from Hoshangabad (22°30′N, 78°E), Madhya Pradesh, in central India. The previously published sample was collected from Thane (19°12′N, 73°E), Maharashtra, near the west coast of India (Chakraborty et al. 1994). Two short Δ14C time series were reconstructed with these tree samples to capture the bomb peak of atmospheric 14C and the spatial variability in this record. These time series represent the periods 1954–1977 and 1959–1980 for Hoshangabad and Thane, respectively. The 14C peaks in these places appear around 1964–1965. The Hoshangabad tree records a peak Δ14C value of 708 ± 8%, which conforms to the peak value of Northern Hemisphere Zone 3 as described in Hua and Barbetti (2004). But the peak Δ14C at Thane is somewhat less (630 ± 8%) probably due to the dilution by fossil fuel CO2 free of 14C emanating from the neighboring industrial areas. This depletion of peak values has been used to estimate the local emission of fossil fuel CO2, which is approximately 2.3% of the background atmospheric CO2 concentration.

Sign in / Sign up

Export Citation Format

Share Document