scholarly journals Modeling landfill CH4 emissions

Elem Sci Anth ◽  
2021 ◽  
Vol 9 (1) ◽  
Author(s):  
K.A. Spokas ◽  
J. Bogner ◽  
M. Corcoran
Keyword(s):  
Soil Moisture ◽  
Future Climate ◽  
Latitudinal Gradients ◽  
Weather Data ◽  
Ch4 Emission ◽  
Microbial Oxidation ◽  
Site Specific ◽  
Ch4 Emissions ◽  
Cover Soil ◽  
Biogas Recovery

The current IPCC landfill methane (CH4) methodology excludes critical process drivers now known to control emissions. These include site-specific (1) operational factors (i.e., thickness and composition of various cover soils; physical extent of engineered biogas recovery) and (2) temporal climate effects on soil moisture/temperature profiles in each cover which, in turn, drive gaseous transport, microbial methanotrophic oxidation, and temporally variable “net” CH4 emissions over an annual cycle. Herein, we address the international field validation and application of a process-based model CAlifornia Landfill Methane Inventory Model (CALMIM) which encompasses site-specific climate, cover soils, engineered biogas recovery, and other site-specific strategies. Using embedded soil microclimate models with (a) default 30-year climate data, (b) site-specific annual weather data, or (c) future climate predictions (i.e., CMIP5), the transient soil moisture and temperature effects on bidirectional diffusive CH4/oxygen transport and microbial oxidation can be estimated for any cover soil at any global location. We focus on site-specific field data comparisons to CALMIM-predicted annual and monthly CH4 emissions both without and without methanotrophic oxidation. Overall, 74% of 168 individual surface CH4 emission measurements across 34 international sites were consistent with CALMIM-modeled annual predictions with oxidation (+ or – SD). Notably, the model overpredicted 30 comparisons and underpredicted 13 comparisons. In addition to improving site-specific landfill CH4 inventories, we address how this freely available tool can be used to (a) recommend site-specific cover soil modifications to minimize emissions; (b) systematically compare the spatial and temporal variability of emissions for diverse global locations, latitudinal gradients, extreme climates, and future climate scenarios; (c) assist scheduling of field campaigns to capture seasonal variability; and (d) provide a 12-month annual framework with average monthly CH4 emission statistics for comparison to periodic temporal results from diverse bottom-up and top-down field techniques with variable uncertainties. Importantly, CALMIM does not require intensive site-specific model calibrations.

scholarly journals Probabilistic inference of ecohydrological parameters using observations from point to satellite scales

2018 ◽  
Vol 22 (6) ◽  
pp. 3229-3243 ◽  
Author(s):  
Maoya Bassiouni ◽  
Chad W. Higgins ◽  
Christopher J. Still ◽  
Stephen P. Good
Keyword(s):  
Soil Moisture ◽  
Water Balance ◽  
Soil Water ◽  
Dry Season ◽  
Soil Water Balance ◽  
Rainfall Pattern ◽  
Site Specific ◽  
Soil Moisture Dynamics ◽  
Soil Saturation ◽  
Moisture Dynamics

Abstract. Vegetation controls on soil moisture dynamics are challenging to measure and translate into scale- and site-specific ecohydrological parameters for simple soil water balance models. We hypothesize that empirical probability density functions (pdfs) of relative soil moisture or soil saturation encode sufficient information to determine these ecohydrological parameters. Further, these parameters can be estimated through inverse modeling of the analytical equation for soil saturation pdfs, derived from the commonly used stochastic soil water balance framework. We developed a generalizable Bayesian inference framework to estimate ecohydrological parameters consistent with empirical soil saturation pdfs derived from observations at point, footprint, and satellite scales. We applied the inference method to four sites with different land cover and climate assuming (i) an annual rainfall pattern and (ii) a wet season rainfall pattern with a dry season of negligible rainfall. The Nash–Sutcliffe efficiencies of the analytical model's fit to soil observations ranged from 0.89 to 0.99. The coefficient of variation of posterior parameter distributions ranged from < 1 to 15 %. The parameter identifiability was not significantly improved in the more complex seasonal model; however, small differences in parameter values indicate that the annual model may have absorbed dry season dynamics. Parameter estimates were most constrained for scales and locations at which soil water dynamics are more sensitive to the fitted ecohydrological parameters of interest. In these cases, model inversion converged more slowly but ultimately provided better goodness of fit and lower uncertainty. Results were robust using as few as 100 daily observations randomly sampled from the full records, demonstrating the advantage of analyzing soil saturation pdfs instead of time series to estimate ecohydrological parameters from sparse records. Our work combines modeling and empirical approaches in ecohydrology and provides a simple framework to obtain scale- and site-specific analytical descriptions of soil moisture dynamics consistent with soil moisture observations.

A comment on scaling methane emissions from vegetation and grazing ruminants in New Zealand

2006 ◽  
Vol 33 (7) ◽  
pp. 613 ◽  
Author(s):  
Francis M. Kelliher ◽  
Harry Clark ◽  
Zheng Li ◽  
Paul C. D. Newton ◽  
Anthony J. Parsons ◽  
...  
Keyword(s):  
New Zealand ◽  
Standard Deviation ◽  
Forest Canopy ◽  
Emission Rate ◽  
Oxidative Capacity ◽  
Emission Rates ◽  
Ch4 Emission ◽  
Ch4 Emissions ◽  
Grazed Pasture ◽  
Indigenous Forest

Keppler et al. (2006, Nature 439, 187–191) showed that plants produce methane (CH4) in aerobic environments, leading Lowe (2006, Nature 439, 148–149) to postulate that in countries such as New Zealand, where grazed pastures have replaced forests, the forests could have produced as much CH4 as the ruminants currently grazing these areas. Estimating CH4 emissions from up to 85 million ruminants in New Zealand is challenging and, for completeness, the capacity of forest and pastoral soils to oxidise CH4 should be included. On average, the CH4 emission rate of grazing ruminants is estimated to be 9.6 ± 2.6 g m–2 year–1 (±standard deviation), six times the corresponding estimate for an indigenous forest canopy (1.6 ± 1.1 g m–2 year–1). The forest’s soil is estimated to oxidise 0.9 ± 0.2 g m–2 year–1 more CH4 than representative soils beneath grazed pasture. Taking into account plant and animal sources and the soil’s oxidative capacity, the net CH4 emission rates of forest and grazed ecosystems are 0.6 ± 1.1 and 9.8 ± 2.6 g m–2 year–1, respectively.

scholarly journals Soil moisture control over autumn season methane flux, Arctic Coastal Plain of Alaska

2012 ◽  
Vol 9 (4) ◽  
pp. 1423-1440 ◽  
Author(s):  
C. S. Sturtevant ◽  
W. C. Oechel ◽  
D. Zona ◽  
Y. Kim ◽  
C. E. Emerson
Keyword(s):  
Large Scale ◽  
Winter Season ◽  
Methane Flux ◽  
Soil Freezing ◽  
The Arctic ◽  
Freezing Process ◽  
Unfrozen Water ◽  
Ch4 Emission ◽  
Ch4 Emissions ◽  
Autumn Season

Abstract. Accurate estimates of annual budgets of methane (CH4) efflux in arctic regions are severely constrained by the paucity of non-summer measurements. Moreover, the incomplete understanding of the ecosystem-level sensitivity of CH4 emissions to changes in tundra moisture makes prediction of future CH4 release from the Arctic extremely difficult. This study addresses some of these research gaps by presenting an analysis of eddy covariance and chamber measurements of CH4 efflux and supporting environmental variables during the autumn season and associated beginning of soil freeze-up at our large-scale water manipulation site near Barrow, Alaska (the Biocomplexity Experiment). We found that the autumn season CH4 emission is significant (accounting for 21–25% of the average growing season emission), and that this emission is mostly controlled by the fraction of inundated landscape, atmospheric turbulence, and the decline in unfrozen water during the period of soil freezing. Drainage decreased autumn CH4 emission by a factor of 2.4 compared to our flooded treatment. Flooding slowed the soil freezing process which has implications for extending elevated CH4 emissions longer into the winter season.

scholarly journals PENENTUAN MUSIM TANAM, JENIS VARIETAS, DAN TEKNIK BUDIDAYA TANAMAN PADI TERKAIT MITIGASI EMISI METANA (CH4) (Determination of Early Planting Season, Type Varieties, and Cultivation Techniques of Rice as Mitigation to Methane Emission)

2018 ◽  
Vol 24 (1) ◽  
pp. 1
Author(s):  
Lilik Slamet Supriatin
Keyword(s):  
Rainy Season ◽  
Growing Season ◽  
Dry Season ◽  
Wetland Mitigation ◽  
Annual Rainfall ◽  
Ch4 Emission ◽  
Ch4 Emissions ◽  
Cultivation Techniques ◽  
Planting Season

ABSTRAKEmisi metana (CH4) dari pertanian padi lahan sawah dapat dipengaruhi oleh faktor-faktor seperti cara pemberian air, pengolahan tanah, varietas padi, dan iklim. Pada penelitian ini dikaji tahap penentuan musim tanam, pemilihan varietas padi, dan tahap terakhir adalah teknik budidaya pertanian padi lahan sawah yang terkait mitigasi emisi CH4. Hasil kajian menunjukkan bahwa musim tanam padi pada musim kemarau menghasilkan emisi CH4 lebih kecil daripada di musim hujan dengan pengurangan emisi CH4 sebesar 18,13%. Indonesia yang memiliki tiga tipe pola curah hujan tahunan (monsunal, equatorial, lokal) mengakibatkan periode musim tanam rendah emisi CH4 berbeda antara tipe curah hujan yang satu dengan lainnya. Varietas padi Way apo buru adalah varietas yang menghasilkan emisi CH4 terendah tetapi tetap optimum dalam produksi gabah sehingga dapat dipilih menjadi prioritas pertama untuk ditanam. Teknik budidaya pertanian padi lahan sawah yang menghasilkan rendah emisi CH4 dapat dilakukan dengan membuat genangan air yang dangkal saja, dengan cara pemberian air berselang, dan kombinasi antara pemeliharaan padi, ganggang, tanaman paku air, ikan air tawar, dan bakteri metanotrof dalam satu petak lahan sawah (mina padi plus). Pemberian air dengan cara berselang menurunkan emisi CH4 pada musim kemarau sebesar 59,36% dan pada musim hujan sebesar 51,68% jika dibandingkan dengan pemberian air secara terus-menerus (kontinyu). Teknik budidaya mina padi plus mengurangi emisi CH4 sebesar 21,5 kg/ha/musim tanam dan bakteri metanotrof mengurangi emisi CH4 ke atmosfer sebesar 20-60 Tg. Sawah dapat dijadikan sebagai instalasi terbuka pengolahan udara berlimbah CH4. ABSTRACTMethane (CH4) emissions from rice cultivation can be influenced by several factors i.e. the provision of water, soil cultivation, varieties of rice, and the climate. This study will examine the determination of the growing season, the selection of rice varieties and cultivation techniques of rice agriculture-related wetland mitigation of the CH4 emission. The results showed that the rice planting season in the dry season produces CH4 emissions is smaller than in the rainy season with CH4 emission reduction of 18.13%. Indonesia, which has three types of annual rainfall patterns resulting in periods of low growing season CH4 emissions differ between types of rainfall each other. Way apo buru rice species are varieties that produce low emissions of CH4 but remains optimum in grain production. Cultivation techniques of rice farming rice fields that produce low emissions of CH4 can be done by creating a pool of shallow water only, by way of provision of water intermittent, and the combination of maintenance of rice, algae, plants salviniales, freshwater fish, and bacteria metanotrof in a wetland. The provision of water by intermittent lowering emissions of CH4 in the dry season by 59.36% and in the rainy season amounted to 51.68% when compared to the provision of water continuously (continuous). Mina padi plus cultivation techniques reduce CH4 emissions by 21.5 kg/ha/planting and metanotrof bacteria can reduce CH4 emissions to the atmosphere by 20-60 Tg. 

scholarly journals Declining risk of ozone impacts on vegetation in Europe 1990–2050 due to reduced precursor emissions in a changed climate

2014 ◽  
Vol 11 (1) ◽  
pp. 625-655
Author(s):  
J. Klingberg ◽  
M. Engardt ◽  
P. E. Karlsson ◽  
J. Langner ◽  
H. Pleijel
Keyword(s):  
Climate Change ◽  
Soil Moisture ◽  
Emission Scenario ◽  
Growing Season ◽  
Future Climate ◽  
Ozone Exposure ◽  
Emission Reductions ◽  
Ozone Uptake ◽  
Ozone Concentrations ◽  
Ozone Precursor

Abstract. The impacts of climate change and changes in ozone precursor emission on ozone exposure (AOT40) of the vegetation in Europe were investigated. In addition, meteorological conditions influencing stomatal uptake of ozone were analysed to find out if climate change is likely to affect the risk for ozone damage to vegetation. Climate simulations based on the IPCC SRES A1B scenario were combined with ozone precursor emission changes from the RCP4.5 scenario and used as input to the Eulerian Chemical Transport Model MATCH from which projections of ozone concentrations were derived. Provided that the climate projections are realistic and the emission reductions of the emission scenario are undertaken, the ozone exposure of vegetation over Europe will be significantly reduced between the two time periods 1990–2009 and 2040–2059. This decline in AOT40 is larger than the reduction in average ozone concentrations. The reduction is driven by the emission reductions assumed by the RCP4.5 emission scenario, rather than changes in the climate. Higher temperatures in a future climate will result in a prolonged growing season over Europe as well as larger temperature sums during the growing season. Both the extended growing season and higher temperatures may enhance ozone uptake by plants in colder parts of Europe. The future climate suggested by the regional climate model will be dryer in terms of higher vapour pressure deficit (VPD) and lower soil moisture in southern Europe, which may reduce ozone uptake. VPD and soil moisture was not projected to change in north and north-west Europe to an extent that would influence ozone uptake by vegetation. This study shows that substantial reductions of ozone precursor emissions have the potential to strongly reduce the risk for ozone effects on vegetation, even if concurrent climate change promotes ozone formation.

scholarly journals Spatial and temporal variation of methane emissions in drained eutrophic peat agro-ecosystems: drainage ditches as emission hotspots

2008 ◽  
Vol 5 (2) ◽  
pp. 1237-1261 ◽  
Author(s):  
A. P. Schrier-Uijl ◽  
E. M. Veenendaal ◽  
P. A. Leffelaar ◽  
J. C. van Huissteden ◽  
F. Berendse
Keyword(s):  
Soil Moisture ◽  
Moisture Content ◽  
Water Table ◽  
Soil Moisture Content ◽  
Explanatory Variable ◽  
Spatial And Temporal Variation ◽  
Spatial And Temporal Variability ◽  
Ch4 Emissions ◽  
Intensively Managed ◽  
Moisture Conditions

Abstract. Our research investigates the spatial and temporal variability of methane (CH4) emissions in two drained eutrophic peat areas (one intensively managed and the other less intensively managed) and the correlation between CH4 emissions and soil temperature, air temperature, soil moisture content and water table. We stratified the landscape into landscape elements that represent different conditions in terms of topography and therefore differ in moisture conditions. There was great spatial variability in the fluxes in both areas; the ditches and ditch edges (together 27% of the landscape) were methane hotspots whereas the dry fields had the smallest fluxes. In the intensively managed site the fluxes were significantly higher by comparison with the less intensively managed site. In all the landscape element elements the best explanatory variable for CH4 emission was temperature. Neither soil moisture content nor water table correlated significantly with CH4 emissions, except in April, where soil moisture was the best explanatory variable.

scholarly journals The role of termite CH<sub>4</sub> emissions on ecosystem scale: a case study in the Amazon rain forest

2020 ◽  
Author(s):  
Hella van Asperen ◽  
João Rafael Alves-Oliveira ◽  
Thorsten Warneke ◽  
Bruce Forsberg ◽  
Alessandro Carioca de Araujo ◽  
...  
Keyword(s):  
Rain Forest ◽  
Emission Factor ◽  
Field Studies ◽  
Ch4 Emission ◽  
Termite Mound ◽  
Flux Chamber ◽  
Termite Mounds ◽  
Ch4 Emissions ◽  
Amazon Rain Forest

Abstract. The magnitude of termite methane (CH4) emissions is still an uncertain part of the global CH4 budget and current emission estimates are based on limited field studies. We present in-situ CH4 emission measurements of termite mounds and termite mound sub samples, performed in the Amazon rain forest. Emissions of five termite mounds of the species Neocapritermes brasiliensis were measured by use of a large flux chamber connected to a portable gas analyser, measuring CH4 and CO2. In addition, the emission of mound sub samples was measured, after which termites were counted, so that a termite CH4 and CO2 emission factor could be determined. Mound emissions were found to range between 17.0–34.8 nmol mound−1 s−1 for CH4 and between 1.6–13.5 μmol mound−1 s−1 for CO2. A termite emission factor of 0.32 μmol CH4 gtermite−1 h−1 was found, which is twice as high as the only other reported average value for the Amazon. By combining mound emission measurements with the termite emission factor, colony sizes could be estimated, which were found to range between 50–120 thousand individuals. Estimates were similar to literature values, and we therefore propose that this method can be used as a quick non-intrusive method to estimate termite colony size in the field. The role of termites in the ecosystems CH4 budget was evaluated by use of two approaches. Termite mound emission values were combined with local termite mound density numbers, leading to an estimate of 0.15–0.71 nmol CH4 m−2 s−1 on average emitted by termite mounds. In addition, the termite CH4 emission factor from this study was combined with termite density numbers, resulting in an estimate of termite emitted CH4 of ~1.0 nmol m−2 s−1. Considering the relatively low net CH4 emissions previously measured at this ecosystem, we expect that termites play an important role in the CH4 budget of this Terra Firme ecosystem.

scholarly journals Impacts of compound hot–dry extremes on US soybean yields

2021 ◽  
Vol 12 (4) ◽  
pp. 1371-1391
Author(s):  
Raed Hamed ◽  
Anne F. Van Loon ◽  
Jeroen Aerts ◽  
Dim Coumou
Keyword(s):  
Soil Moisture ◽  
Synergistic Effects ◽  
Weather Data ◽  
Yield Variability ◽  
Critical Element ◽  
Early Season ◽  
Soybean Yield ◽  
Late Season ◽  
The Us ◽  
Dry Conditions

Abstract. The US agriculture system supplies more than one-third of globally traded soybean, and with 90 % of US soybean produced under rainfed agriculture, soybean trade is particularly sensitive to weather and climate variability. Average growing season climate conditions can explain about one-third of US soybean yield variability. Additionally, crops can be sensitive to specific short-term weather extremes, occurring in isolation or compounding at key moments throughout crop development. Here, we identify the dominant within-season climate drivers that can explain soybean yield variability in the US, and we explore the synergistic effects between drivers that can lead to severe impacts. The study combines weather data from reanalysis and satellite-informed root zone soil moisture fields with subnational crop yields using statistical methods that account for interaction effects. On average, our models can explain about two-thirds of the year-to-year yield variability (70 % for all years and 60 % for out-of-sample predictions). The largest negative influence on soybean yields is driven by high temperature and low soil moisture during the summer crop reproductive period. Moreover, due to synergistic effects, heat is considerably more damaging to soybean crops during dry conditions and is less problematic during wet conditions. Compounding and interacting hot and dry (hot–dry) summer conditions (defined by the 95th and 5th percentiles of temperature and soil moisture respectively) reduce yields by 2 standard deviations. This sensitivity is 4 and 3 times larger than the sensitivity to hot or dry conditions alone respectively. Other relevant drivers of negative yield responses are lower temperatures early and late in the season, excessive precipitation in the early season, and dry conditions in the late season. We note that the sensitivity to the identified drivers varies across the spatial domain. Higher latitudes, and thus colder regions, are positively affected by high temperatures during the summer period. On the other hand, warmer southeastern regions are positively affected by low temperatures during the late season. Historic trends in identified drivers indicate that US soybean production has generally benefited from recent shifts in weather except for increasing rainfall in the early season. Overall, warming conditions have reduced the risk of frost in the early and late seasons and have potentially allowed for earlier sowing dates. More importantly, summers have been getting cooler and wetter over the eastern US. Nevertheless, despite these positive changes, we show that the frequency of compound hot–dry summer events has remained unchanged over the 1946–2016 period. In the longer term, climate models project substantially warmer summers for the continental US, although uncertainty remains as to whether this will be accompanied by drier conditions. This highlights a critical element to explore in future studies focused on US agricultural production risk under climate change.

Sign in / Sign up

Export Citation Format

Share Document