scholarly journals Large and increasing methane emissions from eastern Amazonia derived from satellite data, 2010–2018

2021 ◽  
Vol 21 (13) ◽  
pp. 10643-10669
Author(s):  
Chris Wilson ◽  
Martyn P. Chipperfield ◽  
Manuel Gloor ◽  
Robert J. Parker ◽  
Hartmut Boesch ◽  
...  
Keyword(s):  
South America ◽  
Satellite Data ◽  
Amazon Basin ◽  
Fossil Fuels ◽  
Amazon River ◽  
Positive Trend ◽  
Wet Season ◽  
Ch4 Emissions ◽  
Vertical Profiling ◽  
Independent Observations

Abstract. We use a global inverse model, satellite data and flask measurements to estimate methane (CH4) emissions from South America, Brazil and the basin of the Amazon River for the period 2010–2018. We find that emissions from Brazil have risen during this period, most quickly in the eastern Amazon basin, and that this is concurrent with increasing surface temperatures in this region. Brazilian CH4 emissions rose from 49.8 ± 5.4 Tg yr−1 in 2010–2013 to 55.6 ± 5.2 Tg yr−1 in 2014–2017, with the wet season of December–March having the largest positive trend in emissions. Amazon basin emissions grew from 41.7 ± 5.3 to 49.3 ± 5.1 Tg yr−1 during the same period. We derive no significant trend in regional emissions from fossil fuels during this period. We find that our posterior distribution of emissions within South America is significantly and consistently changed from our prior estimates, with the strongest emission sources being in the far north of the continent and to the south and south-east of the Amazon basin, at the mouth of the Amazon River and nearby marsh, swamp and mangrove regions. We derive particularly large emissions during the wet season of 2013/14, when flooding was prevalent over larger regions than normal within the Amazon basin. We compare our posterior CH4 mole fractions, derived from posterior fluxes, to independent observations of CH4 mole fraction taken at five lower- to mid-tropospheric vertical profiling sites over the Amazon and find that our posterior fluxes outperform prior fluxes at all locations. In particular the large emissions from the eastern Amazon basin are shown to be in good agreement with independent observations made at Santarém, a location which has long displayed higher mole fractions of atmospheric CH4 in contrast with other basin locations. We show that a bottom-up wetland flux model can match neither the variation in annual fluxes nor the positive trend in emissions produced by the inversion. Our results show that the Amazon alone was responsible for 24 ± 18 % of the total global increase in CH4 flux during the study period, and it may contribute further in future due to its sensitivity to temperature changes.

scholarly journals Large and increasing methane emissions from Eastern Amazonia derived from satellite data, 2010–2018

2020 ◽  
Author(s):  
Chris Wilson ◽  
Martyn P. Chipperfield ◽  
Manuel Gloor ◽  
Robert J. Parker ◽  
Hartmut Boesch ◽  
...  
Keyword(s):  
South America ◽  
Satellite Data ◽  
Amazon Basin ◽  
Fossil Fuels ◽  
Positive Trend ◽  
Wet Season ◽  
Ch4 Emissions ◽  
Vertical Profiling ◽  
Independent Observations ◽  
Global Increase

Abstract. We use a global inverse model, satellite data and flask measurements to estimate methane (CH4) emissions from South America, Brazil and the basin of the Amazon River for the period 2010–2018. We find that emissions from Brazil have risen during this period, most quickly in the Eastern Amazon Basin, and that this concurrent with increasing surface temperatures in this region. Brazilian CH4 emissions rose from 49.8 ± 5.4 Tg(CH4)/yr in 2010–2013 to 55.6 ± 5.2 Tg(CH4)/yr in 2014–2017, with the wet season of December–March having the largest positive trend in emissions. We derive no significant trend in regional emissions from fossil fuels during this period. We find that our posterior distribution of emissions within South America is significantly and consistently changed from our prior estimates, with the strongest emission sources being in the far north of the continent and to the south and south-east of the Amazon Basin, near the mouth of the Amazon and in other wetland regions. We derive particularly large emissions during the wet season of 2013/14, when flooding was prevalent over larger regions than normal within the Amazon Basin. We compare our posterior CH4 mole fractions, derived from posterior fluxes, to independent observations of CH4 mole fraction taken at five lower to mid tropospheric vertical profiling sites over the Amazon and find that our posterior fluxes outperform prior fluxes at all locations. In particular the large emissions from the eastern Basin are shown to be in good agreement with independent observations made at Santarém, a location which has long displayed higher mole fractions of atmospheric CH4 in contrast with other Basin locations. We show that a bottom-up flux model cannot match the variation in annual fluxes, nor the positive trend in emissions, produced by the inversion. Our results show that the Amazon alone was responsible for 24 ± 18 % of the total global increase in CH4 flux during the study period, and it may contribute further in future due to its sensitivity to temperature changes.

scholarly journals On the importance of cascading moisture recycling in South America

2014 ◽  
Vol 14 (23) ◽  
pp. 13337-13359 ◽  
Author(s):  
D. C. Zemp ◽  
C.-F. Schleussner ◽  
H. M. J. Barbosa ◽  
R. J. van der Ent ◽  
J. F. Donges ◽  
...  
Keyword(s):  
Land Use ◽  
South America ◽  
Complex Network ◽  
Amazon Basin ◽  
South American ◽  
Total Precipitation ◽  
Wet Season ◽  
La Plata ◽  
Moisture Recycling ◽  
La Plata Basin

Abstract. Continental moisture recycling is a crucial process of the South American climate system. In particular, evapotranspiration from the Amazon basin contributes substantially to precipitation regionally as well as over other remote regions such as the La Plata basin. Here we present an in-depth analysis of South American moisture recycling mechanisms. In particular, we quantify the importance of cascading moisture recycling (CMR), which describes moisture transport between two locations on the continent that involves re-evaporation cycles along the way. Using an Eulerian atmospheric moisture tracking model forced by a combination of several historical climate data sets, we were able to construct a complex network of moisture recycling for South America. Our results show that CMR contributes about 9–10% to the total precipitation over South America and 17–18% over the La Plata basin. CMR increases the fraction of total precipitation over the La Plata basin that originates from the Amazon basin from 18–23 to 24–29% during the wet season. We also show that the south-western part of the Amazon basin is not only a direct source of rainfall over the La Plata basin, but also a key intermediary region that distributes moisture originating from the entire Amazon basin towards the La Plata basin during the wet season. Our results suggest that land use change in this region might have a stronger impact on downwind rainfall than previously thought. Using complex network analysis techniques, we find the eastern side of the sub-tropical Andes to be a key region where CMR pathways are channeled. This study offers a better understanding of the interactions between the vegetation and the atmosphere on the water cycle, which is needed in a context of land use and climate change in South America.

scholarly journals First record of Annonaceae wood for the Neogene of South America, Amazon Basin, Brazil

2017 ◽  
Vol 47 (1) ◽  
pp. 95-108 ◽  
Author(s):  
Emilio Alberto Amaral Soares ◽  
Adriana Cabral Kloster ◽  
Silvia Cristina Gnaedinger ◽  
Silvio Roberto Riker ◽  
Felipe José da Cruz Lima ◽  
...  
Keyword(s):  
South America ◽  
Amazon Basin ◽  
River System ◽  
First Record ◽  
Morphological Data ◽  
Amazon River ◽  
Left Bank ◽  
Paleoenvironmental Reconstruction ◽  
Depositional Processes ◽  
Systematic Character

ABSTRACT: The relief of the regions of Manaus and Itacoatiara, Central Amazon, is supported by Neogene siliciclastic rocks, bounded at the base and top by lateritic paleosols and covered by quaternary sedimentary deposits from the Solimões-Amazon river system. This unit is informally assigned to the Novo Remanso Formation, consists of usually reddish and ferruginized sandstones, conglomerates and pelites, with few identified fossil records, a fact that has hindered its stratigraphic position, and the paleoenvironmental reconstruction of the last phase of the Amazon Basin settling. This study describes, for the first time, the occurrence of fossil wood in outcroppings of the left bank of the Amazon River, where anatomical and morphological data has enabled its characterization to the species level. Thus, the data marks the record of the Annonaceae in South America, as well as the depositional processes related to incorporation of organic material in the sandy layer and the fossilization processes that allowed its preservation. In an unprecedented way, this study has described Duguetiaxylon amazonicum nov. gen and sp. and provided information on the anatomical and systematic character, as well as data on plant-insect interaction, and a better understanding of the family.

scholarly journals On the importance of cascading moisture recycling in South America

2014 ◽  
Vol 14 (11) ◽  
pp. 17479-17526 ◽  
Author(s):  
D. C. Zemp ◽  
C.-F. Schleussner ◽  
H. M. J. Barbosa ◽  
R. J. Van der Ent ◽  
J. F. Donges ◽  
...  
Keyword(s):  
South America ◽  
River Basin ◽  
Amazon Basin ◽  
South American ◽  
The South ◽  
Wet Season ◽  
La Plata ◽  
Moisture Recycling ◽  
La Plata Basin ◽  
Recycling Networks

Abstract. Continental moisture recycling is a crucial process of the South American climate system. Evapotranspiration from the Amazon river basin contributes to precipitation regionally and in the La Plata river basin. Here we present an in-depth analysis of South American moisture recycling. We quantify the importance of "cascading moisture recycling", which describes the exchange of moisture between the vegetation and the atmosphere through precipitation and re-evaporation cycles on its way between two locations on the continent. We use the Water Accounting Model 2-layers (WAM-2layers) forced by precipitation from TRMM and evapotranspiration from MODIS for the period 2001 until 2010 to construct moisture recycling networks. These networks describe the direction and amount of moisture transported from its source (evapotranspiration) to its destination (precipitation) in South America. Model-based calculations of continental and regional recycling ratios in the Amazon basin compare well with other existing studies using different datasets and methodologies. Our results show that cascading moisture recycling contributes about 10% to the total precipitation over South America and 17% over the La Plata basin. Considering cascading moisture recycling increases the total dependency of the La Plata basin on moisture from the Amazon basin by about 25% from 23 to 29% during the wet season. Using tools from complex network analysis, we reveal the importance of the south-western part of the Amazon basin as a key intermediary region for continental moisture transport in South America during the wet season. Our results suggest that land use change in this region might have a stronger impact on downwind rainfed agriculture and ecosystem stability than previously thought.

scholarly journals Amazonia as the Origin and Diversification Area of Didelphidae (Mammalia: Metatheria), and a Review of the Fossil Record of the Clade

2021 ◽  
Author(s):  
Mariela C. Castro ◽  
Murilo J. Dahur ◽  
Gabriel S. Ferreira
Keyword(s):  
South America ◽  
Amazon Basin ◽  
Parametric Models ◽  
Isthmus Of Panama ◽  
Biogeographic History ◽  
Early Diversification ◽  
Northern Portion ◽  
History Of ◽  
Environmental Events ◽  
Fossil Records

AbstractDidelphidae is the largest New World radiation of marsupials, and is mostly represented by arboreal, small- to medium-sized taxa that inhabit tropical and/or subtropical forests. The group originated and remained isolated in South America for millions of years, until the formation of the Isthmus of Panama. In this study, we present the first reconstruction of the biogeographic history of Didelphidae including all major clades, based on parametric models and stratified analyses over time. We also compiled all the pre-Quaternary fossil records of the group, and contrasted these data to our biogeographic inferences, as well as to major environmental events that occurred in the South American Cenozoic. Our results indicate the relevance of Amazonia in the early diversification of Didelphidae, including the divergence of the major clades traditionally ranked as subfamilies and tribes. Cladogeneses in other areas started in the late Miocene, an interval of intense shifts, especially in the northern portion of Andes and Amazon Basin. Occupation of other areas continued through the Pliocene, but few were only colonized in Quaternary times. The comparison between the biogeographic inference and the fossil records highlights some further steps towards better understanding the spatiotemporal evolution of the clade. Finally, our results stress that the early history of didelphids is obscured by the lack of Paleogene fossils, which are still to be unearthed from low-latitude deposits of South America.

scholarly journals Coupling between the JULES land-surface scheme and the CCATT-BRAMS atmospheric chemistry model (JULES-CCATT-BRAMS1.0): applications to numerical weather forecasting and the CO<sub>2</sub> budget in South America

2013 ◽  
Vol 6 (1) ◽  
pp. 453-494 ◽  
Author(s):  
D. S. Moreira ◽  
S. R. Freitas ◽  
J. P. Bonatti ◽  
L. M. Mercado ◽  
N. M. É. Rosário ◽  
...  
Keyword(s):  
South America ◽  
Atmospheric Chemistry ◽  
Land Surface ◽  
Amazon Basin ◽  
Mean Squared Error ◽  
Weather Forecasting ◽  
Dew Point ◽  
Surface Model ◽  
Co2 Concentrations ◽  
Wide Range

Abstract. This article presents the development of a new numerical system denominated JULES-CCATT-BRAMS, which resulted from the coupling of the JULES surface model to the CCATT-BRAMS atmospheric chemistry model. The performance of this system in relation to several meteorological variables (wind speed at 10 m, air temperature at 2 m, dew point temperature at 2 m, pressure reduced to mean sea level and 6 h accumulated precipitation) and the CO2 concentration above an extensive area of South America is also presented, focusing on the Amazon basin. The evaluations were conducted for two periods, the wet (March) and dry (September) seasons of 2010. The statistics used to perform the evaluation included bias (BIAS) and root mean squared error (RMSE). The errors were calculated in relation to observations at conventional stations in airports and automatic stations. In addition, CO2 concentrations in the first model level were compared with meteorological tower measurements and vertical CO2 profiles were compared with aircraft data. The results of this study show that the JULES model coupled to CCATT-BRAMS provided a significant gain in performance in the evaluated atmospheric fields relative to those simulated by the LEAF (version 3) surface model originally utilized by CCATT-BRAMS. Simulations of CO2 concentrations in Amazonia and a comparison with observations are also discussed and show that the system presents a gain in performance relative to previous studies. Finally, we discuss a wide range of numerical studies integrating coupled atmospheric, land surface and chemistry processes that could be produced with the system described here. Therefore, this work presents to the scientific community a free tool, with good performance in relation to the observed data and re-analyses, able to produce atmospheric simulations/forecasts at different resolutions, for any period of time and in any region of the globe.

Impact of strong El Niño events on river discharge in South America

2021 ◽  
Author(s):  
Markus Deppner ◽  
Bedartha Goswami
Keyword(s):  
Machine Learning ◽  
Missing Data ◽  
South America ◽  
River Discharge ◽  
Amazon Basin ◽  
Missing Values ◽  
Southern Oscillation ◽  
Enso Events ◽  
Streamflow Data ◽  
The Impact

&lt;p&gt;The impact of the El Ni&amp;#241;o Southern Oscillation (ENSO) on rivers are well known, but most existing studies involving streamflow data are severely limited by data coverage. Time series of gauging stations fade in and out over time, which makes hydrological large scale and long time analysis or studies of rarely occurring extreme events challenging. Here, we use a machine learning approach to infer missing streamflow data based on temporal correlations of stations with missing values to others with data. By using 346 stations, from the &amp;#8220;Global Streamflow Indices and Metadata archive&amp;#8221; (GSIM), that initially cover the 40 year timespan in conjunction with Gaussian processes we were able to extend our data by estimating missing data for an additional 646 stations, allowing us to include a total of 992 stations. We then investigate the impact of the 6 strongest El Ni&amp;#241;o (EN) events on rivers in South America between 1960 and 2000. Our analysis shows a strong correlation between ENSO events and extreme river dynamics in the southeast of Brazil, Carribean South America and parts of the Amazon basin. Furthermore we see a peak in the number of stations showing maximum river discharge all over Brazil during the EN of 1982/83 which has been linked to severe floods in the east of Brazil, parts of Uruguay and Paraguay. However EN events in other years with similar intensity did not evoke floods with such magnitude and therefore the additional drivers of the 1982/83&amp;#160; floods need further investigation. By using machine learning methods to infer data for gauging stations with missing data we were able to extend our data by almost three-fold, revealing a possible heavier and spatially larger impact of the 1982/83 EN on South America's hydrology than indicated in literature.&lt;/p&gt;

scholarly journals Evapotranspiration seasonality across the Amazon basin

2017 ◽  
Author(s):  
Eduardo Eiji Maeda ◽  
Xuanlong Ma ◽  
Fabien Wagner ◽  
Hyungjun Kim ◽  
Taikan Oki ◽  
...  
Keyword(s):  
Amazon Basin ◽  
Regional Climate ◽  
Root Water Uptake ◽  
Environmental Drivers ◽  
Seasonal Patterns ◽  
Wet Season ◽  
Important Indicator ◽  
Seasonally Dry ◽  
Basin Scale ◽  
Terrestrial Water

Abstract. Evapotranspiration (ET) of Amazon forests is a main driver of regional climate patterns and an important indicator of ecosystem functioning. Despite its importance, the seasonal variability of ET over Amazon forests, and its relationship with environmental drivers, is still poorly understood. In this study, we carry out a water balance approach to analyse seasonal patterns in ET and their relationships with water and energy drivers over five sub-basins across the Amazon basin. We used in-situ measurements of river discharge, and remotely sensed estimates of terrestrial water storage, rainfall, and solar radiation. We show that the characteristics of ET seasonality in all sub-basins differ in timing and magnitude. The highest mean annual ET was found in the northern Rio Negro basin (~ 1497 mm year−1) and the lowest values in the Solimões River basin (~ 986 mm year−1). For the first time in a basin-scale study, using observational data, we show that factors limiting ET vary across climatic gradients in the Amazon, confirming local-scale eddy covariance studies. Both annual mean and seasonality in ET are driven by a combination of energy and water availability, as neither rainfall nor radiation alone could explain patterns in ET. In southern basins, despite seasonal rainfall deficits, deep root water uptake allows increasing rates of ET during the dry season, when radiation is usually higher than in the wet season. We demonstrate contrasting ET seasonality with satellite greenness across Amazon forests, with strong asynchronous relationships in ever-wet watersheds, and positive correlations observed in seasonally dry watersheds. Finally, we compared our results with estimates obtained by two ET models, and we conclude that neither of the two tested models could provide a consistent representation of ET seasonal patterns across the Amazon.

scholarly journals Redescription of Odontostilbe pulchra (Gill, 1858) (Teleostei: Characidae: Cheirodontinae), and description of two new species from the río Orinoco basin

2007 ◽  
Vol 5 (1) ◽  
pp. 1-20 ◽  
Author(s):  
Cristina M. Bührnheim ◽  
Luiz R. Malabarba
Keyword(s):  
New Species ◽  
South America ◽  
Amazon Basin ◽  
Rio Negro ◽  
Species Inquirenda ◽  
Two New Species ◽  
Northern South America

Odontostilbe pulchra, previously considered species inquirenda in Cheirodontinae and doubtfully assigned from the río Orinoco basin, is redescribed with the rediscovery of two syntypes. Originally described to the Island of Trinidad, O. pulchra is widespread in Venezuela, the río Orinoco basin, in smaller coastal drainages of northern South America, in the Lake Valencia system, and río Essequibo basin. A punctual occurrence in the upper rio Negro, near southernmost headwaters of the río Orinoco, extends its distribution to the Amazon basin. Additionally, two new species of Odontostilbe from the río Orinoco basin are described.

scholarly journals Carbon monoxide and related trace gases and aerosols over the Amazon Basin during the wet and dry seasons

2012 ◽  
Vol 12 (13) ◽  
pp. 6041-6065 ◽  
Author(s):  
M. O. Andreae ◽  
P. Artaxo ◽  
V. Beck ◽  
M. Bela ◽  
S. Freitas ◽  
...  
Keyword(s):  
Carbon Monoxide ◽  
Southern Hemisphere ◽  
Biomass Burning ◽  
Large Scale ◽  
Amazon Basin ◽  
Photochemical Degradation ◽  
Wet Season ◽  
Biomass Smoke ◽  
Airborne Measurements ◽  
Basin Scale

Abstract. We present the results of airborne measurements of carbon monoxide (CO) and aerosol particle number concentration (CN) made during the Balanço Atmosférico Regional de Carbono na Amazônia (BARCA) program. The primary goal of BARCA is to address the question of basin-scale sources and sinks of CO2 and other atmospheric carbon species, a central issue of the Large-scale Biosphere-Atmosphere (LBA) program. The experiment consisted of two aircraft campaigns during November–December 2008 (BARCA-A) and May–June 2009 (BARCA-B), which covered the altitude range from the surface up to about 4500 m, and spanned most of the Amazon Basin. Based on meteorological analysis and measurements of the tracer, SF6, we found that airmasses over the Amazon Basin during the late dry season (BARCA-A, November 2008) originated predominantly from the Southern Hemisphere, while during the late wet season (BARCA-B, May 2009) low-level airmasses were dominated by northern-hemispheric inflow and mid-tropospheric airmasses were of mixed origin. In BARCA-A we found strong influence of biomass burning emissions on the composition of the atmosphere over much of the Amazon Basin, with CO enhancements up to 300 ppb and CN concentrations approaching 10 000 cm−3; the highest values were in the southern part of the Basin at altitudes of 1–3 km. The ΔCN/ΔCO ratios were diagnostic for biomass burning emissions, and were lower in aged than in fresh smoke. Fresh emissions indicated CO/CO2 and CN/CO emission ratios in good agreement with previous work, but our results also highlight the need to consider the residual smoldering combustion that takes place after the active flaming phase of deforestation fires. During the late wet season, in contrast, there was little evidence for a significant presence of biomass smoke. Low CN concentrations (300–500 cm−3) prevailed basinwide, and CO mixing ratios were enhanced by only ~10 ppb above the mixing line between Northern and Southern Hemisphere air. There was no detectable trend in CO with distance from the coast, but there was a small enhancement of CO in the boundary layer suggesting diffuse biogenic sources from photochemical degradation of biogenic volatile organic compounds or direct biological emission. Simulations of CO distributions during BARCA-A using a range of models yielded general agreement in spatial distribution and confirm the important contribution from biomass burning emissions, but the models evidence some systematic quantitative differences compared to observed CO concentrations. These mismatches appear to be related to problems with the accuracy of the global background fields, the role of vertical transport and biomass smoke injection height, the choice of model resolution, and reliability and temporal resolution of the emissions data base.

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