scholarly journals Observations of a stratospheric aerosol veil from a tropical volcanic eruption in December 1808: is this the "Unknown" ~1809 eruption?

2014 ◽  
Vol 10 (2) ◽  
pp. 1901-1932
Author(s):  
A. Guevara-Murua ◽  
C. A. Williams ◽  
E. J. Hendy ◽  
A. C. Rust ◽  
K. V. Cashman
Keyword(s):  
Latin American ◽  
Volcanic Eruption ◽  
Ice Core ◽  
Stratospheric Aerosol ◽  
Climate Impacts ◽  
Atmospheric Effects ◽  
Optical Effects ◽  
Volcanic Aerosols ◽  
Meteorological Observations ◽  
The City

Abstract. The "Unknown" eruption of 1808/1809 was the second most explosive SO2-rich volcanic eruption in the last two centuries, only eclipsed by the cataclysmic VEI 7 Tambora eruption in April 1815. However, no eyewitness accounts of the event, and therefore its location, or the atmospheric optical effects associated with its aerosols have been documented from historical records. Here we report on two meteorological observations dating from the end of 1808 that describe phenomena we attribute to volcanic-induced atmospheric effects caused by the Unknown eruption. The observations were made by two highly respected Latin American scientists. The first, Francisco José de Caldas, describes a stratospheric aerosol haze, a "transparent cloud that obstructs the sun's brilliance", that was visible over the city of Bogotá, Colombia, from 11 December 1808 to at least mid-February 1809. The second, made by physician José Hipólito Unanue in Lima, Peru, describes sunset after-glows (akin to well-documented examples known to be caused by stratospheric volcanic aerosols) from mid-December 1808 to February 1809. These two accounts provide direct evidence of a persistent stratospheric aerosol veil that spanned at least 2600 km into both Northern and Southern Hemispheres and establish that the source was a tropical volcano. Moreover, these observations confirm that the Unknown eruption, previously identified and tentatively assigned to February 1809 (±4 months) from analysis of ice core sulphate records, occurred in late November or early December 1808 (4 December 1808 ± 7 days). This date has important implications for the associated hemispheric climate impacts and temporal pattern of aerosol dispersal.

scholarly journals Observations of a stratospheric aerosol <i>veil</i> from a tropical volcanic eruption in December 1808: is this the <i>Unknown</i> ∼1809 eruption?

2014 ◽  
Vol 10 (5) ◽  
pp. 1707-1722 ◽  
Author(s):  
A. Guevara-Murua ◽  
C. A. Williams ◽  
E. J. Hendy ◽  
A. C. Rust ◽  
K. V. Cashman
Keyword(s):  
Latin American ◽  
Volcanic Eruption ◽  
Ice Core ◽  
Stratospheric Aerosol ◽  
Climate Impacts ◽  
Atmospheric Effects ◽  
Optical Effects ◽  
Volcanic Aerosols ◽  
Meteorological Observations ◽  
The City

Abstract. The Unknown eruption of 1808/1809 was the second most explosive SO2-rich volcanic eruption in the last two centuries, eclipsed only by the cataclysmic VEI 7 Tambora eruption in April 1815. However, no eyewitness accounts of the event, and therefore its location, or the atmospheric optical effects associated with its aerosols have been documented from historical records. Here we report on two meteorological observations dating from the end of 1808 that describe phenomena we attribute to volcanic-induced atmospheric effects caused by the Unknown eruption. The observations were made by two highly respected Latin American scientists. The first, Francisco José de Caldas, describes a stratospheric aerosol haze, a "transparent cloud that obstructs the sun's brilliance", that was visible over the city of Bogotá, Colombia, from 11 December 1808 to at least mid-February 1809. The second, made by physician José Hipólito Unanue in Lima, Peru, describes sunset after-glows (akin to well-documented examples known to be caused by stratospheric volcanic aerosols) from mid-December 1808 to February 1809. These two accounts provide direct evidence of a persistent stratospheric aerosol veil that spanned at least 2600 km into both Northern and Southern Hemispheres and establish that the source was a tropical volcano. Moreover, these observations confirm that the Unknown eruption, previously identified and tentatively assigned to February 1809 (±4 months) from analysis of ice core sulfate records, occurred in late November or early December 1808 (4 December 1808 ±7 days). This date has important implications for the associated hemispheric climate impacts and temporal pattern of aerosol dispersal.

scholarly journals Radiative and climate impacts of a large volcanic eruption during stratospheric sulfur geoengineering

2015 ◽  
Vol 15 (15) ◽  
pp. 21837-21881 ◽  
Author(s):  
A. Laakso ◽  
H. Kokkola ◽  
A.-I. Partanen ◽  
U. Niemeier ◽  
C. Timmreck ◽  
...  
Keyword(s):  
Volcanic Eruption ◽  
Climate Model ◽  
Regional Climate ◽  
Volcanic Eruptions ◽  
Stratospheric Aerosol ◽  
Climate Impacts ◽  
Solar Radiation Management ◽  
Atmospheric Conditions ◽  
Concurrent Case ◽  
Radiation Management

Abstract. Both explosive volcanic eruptions, which emit sulfur dioxide into the stratosphere, and stratospheric geoengineering via sulfur injections can potentially cool the climate by increasing the amount of scattering particles in the atmosphere. Here we employ a global aerosol-climate model and an earth system model to study the radiative and climate impacts of an erupting volcano during solar radiation management (SRM). According to our simulations, the radiative impacts of an eruption and SRM are not additive: in the simulated case of concurrent eruption and SRM, the peak increase in global forcing is about 40 % lower compared to a corresponding eruption into a clean background atmosphere. In addition, the recovery of the stratospheric sulfate burden and forcing was significantly faster in the concurrent case since the sulfate particles grew larger and thus sedimented faster from the stratosphere. In our simulation where we assumed that SRM would be stopped immediately after a volcano eruption, stopping SRM decreased the overall stratospheric aerosol load. For the same reasons, a volcanic eruption during SRM lead to only about 1/3 of the peak global ensemble-mean cooling compared to an eruption under unperturbed atmospheric conditions. Furthermore, the global cooling signal was seen only for 12 months after the eruption in the former scenario compared to over 40 months in the latter. In terms of the global precipitation rate, we obtain a 36 % smaller decrease in the first year after the eruption and again a clearly faster recovery in the concurrent eruption and SRM scenario. We also found that an explosive eruption could lead to significantly different regional climate responses depending on whether it takes place during geoengineering or into an unperturbed background atmosphere. Our results imply that observations from previous large eruptions, such as Mt Pinatubo in 1991, are not directly applicable when estimating the potential consequences of a volcanic eruption during stratospheric geoengineering.

Implementing the capability to respond to large volcanic eruptions in the C3S prediction systems

2021 ◽  
Author(s):  
Roberto Bilbao ◽  
Magdalena Balmaseda ◽  
Lauriane Batte ◽  
Markus Donat ◽  
Pablo Ortega ◽  
...  
Keyword(s):  
Volcanic Eruption ◽  
Weather Forecasting ◽  
Volcanic Eruptions ◽  
Atmospheric Model ◽  
Temporal Variations ◽  
Climate Impacts ◽  
Seasonal Forecasts ◽  
Technical Developments ◽  
Aerosol Forcing ◽  
Volcanic Aerosols

&lt;p&gt;Explosive volcanic eruptions have climate impacts on seasonal-to-decadal time-scales. Studies have shown that these climate impacts have high predictive potential, and could therefore be exploited to improve operational climate predictions whenever a new explosive volcanic eruption happens. In preparation for such an event, which has occurred three times in the last 60 years, it is necessary to develop the capability to estimate and ingest the associated stratospheric volcanic forcing into the operational seasonal-to-decadal forecasts systems. This is one of the objectives of the H2020 project CONFESS (CONsistent representation of temporal variations of boundary Forcings in reanalysES and Seasonal forecasts), for which the main tasks envisaged are presented herein. The first task involves several technical developments in the IFS (the atmospheric model of the European Center for Medium-range Weather Forecasting) to improve the model representation of volcanic aerosols. Since for a new major volcanic eruption the evolution and distribution of the volcanic aerosols is initially unknown, the second task is to evaluate a method to estimate them based on several assumptions. For this purpose the recently enhanced emulator of volcanic aerosols EVA_H (Aubrey et al., 2019) will be used to produce the stratospheric volcanic aerosol forcing. In a final task, the outputs of the EVA_H module will be validated by producing the forcings of the past volcanic eruptions of Agung, El Chichon and Pinatubo, and the realism of their climate response will be evaluated in seasonal and multi-annual re-forecasts.&lt;/p&gt;

Reclaiming the City as Commons. Learning from Latin American Housing Movements

2020 ◽  
Vol 46 (1) ◽  
pp. 139-153
Author(s):  
Stavros Stavrides
Keyword(s):  
Latin American ◽  
Housing Conditions ◽  
Urban Living ◽  
City Life ◽  
Urban Condition ◽  
Collective Creativity ◽  
Urban Movements ◽  
The City

This paper explores a renewed problematization of contemporary metropolises' dynamics in the light of speci fic efforts to reclaim the city as commons. Building on Lefebvre's theorizations of the city's virtuality and comparing it to contemporary approaches to the urban condition that emphasize the potentialities of contemporary city-life, it suggests that urban commoning is unleashing the power of collective creativity and collaboration. Struggles to appropriate the city as a crucial milieu for sharing transforms parts of city and produces new patterns of urban living. Examples from Latin American urban movements focused on establishing emancipatory housing conditions are used to illustrate the transformative capabilities of urban commoning.

scholarly journals New Mobility Paradigm and Indigenous Construction of Places: Physical and Symbolic Mobility of Aymara Groups in the Urbanization Process, Chile

2021 ◽  
Vol 13 (8) ◽  
pp. 4382
Author(s):  
Gonzalo Salazar ◽  
Paloma González
Keyword(s):  
Latin American ◽  
Methodological Approach ◽  
Urban Mobility ◽  
Structured Interviews ◽  
Physical Movement ◽  
Rural Municipality ◽  
Political Implications ◽  
Geographical Elements ◽  
Construction Of Place ◽  
The City

In the current global scenario, in which mobility has been strongly impacted, it is relevant to highlight certain mobility experiences of Indigenous Latin American peoples, in which new cultural and geographical elements justify revisiting this phenomenon. In this context, the mobility of the Aymara ethnic group offers an opportunity for such a second look. Although the subject has been approached from the perspectives of internal migration processes and physical movement, as in other Latin American cases, studies have omitted some important aspects for its analysis, such as the practices, meanings, and political implications associated with mobility. Based on the new mobility paradigm, this article seeks to strengthen the perspective on mobility by researching rural-urban mobility practices and their meaning regarding the experiences of Aymara people who migrated from the rural municipality of Putre to settle in the city of Arica from the 1950s. At the same time, it is shown that these Aymara mobility practices imply spatiotemporal dynamics that are key for the construction of place, and allow for a widening of base elements that should be considered in the new mobility paradigm. This research is based on five years of ethnography, including mobile accompaniment and semi-structured interviews. This methodological approach has allowed researchers to explore how elements related to physical and symbolic mobility have constantly constructed relational spaces within the Arica and Parinacota region over time. This shows that mobility does not only refer to physical movement, but to politics, emotions, culture, and memory as well. From these results, the article examines and discusses key elements related to physical and symbolic mobility, and their implications in political and intercultural terms.

scholarly journals GIS-Based Approach to Spatio-Temporal Interpolation of Atmospheric CO2 Concentrations in Limited Monitoring Dataset

Atmosphere ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 384
Author(s):  
Yaroslav Bezyk ◽  
Izabela Sówka ◽  
Maciej Górka ◽  
Jan Blachowski
Keyword(s):  
Seasonal Variability ◽  
Sampling Strategy ◽  
Climate Impacts ◽  
Air Pollutant ◽  
Urban Atmosphere ◽  
Atmospheric Co2 ◽  
Spatial Characteristic ◽  
Interpolation Methods ◽  
Co2 Levels ◽  
The City

Understanding the magnitude and distribution of the mixes of the near-ground carbon dioxide (CO2) components spatially (related to the surface characteristics) and temporally (over seasonal timescales) is critical to evaluating present and future climate impacts. Thus, the application of in situ measurement approaches, combined with the spatial interpolation methods, will help to explore variations in source contribution to the total CO2 mixing ratios in the urban atmosphere. This study presents the spatial characteristic and temporal trend of atmospheric CO2 levels observed within the city of Wroclaw, Poland for the July 2017–August 2018 period. The seasonal variability of atmospheric CO2 around the city was directly measured at the selected sites using flask sampling with a Picarro G2201-I Cavity Ring-Down Spectroscopy (CRDS) technique. The current work aimed at determining the accuracy of the interpolation techniques and adjusting the interpolation parameters for estimating the magnitude of CO2 time series/seasonal variability in terms of limited observations during the vegetation and non-vegetation periods. The objective was to evaluate how different interpolation methods will affect the assessment of air pollutant levels in the urban environment and identify the optimal sampling strategy. The study discusses the schemes for optimization of the interpolation results that may be adopted in areas where no observations are available, which is based on the kriging error predictions for an appropriate spatial density of measurement locations. Finally, the interpolation results were extended regarding the average prediction bias by exploring additional experimental configurations and introducing the limitation of the future sampling strategy on the seasonal representation of the CO2 levels in the urban area.

Latin American Cities: Aspects of Function and Structure

1962 ◽  
Vol 4 (4) ◽  
pp. 473-493 ◽  
Author(s):  
Richard M. Morse
Keyword(s):  
Latin American ◽  
New World ◽  
American City ◽  
American Cities ◽  
The City

This essay will advance two interrelated hypotheses about the Latin American city. The first of them has to do with the role of the city in the settlement of the New World. The second suggests certain characteristics of the modern Latin American metropolis.

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