scholarly journals Pameterization of the responses of subarctic European vegetation to key environmental variables for ozone risk assessment

2021 ◽  
Author(s):  
Stefanie Falk ◽  
Ane V. Vollsnes ◽  
Aud B. Eriksen ◽  
Lisa Emberson ◽  
Connie O'Neill ◽  
...  
Keyword(s):  
Forest Fires ◽  
Global Scale ◽  
Early Summer ◽  
Climate Variables ◽  
Subarctic Region ◽  
Mixing Ratios ◽  
Biomass Loss ◽  
Species Specific ◽  
Climatic Characteristics ◽  
Impacts Of Climate Change

Abstract. The unique vegetation of the subarctic region acclimatized to extremes of cold and midnight sun are likely to be at threat from the combined impacts of climate change and increasing ozone concentrations [O3]. The atmospheric and climatic characteristics of the subarctic are known to lead to pronounced peak [O3] in spring. To date, only a few studies assessed the response of subarctic vegetation to variations in climate and air pollution. This study looks to fill this knowledge gap by examining essential climate variables, in particular ozone, over the past few decades. We evaluate the extent to which two recent years (2018 and 2019) deviate from climatic and [O3] norms and how these potentially more frequent future deviations may influence ozone damage to subarctic vegetation. We find that 2018 was an anomalously warm and bright year, particularly in spring and early summer. Higher than average [O3] was observed in April/May while frequent episodes of ozone volume mixing ratios (VMRs) above 40 ppb occurred in June–August. These episodes are in part attributable to forest fires in the Northern Hemisphere and warmer and sunnier conditions. We apply the integrated flux-metric Phytotoxic Ozone Dose (POD) to determine ozone risk and damage to vegetation as a function of [O3], environmental factors, and species-specific physiology. Our study suggests that using generic parameterizations in assessments likely leads to underestimating the risk of ozone damage in this region. We find that bespoke parameterizations of plant functional types (PFTs) for subarctic vegetation bio-types result in an ozone-induced biomass loss of 2.5 to 17.4 %. For some species, this loss is up to 6 % larger than projected from generic parameterizations. Efforts should be targeted towards accurately defining subarctic vegetations' physiological response to essential climate variables. Our method could help to improve regional and global scale biogeochemical cycling under current and future climates.

scholarly journals Observation and analysis of spatio-temporal characteristics of surface ozone and carbon monoxide at multiple sites in the Kathmandu Valley, Nepal

2017 ◽  
Author(s):  
Khadak Singh Mahata ◽  
Maheswar Rupakheti ◽  
Arnico Kumar Panday ◽  
Piyush Bhardwaj ◽  
Manish Naja ◽  
...  
Keyword(s):  
Air Pollution ◽  
Forest Fires ◽  
Mountain Pass ◽  
Kathmandu Valley ◽  
Emission Flux ◽  
Mixing Ratio ◽  
Top Down ◽  
Monsoon Period ◽  
Temporal Characteristics ◽  
Mixing Ratios

Abstract. Residents of the Kathmandu Valley experience severe particulate and gaseous air pollution throughout most of the year, even during much of the rainy season. The knowledge base for understanding the air pollution in the Kathmandu Valley was previously very limited, but is improving rapidly due to several field measurement studies conducted in the last few years. Thus far, most analyses of observations in the Kathmandu Valley have been limited to short periods of time at single locations. This study extends on the past studies by examining the spatial and temporal characteristics of two important gaseous air pollutant (CO and O3) based on simultaneous observations over a longer period at five locations within the valley and on its rim, including a supersite (at Bode in the valley center, 1345 m above sea level) and four satellite sites (at Paknajol, 1380 m asl in the Kathmandu city center, at Bhimdhunga (1522 m asl), a mountain pass on the valley's western rim, at Nagarkot (1901 m asl), another mountain pass on the eastern rim, and Naikhandi, near the valley's only river outlet). CO and O3 mixing ratios were monitored from January to July 2013, along with other gases and aerosol particles by instruments deployed at the Bode supersite during the international air pollution measurement campaign SusKat-ABC (Sustainable Atmosphere for the Kathmandu Valley – endorsed by the Atmospheric Brown Clouds program of UNEP). The O3 monitoring at Bode, Paknajol and Nagarkot as well as the CO monitoring at Bode were extended beyond July 2013 to investigate their variability over a complete annual cycle. Higher CO mixing ratios were found at Bode than at the outskirt sites (Bhimdhunga, Naikhandi and Nagarkot), and all sites except Nagarkot showed distinct diurnal cycles of CO mixing ratio with morning peaks and daytime lows. Seasonally, CO was higher during the pre-monsoon and winter seasons, especially due to the emissions from brick kiln industries, which only operate during this period, as well as increased domestic heating during winter, and regional forest fires and agro-residue burning. It was lower during the monsoon due to rainfall, which reduces open burning activities within the valley and in the surrounding regions, and thus reduces the sources of CO. The meteorology of the valley also played a key role in determining the CO mixing ratios. Furthermore, there was evidence of some influence of pollution from the greater region around the valley. A top-down estimate of the CO emission flux was made by using the CO mixing ratio and mixing layer height (MLH) measured at Bode. The estimated annual CO flux at Bode was 4.92 μg m−2 s−1, which is 2–14 times higher than that in widely used emission inventory databases (EDGAR HTAP, REAS and INTEX-B). This difference in CO flux between Bode and other emission databases likely arises from large uncertainties in both the top-down and bottom-up approaches to estimating the emission flux. The O3 mixing ratio was found to be highest during the pre-monsoon season at all sites, while the timing of the seasonal minimum varied across the sites. The daily maximum 8 hour average O3 exceeded the WHO recommended guideline of 50 ppb on more days at the hilltop station of Nagarkot (159/357 days) than at the urban valley bottom sites of Paknajol (132/354 days) and Bode (102/353 days), presumably due to the influence of free-tropospheric air at the high-altitude site, as well as to titration of O3 by fresh NOx emissions near the urban sites. More than 78 % of the exceedance days were during the pre-monsoon period at all sites. This was due to both favorable meteorological conditions as well as contributions of precursors from regional sources such as forest fires and agro-residue burning. The high O3 mixing ratio observed during the pre-monsoon period is of a high concern for human health and ecosystems, including agroecosystems in the Kathmandu Valley and surrounding regions.

scholarly journals Air pollution during the 2003 European heat wave as seen by MOZAIC airliners

2007 ◽  
Vol 7 (6) ◽  
pp. 15911-15954 ◽  
Author(s):  
M. Tressol ◽  
C. Ordonez ◽  
R. Zbinden ◽  
V. Thouret ◽  
C. Mari ◽  
...  
Keyword(s):  
Heat Wave ◽  
Forest Fires ◽  
Dispersion Model ◽  
Lower Troposphere ◽  
Lagrangian Model ◽  
Air Masses ◽  
Model Simulations ◽  
Mixing Ratios ◽  
Vertical Extension ◽  
Lagrangian Dispersion

Abstract. This study presents an analysis of both MOZAIC profiles above Frankfurt and Lagrangian dispersion model simulations for the 2003 European heat wave. The comparison of MOZAIC measurements in summer 2003 with the 11-year MOZAIC climatology reflects strong temperature anomalies (exceeding 4°C) throughout the lower troposphere. Higher positive anomalies of temperature and negative anomalies of both wind speed and relative humidity are found for the period defined here as the heat wave (2–14 August 2003), compared to the periods before (16–31 July 2003) and after (16–31 August 2003) the heat wave. In addition, Lagrangian model simulations in backward mode indicate the suppressed long-range transport in the mid- to lower troposphere and the enhanced southern origin of air masses for all tropospheric levels during the heat wave. Ozone and carbon monoxide also present strong anomalies (both ~ +40 ppbv) during the heat wave, with a maximum vertical extension reaching 6 km altitude around 11 August 2003. Pollution in the planetary boundary layer (PBL) is enhanced during the day, with ozone mixing ratios two times higher than climatological values. This is due to a combination of factors, such as high temperature and radiation, stagnation of air masses and weak dry deposition, which favour the accumulation of ozone precursors and the build-up of ozone. A negligible role of a stratospheric-origin ozone tracer has been found for the lower troposphere in this study. From 29 July to 15 August 2003 forest fires burned around 0.3×106 ha) in Portugal and added to atmospheric pollution in Europe. Layers with enhanced CO and NOy mixing ratios, probably advected from Portugal, were crossed by the MOZAIC aircraft in the free troposphere over Frankfurt. A series of forward and backward Lagrangian model simulations have been performed to investigate the origin of these anomalies. During the whole heat wave, European anthropogenic emissions present the strongest contribution to the measured CO levels in the lower troposphere (near 30%). This source is followed by Portuguese forest fires which affect the lower troposphere after 6 August 2003 and even the PBL around 10 August 2003. The averaged biomass burning contribution reaches 35% during the affected period. Anthropogenic CO of North American origin only marginally influences CO levels over Europe during that period.

scholarly journals Deriving stratospheric age of air spectra using chemically active trace gases

2018 ◽  
Author(s):  
Marius Hauck ◽  
Frauke Fritsch ◽  
Hella Garny ◽  
Andreas Engel
Keyword(s):  
Seasonal Cycle ◽  
Inverse Method ◽  
Model Simulation ◽  
Trace Gases ◽  
Global Scale ◽  
Point Of View ◽  
Full Description ◽  
Mixing Ratios ◽  
Tropical Tropopause ◽  
Single Entry

Abstract. Analysis of stratospheric transport from an observational point of view is frequently realized by evaluation of mean age of air values from long-lived trace gases. However, this provides more insight into general transport strength and less into its mechanism. Deriving complete transit time distributions (age spectra) is desirable, but their deduction from direct measurements is difficult and so far primarily achieved by assumptions about dynamics and spectra themselves. This paper introduces a modified version of an inverse method to infer age spectra from mixing ratios of short-lived trace gases. For a full description of transport seasonality the formulation includes an imposed seasonal cycle to gain multimodal spectra. The EMAC model simulation used for a proof of concept features an idealized dataset of 40 radioactive trace gases with different chemical lifetimes as well as 40 chemically inert pulsed trace gases to calculate pulse age spectra. Annual and seasonal mean inverse spectra are compared to pulse spectra including first and second moments as well as the ratio between them to assess the performance on these time scales. Results indicate that the modified inverse age spectra match the annual and seasonal pulse age spectra well on global scale beyond 1.5 years mean age of air. The imposed seasonal cycle emerges as a reliable tool to include transport seasonality in the age spectra. Below 1.5 years mean age of air, tropospheric influence intensifies and breaks the assumption of single entry through the tropical tropopause, leading to inaccurate spectra in particular in the northern hemisphere. The imposed seasonal cycle wrongly prescribes seasonal entry in this lower region and does not lead to a better agreement between inverse and pulse age spectra without further improvement. As the inverse method aims for future implementation on in situ observational data, possible critical factors for this purpose are delineated finally.

scholarly journals CO 2 emission and biomass loss, associated to the occurrence of forest fires in the Biobío Region, Chile: An approach from Ecosystem Services (ES)

2018 ◽  
Vol 75 (1) ◽  
pp. 482-493 ◽  
Author(s):  
María Elisa Díaz ◽  
Ricardo Figueroa ◽  
María Del Rosario Vidal-Abarca ◽  
María Luisa Suárez ◽  
María J. Climent
Keyword(s):  
Ecosystem Services ◽  
Forest Fires ◽  
Biomass Loss

scholarly journals Insects as feed: house fly or black soldier fly?

2020 ◽  
Vol 6 (3) ◽  
pp. 221-229
Author(s):  
A. van Huis ◽  
D.G.A.B. Oonincx ◽  
S. Rojo ◽  
J.K. Tomberlin
Keyword(s):  
Mass Production ◽  
Development Time ◽  
Global Scale ◽  
House Fly ◽  
House Flies ◽  
Numerous Species ◽  
Safety Risks ◽  
Species Specific ◽  
Protein Rich ◽  
Dipteran Species

Industrialised rearing of house flies and black soldier flies in systems for producing protein offers numerous species-specific benefits and challenges. These two dipteran species offer great potential for mass production of protein rich feed ingredients on a global scale. Through this systematic review, various facets of intensive production of these species are evaluated according to criteria, such as development time, abiotic tolerance, ease of rearing, environmental impact, safety risks, range of possible organic side streams, and their role in bioconversion.

scholarly journals Multi-model ensemble projections of climate change effects on global marine biodiversity

2014 ◽  
Vol 72 (3) ◽  
pp. 741-752 ◽  
Author(s):  
Miranda C. Jones ◽  
William W. L. Cheung
Keyword(s):  
Climate Change ◽  
Global Scale ◽  
The Arctic ◽  
Marine Biodiversity ◽  
Change Scenario ◽  
Global Changes ◽  
Distribution Models ◽  
Climate Change Effects ◽  
Distribution Shifts ◽  
Species Specific

Abstract Species distribution models (SDMs) are important tools to explore the effects of future global changes in biodiversity. Previous studies show that variability is introduced into projected distributions through alternative datasets and modelling procedures. However, a multi-model approach to assess biogeographic shifts at the global scale is still rarely applied, particularly in the marine environment. Here, we apply three commonly used SDMs (AquaMaps, Maxent, and the Dynamic Bioclimate Envelope Model) to assess the global patterns of change in species richness, invasion, and extinction intensity in the world oceans. We make species-specific projections of distribution shift using each SDM, subsequently aggregating them to calculate indices of change across a set of 802 species of exploited marine fish and invertebrates. Results indicate an average poleward latitudinal shift across species and SDMs at a rate of 15.5 and 25.6 km decade−1 for a low and high emissions climate change scenario, respectively. Predicted distribution shifts resulted in hotspots of local invasion intensity in high latitude regions, while local extinctions were concentrated near the equator. Specifically, between 10°N and 10°S, we predicted that, on average, 6.5 species would become locally extinct per 0.5° latitude under the climate change emissions scenario Representative Concentration Pathway 8.5. Average invasions were predicted to be 2.0 species per 0.5° latitude in the Arctic Ocean and 1.5 species per 0.5° latitude in the Southern Ocean. These averaged global hotspots of invasion and local extinction intensity are robust to the different SDM used and coincide with high levels of agreement.

Evaluation of the Impacts of Climate Change on Land Suitability for Jatropha Cultivation

2014 ◽  
Vol 955-959 ◽  
pp. 3777-3782 ◽  
Author(s):  
Xiao Feng Zhao ◽  
Bin Le Lin
Keyword(s):  
Climate Change ◽  
Rank Order ◽  
Global Scale ◽  
Land Suitability ◽  
Climate Change Scenarios ◽  
Climate Scenarios ◽  
The West ◽  
The North ◽  
North And South ◽  
Impacts Of Climate Change

We evaluated land suitability for Jatropha cultivation at a global scale under current and future climate scenarios. Areas that are suitable for Jatropha cultivation include southern South America, the west and southeast coasts of Africa, the north of South Asia, and the north and south coasts of Australia. In the predicted climate change scenarios, areas near the equator become less suitable for Jatropha cultivation, and areas further from the equator become more suitable. Our analyses suggest that the rank order of the six climate change scenarios, from the smallest to the largest effects on Jatropha cultivation, was as follows: B1, A1T/B2, A1B, A2, and A1FI.

scholarly journals Sources of long-lived atmospheric VOCs at the rural boreal forest site, SMEAR II

2015 ◽  
Vol 15 (23) ◽  
pp. 13413-13432 ◽  
Author(s):  
J. Patokoski ◽  
T. M. Ruuskanen ◽  
M. K. Kajos ◽  
R. Taipale ◽  
P. Rantala ◽  
...  
Keyword(s):  
Boreal Forest ◽  
Forest Fires ◽  
Source Area ◽  
Proton Transfer Reaction ◽  
Composition Analysis ◽  
Forest Site ◽  
Concentration Data ◽  
Data Set ◽  
Source Areas ◽  
Mixing Ratios

Abstract. In this study a long-term volatile organic compound (VOCs) concentration data set, measured at the SMEAR II (Station for Measuring Ecosystem–Atmosphere Relations) boreal forest site in Hyytiälä, Finland during the years 2006–2011, was analyzed in order to identify source areas and profiles of the observed VOCs. VOC mixing ratios were measured using proton transfer reaction mass spectrometry. Four-day HYSPLIT 4 (Hybrid Single Particle Lagrangian Integrated Trajectory) backward trajectories and the Unmix 6.0 receptor model were used for source area and source composition analysis. Two major forest fire events in Russia took place during the measurement period. The effect of these fires was clearly visible in the trajectory analysis, lending confidence to the method employed with this data set. Elevated volume mixing ratios (VMRs) of non-biogenic VOCs related to forest fires, e.g. acetonitrile and aromatic VOCs, were observed. Ten major source areas for long-lived VOCs (methanol, acetonitrile, acetaldehyde, acetone, benzene, and toluene) observed at the SMEAR II site were identified. The main source areas for all the targeted VOCs were western Russia, northern Poland, Kaliningrad, and the Baltic countries. Industrial areas in northern continental Europe were also found to be source areas for certain VOCs. Both trajectory and receptor analysis showed that air masses from northern Fennoscandia were less polluted with respect to both the VOCs studied and other trace gases (CO, SO2 and NOx), compared to areas of eastern and western continental Europe, western Russia, and southern Fennoscandia.

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