scholarly journals Global modeling of fungal spores with the EMAC chemistryclimate model: uncertainties in emission parametrizations and observations

2019 ◽  
Author(s):  
Meryem Tanarhte ◽  
Sara Bacer ◽  
Susannah M. Burrows ◽  
J. Alex Huffman ◽  
Kyle M. Pierce ◽  
...  
Keyword(s):  
Urban Areas ◽  
Climate Model ◽  
Strong Dependence ◽  
Fungal Spores ◽  
Fungal Spore ◽  
Specific Humidity ◽  
Area Index ◽  
Climate Interactions

Abstract. Primary biological aerosol particles (PBAPs) may impact human health and aerosol-cloud-climate interactions. The role of PBAPs in the earth system is associated with large uncertainties, for example of source estimates and the atmospheric lifetime. We used a chemistry-climate model to simulate PBAPs in the atmosphere including bacteria and fungal spores. Three fungal spore emission parameterizations have been evaluated against an updated set of spore counts synthesized from observations reported in the literature. The comparison indicates an optimal fit for the emission parameterization proposed by Heald and Spracklen (2009) and adapted by Hoose et al. (2010) for particle sizes of 5 µm or 3 µm, although the model still overpredicts PBAP concentrations in some locations. The correlations between the spore count observations and meteorological parameters simulated by the model show a strong dependence on the leaf area index in non-urban areas and the specific humidity in urban areas. Additional evaluation was performed by comparing our combined bacteria and fungal spore simulations to a global dataset of fluorescent biological aerosol particle (FBAP) concentrations. The model predicts the total sum of measured PBAP concentrations relatively well, typically within a factor of two of FBAP. Further, the modeled fungal spore results deviate from the FBAP concentrations when used as a rough proxy for spores, depending on the particle size used in the parametrization. Uncertainties related to technical aspects of the FBAP and direct-counting spore measurements challenge the ability to further refine quantitative comparison on this scale. Additional long-term data of better quality are needed to improve emission parameterizations.

scholarly journals Global modeling of primary biological particle concentrations with the EMAC chemistry-climate model

2018 ◽  
Author(s):  
Meryem Tanarhte ◽  
Sara Bacer ◽  
Susannah M. Burrows ◽  
J. Alex Huffman ◽  
Kyle M. Pierce ◽  
...  
Keyword(s):  
Climate Model ◽  
Atmospheric Transport ◽  
Fungal Spores ◽  
Fungal Spore ◽  
Spores And Pollen ◽  
Sea Salt Aerosols ◽  
Aerosol Mass ◽  
Climate Interactions ◽  
Almost All

Abstract. Primary biological aerosol particles (PBAPs) may impact human health and aerosol-climate interactions. The role of PBAPs in the earth system is associated with large uncertainties, related to source estimates and atmospheric transport. We used a chemistry-climate model to simulate PBAPs in the atmosphere including bacteria, fungal spores and pollen. Three fungal spore emission parameterizations have been evaluated against an updated set of spore counts synthesized from observations reported in the literature. The comparison indicates an optimal fit for the emission parameterization proposed by Heald and Spracklen (2009), although the model significantly over-predicts PBAP concentrations in some locations. Additional evaluation was performed by comparing our combined bacteria and fungal spore simulations to a global dataset of fluorescent biological aerosol particle (FBAP) concentrations. The model predicts the sum total of measured PBAP concentrations relatively well, with an over- or under-prediction of less than a factor of 2 compared to FBAP. The ratio of bacteria to fungal spores reflects a greater difference, however, and the simulated bacteria concentrations outnumber the simulated fungal spore concentrations in almost all locations. Further, the modeled fungal spore results under-predict the FBAP concentrations, which are used here as a rough proxy for spores. Uncertainties related to technical aspects of the FBAP and direct-counting spore measurements challenge the ability to further refine quantitative comparison on this scale. We estimate that the global PBAPs mass concentration (apart from desert dust and sea salt aerosols), i.e. of fungal spores and pollen, amounts to 19 % and 52 % of the total aerosol mass, respectively.

scholarly journals Regional-scale simulations of fungal spore aerosols using an emission parameterization adapted to local measurements of fluorescent biological aerosol particles

2015 ◽  
Vol 15 (11) ◽  
pp. 6127-6146 ◽  
Author(s):  
M. Hummel ◽  
C. Hoose ◽  
M. Gallagher ◽  
D. A. Healy ◽  
J. A. Huffman ◽  
...  
Keyword(s):  
Aerosol Particles ◽  
Regional Scale ◽  
Fungal Spores ◽  
Fungal Spore ◽  
Specific Humidity ◽  
Small Scale ◽  
Area Index ◽  
Reactive Trace Gases ◽  
Mean Square Errors ◽  
Biological Aerosol Particles

Abstract. Fungal spores as a prominent type of primary biological aerosol particles (PBAP) have been incorporated into the COSMO-ART (Consortium for Small-scale Modelling-Aerosols and Reactive Trace gases) regional atmospheric model. Two literature-based emission rates for fungal spores derived from fungal spore colony counts and chemical tracer measurements were used as a parameterization baseline for this study. A third, new emission parameterization for fluorescent biological aerosol particles (FBAP) was adapted to field measurements from four locations across Europe. FBAP concentrations can be regarded as a lower estimate of total PBAP concentrations. Size distributions of FBAP often show a distinct mode at approx. 3 μm, corresponding to a diameter range characteristic for many fungal spores. Previous studies for several locations have suggested that FBAP are in many cases dominated by fungal spores. Thus, we suggest that simulated FBAP and fungal spore concentrations obtained from the three different emission parameterizations can be compared to FBAP measurements. The comparison reveals that simulated fungal spore concentrations based on literature emission parameterizations are lower than measured FBAP concentrations. In agreement with the measurements, the model results show a diurnal cycle in simulated fungal spore concentrations, which may develop partially as a consequence of a varying boundary layer height between day and night. Temperature and specific humidity, together with leaf area index (LAI), were chosen to drive the new emission parameterization which is fitted to the FBAP observations. The new parameterization results in similar root mean square errors (RMSEs) and correlation coefficients compared to the FBAP observations as the previously existing fungal spore emission parameterizations, with some improvements in the bias. Using the new emission parameterization on a model domain covering western Europe, FBAP in the lowest model layer comprise a fraction of 15% of the total aerosol mass over land and reach average number concentrations of 26 L−1. The results confirm that fungal spores and biological particles may account for a major fraction of supermicron aerosol particle number and mass concentration over vegetated continental regions and should thus be explicitly considered in air quality and climate studies.

scholarly journals Drivers of the fungal spore bioaerosol budget: observational analysis and global modeling

2021 ◽  
Vol 21 (6) ◽  
pp. 4381-4401
Author(s):  
Ruud H. H. Janssen ◽  
Colette L. Heald ◽  
Allison L. Steiner ◽  
Anne E. Perring ◽  
J. Alex Huffman ◽  
...  
Keyword(s):  
Statistical Model ◽  
Population Model ◽  
Seasonal Cycle ◽  
Fungal Spores ◽  
Fungal Spore ◽  
Specific Humidity ◽  
Vertical Profiles ◽  
Area Index ◽  
Order Of Magnitude ◽  
Global Emissions

Abstract. Bioaerosols are produced by biological processes and directly emitted into the atmosphere, where they contribute to ice nucleation and the formation of precipitation. Previous studies have suggested that fungal spores constitute a substantial portion of the atmospheric bioaerosol budget. However, our understanding of what controls the emission and burden of fungal spores on the global scale is limited. Here, we use a previously unexplored source of fungal spore count data from the American Academy of Allergy, Asthma, and Immunology (AAAAI) to gain insight into the drivers of their emissions. First, we derive emissions from observed concentrations at 66 stations by applying the boundary layer equilibrium assumption. We estimate an annual mean emission of 62 ± 31 m−2 s−1 across the USA. Based on these pseudo-observed emissions, we derive two models for fungal spore emissions at seasonal scales: a statistical model, which links fungal spore emissions to meteorological variables that show similar seasonal cycles (2 m specific humidity, leaf area index and friction velocity), and a population model, which describes the growth of fungi and the emission of their spores as a biological process that is driven by temperature and biomass density. Both models show better skill at reproducing the seasonal cycle in fungal spore emissions at the AAAAI stations than the model previously developed by Heald and Spracklen (2009) (referred to as HS09). We implement all three emissions models in the chemical transport model GEOS-Chem to evaluate global emissions and burden of fungal spore bioaerosol. We estimate annual global emissions of 3.7 and 3.4 Tg yr−1 for the statistical model and the population model, respectively, which is about an order of magnitude lower than the HS09 model. The global burden of the statistical and the population model is similarly an order of magnitude lower than that of the HS09 model. A comparison with independent datasets shows that the new models reproduce the seasonal cycle of fluorescent biological aerosol particle (FBAP) concentrations at two locations in Europe somewhat better than the HS09 model, although a quantitative comparison is hindered by the ambiguity in interpreting measurements of fluorescent particles. Observed vertical profiles of FBAP show that the convective transport of spores over source regions is captured well by GEOS-Chem, irrespective of which emission scheme is used. However, over the North Atlantic, far from significant spore sources, the model does not reproduce the vertical profiles. This points to the need for further exploration of the transport, cloud processing and wet removal of spores. In addition, more long-term observational datasets are needed to assess whether drivers of seasonal fungal spore emissions are similar across continents and biomes.

scholarly journals Drivers of the fungal spore bioaerosol budget: observational analysis and global modelling

2020 ◽  
Author(s):  
Ruud H. H. Janssen ◽  
Colette L. Heald ◽  
Allison L. Steiner ◽  
Anne E. Perring ◽  
J. Alex Huffman ◽  
...  
Keyword(s):  
Statistical Model ◽  
Population Model ◽  
Seasonal Cycle ◽  
Fungal Spores ◽  
Fungal Spore ◽  
Specific Humidity ◽  
Vertical Profiles ◽  
Area Index ◽  
Order Of Magnitude ◽  
Global Emissions

Abstract. Bioaerosols are produced by biological processes and directly emitted into the atmosphere, where they contribute to ice nucleation and the formation of precipitation. Previous studies have suggested that fungal spores constitute a substantial portion of the atmospheric bioaerosol budget. However, our understanding of what controls the emission and burden of fungal spores on the global scale is limited. Here, we use a previously unexplored source of fungal spore count data from the American Academy of Allergy, Asthma, and Immunology (AAAAI) to gain insight into the drivers of their emissions. First, we derive emissions from observed concentrations at 66 stations by applying the boundary layer equilibrium assumption. We estimate an annual mean emission of 62 ± 31 m−2 s−1 across the USA. Based on these pseudo-observed emissions, we derive two models for fungal spore emissions at seasonal scales: a statistical model, which links fungal spore emissions to meteorological variables that show similar seasonal cycles (2 m specific humidity, leaf area index and friction velocity), and a population model, which describes the growth of fungi and the emission of their spores as a biological process that is driven by temperature and biomass density. Both models show better skill at reproducing the seasonal cycle in fungal spore emissions at the AAAI stations than the model previously developed by Heald and Spracklen (2009) (referred to as HS09). We implement all three emissions models in the chemical transport model GEOS-Chem to evaluate global emissions and burden of fungal spore bioaerosol. We estimate annual global emissions of 3.7 and 3.4 Tg yr−1 for the statistical model and the population model, respectively, which is about an order of magnitude lower than the HS09 model. The global burden of the statistical and the population model is similarly an order of magnitude lower than that of the HS09 model. A comparison with independent datasets shows that the new models reproduce the seasonal cycle of fluorescent biological aerosol particles (FBAP) concentrations at two locations in Europe somewhat better than the HS09 model, although a quantitative comparison is hindered by the ambiguity in interpreting measurements of fluorescent particles. Observed vertical profiles of FBAP show that the convective transport of spores over source regions is captured well by GEOS-Chem, irrespective of which emission scheme is used. However, over the North Atlantic, far from significant spore sources, the model does not reproduce the vertical profiles. This points to the need for further exploration of the transport, cloud processing, and wet removal of spores. In addition, more long-term observational datasets are needed to assess whether drivers of seasonal fungal spore emissions are similar across continents and biomes.

scholarly journals Human Capital, Skills, and Uneven Intraurban Employment Growth: The Case of Göteborg, Sweden, 1990–2008

2014 ◽  
Vol 2014 ◽  
pp. 1-14 ◽  
Author(s):  
Jonathan Borggren ◽  
Rikard H. Eriksson
Keyword(s):  
Human Capital ◽  
Urban Areas ◽  
Employment Growth ◽  
Local Population ◽  
Urban Dynamics ◽  
High Concentrations ◽  
Growth Differences ◽  
Severe Recession

Recent research has elucidated the role of talents to explain urban growth differences but it remains to be shown whether urban dynamics, such as human capital and a mixed local population, can be linked to intraurban employment growth. By use of a unique longitudinal database, we track the economic development through the lens of intraurban employment growth of a number of primary urban areas (PUA) in Göteborg, Sweden. Regarding factors influencing employment growth, we find that relative concentrations of human capital protect areas from rising unemployment during severe recession (1990–1993) and recovery (1990–2000) while the composition of skills is beneficial during recovery (1990–2000) and long-term growth (1990–2008). Our findings suggest that neither too high concentrations of creative occupations nor too low ones are beneficial. Thus, human capital drives much of the employment changes in relation to the recession and early transition from manufacturing to service but composition of skills is more relevant for explaining long-term intraurban employment growth.

scholarly journals Regional Climate Modeling of Vegetation Feedbacks on the Asian–Australian Monsoon Systems

2017 ◽  
Vol 30 (5) ◽  
pp. 1553-1582 ◽  
Author(s):  
Michael Notaro ◽  
Guangshan Chen ◽  
Yan Yu ◽  
Fuyao Wang ◽  
Ahmed Tawfik
Keyword(s):  
Forest Cover ◽  
Climate Model ◽  
Southern China ◽  
Regional Climate ◽  
Specific Humidity ◽  
Area Index ◽  
Climate System Model ◽  
Australian Monsoon ◽  
Community Land Model ◽  
Vegetation Feedbacks

Abstract This study explores the hypothesis that subtropical and tropical monsoon regions exhibit unique responses to vegetation feedbacks. Using the Community Climate System Model (CCSM), M. Notaro et al. concluded that reduced vegetation cover led to an earlier subtropical Chinese monsoon and a delayed, weaker tropical Australian monsoon, yet significant climate and leaf area index (LAI) biases obfuscated the hypothesis’s reliability. To address these concerns, the Regional Climate Model, version 4 (RegCM4), likewise coupled to the Community Land Model but with “observed” LAI boundary conditions, is applied across China and Australia. The model matches the observed dominance of crops, grass, and evergreen trees in southern China and grass and shrubs in northern Australia. The optimal model configuration is determined and applied in control runs for 1960–2013. Monsoon region LAI is modified in a RegCM4 ensemble, aimed at contrasting vegetation feedbacks between tropical and subtropical regions. Greater LAI supports reductions in albedo, temperature, wind speed, boundary layer height, ascending motion, and midlevel clouds and increases in diurnal temperature range (DTR), wind stress, evapotranspiration (ET), specific humidity, and low clouds. In response to greater LAI, rainfall is enhanced during Australia’s pre-to-midmonsoon season but not for China. Modified LAI leads to dramatic changes in the temporal distribution and intensity of Australian rain events. Heterogeneous responses to biophysical feedbacks include amplified impacts (e.g., increased ET and DTR) across China’s croplands and Australia’s shrublands. Inconsistencies between China’s monsoonal responses in the present RegCM4 study and prior CCSM study of M. Notaro et al. are attributed to CCSM’s excessive forest cover and LAI, exaggerated roughness mechanism, and deficient ET response.

scholarly journals Mengkaji Kesehatan Masyarakat Daerah “Urban” Jika Dilihat Dari Konteks Pemuda

2018 ◽  
Vol 4 (4) ◽  
pp. 230
Author(s):  
Robist Hidayat
Keyword(s):  
Urban Health ◽  
Urban Areas ◽  
Central Government ◽  
Urban Community ◽  
Large Cities ◽  
Urban Problems ◽  
The Government ◽  
Descriptive Method

<p><em>Abstra</em><em>k</em><strong><em> -</em></strong> <strong>Kesehatan merupakan faktor penting  kehidupan, tak terkecuali  kaum urban di perkotaan besar di Indonesia, banyak permasalahan terjadi, prasarana idak memadai, kehidupan yang buruk menimbulkan masalah serius baik sekarang dan masa yang akan datang. Salah satu bagian kaum urban adalah pemuda, merupakan kaum di antara anak-anak dan juga dewasa. Sehingga di harapkan memiliki solusi untuk menghadapi permsaalahan tersebut.</strong><strong> </strong><strong>Penelitian ini bertujuan untuk melihat bagaiman peranan pemuda mengkaji permasalahan yang terjadi sehingga bisa mendapatkan solusi sederhana untuk mengatasi permasalahan kaum urban diperkotaan besar. Adapun metode yang digunakan penulis yakni metode deskriptif, mengkaji serta menganalisis literasi-literasi yang ada dan menyimpulkan menjadi sebuah solusi dari permasalahan yang penulis ungkapkan. Adapun hasil dari penelitian ini ,bahwa permasalahan kaum urban terletak pada tidak adanya program yang jelas serta terperinci secara baik, baik itu dari pemerintah daerah maupun pusat. Sehingga hal ini menjadi permasalahan bersama bukan salah satu pihak semata. Adapun yang bisa pemuda berikan solusi: yakni mencangkup program dan juga kebijakan, program yang di berikan yakni terdiri 3 tahap,</strong><strong> </strong><strong>yaitu: jangka pendek, menengah dan panjang. Adapun alasannya yaitu program tersebut di  terapkan sesuai dengan kebutuhan kaum urban serta kebijakan yang  merupakan wewenang dari pemerintah. Bisa disimpulkan, pemuda memiliki peranan penting dalam mengkaji ataupun memberikan solusi yang terbaik untuk kesehatan kaum urban.</strong></p><p><em>Abstract </em><strong>- Health is an important factor of life, including urban in large urban areas in Indonesia, many problems occur, infrastructure is inadequate, a bad life causes serious problems both now and in the future. One part of the urban community is youth, is a family among children and also adults. So that it is expected to have a solution to deal with these problems. This study aims to see how the role of youth examines the problems that occur so that they can get a simple solution to overcome urban problems in large cities. The method used by the author is descriptive method, reviewing and analyzing existing literacy and concluding to be a solution to the problems that the writer reveals. The results of this study, that the problem of urbanites lies in the absence of a clear and well-detailed program, both from the local and central government. So this matter becomes a common problem, </strong><strong>not</strong><strong> only one part. As for what the youth can provide a solution: namely covering the program and also the policy, the program provided is consisting of</strong><strong> </strong><strong>3 stages, namely: short, medium and long term. The reason is that the program is implemented in accordance with the needs of the urbanites and policies that are the authority of the government. It can be concluded, youth have an important role in assessing or providing the best solution for urban health.</strong></p><p><strong><em>Keywords</em></strong> – <em>Role of Youth, </em><em>Urban Community Health, Problems, Programs</em><em></em></p>

Global cities could power economic growth

2015 ◽  
Keyword(s):  
Economic Growth ◽  
Urban Areas ◽  
Content Type ◽  
Large Cities ◽  
Basic Services ◽  
Global Economic Growth ◽  
Basic Infrastructure ◽  
Funding Gap

Subject The role of cities in global economic growth. Significance Cities, defined as metropolitan areas with over 500,000 inhabitants, are powering global economic growth. However, by 2014 the results were uneven, as the cities with the highest growth lie in developing countries, mainly in China, while many North American and European cities remain trapped in recession. Current urbanisation models are unsustainable in the long term, posing threats to future economic prosperity. Impacts Most large cities' economies are growing faster than their respective countries and will continue doing so. The less wealthy developing urban areas will converge economically with their more developed peers. The existing patterns of urban sprawl in many cities will lead to an increasing funding gap in basic infrastructure. This funding gap could cause the failure of many cities to deliver basic services such as transport.

Precipitation–Radiation–Circulation Feedback Processes Associated with Structural Changes of the ITCZ in a Warming Climate during 1980–2014: An Observational Portrayal

2020 ◽  
Vol 33 (20) ◽  
pp. 8737-8749 ◽  
Author(s):  
William K. M. Lau ◽  
Weichen Tao
Keyword(s):  
Relative Humidity ◽  
Large Scale ◽  
Structural Changes ◽  
Climate Model ◽  
Longwave Radiation ◽  
Hadley Circulation ◽  
Specific Humidity ◽  
Necessary Condition ◽  
Multiple Sources

AbstractIn this study, long-term structural changes in the intertropical convergence zone (ITCZ) and associated precipitation–radiation–circulation feedback processes are examined using multiple sources of reanalysis data for temperature, winds, moisture, and observed precipitation and outgoing longwave radiation (OLR) during 1980–2014. Consistent with CMIP5 climate model projections of the “deep tropical squeeze” under greenhouse warming, this period witnessed a warming and wetting (increased specific humidity) global trend, characterized by a narrowing of the ITCZ core with increased precipitation, coupled to widespread tropospheric drying (deficient relative humidity), increased OLR in the subtropics and midlatitudes, a widening of the descending branches of the Hadley circulation, and a poleward shift of the jet streams in both hemispheres. The widespread tropospheric drying stems from 1) a faster rate of increased saturated water vapor with warming, relative to the increase in ambient moisture due to convective and large-scale transport, and 2) enhanced anomalous subsidence, and low-level moisture divergence in the subtropics and midlatitudes. The long-term trend in enhanced precipitation (latent heating) in the ITCZ core region is strongly coupled to increasing OLR (radiative cooling to space) in the expanding dry zones, particularly over land regions in the subtropics and midlatitudes, arguably as a necessary condition for global thermodynamic energy balance. Analyses of the trend patterns in vertical profiles of p velocity, temperature, and relative humidity with respect to ITCZ precipitation rate and OLR reveal that the contrast between the wet and dry regions in the troposphere has been increasing globally, with the ITCZ core getting wetter and contracting, while the marginal convective and dry zones are getting drier and expanding.

scholarly journals Variation in Airborne Fungal Spore Concentrations in Four Different Microclimate Regions in Romania

2013 ◽  
Vol 41 (2) ◽  
pp. 450 ◽  
Author(s):  
Nicoleta IANOVICI ◽  
Cristina MARIA ◽  
Mădălina Nicoleta RĂDUŢOIU ◽  
Anca HANIŞ ◽  
Dorina TUDORICĂ
Keyword(s):  
Urban Areas ◽  
Fungal Spores ◽  
Pollen Grains ◽  
Fungal Spore ◽  
Western Country ◽  
Ambrosia Artemisiifolia ◽  
Habitat Characteristics ◽  
Airborne Spores ◽  
Spores And Pollen ◽  
Airborne Fungal Spore

Airborne fungal counts and types were examined in four regions from Romania. The aim of our study was to determine the concentrations of Alternaria, Cladosporium, Drechslera-type, Epicoccum and Nigrospora atmospheric fungal spores in urban areas: Braşov, Bucharest, Cluj-Napoca and Timişoara. Other objective of this study was to examine the relationships between atmospheric fungal spores and pollen. Few studies have confirmed the high frequency and concentrations for some of these spore types in Romania. The sampling sites differed in habitat characteristics, such as vegetation and microclimate. Airborne spores’ sampling was carried out using the Lanzoni volumetric sampler and during August 2008. The totals of airborne spores recorded in this study show a considerable variation. Cladosporium and Alternaria have been identified as the most abundant and frequent fungal aeroallergens in Timişoara and Bucharest. Drechslera-type, Epicoccum, and Nigrospora had very low values of spore count in all sites. Observations show that seven types of pollen appear regularly and few of these are in great abundance. Fungi are present in the air in concentrations considerably in excess of that of pollen grains. Ambrosia artemisiifolia is the most important pollen allergen in all of the sampled areas discussed here, especially in western country (Timişoara).

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