scholarly journals Spatial and temporal variation of the impact of an extreme Saharan dust event

2012 ◽  
Vol 117 (D11) ◽  
pp. n/a-n/a ◽  
Author(s):  
M. Cabello ◽  
J. A. G. Orza ◽  
M. A. Barrero ◽  
E. Gordo ◽  
A. Berasaluce ◽  
...  
Keyword(s):  
Temporal Variation ◽  
Saharan Dust ◽  
Spatial And Temporal Variation ◽  
Dust Event ◽  
The Impact

scholarly journals Spatial and Temporal Variation of Rainwater Chemistry in Ile-Ife and Its Environ, Osun State, Nigeria

2017 ◽  
Vol 10 (2) ◽  
pp. 203 ◽  
Author(s):  
Aderonke Adetutu Okoya ◽  
Bamikole Walter Osungbemiro ◽  
Temi E. Ologunorisa
Keyword(s):  
Land Use ◽  
Chemical Composition ◽  
Temporal Variation ◽  
Major Ions ◽  
Rain Water ◽  
Spatial And Temporal Variation ◽  
Rainwater Chemistry ◽  
Water Composition ◽  
Physico Chemical ◽  
The Impact

The study of the chemical composition of rain water was conducted in Ile – Ife and environs, an agrarian, commercial, residential and semi-industrialised center of Osun state Nigeria. This was with a view to assessing the impact of land use activities on rain water composition and the temporal variation of rainwater chemistry. Physico-chemical parameters such as Turbidity, pH, TDS, Conductivity, Oxygen parameters, Alkalinity, Acidity, Hardness and Major ions (Ca2+, Mg2+, K+, Na+, NO3-, SO4-, HCO3-) were determined, predominant ions were identified. Turbidity, pH, Conductivity, TDS, D.O B.O.D, Alkalinity, Acidity Hardness ranged between 2.90 - 42.84 NTU, 5.65 - 7.40, 6.71 – 122.33 µScm-1, 4.10 –73.27 mg/L, 3.60 – 10.60 mg/L, 0.13 – 7.20 mg/L, 0.33 – 22.0 mg/L, 2.00 – 15.00 mg/L, 0.04 – 1.23 CaCO3mg/l respectively. The dominant ions detected in the study were HCO3-, Mg2+, Na+ and Ca2+. Generally, the mean concentration of ions as expressed in milli-equivalent per Litre showed order of dominance as HCO3- > NO3- > SO42- for the anions and Mg2+ > Na+ > Ca2+ > K+ for cations. The study concluded that land use activities had influence on all the chemical composition of rain water in the study area but more on pH, alkalinity, acidity, bicarbonate. Except sulphate and Nitrate, all other parameters recorded high values in dry season.

scholarly journals The Spatio-temporal Analysis of b-value in the Banda Arc, Indonesia

2021 ◽  
Vol 873 (1) ◽  
pp. 012010
Author(s):  
Muhammad Bani Al-Rasyid ◽  
Mira Nailufar Rusman ◽  
Daniel Hamonangan ◽  
Pepen Supendi ◽  
Kartika Hajar Kirana
Keyword(s):  
Temporal Variation ◽  
Temporal Analysis ◽  
B Value ◽  
Spatial And Temporal Variation ◽  
Tectonic Structure ◽  
Time Period ◽  
Banda Arc ◽  
Spatio Temporal ◽  
The Impact ◽  
Large Earthquakes

Abstract Banda arc is a complex tectonic structure manifests by high seismicity due to the collision of a continent and an intra-oceanic island arc. Using the relocated earthquakes data from ISC-EHB and BMKG catalogues from the time period of 1960 to 2018, we have conducted a spatial and temporal variation of b-value using the Guttenberg-Richter formula in the area. Our results show that the spatial distribution of low b-values located in the south of Ambon Island and southeast of Buru Island. On the other hand, the temporal variation of b-value shows a decrease in the northern part of the Banda sea probably high potential to produce large earthquakes in the future. Therefore, further mitigation is needed to minimize the impact of earthquakes in the area.

scholarly journals Human birth seasonality: latitudinal gradient and interplay with childhood disease dynamics

2014 ◽  
Vol 281 (1783) ◽  
pp. 20132438 ◽  
Author(s):  
Micaela Martinez-Bakker ◽  
Kevin M. Bakker ◽  
Aaron A. King ◽  
Pejman Rohani
Keyword(s):  
Temporal Variation ◽  
Latitudinal Gradient ◽  
Spatial And Temporal Variation ◽  
Model Parameters ◽  
Multiple Model ◽  
Frequency Locking ◽  
Birth Seasonality ◽  
Childhood Disease ◽  
Southern States ◽  
The Impact

More than a century of ecological studies have demonstrated the importance of demography in shaping spatial and temporal variation in population dynamics. Surprisingly, the impact of seasonal recruitment on infectious disease systems has received much less attention. Here, we present data encompassing 78 years of monthly natality in the USA, and reveal pronounced seasonality in birth rates, with geographical and temporal variation in both the peak birth timing and amplitude. The timing of annual birth pulses followed a latitudinal gradient, with northern states exhibiting spring/summer peaks and southern states exhibiting autumn peaks, a pattern we also observed throughout the Northern Hemisphere. Additionally, the amplitude of United States birth seasonality was more than twofold greater in southern states versus those in the north. Next, we examined the dynamical impact of birth seasonality on childhood disease incidence, using a mechanistic model of measles. Birth seasonality was found to have the potential to alter the magnitude and periodicity of epidemics, with the effect dependent on both birth peak timing and amplitude. In a simulation study, we fitted an susceptible-exposed-infected-recovered model to simulated data, and demonstrated that ignoring birth seasonality can bias the estimation of critical epidemiological parameters. Finally, we carried out statistical inference using historical measles incidence data from New York City. Our analyses did not identify the predicted systematic biases in parameter estimates. This may be owing to the well-known frequency-locking between measles epidemics and seasonal transmission rates, or may arise from substantial uncertainty in multiple model parameters and estimation stochasticity.

scholarly journals The impact of mineral dust on cloud formation during the Saharan dust event in April 2014 over Europe

2018 ◽  
Author(s):  
Michael Weger ◽  
Bernd Heinold ◽  
Ina Tegen ◽  
Christa Engler ◽  
Patric Seifert ◽  
...  
Keyword(s):  
Cloud Cover ◽  
Mineral Dust ◽  
Dust Cloud ◽  
Ice Nucleation ◽  
Saharan Dust ◽  
Cloud Formation ◽  
Cirrus Cloud ◽  
Dust Event ◽  
The Impact

Abstract. A regional modeling study on the impact of desert dust on cloud formation is presented for a major Saharan dust outbreak over Europe from 2 April to 5 April 2014. The dust event coincided with an extensive and dense cirrus cloud layer, suggesting an influence of dust on atmospheric ice nucleation. Using interactive simulation with the regional dust model COSMO-MUSCAT, we investigate cloud and precipitation representation in the model and test the sensitivity of cloud parameters to dust-cloud and dust-radiation interactions of the simulated dust plume. We evaluate model results with ground-based and space-borne remote sensings of aerosol and cloud properties, as well as the in situ measurements obtained during the ML-CIRRUS aircraft campaign. A run of the model with single-moment bulk microphysics without online dust feedback considerably underestimated cirrus cloud cover over Germany in the comparison with infrared satellite imagery. This was also reflected in simulated upper-tropospheric ice water content (IWC), which accounted only for 20 % of the observed values. The interactive dust simulation with COSMO-MUSCAT, including a two-moment bulk microphysics scheme and dust-cloud as well as dust-radiation feedback, in contrast, led to significant improvements. The modeled cirrus cloud cover and IWC were by at least a factor of two higher in the relevant altitudes compared to the non-interactive model run. We attributed these improvements mainly to enhanced deposition freezing in response to the high mineral dust concentrations. This was corroborated further in a significant decrease in ice particle radii towards more realistic values, as compared to in situ measurements from the ML-CIRRUS aircraft campaign. By testing different empirical ice nucleation parameterizations, we further demonstrate that remaining uncertainties in the ice nucleating properties of mineral dust affect the model performance at least as significantly as to whether including the online representation of the mineral distribution. Dust-radiation interactions played a secondary role for cirrus cloud formation, but contributed to a more realistic representation of precipitation by suppressing moist convection in southern Germany. In addition, a too low specific humidity in the 7 to 10 km altitude range in the boundary conditions was identified as a main reason of misrepresentation of cirrus clouds in this model study.

scholarly journals Particulate Matter Concentrations and Their Association With COVID-19 Related Mortality in Mexico During June 2020 Saharan Dust Event 

2021 ◽  
Author(s):  
Gurusamy Kutralam-Muniasamy ◽  
Fermín Pérez-Guevara ◽  
Ignacio Elizalde Martínez ◽  
Shruti Venkata Chari
Keyword(s):  
Particulate Matter ◽  
Hazard Quotient ◽  
Human Health Risk ◽  
Daily Intake ◽  
Positive Association ◽  
Saharan Dust ◽  
Dust Event ◽  
Potential Health ◽  
The Impact ◽  
Related Mortality

Abstract The present study evaluated the impact of Saharan dust event on particulate matter (PM; PM10 and PM2.5) concentrations by analyzing the daily average PM data between Saharan dust days (June 23 - 29, 2020) and non-Saharan dust days (June 15 to June 22 and June 30 to July 12, 2020) for four major affected regions in Mexico and by comparing with three major previous events (2015, 2018 and 2019). The results showed PM10 and PM2.5 concentrations were 2-5 times higher during the Saharan dust event with the highest daily averages of 197 μg/m3 and 94 μg/m3, respectively and exceeded the Mexican standard norm (NOM-020-SSA1-2014). When comparing with the previous Saharan dust episodes of 2015, 2018 and 2019, the levels of PM10 and PM2.5 considerably increased and more than doubled across Mexico. The correlation analysis revealed a positive association of PM levels with the number of daily COVID-19 cases and deaths during Saharan dust event. Furthermore, the human health risk assessment showed that the chronic daily intake and hazard quotient values incremented during Saharan dust days compared to non-Saharan days, indicating potential health effects and importance of taking necessary measures to ensure better air quality following the COVID-19 pandemic.

scholarly journals The impact of mineral dust on cloud formation during the Saharan dust event in April 2014 over Europe

2018 ◽  
Vol 18 (23) ◽  
pp. 17545-17572 ◽  
Author(s):  
Michael Weger ◽  
Bernd Heinold ◽  
Christa Engler ◽  
Ulrich Schumann ◽  
Axel Seifert ◽  
...  
Keyword(s):  
Cloud Cover ◽  
Mineral Dust ◽  
Dust Cloud ◽  
Ice Nucleation ◽  
Saharan Dust ◽  
Cloud Formation ◽  
Cirrus Cloud ◽  
Dust Event ◽  
The Impact

Abstract. A regional modeling study on the impact of desert dust on cloud formation is presented for a major Saharan dust outbreak over Europe from 2 to 5 April 2014. The dust event coincided with an extensive and dense cirrus cloud layer, suggesting an influence of dust on atmospheric ice nucleation. Using interactive simulation with the regional dust model COSMO-MUSCAT, we investigate cloud and precipitation representation in the model and test the sensitivity of cloud parameters to dust–cloud and dust–radiation interactions of the simulated dust plume. We evaluate model results with ground-based and spaceborne remote sensing measurements of aerosol and cloud properties, as well as the in situ measurements obtained during the ML-CIRRUS aircraft campaign. A run of the model with single-moment bulk microphysics without online dust feedback considerably underestimated cirrus cloud cover over Germany in the comparison with infrared satellite imagery. This was also reflected in simulated upper-tropospheric ice water content (IWC), which accounted for only 20 % of the observed values. The interactive dust simulation with COSMO-MUSCAT, including a two-moment bulk microphysics scheme and dust–cloud as well as dust–radiation feedback, in contrast, led to significant improvements. The modeled cirrus cloud cover and IWC were by at least a factor of 2 higher in the relevant altitudes compared to the noninteractive model run. We attributed these improvements mainly to enhanced deposition freezing in response to the high mineral dust concentrations. This was corroborated further in a significant decrease in ice particle radii towards more realistic values, compared to in situ measurements from the ML-CIRRUS aircraft campaign. By testing different empirical ice nucleation parameterizations, we further demonstrate that remaining uncertainties in the ice-nucleating properties of mineral dust affect the model performance at least as significantly as including the online representation of the mineral dust distribution. Dust–radiation interactions played a secondary role for cirrus cloud formation, but contributed to a more realistic representation of precipitation by suppressing moist convection in southern Germany. In addition, a too-low specific humidity in the 7 to 10 km altitude range in the boundary conditions was identified as one of the main reasons for misrepresentation of cirrus clouds in this model study.

scholarly journals Saharan dust event impacts on cloud formation and radiation over Western Europe

2012 ◽  
Vol 12 (9) ◽  
pp. 4045-4063 ◽  
Author(s):  
M. Bangert ◽  
A. Nenes ◽  
B. Vogel ◽  
H. Vogel ◽  
D. Barahona ◽  
...  
Keyword(s):  
Cloud Droplet ◽  
Short Wave ◽  
Number Concentration ◽  
Ice Crystals ◽  
Saharan Dust ◽  
Dust Particles ◽  
Wave Radiation ◽  
Dust Event ◽  
Homogeneous Freezing ◽  
The Impact

Abstract. We investigated the impact of mineral dust particles on clouds, radiation and atmospheric state during a strong Saharan dust event over Europe in May 2008, applying a comprehensive online-coupled regional model framework that explicitly treats particle microphysics and chemical composition. Sophisticated parameterizations for aerosol activation and ice nucleation, together with two-moment cloud microphysics are used to calculate the interaction of the different particles with clouds depending on their physical and chemical properties. The impact of dust on cloud droplet number concentration was found to be low, with just a slight increase in cloud droplet number concentration for both uncoated and coated dust. For temperatures lower than the level of homogeneous freezing, no significant impact of dust on the number and mass concentration of ice crystals was found, though the concentration of frozen dust particles reached up to 100 l−1 during the ice nucleation events. Mineral dust particles were found to have the largest impact on clouds in a temperature range between freezing level and the level of homogeneous freezing, where they determined the number concentration of ice crystals due to efficient heterogeneous freezing of the dust particles and modified the glaciation of mixed phase clouds. Our simulations show that during the dust events, ice crystals concentrations were increased twofold in this temperature range (compared to if dust interactions are neglected). This had a significant impact on the cloud optical properties, causing a reduction in the incoming short-wave radiation at the surface up to −75 W m−2. Including the direct interaction of dust with radiation caused an additional reduction in the incoming short-wave radiation by 40 to 80 W m−2, and the incoming long-wave radiation at the surface was increased significantly in the order of +10 W m−2. The strong radiative forcings associated with dust caused a reduction in surface temperature in the order of −0.2 to −0.5 K for most parts of France, Germany, and Italy during the dust event. The maximum difference in surface temperature was found in the East of France, the Benelux, and Western Germany with up to −1 K. This magnitude of temperature change was sufficient to explain a systematic bias in numerical weather forecasts during the period of the dust event.

Spatial and temporal variation in soil Mn2+ concentrations and the impact of manganese toxicity on lucerne and subterranean clover seedlings

2012 ◽  
Vol 63 (9) ◽  
pp. 875 ◽  
Author(s):  
R. C. Hayes ◽  
M. K. Conyers ◽  
G. D. Li ◽  
G. J. Poile ◽  
A. Price ◽  
...  
Keyword(s):  
Temporal Variation ◽  
Soil Ph ◽  
Seedling Survival ◽  
Subterranean Clover ◽  
Spatial And Temporal Variation ◽  
Pot Experiments ◽  
South Wales ◽  
Soil Temperatures ◽  
High Concentrations ◽  
The Impact

Spatial and temporal variation in soil Mn2+ was observed over a 12-month period at two field sites near Gerogery and Binalong in southern New South Wales (NSW), Australia. Three pot experiments were then conducted to emulate the range of soil Mn2+ concentrations observed in the field and to determine the effect of different concentrations on lucerne and subterranean clover seedling growth, as well as to determine the effect of heating a soil on pH and Mn2+ concentrations. Concentrations of soil Mn2+ in the surface 0.20 m varied at a given sampling date by up to 288% (2.5–9.7 µg/mL) and 183% (8.7–24.6 µg/mL) across the Gerogery and Binalong field sites, respectively. At both sites, the concentration of soil Mn2+ in a given plot also varied by up to 175% between sampling times. There was little consistency between sites for seasonal fluctuations of soil Mn2+, although in both instances, peaks occurred during months in which newly sown lucerne plants might be emerging in southern NSW. Pot experiments revealed that high concentrations of soil Mn2+ reduced lucerne seedling survival by 35%, and on seedlings that did survive, reduced shoot growth by 19% and taproot length by 39%. Elevated concentrations of soil Mn2+ also reduced subterranean clover seedling survival by up to 55% and taproot length by 25%, although there were few effects on subterranean clover in treatments other than those imposing the highest soil Mn2+ concentrations. The third pot experiment demonstrated that elevated soil temperatures led to increased soil pH and increased soil Mn2+ concentrations, attributable to a decrease in biological oxidation of soil Mn2+. This was in contrast to the commonly anticipated response of a decline in soil Mn2+concentrations as soil pH increased.

A review of spatial and temporal variation in grey and common seal diet in the United Kingdom and Ireland

2012 ◽  
Vol 92 (8) ◽  
pp. 1711-1722 ◽  
Author(s):  
Susie L. Brown ◽  
Stuart Bearhop ◽  
Chris Harrod ◽  
Robbie A. McDonald
Keyword(s):  
Spatial Variation ◽  
Temporal Variation ◽  
Large Scale ◽  
Fish Assemblages ◽  
Prey Availability ◽  
Spatial And Temporal Variation ◽  
Spatial And Temporal Scales ◽  
The United Kingdom ◽  
The Impact ◽  
Seal Diet

Knowledge about the diet of fish-eating predators is critical when evaluating conflicts with the fishing industry. Numerous primary studies have examined the diet of grey seals Halichoerus grypus and common seals Phoca vitulina in a bid to understand the ecology of these predators. However, studies of large-scale spatial and temporal variation in seal diet are limited. Therefore this review combines the results of seal diet studies published between 1980 and 2000 to examine how seal diet varies at a range of spatial and temporal scales. Our results revealed extensive spatial variation in gadiform, perciform and flatfish consumption, likely reflecting variation in prey availability. Flatfish and gadiform consumption varied between years, reflecting changes in fish assemblages as a consequence of factors such as varying fishing pressures, climate change and natural fluctuations in populations. Perciform and gadiform consumption varied seasonally: in addition there was a significant interaction between season and seal species, indicating that grey and common seals exhibited different patterns of seasonal variation in their consumption of Perciformes and Gadiformes. Multivariate analysis of grey seal diet revealed spatial variation at a much smaller scale, with different species dominating the diet in different areas. The existence of spatial and temporal variation in seal diet emphasizes that future assessments of the impact of seal populations should not be based on past or localized estimates of diet and highlights the need for up-to-date, site specific estimates of diet composition in the context of understanding and resolving seal/fisheries conflict.

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