scholarly journals Aerosol meteorology of Maritime Continent for the 2012 7SEAS southwest monsoon intensive study – Part 2: Philippine receptor observations of fine-scale aerosol behavior

2016 ◽  
Vol 16 (22) ◽  
pp. 14057-14078 ◽  
Author(s):  
Jeffrey S. Reid ◽  
Nofel D. Lagrosas ◽  
Haflidi H. Jonsson ◽  
Elizabeth A. Reid ◽  
Samuel A. Atwood ◽  
...  
Keyword(s):  
Life Cycle ◽  
Biomass Burning ◽  
Marine Boundary Layer ◽  
Aerosol Particles ◽  
Anthropogenic Pollution ◽  
Southwest Monsoon ◽  
The Philippines ◽  
Small Scale ◽  
Maritime Continent ◽  
Squall Lines

Abstract. The largest 7 Southeast Asian Studies (7SEAS) operations period within the Maritime Continent (MC) occurred in the August–September 2012 biomass burning season. Data included were observations aboard the M/Y Vasco, dispatched to the Palawan Archipelago and Sulu Sea of the Philippines for September 2012. At these locations, the Vasco observed MC smoke and pollution entering the southwest monsoon (SWM) monsoonal trough. Here we describe the research cruise findings and the finer-scale aerosol meteorology of this convectively active region. This 2012 cruise complemented a 2-week cruise in 2011 and was generally consistent with previous findings in terms of how smoke emission and transport related to monsoonal flows, tropical cyclones (TC), and the covariance between smoke transport events and the atmosphere's thermodynamic structure. Biomass burning plumes were usually mixed with significant amounts of anthropogenic pollution. Also key to aerosol behavior were squall lines and cold pools propagating across the South China Sea (SCS) and scavenging aerosol particles in their path. However, the 2012 cruise showed much higher modulation in aerosol frequency than its 2011 counterpart. Whereas in 2011 large synoptic-scale aerosol events transported high concentrations of smoke into the Philippines over days, in 2012 measured aerosol events exhibited a much shorter-term variation, sometimes only 3–12 h. Strong monsoonal flow reversals were also experienced in 2012. Nucleation events in cleaner and polluted conditions, as well as in urban plumes, were observed. Perhaps most interestingly, several cases of squall lines preceding major aerosol events were observed, as opposed to 2011 observations where these lines largely scavenged aerosol particles from the marine boundary layer. Combined, these observations indicate pockets of high and low particle counts that are not uncommon in the region. These perturbations are difficult to observe by satellite and very difficult to model. Indeed, the Navy Aerosol Analysis and Prediction System (NAAPS) simulations captured longer period aerosol events quite well but largely failed to capture the timing of high-frequency phenomena. Ultimately, the research findings of these cruises demonstrate the real world challenges of satellite-based missions, significant aerosol life cycle questions such as those the future Aerosol/Clouds/Ecosystems (ACE) will investigate, and the importance of small-scale phenomena such as sea breezes, squall lines, and nucleation events embedded within SWM patterns in dominating aerosol life cycle and potential relationships to clouds.

scholarly journals Aerosol meteorology and Philippine receptor observations of Maritime Continent aerosol emissions for the 2012 7SEAS southwest monsoon intensive study

2016 ◽  
Author(s):  
Jeffrey S. Reid ◽  
Nofel D. Lagrosas ◽  
Haflidi H. Jonsson ◽  
Elizabeth A. Reid ◽  
Samuel A. Atwood ◽  
...  
Keyword(s):  
South China Sea ◽  
Biomass Burning ◽  
South China ◽  
Aerosol Particles ◽  
Flow Patterns ◽  
Southwest Monsoon ◽  
The Philippines ◽  
The South China Sea ◽  
Maritime Continent ◽  
Squall Lines

Abstract. The largest 7 Southeast Asian Studies (7-SEAS) operations period within the Maritime Continent occurred in the 2012 August–September biomass burning season. Included where an enhanced deployment of Aerosol Robotic Network (AERONET) sun photometers, of multiple lidars, and of a Singapore supersite. Simultaneously, a ship was dispatched to the Palawan Archipelago and Sulu Sea of the Philippines for September 2012 to observe transported smoke and pollution as it entered the southwest monsoon monsoonal trough. Here we describe the nature of the overall 2012 southwest monsoon biomass burning season, but focus on the findings of the research cruise and the aerosol meteorology of this convectively active region. This 2012 cruise followed a 2 week cruise in 2011, and was in part consistent with the findings of that cruise for how smoke emission and transport relate to monsoonal flows, the propagation of the Madden Julian Oscillation (MJO), tropical cyclones, and covariance between smoke transport events and the atmosphere’s thermodynamic structure. Aerosol observations in the 2011 cruise also highlighted the importance of squall lines and cold pools as they propagate across the South China Sea, scavenging aerosol particles in their path. For 2012, the cruise experienced differing environments. The monsoonal flow direction was perturbed by easterly waves, leading at times to total flow reversal in the South China Sea. Two category 5 typhoons just east of the Philippines also modulated flow patterns and convection. Whereas in 2011 large synoptic scale aerosol events transported high concentrations of smoke into the Philippines over days, in 2012, measured aerosol events exhibited a much more short term variation, sometimes only over 3–12 hours. Navy Aerosol Analysis and Prediction System (NAAPS) simulations captured longer wavelength aerosol events quite well, but largely failed to capture the timing in high frequency phenomena. Also observed were nucleation events in cleaner and polluted conditions, as well as in urban plumes. Combined, observations indicate pockets of high particle counts are not uncommon in the region. Perhaps most interestingly, several cases of squall lines heralding major aerosol events were observed, as opposed to the previous observations in 2011 of these lines largely scavenging aerosol particles from the marine boundary layer. We hypothesize that these phenomena may originate from weakly forced convection ahead of polluted land breeze fronts caught in strong monsoonal flows. Ultimately, the research findings of the 2012 cruise nicely complement the narrative started by the 2011 research cruise, and point to the importance of small scale phenomena such as sea breezes and squall lines embedded in the large scale monsoonal flow patterns in dominating aerosol lifecycle and potentially effects. “Pure” biomass burning plumes are relatively rare and are usually mixed with significant amounts of anthropogenic pollution.

Life cycle energy use and CO2 emissions of small-scale gold mining and refining processes in the Philippines

2017 ◽  
Vol 23 (10) ◽  
pp. 1928-1939 ◽  
Author(s):  
Marie Chela B. Cenia ◽  
Mili-Ann M. Tamayao ◽  
Virginia J. Soriano ◽  
Kristine Mae C. Gotera ◽  
Benette P. Custodio
Keyword(s):  
Life Cycle ◽  
Co2 Emissions ◽  
Gold Mining ◽  
Energy Use ◽  
The Philippines ◽  
Small Scale ◽  
Refining Processes

scholarly journals Overview of aerosol optical properties over southern West Africa from DACCIWA aircraft measurements

2020 ◽  
Vol 20 (8) ◽  
pp. 4735-4756 ◽  
Author(s):  
Cyrielle Denjean ◽  
Thierry Bourrianne ◽  
Frederic Burnet ◽  
Marc Mallet ◽  
Nicolas Maury ◽  
...  
Keyword(s):  
Optical Properties ◽  
West Africa ◽  
Black Carbon ◽  
Biomass Burning ◽  
Aerosol Particles ◽  
Anthropogenic Pollution ◽  
Aerosol Optical Properties ◽  
Air Masses ◽  
Carbon Particles ◽  
Biomass Burning Particles

Abstract. Southern West Africa (SWA) is an African pollution hotspot but a relatively poorly sampled region of the world. We present an overview of in situ aerosol optical measurements collected over SWA in June and July 2016 as part as of the DACCIWA (Dynamics-Aerosol-Chemistry-Clouds Interactions in West Africa) airborne campaign. The aircraft sampled a wide range of air masses, including anthropogenic pollution plumes emitted from the coastal cities, long-range transported biomass burning plumes from central and southern Africa and dust plumes from the Sahara and Sahel region, as well as mixtures of these plumes. The specific objective of this work is to characterize the regional variability of the vertical distribution of aerosol particles and their spectral optical properties (single scattering albedo: SSA, asymmetry parameter, extinction mass efficiency, scattering Ångström exponent and absorption Ångström exponent: AAE). The first findings indicate that aerosol optical properties in the planetary boundary layer were dominated by a widespread and persistent biomass burning loading from the Southern Hemisphere. Despite a strong increase in aerosol number concentration in air masses downwind of urban conglomerations, spectral SSA were comparable to the background and showed signatures of the absorption characteristics of biomass burning aerosols. In the free troposphere, moderately to strongly absorbing aerosol layers, dominated by either dust or biomass burning particles, occurred occasionally. In aerosol layers dominated by mineral dust particles, SSA varied from 0.81 to 0.92 at 550 nm depending on the variable proportion of anthropogenic pollution particles externally mixed with the dust. For the layers dominated by biomass burning particles, aerosol particles were significantly more light absorbing than those previously measured in other areas (e.g. Amazonia, North America), with SSA ranging from 0.71 to 0.77 at 550 nm. The variability of SSA was mainly controlled by variations in aerosol composition rather than in aerosol size distribution. Correspondingly, values of AAE ranged from 0.9 to 1.1, suggesting that lens-coated black carbon particles were the dominant absorber in the visible range for these biomass burning aerosols. Comparison with the literature shows a consistent picture of increasing absorption enhancement of biomass burning aerosol from emission to remote location and underscores that the evolution of SSA occurred a long time after emission. The results presented here build a fundamental basis of knowledge about the aerosol optical properties observed over SWA during the monsoon season and can be used in climate modelling studies and satellite retrievals. In particular and regarding the very high absorbing properties of biomass burning aerosols over SWA, our findings suggest that considering the effect of internal mixing on absorption properties of black carbon particles in climate models should help better assess the direct and semi-direct radiative effects of biomass burning particles.

scholarly journals Aerosol meteorology of the Maritime Continent for the 2012 7SEAS southwest monsoon intensive study – Part 1: regional-scale phenomena

2016 ◽  
Vol 16 (22) ◽  
pp. 14041-14056 ◽  
Author(s):  
Jeffrey S. Reid ◽  
Peng Xian ◽  
Brent N. Holben ◽  
Edward J. Hyer ◽  
Elizabeth A. Reid ◽  
...  
Keyword(s):  
Biomass Burning ◽  
El Niño ◽  
El Nino ◽  
Southern Oscillation ◽  
Regional Scale ◽  
Intraseasonal Oscillation ◽  
Southwest Monsoon ◽  
Boreal Summer ◽  
Maritime Continent ◽  
Fire Activity

Abstract. The largest 7 Southeast Asian Studies (7SEAS) operation period within the Maritime Continent (MC) occurred in the August–September 2012 biomass burning season. Included was an enhanced deployment of Aerosol Robotic Network (AERONET) sun photometers, multiple lidars, and field measurements to observe transported smoke and pollution as it left the MC and entered the southwest monsoon trough. Here we describe the nature of the overall 2012 southwest monsoon (SWM) and biomass burning season to give context to the 2012 deployment. The MC in 2012 was in a slightly warm El Niño/Southern Oscillation (ENSO) phase and with spatially typical burning activity. However, overall fire counts for 2012 were 10 % lower than the Reid et al. (2012) baseline, with regions of significant departures from this norm, ranging from southern Sumatra (+30 %) to southern Kalimantan (−42 %). Fire activity and monsoonal flows for the dominant burning regions were modulated by a series of intraseasonal oscillation events (e.g., Madden–Julian Oscillation, or MJO, and boreal summer intraseasonal oscillation, or BSISO). As is typical, fire activity systematically progressed eastward over time, starting with central Sumatran fire activity in June related to a moderately strong MJO event which brought drier air from the Indian Ocean aloft and enhanced monsoonal flow. Further burning in Sumatra and Kalimantan Borneo occurred in a series of significant events from early August to a peak in the first week of October, ending when the monsoon started to migrate back to its wintertime northeastern flow conditions in mid-October. Significant monsoonal enhancements and flow reversals collinear with tropical cyclone (TC) activity and easterly waves were also observed. Islands of the eastern MC, including Sulawesi, Java, and Timor, showed less sensitivity to monsoonal variation, with slowly increasing fire activity that also peaked in early October but lingered into November. Interestingly, even though fire counts were middling, resultant AERONET 500 nm aerosol optical thickness (AOT) from fire activity was high, with maximums of 3.6 and 5.6 in the Sumatra and Kalimantan source regions at the end of the burning season and an average of ∼ 1. AOTs could also be high at receptor sites, with a mean and maximum of 0.57 and 1.24 in Singapore and 0.61 and 0.8 in Kuching Sarawak. Ultimately, outside of the extreme 2015 El Niño event, average AERONET AOT values were higher than any other time since sites were established. Thus, while satellite fire data, models, and AERONET all qualitatively agree on the nature of smoke production and transport, the MC's complex environment resulted in clear differences in quantitative interpretation of these datasets.

scholarly journals Light absorption properties of aerosols over Southern West Africa

2019 ◽  
Author(s):  
Cyrielle Denjean ◽  
Thierry Bourrianne ◽  
Frederic Burnet ◽  
Marc Mallet ◽  
Nicolas Maury ◽  
...  
Keyword(s):  
Optical Properties ◽  
West Africa ◽  
Biomass Burning ◽  
Aerosol Particles ◽  
Anthropogenic Pollution ◽  
Absorption Properties ◽  
Air Masses ◽  
Carbon Particles ◽  
Biomass Burning Aerosol ◽  
Biomass Burning Particles

Abstract. Southern West Africa (SWA) is an African pollution hotspot but a relatively poorly sampled region of the world. We present an overview of in-situ aerosol optical measurements collected over SWA in June and July 2016 as part as the DACCIWA (Dynamics–Aerosol–Chemistry–Clouds Interactions in West Africa) airborne campaign. The aircraft sampled a wide range of air masses, including anthropogenic pollution plumes emitted from the coastal cities, long-range transported biomass burning plumes from Central and Southern Africa and dust plumes from the Sahara and Sahel region, as well as mixtures of these plumes. The specific objective of this work is to characterize the regional variability of the vertical distribution of aerosol particles and their spectral optical properties (single scattering albedo: SSA, asymmetry parameter, extinction mass efficiency, scattering Ångström exponent and absorption Ångström exponent: AAE). First findings indicate that aerosol optical properties in the planetary boundary layer were dominated by a widespread and persistent biomass burning loading from the Southern Hemisphere. Despite a strong increase of aerosol number concentration in air masses downwind of urban conglomerations, spectral SSA were comparable to the background and showed signatures of the absorption characteristics of biomass burning aerosols. In the free troposphere, moderately to strongly absorbing aerosol layers, dominated by either dust or biomass burning particles, occurred occasionally. In aerosol layers dominated by mineral dust particles, SSA varied from 0.81 to 0.92 at 550 nm depending on the variable proportion of anthropogenic pollution particles externally mixed with the dust. Biomass burning aerosol particles were significantly more light absorbing than those previously measured in other areas (e.g. Amazonia, North America) with SSA ranging from 0.71 to 0.77 at 550 nm. The variability of SSA was mainly controlled by variations in aerosol composition rather than in aerosol size distribution. Correspondingly, values of AAE ranged from 0.9 to 1.1, suggesting that lens-coated black carbon particles were the dominant absorber in the visible range for these biomass burning aerosols. Comparison with literature shows a consistent picture of increasing absorption enhancement of biomass burning aerosol from emission to remote location and underscores that the evolution of SSA occurred a long time after emission. The results presented here build a fundamental basis of knowledge about the aerosol optical properties observed over SWA during the monsoon season and can be used in climate modelling studies and satellite retrievals. In particular and regarding the very high absorbing properties of biomass burning aerosols over SWA, our findings suggest that considering the effect of internal mixing on absorption properties of black carbon particles in climate models should help better assessing the direct and semi-direct radiative effects of biomass burning particles.

Life Cycle Development of Successful Women-owned Enterprises

2020 ◽  
Vol 3 (4) ◽  
pp. 142-152
Author(s):  
Mohammad Waliul Hasanat ◽  
Kamna Anum ◽  
Ashikul Hoque ◽  
Mahmud Hamid ◽  
Sandy Francis Peris ◽  
...  
Keyword(s):  
Life Cycle ◽  
Data Collection ◽  
Research Work ◽  
Primary Data ◽  
Small Scale ◽  
Data Collection Process ◽  
Theoretical Finding ◽  
Successful Women ◽  
Two Phases ◽  
Life Cycle Development

In developing countries, the role of women in the business sector is continuously improving. As a result, female enterprises have also been encouraged in Pakistan. This study is based on life cycle development phases from which women-owned enterprises have to go through in order to become successful. As a primary data source, face-to-face interviews with owners of successful women-owned enterprises were preferred. The data collection process was divided into two phases i.e. Phase-I and Phase-II. After data collection, qualitative analysis has been performed using NVIVO. Findings provide both generic and specific factors involved in life cycle development of women-owned enterprises. This study provides a detailed view of life cycle development model followed by successful women enterprises. The outcome of this research work is a theoretical finding which can be utilized by entrepreneurs owning small scale enterprises to improve their level of performance. Findings can also be helpful for potentially talented women interested in setting up their own business.

scholarly journals The composition and variability of atmospheric aerosol over Southeast Asia during 2008

2012 ◽  
Vol 12 (2) ◽  
pp. 1083-1100 ◽  
Author(s):  
W. Trivitayanurak ◽  
P. I. Palmer ◽  
M. P. Barkley ◽  
N. H. Robinson ◽  
H. Coe ◽  
...  
Keyword(s):  
Southeast Asia ◽  
Gas Phase ◽  
Biomass Burning ◽  
Organic Aerosol ◽  
Sea Salt ◽  
Dust Aerosol ◽  
Small Scale ◽  
Formation Mechanisms ◽  
Sulphate Aerosol ◽  
Phase Oxidation

Abstract. We use a nested version of the GEOS-Chem global 3-D chemistry transport model to better understand the composition and variation of aerosol over Borneo and the broader Southeast Asian region in conjunction with aircraft and satellite observations. Our focus on Southeast Asia reflects the importance of this region as a source of reactive organic gases and aerosols from natural forests, biomass burning, and food and fuel crops. We particularly focus on July 2008 when the UK BAe-146 research aircraft was deployed over northern Malaysian Borneo as part of the ACES/OP3 measurement campaign. During July 2008 we find using the model that Borneo (defined as Borneo Island and the surrounding Indonesian islands) was a net exporter of primary organic aerosol (42 kT) and black carbon aerosol (11 kT). We find only 13% of volatile organic compound oxidation products partition to secondary organic aerosol (SOA), with Borneo being a net exporter of SOA (15 kT). SOA represents approximately 19% of the total organic aerosol over the region. Sulphate is mainly from aqueous-phase oxidation (68%), with smaller contributions from gas-phase oxidation (15%) and advection into the regions (14%). We find that there is a large source of sea salt, as expected, but this largely deposits within the region; we find that dust aerosol plays only a relatively small role in the aerosol burden. In contrast to coincident surface measurements over Northern Borneo that find a pristine environment with evidence for substantial biogenic SOA formation we find that the free troposphere is influenced by biomass burning aerosol transported from the northwest of the Island and further afield. We find several transport events during July 2008 over Borneo associated with elevated aerosol concentrations, none of which coincide with the aircraft flights. We use MODIS aerosol optical depths (AOD) data and the model to put the July campaign into a longer temporal perspective. We find that Borneo is where the model has the least skill at reproducing the data, where the model has a negative bias of 76% and only captures 14% of the observed variability. This model performance reflects the small-scale island-marine environment and the mix of aerosol species, with the model showing more skill at reproducing observed AOD over larger continental regions such as China where AOD is dominated by one aerosol type. The model shows that AOD over Borneo is approximately evenly split between organic and sulphate aerosol with sea salt representing 10–20% during May–September; we find a similar breakdown over continental Southeast Asia but with less sea salt aerosol and more dust aerosol. In contrast, East China AOD is determined mainly by sulphate aerosol and a seasonal source of dust aerosol, as expected. Realistic sensitivity runs, designed to test our underlying assumptions about emissions and chemistry over Borneo, show that model AOD is most sensitive to isoprene emissions and organic gas-phase partitioning but all fail to improve significantly upon the control model calculation. This emphasises the multi-faceted dimension of the problem and the need for concurrent and coordinated development of BVOC emissions, and BVOC chemistry and organic aerosol formation mechanisms.

scholarly journals Accurate age estimation in small-scale societies

2017 ◽  
Vol 114 (31) ◽  
pp. 8205-8210 ◽  
Author(s):  
Yoan Diekmann ◽  
Daniel Smith ◽  
Pascale Gerbault ◽  
Mark Dyble ◽  
Abigail E. Page ◽  
...  
Keyword(s):  
Life History ◽  
Bayesian Approach ◽  
Age Estimation ◽  
Human Life ◽  
The Philippines ◽  
Monte Carlo Algorithm ◽  
Small Scale ◽  
Hunter Gatherers ◽  
Cultural Life ◽  
Ranking Order

Precise estimation of age is essential in evolutionary anthropology, especially to infer population age structures and understand the evolution of human life history diversity. However, in small-scale societies, such as hunter-gatherer populations, time is often not referred to in calendar years, and accurate age estimation remains a challenge. We address this issue by proposing a Bayesian approach that accounts for age uncertainty inherent to fieldwork data. We developed a Gibbs sampling Markov chain Monte Carlo algorithm that produces posterior distributions of ages for each individual, based on a ranking order of individuals from youngest to oldest and age ranges for each individual. We first validate our method on 65 Agta foragers from the Philippines with known ages, and show that our method generates age estimations that are superior to previously published regression-based approaches. We then use data on 587 Agta collected during recent fieldwork to demonstrate how multiple partial age ranks coming from multiple camps of hunter-gatherers can be integrated. Finally, we exemplify how the distributions generated by our method can be used to estimate important demographic parameters in small-scale societies: here, age-specific fertility patterns. Our flexible Bayesian approach will be especially useful to improve cross-cultural life history datasets for small-scale societies for which reliable age records are difficult to acquire.

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