Subsidence Inversion Research Articles

Review and updates of the lithosphere structure and geodynamics evolution of the Neogene Transcarpathian Basin and its substratum (Ukraine)

Geological and geophysical data about the structure of Mukachevo and Solotvyno sub-basins of Transcarpathian Basin (TB), located in hinterland of Outer Carpathians, are integrated and adapted to modern ideas about the Carpathian realm geodynamics. Analysis of published data and newly compiled geological map and cross-sections suggests: Mukachevo sub-basin substratum can be attributed to Alcapa terrane, and significant portion of Solotvyno sub-basin basement may belong to Pieniny Klippen Belt. Model of lithospheric structure, supported by deep seismic PANCAKE and P-17 profiles, and density modeling identifies crustal domain beneath Mukachevo sub-basin as rootless fragment of Alcapa terrane. Substratum of Solotvyno sub-basin is interpreted as thrust-sheets of Pieniny Klippen Belt, Czorsztyn continental block, Monastyrets nappe, and Tisza-Dacia terrane at their base. Paleostress reconstruction allowed to identify four evolutionary phases: (1) opening of TB as dextral shear pull-apart (earliest Middle Miocene), (2) rapid subsidence of TB (Badenian), (3) inversion of Solotvyno and slow subsidence in Mukachevo sub-basins (Sarmatian - Pliocene), (4) inversion of TB (Quaternary). Lithosphere of TB is significantly thermally reworked and is characterized by: 1) thinned crust with zones of reduced velocity and density, 2) astenospheric uplift, 3) absence of residual slab, 4) presence of reflector in upper mantle descending under the Carpathians.

The Turkana Jet Diurnal Cycle in Observations and Reanalysis

Abstract The Turkana jet is an equatorial low-level jet (LLJ) in East Africa. The jet influences both flooding and droughts, and powers Africa’s largest wind farm. Much of what we know about the jet, including the characteristics of its diurnal cycle, derives from reanalysis simulations that are not constrained by radiosonde observations in the region. Here, we report the characteristics of the Turkana jet with data from a field campaign during March–April 2021: The Radiosonde Investigation for the Turkana Jet (RIFTJet). The southeasterly jet forms on average at 380 m above the surface, with mean speeds of 15.0 m s−1. The strongest low-level winds are during the night and early morning from 0300 to 0600 LT (>16 m s−1). The average wind profile retains a characteristic low-level jet structure throughout the day, with the low-level wind maximum weakening to a minimum of 10.9 m s−1 at 1500 LT. There is significant shear, of up to 1.5 m s−1 (100 m)−1 maintained through the 1000 m above the wind maximum. The diurnal cycle of the jet is associated with the nocturnal strengthening and lowering of elevated subsidence inversions, which form above the jet. Reanalysis simulations (ERA5 and MERRA-2) do not capture the daytime persistence of the jet and underestimate the speed of the jet throughout the diurnal cycle. The largest absolute errors of over 4.5 m s−1 (−35%) occur at 0900 LT. The reanalyses also fail to simulate the elevated subsidence inversions above the jet and associated dry layer in the lower troposphere.

Identification and Prediction Inversion of Mining Area Subsidence by Integrating SBAS-InSAR and EMD-ARIMA Model

Identification and Prediction Inversion of Mining Area Subsidence by Integrating SBAS-InSAR and EMD-ARIMA Model

Late Cretaceous–Early Paleogene tectonic events in the “North–South Axis” of Central Tunisia

In order to better constrain the structural evolution of the North–South Axis (NOSA) running through central Tunisia, a multidisciplinary approach based on geological mapping, field observations and paleostress analysis was used. The geological study of the middle part of the NOSA including the Gadoum, Akrouta, Sidi Khalif, Khechem El Kaleb and Faïd structures, showed the predominance of N–S and E–W fault sets. Movement on the faults of this fault network caused the formation of depositional areas and the collapsed and tilting of fault bounded blocks located in the Southern part of the Gadoum–Akrouta sector. The Gadoum and Akrouta Jebels formed as a result of slip and rotation on a single N–S trending listric fault in the Cenomanian during which time reactivation of both the N–S and E–W fault sets occurred. During Coniacian–Santonian times, when the Aleg Formation was being deposited, the study area was affected by a transtensive regime. This regime led to the division of the area into blocks (e.g., the Gadoum–Akrouta block and the Wadi El Abiod Syncline) and this resulted in the Aleg Formation being deposited with variable thicknesses. During the Campanian–Early Maastrichtian, a N–S transpressive regime was established, and this regime, coupled with the salt tectonics, resulted in the formation of an angular unconformity, subsidence inversion and lateral thickness variations of the Abiod Formation. During the Early Eocene, an E–W fault network affected the sedimentary basin. These faults, arranged in steps, generated accommodation spaces for sediments which increase in thickness along the North–South Axis.

Mining Subsidence Monitoring Based on InSAR Method Fusing Multi-threshold Target

In view of the limitations of traditional InSAR technology in selecting stable target point for orbit refining and surface subsidence inversion in complicated mining area, this paper proposes a time-series InSAR mining area subsidence monitoring method based on the fusion of multi threshold targets. On the basis of the traditional technology, the deviation threshold parameters, the regional window threshold parameters and the coherence threshold parameters are set to extract the relatively stable target points on the ground. Applying this method and traditional InSAR method to practical cases, the monitoring results of surface subsidence in the study area are obtained and verified. The results show that: (1) there are three mining subsidence areas in the mining area, the maximum annual average subsidence rate is -156 mm/a, and the maximum subsidence is -376 mm. Compared with the optical image data, the location of the mining subsidence area is consistent with the mining work area of the coal mine; (2) The absolute average difference of subsidence in the mining area using the two methods shall not exceed 12 mm. It shows that the InSAR method of fusing multi threshold targets can not only effectively overcome the limitations of traditional InSAR, but also ensure high accuracy, and has more advantages in the monitoring of surface subsidence in mining areas.

Integrated highland wildfire, smoke, and haze management in the Upper Indochina region

Fire has long been used in Southeast Asia for the purposes of cooking, protection, and warmth. However, climate change and economic pressure have modified the life of locals, including fire practices in daily life and other fire uses. The land use of forest cover in highland area (mostly deciduous forest) has shifted to cultivation, with the application of slash-and-burn techniques. This results in frequent unplanned fires causing pollution in the form of smoke and haze. A zero-burn policy has been implemented to tackle this problem but such a policy may not be appropriate as people still need fire as a basic tool for agriculture land preparation. Moreover, the deciduous forest is a fire-dependent ecosystem to maintain its ecosystem. Frequent burning by local people or excessive government intervention in preventing fires can impact this ecosystem. In the highlands, shifting cultivation has gradually been replaced by rotational agricultural practice with a cycle of 2 to 5 years. However, the fuel load for a 2-year rotation period is only 0.25 tha-1 higher than that of a mixed deciduous forest. New fire risk maps classified according to forest types were produced for Thailand, Lao PDR, and Myanmar. We report that the mixing layer (ML) height in Chiang Mai Province was, on average, 500 m during March, with common occurrence of subsidence inversion resulting in further lowering of air quality during this month. A participatory process to develop a Community Based Fire Management (CBFiM) was undertaken and it was observed that a successful implementation would need a community with a strong leadership.

Analysis of Coastal Fog from a Ship During the C-FOG Campaign

This work presents ship-based measurements of fog off St John’s, Newfoundland, on 13 September 2018 during the Coastal Fog field campaign. The measurements included cloud-particle spectra, cloud-base height and aerosol backscatter, radiation, turbulence, visibility, and sea-surface temperature. Radiosonde soundings were made at intervals of less than 2 h. Fog occurred in two episodes during the passage of an eastward-moving synoptic low-pressure system. The boundary-layer structure during the first fog episode consisted of three layers, separated by two saturated temperature inversions, and capped by a subsidence inversion. The lowest layer was fog, and the upper layers were cloud. The second fog episode consisted of one well-mixed fog layer capped by a subsidence inversion. Low wind speeds and stable stratification maintained low surface-layer turbulence during fog. Droplet size distributions had typical bimodal distributions. The visibility correlated with the droplet number concentration and liquid water content. The air temperature was higher than the sea-surface temperature for the first 30 min of the first fog episode but was lower than the sea for the remainder of all fog. The sensible heat flux was upward, from sea to air, for the first 62% of the first fog episode and then reversed to downward, from air to sea, for the remainder of the first fog episode and the second fog episode. The counter-gradient heat fluxes observed (i.e., opposite to what is expected from the instantaneous air–sea temperature difference) appear to be related to turbulence, entrainment, and stratification in the fog layer that overwhelmed the influence of the air–sea temperature difference. While the synoptic-scale dynamics preconditioned the area for fog formation, the final step of fog appearance in this case was nuanced by stratification–turbulence interactions, local advective processes, and microphysical environment.

Underestimated marine stratocumulus cloud feedback associated with overly active deep convection in models

Cloud feedback remains the largest source of uncertainty in equilibrium climate sensitivity (ECS). Many studies have attempted to narrow uncertainties in cloud feedback and ECS by proposing observable metrics with high skill at predicting future climate, referred to as emergent constraints. These constraints are often associated with clouds, convection, and circulation, and are interrelated. However, physical explanations for these connections remain unclear. Here, we propose a new mechanism relating convection and clouds across multiple climate models. Some models show overly active deep convection on daily timescales in the subtropical low cloud regions, which contributes to weaker subsidence inversion and smaller amounts of low-level clouds. Such models predict smaller shortwave (SW) cloud feedback. Using precipitation frequency in these regions as an emergent constraint, encapsulating this mechanism, models with lower SW cloud feedback (<0.50 W m−2 °C−1) are found to exhibit erroneously frequent convection. Our results suggest that further improvements in understanding and better modeling of cloud and convective systems are necessary for accurate climate predictions.

Tropical Convection in the Caribbean and Surrounding Region during a Regional, Warming Sea-Surface Temperature Period, 1982–2020

Warming sea-surface temperatures (SSTs) have implications for the climate-sensitive Caribbean region, including potential impacts on precipitation. SSTs have been shown to influence deep convection and rainfall, thus understanding the impacts of warming SSTs is important for predicting regional hydrometeorological conditions. This study investigates the long-term annual and seasonal trends in convection using the Galvez-Davison Index (GDI) for tropical convection from 1982–2020. The GDI is used to describe the type and potential for precipitation events characterized by sub-indices that represent heat and moisture availability, cool/warm mid-levels at 500 hPa, and subsidence inversion, which drive the regional Late, Early, and Dry Rainfall Seasons, respectively. Results show that regional SSTs are warming annually and per season, while regionally averaged GDI values are decreasing annually and for the Dry Season. Spatial analyses show the GDI demonstrates higher, statistically significant correlations with precipitation across the region than with sea-surface temperatures, annually and per season. Moreover, the GDI climatology results show that regional convection exhibits a bimodal pattern resembling the characteristic bimodal precipitation pattern experienced in many parts of the Caribbean and surrounding region. However, the drivers of these conditions need further investigation as SSTs continue to rise while the region experiences a drying trend.

Elevated Ducts and Low Clouds over the Central Western Pacific Ocean in Winter Based on GPS Soundings and Satellite Observation

Both low clouds and elevated ducts are common phenomena in the oceanic atmosphere. Low clouds affect elevated ducts by changing the structure of atmospheric temperature and humidity. However, due to the limitation of met-ocean measurements, research on them is still scattered. This paper presents the distribution of elevated ducts and clouds over the central Western Pacific Ocean (WPO) based on Global Position System (GPS) sounding data and Himawari-8 satellite products from November 2015 to January 2016. Results show that the frequency of elevated ducts detected by ship-based GPS soundings was as high as 77% over the central WPO. The height and frequency of elevated ducts are closely related to the low clouds. If there are no clouds, the occurrence probability and mean base height of the elevated ducts are 14% and 730 m, respectively. By comparison, the occurrence probability and mean base height increase up to 24% and 1471 m, respectively, in the presence of cumulus (Cu) clouds, and 22% and 1511 m, respectively, in the presence of stratocumulus (Sc) clouds. Elevated ducts occur near the cloud top. The analysis of geopotential height and wind fields from the European Centre for Medium-Range Weather Forecasts (ECMWF) reanalysis dataset (ERA-interim) shows that the study area is covered by a strong and stable subtropical high, and slowly sinking dry air masses inside the subtropical high are above the moist boundary-layer air mass. The appearance and evolution of low clouds will adjust the temperature and humidity structure of the lower troposphere. If there are no clouds, the marine boundary layer (MBL) is the classic mixed boundary layer. Humidity gradient and subsidence inversion are formed atop the mixed layer. When low clouds are present, long wave radiation and entrainment atop clouds form a strong temperature inversion and humidity gradient, which strengthen elevated ducts. However, when Sc clouds are decoupled, a weaker temperature inversion and humidity gradient may occur between the surface mixed layer and subcloud layer, leading to a weak elevated duct atop the mixed layer.

Evolution of Urban Haze in Greater Bangkok and Association with Local Meteorological and Synoptic Characteristics during Two Recent Haze Episodes.

This present work investigates several local and synoptic meteorological aspects associated with two wintertime haze episodes in Greater Bangkok using observational data, covering synoptic patterns evolution, day-to-day and diurnal variation, dynamic stability, temperature inversion, and back-trajectories. The episodes include an elevated haze event of 16 days (14–29 January 2015) for the first episode and 8 days (19–26 December 2017) for the second episode, together with some days before and after the haze event. Daily PM2.5 was found to be 50 µg m−3 or higher over most of the days during both haze events. These haze events commonly have cold surges as the background synoptic feature to initiate or trigger haze evolution. A cold surge reached the study area before the start of each haze event, causing temperature and relative humidity to drop abruptly initially but then gradually increased as the cold surge weakened or dissipated. Wind speed was relatively high when the cold surge was active. Global radiation was generally modulated by cloud cover, which turns relatively high during each haze event because cold surge induces less cloud. Daytime dynamic stability was generally unstable along the course of each haze event, except being stable at the ending of the second haze event due to a tropical depression. In each haze event, low-level temperature inversion existed, with multiple layers seen in the beginning, effectively suppressing atmospheric dilution. Large-scale subsidence inversion aloft was also persistently present. In both episodes, PM2.5 showed stronger diurnality during the time of elevated haze, as compared to the pre- and post-haze periods. During the first episode, an apparent contrast of PM2.5 diurnality was seen between the first and second parts of the haze event with relatively low afternoon PM2.5 over its first part, but relatively high afternoon PM2.5 over its second part, possibly due to the role of secondary aerosols. PM2.5/PM10 ratio was relatively lower in the first episode because of more impact of biomass burning, which was in general agreement with back-trajectories and active fire hotspots. The second haze event, with little biomass burning in the region, was likely to be caused mainly by local anthropogenic emissions. These findings suggest a need for haze-related policymaking with an integrated approach that accounts for all important emission sectors for both particulate and gaseous precursors of secondary aerosols. Given that cold surges induce an abrupt change in local meteorology, the time window to apply control measures for haze is limited, emphasizing the need for readiness in mitigation responses and early public warning.

Maintenance and Sudden Change of a Strong Elevated Ducting Event Associated with High Pressure and Marine Low-Level Jet

Capture of a strong elevated ducting event, especially its maintenance and sudden change, is of great value to airborne radar to achieve its beyond-the-line-of-sight detection. However, the knowledge is not easily accessible over the open ocean and hence very rare. During the Air-Sea Interaction Survey (ASIS) over the western North Pacific (WNP) in May 2016, a strong elevated ducting event with a long-life period and sudden change in its evolution was observed. Measurements from the ASIS, images from the Himawari-8 satellite, reanalysis data from the ECMWF, and Weather Research and Forecasting (WRF) model, were used to analyze the maintenance and sudden change of this strong ducting event, together with the model performance on simulating it. The results showed that the maintenance of strong elevated ducts, with their tops ranging from 750 to 1050 m and average strength of approximately 38 M units, was caused by a strong dry air mass capping over the wet marine atmospheric boundary layer (MABL), together with the subsidence inversion associated with high pressure. The WRF model performs well in simulating them. However, a sudden increase in duct height with a slight decrease of strength was recorded by the subsequent GPS radiosonde, which was finally contributed to the mechanical turbulent inversion and hydrolapse associated with the marine low-level jet (MLLJ). The height of the maximum horizontal wind speed (Umh) of the MLLJ corresponds well with the bottom of the trapping layer. However, these jet-relevant ducts are generally weak and it is difficult to accurately simulate them by using the mesoscale numerical model, since the wind-shear produced eddies are too small to be properly parameterized.

Impact of “blocking” structure in the troposphere on the wintertime persistent heavy air pollution in northern China

In the winters of 2012–2018, a total of 25 ‘ultra-long’ (≥6 days), wide-ranging pollution events occurred in northern China. The results showed that the atmospheric circulation pattern corresponding to 62.5% of the persistent ‘most serious’ and ‘more serious’ air pollution events in northern China were the blocking structures, and that 43.75% of the 500-hPa atmospheric circulation anomalies in the middle and high latitudes of Eurasia were ‘dual-blocking’, 18.75% of them were ‘single-blocking’. The abnormally stable blocking situation provided a special circulation background for the occurrence and maintenance of persistent heavy air pollution in northern China. The Okhotsk blocking is significantly positively correlated with the persistent ‘most serious’ air pollution events. ‘Stagnation’ of the blocking system and its dynamic effect play an important role in regulating atmospheric environmental capacity and accelerating the accumulation of aerosols during the persistent heavy pollution episodes. Due to the synergy between the weak wind effect of the leeward slope on the eastern side of the Loess Plateau in this region and the downward airflow of the large-scale blocking system, the effect of sustained suppression of atmospheric pollutant diffusion in northern China is more significant. The downward air flow along the eastern leeward slope of the Loess Plateau is very important for accumulation of air pollutants, which is controlled by the tropospheric blocking high. In addition, the ‘subsidence (temperature) inversion’ effect produced by the synergy between the downward airflow of the eastern leeward slope of the Loess Plateau and the large-scale blocking system creates a continuous and stable ‘warm-cover’ structure in the middle of the troposphere on the eastern of the Loess Plateau; this effect strengthens the radiation effect of aerosols in the atmospheric pollutants, as well as the ‘two-way feedback’ mechanism between adverse meteorological conditions in the boundary layer and atmospheric pollutants.

Comprehensive temporal analysis of temperature inversions across urban atmospheric boundary layer of Tehran within 2014–2018

The present study attempted to assess the surface-based inversion characteristics in Tehran city, capital of Iran, using upper air sounding data, in different temporal scales during 2014–2018. Some characteristics such as the height and temperature of the inversion layers in addition to the environmental lapse rate and inversion intensity index were investigated in this study. From a total set of 1343 diurnal inversions within 2014–2018, the highest frequency of inversions was registered in 2017 by 317 days, and the lowest frequency was recorded in 2014 by 227 days. Averagely, radiation inversions with a frequency of 1030 (73% from total inversions) were estimated more than subsidence inversions with a frequency of 313 (23%). The higher values of temperature gradient of the inversion layer (DTINV) coincided with the radiation inversions, depending on the most intensive inversions (0.1693) and the highest lapse rate (0.061). During the radiation inversion days, including intensive inversions in autumn and winter periods, the climatic variables of upward long-wave radiation, land surface temperature, surface sensible-heat flux, and vertical motion of air mass were in minimum levels across the atmospheric boundary layer, while the concentration of nitrogen dioxide was significantly in the highest value. All aforementioned climatic variables are reverted during the subsidence inversion days in the summer period with ticker but wicker inversion layers. Ultimately, the statistical analysis revealed the significant and positive correlation between nitrogen dioxide concentration and three characteristics of radiation inversion event, inversion intensity, and environmental lapse rate (R from 0.735 to 0.859) at 75–85% of the confidence level based on monthly data.

PM2.5 in Thailand

This mini review aims to indicate how radiation inversion had an impact on PM2.5 accumulation during the winter in Thailand. Smoke sky occurred in the North and South of the country was attribute to smoke from forest fire and burnings in farmlands during September–October (Rainy season) and March–April (Summer season). While the haze sky in the wintertime was rarely observed. Until January 2018 the haze of PM2.5 occupied the sky in Bangkok and major provinces for several days and returned in December 2018 - February 2019. The radiation inversion and subsidence inversion were observed during January– February 2019, the synergy of two inversions might cause haze sky of high PM2.5 level. Radiation inversion was able to produce a double increase to the moving 24-hour PM2.5. If new target value of 24-hour PM2.5 will be applied by 2024, the reduction of PM2.5 emission based on radiation inversion’s effect should be around 25%.

Investigation of the atmospheric boundary layer during an unexpected summertime persistent severe haze pollution period in Beijing

Persistent severe haze pollution seldom happens in summer in Beijing. In this study, a persistent severe haze pollution event, defined as daily PM2.5 concentration higher than 150 μg m−3 on 5 consecutive days, was observed in Beijing from 26 to 30 in July 2010. It was not caused by crop residue burning during the harvest period. Weak pressure systems dominated at surface and implicated weak advection. Regional weak southerly winds with speeds of 2–3 m s−1 consistently brought pollutants from southern large-emission regions to Beijing. Surface convergence resulted from northerly winds prevailing in northern regions induced pollutants remaining in Beijing, which contributed to the maximum daily PM2.5 concentration on 26 in July. A continental high-pressure system persisted in the northwest of Beijing at 500 hPa, which led to significant sinking motion. Elevated inversion was found in the form of subsidence inversion, and this was confirmed by a skew T-logp diagram and vertical velocity analysis. It is much different from the vertical boundary layer structure in wintertime pollution period that surface-based inversion dominates. The subsidence inversion was an extremely stable layer with an average depth of hundred meters and strength of 1.4 °C. The capping effect of the inversion layer at low altitude of average 720 m limited vertical diffusion of pollutants and trapped them in a shallow layer, and thus, extremely high concentration of PM2.5 remained. WRF-Chem model simulation demonstrated that about 70% of PM2.5 was transported to Beijing from its southern regions.

Two typical weather patterns of persistent heavy pollution in Beijing - Tianjin - Hebei

The persistent heavy pollution weather which occured in Beijing - Tianjin - Hebei from January 26 to 31, 2013 and February 20 to 26, 2014 were compared and analysed by using meteorological elements and air quality observation data and meteorological model field re-analysis data. The results show that both the two events belong to the stagnant accumulation type. The typical configuration of weather system is zonal circulation in 500 hPa, the cold air is not active. The south branch trough is very weak, the condition of water vapor transport is quite poor, which is not conducive to precipitation. The increase of temperature in 800-850 hPa is beneficial to the formation of stable stratification near the ground. Small wind speed near the ground is not conducive to the horizontal diffusion of pollutants. High relative humidity near the ground makes for the hygroscopic growth and secondary transformation of fine particulate. But the mechanism of establishing and maintaining the static and stable situation is different between the two heavy pollution processes. It shows a dry air subsidence area in the middle and low troposphere between 700 hPa and 900 hPa in January 2013. The superposition of subsidence inversion and night radiation inversion in clear sky resulted in extremely stable atmospheric stratification, and the inversion intensity is obviously stronger than that in February 2014. The sinking motion reduces the height of the mixing layer. An extremely low boundary layer height effectively inhibits the vertical diffusion of pollutants, leads to the pollution growing rapidly. The visibility shows obvious diurnal variation with high value in the daytime and extremely low at night in January 2013. While it is a weak rising area of wet air over the polluted area between 850 hPa and near the ground in February 2014. The inversion temperature is not so strong and the height of the mixing layer is a little higher than that in January 2013. The relative humidity of the middle and lower troposphere is high and the cloud cover is more, which results in the less solar radiation received by surface during the daytime, the lower temperature and the higher atmospheric stability. The maintaining of atmospheric static stability makes the pollution gradually accumulating. The visibility always keeps low value at all times in February 2014.

Research on probability integration parameter inversion of mining-induced surface subsidence based on quantum annealing

Probability integral method is an official prediction method for mining subsidence in China. However, how to obtain the probability integral method parameters based on the measured data is the premise of realizing the accurate prediction of the probability integral method. Simulated annealing (SA) is an effective nonlinear optimization algorithm that has recently been introduced into the mining subsidence field to obtain the parameters of the probability integration method. To solve the problems of slow convergence speed and easily falling into the local optimal solution in the method of parameters inversion in probability integral method based on SA (MPIPIMSA), the method of parameters inversion in probability integral method based on quantum annealing (MPIPIMQA) is proposed by combining the quantum fluctuation mechanism and simulated annealing theory. The simulation experimental results show that MPIPIMQA is superior to MPIPIMSA in the accuracy and stability of parameters, and MPIPIMQA has a stronger anti-interference ability for local losing observation points, random errors and gross errors in observation data. Finally, the parameters of probability integral method for the 1414(1) working face of the Guqiao Coal Mine in Huainan mining area were obtained by using MPIPIMQA, namely, q = 0.9916, tanβ = 1.9277, b = 0.4190, θ = 84.3381, Su = − 7.3715, Sd = − 14.7126, Sl = 59.0695, and Sr = 32.6381, and the fitting error is 106.8863 mm. The research results have important reference values for accurate inversion of probability integral parameters.

Ozone and volatile organic compounds in the metropolitan area of Lima-Callao, Peru

This study analyzes ozone formation in the metropolitan area of Lima-Callao as a function of meteorological patterns and the concentrations of nitrogen oxides and reactive organic gases. The study area is located on the west coast of South America (12°S) in an upwelling region that is markedly affected by the Southeast Pacific anticyclone. The vertical stability and diurnal evolution of the mixing layer were analyzed from radiosondes launched daily during 1992–2014 and from two intensive campaigns in 2009. Vertical profiles show that during June–November, the subsidence inversion base ranges from 0.6 to 0.9 km above sea level (asl). In contrast, during December–May, subsidence inversion dissipates, leading to weak surface inversions from 0.1 to 0.6 km asl. At the surface level, compliance with the ozone standard of 51 parts per billion by volume (ppbv) is explained by the marine boundary layer effect and by strong inhibition of ozone formation due to titration with nitric oxide. Day-of-the-week variations in ozone and nitrogen oxides suggest a VOC-limited ozone-formation regime in the atmosphere of Lima. Furthermore, the pattern of C6–C12 species indicates that gasoline-powered vehicles are the main source of volatile organic compounds (VOCs), whereas the species with the greatest ozone-forming potential corresponded to the sum of the isomers m- and p-xylene. Mean benzene concentrations exceeded the standard of 0.63 ppbv, reaching 1.2 ppbv east of Lima. Nevertheless, the cancer risk associated with the inhalation of benzene was deemed acceptable, according to USEPA and WHO criteria.

Polyphasic evolution of the Jeffara basin in southern Tunisia, influence of halokinesis on the passive margin structuration in the Mesozoic and the Cenozoic

During the Mesozoic and Cenozoic rifting, the Pelagian Sea recorded the consequences of the African and European plate’s rapprochement. The interpretation of surface and subsurface data that is the 2D seismic reflection and petroleum well data show new ideas on the geodynamic evolution and halokinesis of the Jeffara basin during the Mesozoic and Cenozoic period. Seismic lines interpretations of the subsurface mainly reveal normal syn-sedimentary NW-SE faulting and where the Jeffara fault seems to be the major play. This syn-sedimentary faulting induced horst and graben structures materialized by major sedimentary sequences thicknesses as well as depths variations on the seismic profiles from the Jeffara fault zone overall towards the East of Jeffara basin. After the Hercynian event of the Permian - Carboniferous age, a general extension took place, which gave rise to the Tethyan opening. This extension has favored the individualization of the Jeffara basin in the South East of Tunisia, characterized by a structuring in Horst and Graben with a Permian carbonate subsidence. During the Triassic - Middle Jurassic period, the Jeffara basin is marked by a pronounced subsidence of essentially evaporate sedimentation accompanied by the birth of normal syn-sedimentary NW-SE faults following an NE-SW extension. This subsidence continuing during the Upper Jurassic period, the accentuation of which is towards the NE of the study zone at the Jerba and El Bibane sub-basin with a dominance of bioclastic limestone and dolomites sedimentation in the same extensive NE-SW direction, during this period, the Jeffara basin was characterized by a beginning of salt activity indicated by the appearance of salt nuclei at the base of the preexisting NW-SE normal faults. During the Lower Cretaceous, we are witnessing an individualization of salt complexes in the SE of the study area at Rass Ajil sub-basin, where this reactive diapirism has produced high zones and erosions in the crest above the salt bodies. During the mid Cretaceous period, the Zebbag formation, hatched by the Gattar carbonate bar, recorded a subsidence inversion phenomenon between the three sub-basins Jerba, El Bibane and Rass Ajil sub-basin, and showed the change of movement of the African plate relative to the European plate related to the opening of the North Atlantic and the beginning of the drift towards the North of Africa. This phenomenon is concretized towards the Upper Cretaceous, where we witness a strong subsidence towards the southeastern part of the study area at Rass Ajil sub-basin with sandstone, marl and clay sedimentation under a regional extensive regime and the individualization of high zones at Jerba sub-basin. The salt movements present an active aspect by piercing their cover and inducing rim synclines in the surroundings. The Cenozoic period is characterized by a strong subsidence of sandstone, clays and carbonates along the Jeffara basin, the salt activity shows a passive aspect at the beginning of this period which slows down and eventually stopped at the late Miocene period, thus indicating the probable exhaustion of the source of the salt material.