Diurnal Distribution Research Articles

Characteristics and source apportionment of winter black carbon aerosols in two Chinese megacities of Xi'an and Hong Kong.

Black carbon (BC) aerosols were observed over Xi'an (XA) and Hong Kong (HK) to better compare its properties and sources in two geographically separate regions in China. High-BC (7.9 ± 3.3μg·m-3) and -PM2.5 (182 ± 80.5μg·m-3) concentrations were observed in XA, and these were much higher than those in HK (BC, 3.2 ± 0.9μg·m-3; PM2.5, 34.5 ± 9.3μg·m-3). The contribution of BC to PM2.5 in HK reached 10.7%, which was ~ 1.5 times than that in XA (7.6%). The results emphasized that BC played an important role in HK PM2.5. The diurnal distribution of HK BC was highly correlated with vehicle emissions during the daytime; it peaked during heavy traffic times. Whereas XA BC exhibited flat distribution owing to stable BC sources. It is not markedly driven by traffic patterns. Additionally, the potential source contribution function (PSCF) analysis showed that XA BC mainly originated from local emissions while nearly half of the HK BC originated from distant sources, such as industrial emissions from northeastern regions and ship emissions from marine regions. These anthropogenic BC sources were found to be regional in nature based on multilinear engine (ME-2) analysis. Specifically, the XA BC sources were dominated by three factors: 22.5% from coal burning, 19.6% from biomass burning, and 32.9% from vehicle emissions. In HK, the majority of BC contributions originated from vehicle and ship emissions (78.9%), while only 14.5% and 1.5% originated from coal and biomass burning from residential combustion, as well as industrial and power plants in inland China.

Behavior and distribution patterns of Katahdin rams in southern-pine silvopastures with cool-season forages

Selection of a suitable grazing livestock is a key for successful management of silvopasture systems. Previous studies have pointed out some damaging behavior of Kiko, a meat goat breed, wethers on pine trees in mixed-pine silvopastures, thereby indicating the need for identifying alternative animal species for this system. Our objective was to determine the diurnal behavior and distribution patterns of Katahdin, a hair sheep breed, rams in southern-pine silvopastures during the cool-season grazing period. The study was conducted during the spring of 2017 at the Atkins Agroforestry Research and Demonstration Site, Tuskegee University, Tuskegee, Alabama, USA. Three 0.4-ha longleaf (Pinus palustris Mill.)-loblolly (Pinus taeda L.) mixed-pine silvopasture plots were planted with three different combinations of coolseason forages in separate subplots. Forage samples were collected before bringing animals into the plots, and analyzed for productivity and quality. Six Katahdin rams (12–15 months old, 72.7 ± 4.80 kg live weight) were rotationally stocked in the study plots, and their diurnal (dawn-dusk) behavior and distribution patterns were observed. Grazing was the most dominating behavior (44%) of rams followed by lying (39%) and loafing (10%). Rams used tree shade while resting and stayed in shelters during the rain. There was no pine debarking by rams throughout the observation period. Rams in silvopastures spent more time grazing during morning (dawn-1100 h) and post-midday (1500 h-dusk) periods, and lying during the midday (1100–1500 h) period. They mostly stayed together irrespective of where they went, resulting in a small value of distribution evenness index. Katahdin rams were found safe to graze in mixed southern-pine silvopasture systems consisting of 12-year-old trees during the coolseason grazing period.

Eating behavior, milk production, rumination, and digestibility characteristics of high- and low-efficiency lactating cows fed a low-roughage diet

This study aimed to identify individual characteristics differing among high-efficiency (HEf; upper 20%, n = 31), low-efficiency (LEf; lower 20%, n = 31), and mid-efficiency (MEf, 60% n = 93) lactating cows. Primiparous (37) and multiparous (118) high-producing milking cows at 30 to 180 d in milk were fed individually a low-roughage diet [31.6% of dry matter (DM)] for 4 wk. Daily average DM intake, rate of eating, visit duration, meal size, and daily rumination time were higher in LEf compared with HEf cows. On the other hand, HEf cows exhibited higher digestibility of DM, crude protein, and neutral detergent fiber than the LEf cows. Daily eating time was similar in the HEf and LEf groups and higher than that of the MEf cows. Visit and meal frequency, average visit and meal duration, daily lying time, and pedometer activity were similar in the HEf, LEf, and MEf groups. The HEf cows produced 1.75% more milk, but similar energy-corrected milk compared with the LEf cows. Milk fat and protein content were lower by 1.8 and 3.8%, respectively, in the HEf cows than in the LEf group. Body weight (BW) and BW gain were similar in the 3 efficiency groups. Diurnal distribution of DM intake showed 6 distinct major meals, each composed of 1.1 to 1.6 visits. Higher intake peaks (greater meal size) were found in the LEf cows compared with the HEf group. Daily DM intake was highly correlated (affected) with energy-corrected milk production (r = 0.61), BW (r = 0.4), eating rate (r = 0.57), and visit size (r = 0.54). Energy balance showed that the lower efficiency of the LEf cows was attributed to their excess heat production and energy loss.

Characteristics of and Factors Affecting Atmospheric CO2 Concentration in Hangzhou

In situ measurement of CO2 concentration(volume fraction) was carried out in both urban and rural areas of Hangzhou from August 2015 to September 2016. The characteristics of CO2 concentration at the urban site were compared to those at the rural site, and the factors affecting CO2 concentration in Hangzhou were analyzed via wind direction, weekday-weekend difference in CO2 concentration, and evolution of CO2 concentration during the G20 summit. The results revealed that the diurnal variation of CO2 concentration in both the urban and rural areas presented a single peak curve most of the time, which resulted from the daily evolution of plant photosynthesis/respiration and atmospheric transport conditions. The diurnal variation of the difference in CO2 concentration observed at the urban and rural sites showed a bimodal peak curve, because anthropogenic emissions played a more important role. The diurnal amplitude of CO2 concentration in rural area was higher than that in urban area in spring and summer, but lower in autumn. The seasonal variation of CO2 concentration in both the urban and rural areas showed the same trend, with higher values appearing in winter and spring and lower values in summer. The difference in CO2 concentration observed at the urban and rural sites reached its highest level in winter, and dropped to its lowest in summer. The wind direction induction of high CO2 concentration was consistent with the location of the surrounding urban areas. A weekday-weekend difference in CO2 concentration was observed in Hangzhou, especially in urban area, as traffic emissions had an impact on the weekday-weekend difference in diurnal distribution of CO2 concentration. The average volume fraction of CO2 in urban area of Hangzhou was 9.3×10-6 higher than that in rural area, and the reduction of anthropogenic emissions during the G20 summit reduced the atmospheric CO2 concentration effectively, especially in urban area.

Does convection-permitting simulate better rainfall distribution and extreme over Guinean coast and surroundings?

This research work focuses on the problem of climate simulation of rainfall over West Africa and particularly over coastal countries of the Gulf of Guinea by Regional Climate Models. The sensitivities of Weather Research and Forecasting (WRF) Model were tested for changes in horizontal resolution (convection permitting versus parameterized) on the replication of West African monsoon for the year 2014. Sensitivity test was also performed for response of rainfall to changes in microphysics (MP) and planetary boundary layer (PBL) schemes. Generally, the result shows that WRF is able to replicates rainfall distribution with an adequate representation of the dynamical features of West African monsoon system. The high-resolution (wrf-4km) shows dry bias along the coast of the Gulf of Guinea but generally outperforms wrf-24km run especially in replication of the extreme rainfall distribution. The dry bias along the coastal area is suggested to not to be only related to convection but mostly to microphysics and PBL parameterisation schemes. Differences were noticed between the dynamics of WRF and ERA-interim outputs despite the use of spectral nudging in the experiment which then suggest strong interactions between scales. These differences were observed to be restricted mainly to the low-layer monsoon flow in JJA. Both runs at 24 and 4 km hardly simulate the typical diurnal distribution of rainfall. The sensitivity of WRF to MP (only sophisticated MP were tested) and PBL reveals a stronger impact of PBL than MP on rainfall distribution and the most significant added value over the Guinean coast and surroundings area was provided by the configurations using non-local PBL scheme (as ACM2). The changes in MP and PBL schemes in general seem to have less effect on the explicit runs (wrf-4km) in the replication of the rainfall over the Gulf of Guinea and the surroundings seaboard.

Diurnal behavior and distribution patterns of Kiko wethers in southern-pine silvopastures during the cool-season grazing period

Goats are commonly used to utilize the understory vegetation in pine silvopasture systems. Understanding goats’ behavior and their distribution patterns is necessary to manage this system well. The objective of this study was to evaluate the diurnal behavior and distribution patterns of goats in Southern-pine silvopastures during the cool-season grazing period. This study was conducted in 2015 and 2016 in Tuskegee, Alabama, USA. Eight different cool-season forages were planted in separate subplots within each plot in mixed-pine silvopasture systems with three replications (3 plots, 0.4-ha each) in the fall of 2014 and 2015. Trees in the silvopasture consisted of longleaf (Pinus palustris Mill.) and loblolly pine (Pinus taeda L.). Twenty-eight Kiko wethers were rotationally stocked in the silvopasture plots in April 2015, and January to April 2016. When study began, trees were 10 years old (DBH: 12 ± 0.2 cm; height: 7 ± 0.1 m), and animals were 5–7 months old. The diurnal behavior (grazing, browsing, loafing, lying, and debarking) and distribution patterns of goats were monitored from dawn to dusk for two consecutive days (2015) or one day (2016) in each plot at each grazing rotation. Grazing was the most dominant diurnal behavior (36–54%) of Kiko wethers followed by lying (29–34%) and loafing (15–22%). The distribution evenness index was more even in 2016 vs. 2015, spring vs. winter, and mid-day vs. morning. Goats also showed some debarking behavior (< 2%), mostly on longleaf pine. The study showed that goats’ behavior and distribution patterns were influenced by year (age), season, and part of the day.

Diurnal spatial distributions of aerosol optical and cloud micro-macrophysics properties in Africa based on MODIS observations

The diurnal spatial distribution of both natural and anthropogenic aerosols, as well as liquid and ice cloud micro-macrophysics have been evaluated over Africa using Terra and Aqua MODIS collection 6 products. The variability of aerosol optical depth (AOD), Ångström exponent (AE), liquid and ice cloud microphysics (Liquid cloud effective radius LCER, Ice cloud effective radius ICER) and cloud macrophysics (Liquid cloud optical thickness LCOT, Liquid cloud water path LCWP, Ice cloud optical thickness ICOT, Ice cloud water path ICWP) parameters were investigated from the morning to afternoon over Africa from 2010 to 2014. In both the morning (Terra) and afternoon (Aqua) heavy pollution (AOD ≥ 0.6) occurs in the coastal and central areas (between 120 N-170 N and 100 E-150 E) of West of Africa (WA), Central of Africa (CA) (0.50 S-70S and 100 E-250 E),. Moderate pollution (0.3 < AOD < 0.6) often occurs in West and North of Africa (between 50 N-270 N and 160 W-50E), and clean environmental (AOD < 0.3) conditions are common in South of Africa (SA), East of Africa (EA) and some regions in North of Africa (NA). The West-North of Africa (WNA) and Central-South of Africa (CSA) regions are dominated by dust (AE < 0.7) and biomass burning (AE > 1.2) aerosols. The mixture of dust and biomass burning aerosols (0.7 < AE < 1.2) are found at the coastal areas in West of Africa (CoWA) and Central of Africa (CA) (50 N-80N and 100 E-340 E), particularly in the morning and afternoon respectively. The LCER often decrease from the morning to the afternoon in all seasons, but an increase occur from the morning to the afternoon in CSA (50 S-220 S) in DJF, both CA (20 S-50N) and CoWA in JJA and SON. The ICER increase from the morning to afternoon in all seasons over Africa and decreases in South of Africa (50 S-200 S) in DJF. The LCOT increases from the morning to afternoon in NA and SA while a decrease occur in CA in all seasons. The LCWP increase in many regions of Africa in all seasons while a decrease occurs in CoWA during JJA. The ICOT and ICWP show a remarkable increase from the morning to afternoon in regions dominated by biomass burning (CSA) compared to regions dominated by dust (WNA) aerosols in DJF, MAM and SON. Dust aerosols are mainly distributed in WNA by northerly and westerly winds in both January and April, southerly and southwesterly winds in July, and southerly and southwesterly winds in October, while biomass burning aerosols are mainly distributed in CSA by the northerly and northeasterly winds in January, easterly winds in April, July and October. The diurnal variability of cloud parameters is associated with both convective processes and cloud types. The knowledge of interactions between natural and anthropogenic aerosols with liquid and ice cloud microphysics parameters could contribute to improve aerosol and cloud remote sensing retrieval.

Spread F in the Midlatitude Ionosphere According to DPS-4 Ionosonde Data

The results of studying spread F obtained from the DPS-4 ionosonde data at the observatory of the Pushkov Institute of Terrestrial Magnetism, Ionosphere, and Radio Wave Propagation (Moscow) are presented. The methodical questions that arise during the study of a spread F phenomenon in the ionosphere are considered; the current results of terrestrial observations are compared with previously published data and the results of sounding onboard an Earth-satellite vehicle. The automated algorithm for estimation of the intensity of frequency spread F, which was developed by the authors and was successfully verified via comparison of the data of the digisonde DPS-4 and the results of manual processing, is described. The algorithm makes it possible to quantify the intensity of spread F in megahertz (the dFs parameter) and in the number of points (0, 1, 2, 3). The strongest spread (3 points) is shown to be most likely around midnight, while the weakest spread (0 points) is highly likely to occur during the daytime. The diurnal distribution of a 1–2 point spread F in the winter indicates the presence of additional maxima at 0300–0600 UT and 1400–1700 UT, which may appear due to the terminator. Despite the large volume of processed data, we can not definitively state that the appearance of spread F depends on the magnetic activity indices Kp, Dst, and AL, although the values of the dFs frequency spread interval strongly increased both at day and night during the magnetic storm of March 17–22, 2015, especially in the phase of storm recovery on March 20–22.

Effect of geomagnetic storms on the daytime low-latitude thermospheric wave dynamics

The equatorial- and low-latitude thermospheric dynamics is affected by both equatorial electrodynamics and neutral wave dynamics, the relative variation of which is dependent on the prevalent background conditions, which in turn has a seasonal dependence. Depending on the ambient thermospheric conditions, varying effects of the geomagnetic disturbances on the equatorial- and low-latitude thermosphere are observed. To investigate the effect of these disturbances on the equatorial- and low-latitude neutral wave dynamics, daytime airglow emission intensities at OI 557.7 nm, OI 630.0 nm, and OI 777.4 nm are used. These emissions from over a large field-of-view (FOV∼1000) have been obtained using a high resolution slit spectrograph, MISE (Multiwavelength Imaging Spectrograph using Echelle grating), from a low-latitude location, Hyderabad (17.50N, 78.40E; 8.90N MLAT), in India. Variations of the dayglow emission intensities are investigated during three geomagnetic disturbance events that occurred in different seasons. It is seen that the neutral dayglow emission intensities at all the three wavelengths showed different type of variations with the disturbance storm time (Dst) index in different seasons. Even though the dayglow emission intensities over low-latitude regions are sensitive to the variation in the equatorial electric fields, during periods of geomagnetic disturbances, especially in solstices, these are dependent on thermospheric O/N2 values. This shows the dominance of neutral dynamics over electrodynamics in the low-latitude upper atmosphere during geomagnetic disturbances. Further, spectral analyses have been carried out to obtain the zonal scale sizes in the gravity wave regime and their diurnal distributions are compared for geomagnetic quiet and disturbed days. Broadly, the zonal scales seem to be breaking into various scale sizes on days of geomagnetic disturbances when compared to those on quiet days. This contrast in the diurnal distribution of the zonal scale sizes brings to light, for the first time, the varying nature of the neutral wave coupling in the daytime thermosphere during periods of geomagnetic disturbances.

Application of Finite Difference Method for determining lunar regolith diurnal temperature distribution

This study was performed in order to verify viability of using finite difference method and proposed simple astrometrical model for modelling heat transfer in lunar regolith. The concept was examined by developing FD model of heat flow for upper 0,9 m of lunar regolith, and comparing obtained results with in situ measurements provided by Apollo 15 and 17 heat flow experiments. The model was based on FDM approximation of Fourier’s law for one dimensional transient heat flow. Both constant and temperature-dependent thermophysical properties of lunar regolith were obtained from in situ measurements. Thermal boundary conditions were assumed on in situ measurements and on remote sensing based analytical model. In order to approximate Sun's position at lunar sky, simple analytical astrometric model of lunar rotation was developed. Matlab 2012a was used to conduct the calculations. Stable solutions were obtained for latitudes between 0 and 80°. Satisfactory agreement between Apollo 15 and 17 in situ measurements and FDM modelling was observed. A conclusion was reached, that both FDM and proposed astrometrical model are to be successfully applied for modelling heat transfer in lunar regolith.

Diurnal Course of Evaporation From the Dead Sea in Summer: A Distinct Double Peak Induced by Solar Radiation and Night Sea Breeze

AbstractPartitioning between the relative effects of the radiative and aerodynamic components of the atmospheric forcing on evaporation is challenging since diurnal distributions of wind speed and solar radiation typically overlap. The Dead Sea is located about a 100 km off the Eastern Mediterranean coast, where and the Mediterranean Sea breeze front reaches it after sunset. Therefore, in the Dead Sea the peaks of solar radiation and wind speed diurnal cycles in the Dead Sea are distinctly separated in time, offering a unique opportunity to distinguish between their relative impacts on evaporation. We present mid‐summer eddy covariance and meteorological measurements of evaporation rate and surface energy fluxes over the Dead Sea. The evaporation rate is characterized by a clear diurnal cycle with a daytime peak, few hours after solar radiation peak, and a nighttime peak coincident with wind speed peak. Evaporation rate is minimum during sunrise and sunset. Measurements of evaporation rate from two other water bodies that are closer to the Mediterranean coast, Eshkol Reservoir, and Lake Kinneret, present a single afternoon peak, synchronous with the sea breeze. The inland diurnal evaporation rate cycle varies with the distance from the Mediterranean coast, following the propagation of sea breeze front: near the coast, wind speed, and radiation peaks are close and consequently a single daily evaporation peak appears in the afternoon; at the Dead Sea, about a 100 km inland, the sea breeze front arrives at sunset, resulting in a diurnal evaporation cycle characterized by a distinct double peak.

Investigating vertical distribution patterns of lower tropospheric PM2.5 using unmanned aerial vehicle measurements

A lightweight unmanned aerial vehicle (UAV) was outfitted with miniaturized sensors to investigate the vertical distribution patterns and sources of fine aerosol particles (PM2.5) within the 1 000 m lower troposphere. A total of 16 UAV flights were conducted in the Yangtze River Delta (YRD) region, China, from the summer to winter in 2014. The associated ground-level measurements from two environmental monitoring stations were also used for background analysis. The results show that ground-level PM2.5 concentrations demonstrated a decreasing trend from Feb. to Jul. and an increasing trend from Aug. to Jan. (the following year). Higher PM2.5 concentrations during the day were mainly observed in the morning (Local Time, LT 05-09) in the spring and summer. However, higher PM2.5 concentrations occurred mainly in the late afternoon and evening (LT 16-20) in the autumn and winter, excluding severe haze pollution days when higher PM2.5 concentrations were also observed during the morning periods. Lower tropospheric PM2.5 concentrations exhibited similar diurnal vertical distribution patterns from the summer to winter. The PM2.5 concentrations decreased with height in the morning, with significantly large vertical gradients from the summer to winter. By contrast, the aerosol particles were well mixed with PM2.5 concentrations of lower than 35 μg⋅m−3 in the early afternoon (LT 12-16) due to sufficient expansions of the planetary boundary layer. The mean vertical PM2.5 concentrations within the 1 000 m lower troposphere in the morning were much larger in the winter (∼87.5 μg⋅m−3) than in the summer and autumn (∼20 μg⋅m−3). However, subtle differences of ∼11 μg⋅m−3 in the mean vertical PM2.5 concentrations were observed in the early afternoon from the summer to winter. The vertical distribution patterns of black carbon and its relationships with PM2.5 indicated that the lower tropospheric aerosol particles might be mainly derived from fossil-fuel combustion sources. In addition, a 48-h backward trajectory analysis of air parcels showed that the lower tropospheric aerosol particles were mainly from emissions of local sources in the YRD region in the summer and autumn. By sharp contrast, the aerosol particles of this region in the winter were mainly of long-range transport sources from the north and northwest China due to the impact of Asian winter monsoon.

Temporal distribution and other characteristics of new particle formation events in an urban environment.

Studying the characteristics of new particle formation (NPF) is important as it is generally recognized as a major contributor to particle pollution in urban environments. We investigated NPF events that occurred during a 1-year period in the urban environment of Brisbane, Australia, using a neutral cluster and air ion spectrometer (NAIS) which is able to monitor both neutral and charged particles and clusters down to a size of 0.8nm. NPF events occurred on 41% of days, with the occurrence rate of 7% greater in the summer than in the winter. We derived the first diurnal event distribution of NPF events anywhere in the world and showed that the most probable starting time of an NPF event was near 08:30 a.m., being about an hour earlier in the winter than in the summer. During NPF days, 10% of particles were charged. The mean neutral and charged particle concentrations on NPF days were, respectively, 49% and 14% higher than those on non-event days. The mean formation rate of 2-3nm particles during an NPF event was 20.8cm-3s-1. The formation rate of negatively charged particles was about 10% higher than that of positively charged particles. The mean particle growth rate in the size range up to 20nm was 6.2nmh-1. These results are compared and contrasted with corresponding values that have been derived with the scanning mobility particle sizer (SMPS) at the same location and with values that have been reported with the NAIS at other locations around the world. This is the first comprehensive study of the characteristics of NPF events over a significantly long period in Australia.

A TRMM/GPM retrieval of the total mean generator current for the global electric circuit

AbstractA specialized satellite version of the passive microwave electric field retrieval algorithm (Peterson et al., 2015) is applied to observations from the Tropical Rainfall Measuring Mission (TRMM) and Global Precipitation Measurement (GPM) satellites to estimate the generator current for the Global Electric Circuit (GEC) and compute its temporal variability. By integrating retrieved Wilson currents from electrified clouds across the globe, we estimate a total mean current of between 1.4 kA (assuming the 7% fraction of electrified clouds producing downward currents measured by the ER‐2 is representative) to 1.6 kA (assuming all electrified clouds contribute to the GEC). These current estimates come from all types of convective weather without preference, including Electrified Shower Clouds (ESCs). The diurnal distribution of the retrieved generator current is in excellent agreement with the Carnegie curve (RMS difference: 1.7%). The temporal variability of the total mean generator current ranges from 110% on semi‐annual timescales (29% on an annual timescale) to 7.5% on decadal timescales with notable responses to the Madden‐Julian Oscillation and El Nino Southern Oscillation. The geographical distribution of current includes significant contributions from oceanic regions in addition to the land‐based tropical chimneys. The relative importance of the Americas and Asia chimneys compared to Africa is consistent with the best modern ground‐based observations and further highlights the importance of ESCs for the GEC.

Impact of urbanization on summer rainfall in Beijing–Tianjin–Hebei metropolis under different climate backgrounds

The Beijing–Tianjin–Hebei region experienced the most rainfall in 1994 and the least rainfall in 1997 during the last 20 years. Utilizing the Weather Research and Forecasting (WRF) model coupled with a single-layer urban canopy model (UCM), we investigate the possible effects of urbanization on summer precipitation under different climate backgrounds using the two extreme years. By comparing the results of control and sensitivity runs, we find totally different effects in the 2 years. In 1994, the rainfall and rainfall frequency decrease in most areas due to urbanization, and decreases in the rainfall intensity occur in urban areas of Beijing, Tangshan, and Shijiazhuang. In 1997, the rainfall, rainfall frequency, and intensity are reduced in southwest of Beijing–Tianjin–Hebei, while the change is opposite in northeast. Urbanization alters the diurnal distribution of rainfall, the energy budget, and the water vapor content in the atmosphere. Due to the decrease in city evaporation and transpiration, the surface latent heat flux is reduced. The water vapor mixing ratio in urban area decreases apparently from surface to 850 hPa, while it increases from 850 to 600 hPa. Overall, the reduction of water vapor mixing ratio in 1994 is more than that in 1997, which implies that the “dry island effect” caused by urbanization is stronger in the wet year than that in the dry year. Results also show that the inhibition (enhancement) of deep convection may explain the modification of precipitation.

Co-ingested alcohol and the timing of deliberate self-poisonings.

Investigating diurnal variation in the timing of suicidal behaviours offers opportunity to better understand its various proximal risk factors. Acute use of alcohol is a potent proximal risk factor for suicidal behaviour, though the nature of this risk is poorly understood. The aim of this study was to compare the diurnal variation in time of poison ingestion between deliberate self-poisonings that involve alcohol versus those that do not. A retrospective analysis of consecutive presentations to a toxicology service following deliberate self-poisoning, 1996-2016. An independent samples Kolmogorov-Smirnov test was performed to test the null hypothesis that the diurnal distribution of poison ingestion time was equal across self-poisonings that did and did not involve alcohol co-ingestion. Presence of circadian rhythmicity was established using cosinor analysis. A total of 11,088 deliberate self-poisoning records, for 7467 patients (60.8% females), were included in the analysis. In all, 31.3% of the total records involved alcohol co-ingestion. Distribution of exposure time was significantly different between deliberate self-poisonings that did and did not involve alcohol ( p < 0.001). The alcohol co-ingestion group showed a significantly greater prominent peak with poisoning occurring later in the evening (~20:00 hours) compared to poisonings that did not involve alcohol (~18:00 hours). This study exposed the differential diurnal patterns in deliberate self-poisoning according to the presence of alcohol co-ingestion. This analysis adds to the accumulating evidence that suicidal behaviour that involves alcohol co-ingestion represents a distinct subtype, which may be driven by alcohol consumption patterns in society. This also means that this large proportion of deliberate self-poisonings may not otherwise have occurred if it were not for alcohol consumption, underscoring the importance of drug and alcohol services for alcohol-related self-harm.

Major role of water bodies on diurnal precipitation regimes in Eastern Africa

ABSTRACTMean diurnal rainfall regimes over Eastern Africa (also referred to as the Greater Horn of Africa) are studied based on 3‐hourly data from the TRMM 3B42 data set, averaged over a 17‐year period (1998–2014). The consistency with long‐term mean raingauge data, available for partly independent periods, varies from good (Sudan, Ethiopia, Eritrea and Somalia) to very good (Kenya, Tanzania and Uganda). Over sea (Indian Ocean and Red Sea), the diurnal rainfall distribution is quite uniform; however, a morning peak dominates and there is evidence of offshore phase propagation south of the equator. Over land, both rainfall frequency and rainfall amounts show a dominant afternoon maximum (1500–1800 East African Time, i.e. GMT + 3). However, many inland regions show a delayed rainfall maximum (evening, night‐time or morning). The evening to night‐time maximum found over some land areas is associated with a phase propagation from areas showing an afternoon peak. This occurs west of high ground areas (Sudan and parts of the Great Lakes region) and in belts parallel to the seashores (Eritrea, northeastern Ethiopia, Somalia and eastern Kenya). The latter provide indirect evidence that sea breeze effects can be detected at unexpectedly great distances from the coast (up to 300–400 km) in parts of Eastern Africa. A remarkable ring of early afternoon (1500) maxima is found around most lakes, although some east–west asymmetries occur. Over the lakes, a morning or late night maximum is mostly found. It is generally inversely related to the distance to the shorelines for the larger lakes, but over the mid‐size lakes it is replaced by or competes with a late afternoon to evening maximum.

Variability of virtual layered phenomena in the mesosphere observed with medium frequency radars at 69°N

The MF-Saura radar positioned at polar latitudes is very sensitive to enhanced ionization caused by solar and geomagnetic activity. Differing from the intensities normally detected by partial reflections from the ionospheric D region during quiet conditions, distinct layers can be seen due to intense increase of electron number density at as low as 50 km altitude caused by particle precipitation. Effects of energetic particle precipitation on observations by medium frequency (MF) radars have been rarely reported so far, generally associated with solar proton events, which are rather scarce especially during solar minimum conditions. Here, we focus on events associated with precipitation of particles with lower energy (<10 MeV), which are seen by the MF radar with occurrence rates of as much as 40% at times. Such situations are studied for a period of continuous observations for one solar cycle and statistical results like diurnal and annual distributions are presented.

Dynamic, Interactive and Visual Analysis of Population Distribution and Mobility Dynamics in an Urban Environment Using the Mobility Explorer Framework

This paper investigates the extent to which a mobile data source can be utilised to generate new information intelligence for decision-making in smart city planning processes. In this regard, the Mobility Explorer framework is introduced and applied to the City of Vienna (Austria) by using anonymised mobile phone data from a mobile phone service provider. This framework identifies five necessary elements that are needed to develop complex planning applications. As part of the investigation and experiments a new dynamic software tool, called Mobility Explorer, has been designed and developed based on the requirements of the planning department of the City of Vienna. As a result, the Mobility Explorer enables city stakeholders to interactively visualise the dynamic diurnal population distribution, mobility patterns and various other complex outputs for planning needs. Based on the experiences during the development phase, this paper discusses mobile data issues, presents the visual interface, performs various user-defined analyses, demonstrates the application’s usefulness and critically reflects on the evaluation results of the citizens’ motion exploration that reveal the great potential of mobile phone data in smart city planning but also depict its limitations. These experiences and lessons learned from the Mobility Explorer application development provide useful insights for other cities and planners who want to make informed decisions using mobile phone data in their city planning processes through dynamic visualisation of Call Data Record (CDR) data.

The effect of diurnal distribution of carbohydrates and fat on glycaemic control in humans: a randomized controlled trial

Diurnal carbohydrate and fat distribution modulates glycaemic control in rodents. In humans, the optimal timing of both macronutrients and its effects on glycaemic control after prolonged consumption are not studied in detail. In this cross-over trial, 29 non-obese men were randomized to two four-week diets: (1) carbohydrate-rich meals until 13.30 and fat-rich meals between 16.30 and 22.00 (HC/HF) versus (2) inverse sequence of meals (HF/HC). After each trial period two meal tolerance tests were performed, at 09.00 and 15.40, respectively, according to the previous intervention. On the HF/HC diet, whole-day glucose level was increased by 7.9% (p = 0.026) in subjects with impaired fasting glucose and/or impaired glucose tolerance (IFG/IGT, n = 11), and GLP-1 by 10.2% (p = 0.041) in normal glucose-tolerant subjects (NGT, n = 18). Diet effects on fasting GLP-1 (p = 0.009) and PYY (p = 0.034) levels were observed in IFG/IGT, but not in NGT. Afternoon decline of glucose tolerance was more pronounced in IFG/IGT and associated with a stronger decrease of postprandial GLP-1 and PYY levels, but not with changes of cortisol rhythm. In conclusion, the HF/HC diet shows an unfavourable effect on glycaemic control in IFG/IGT, but not in NGT subjects. Consequently, large, carbohydrate-rich dinners should be avoided, primarily by subjects with impaired glucose metabolism.