scholarly journals SAFIR-3000 Lightning Statistics over the Beijing Metropolitan Region during 2005–07

2016 ◽  
Vol 55 (12) ◽  
pp. 2613-2633 ◽  
Author(s):  
Fan Wu ◽  
Xiaopeng Cui ◽  
Da-Lin Zhang ◽  
Dongxia Liu ◽  
Dong Zheng
Keyword(s):  
Spatial Pattern ◽  
Early Morning ◽  
Spatial Variations ◽  
Lightning Activity ◽  
Metropolitan Region ◽  
Topographic Effects ◽  
Spatiotemporal Variations ◽  
Opposite Pattern ◽  
Late Night ◽  
Cg Lightning

AbstractIn this study, the spatiotemporal characteristics of cloud-to-ground (CG) and intracloud (IC) lightning flashes observed by Surveillance et Alerte Foudre par Interférometrie Radioélectrique (SAFIR)-3000 over the Beijing metropolitan region (BMR) during 2005–07 were investigated. The results showed the presence of 299 lightning days with 241 688 flashes, most of which were IC lightning flashes. Only 19% of the total flashes were CG lightning flashes; 14% of these CG flashes were positive. Most lightning activity occurred during the summer months (June–August), with a major diurnal peak around 1900 Beijing standard time (BST) and a secondary peak around 2300 BST. Spatial variations in flash density and lightning days both exhibited an obvious southeastwardly increasing pattern, with higher flash densities or more lightning days occurring in the southeastern plains and lower values distributed on the northwestern mountains. The Z ratio (IC/CG lightning flashes) exhibited a similar spatial pattern, but the percentage of positive CG lightning flashes showed an almost opposite pattern. The results also showed significant topographic effects on the spatiotemporal variations in lightning activity. That is, flash counts on the northeastern and southwestern mountains peaked in the afternoon, whereas those on the southeastern plains peaked in the late night to early morning, which could be attributed to the propagation of thunderstorms from the mountains to the plains. The results showed that the SAFIR-3000 lightning data are more useful than CG lightning data alone for forecasting the development and propagation of thunderstorms over the BMR.

scholarly journals Distinct aerosol effects on cloud-to-ground lightning in the plateau and basin regions of Sichuan, Southwest China

2020 ◽  
Vol 20 (21) ◽  
pp. 13379-13397
Author(s):  
Pengguo Zhao ◽  
Zhanqing Li ◽  
Hui Xiao ◽  
Fang Wu ◽  
Youtong Zheng ◽  
...  
Keyword(s):  
Cloud Droplet ◽  
Lightning Activity ◽  
Freezing Process ◽  
Plateau Region ◽  
Freezing Level ◽  
Aerosol Loading ◽  
Cloud To Ground Lightning ◽  
Basin Region ◽  
Total Column ◽  
Cg Lightning

Abstract. The joint effects of aerosol, thermodynamic, and cloud-related factors on cloud-to-ground lightning in Sichuan were investigated by a comprehensive analysis of ground-based measurements made from 2005 to 2017 in combination with reanalysis data. Data include aerosol optical depth, cloud-to-ground (CG) lightning density, convective available potential energy (CAPE), mid-level relative humidity, lower- to mid-tropospheric vertical wind shear, cloud-base height, total column liquid water (TCLW), and total column ice water (TCIW). Results show that CG lightning density and aerosols are positively correlated in the plateau region and negatively correlated in the basin region. Sulfate aerosols are found to be more strongly associated with lightning than total aerosols, so this study focuses on the role of sulfate aerosols in lightning activity. In the plateau region, the lower aerosol concentration stimulates lightning activity through microphysical effects. Increasing the aerosol loading decreases the cloud droplet size, reducing the cloud droplet collision–coalescence efficiency and inhibiting the warm-rain process. More small cloud droplets are transported above the freezing level to participate in the freezing process, forming more ice particles and releasing more latent heat during the freezing process. Thus, an increase in the aerosol loading increases CAPE, TCLW, and TCIW, stimulating CG lightning in the plateau region. In the basin region, by contrast, the higher concentration of aerosols inhibits lightning activity through the radiative effect. An increase in the aerosol loading reduces the amount of solar radiation reaching the ground, thereby lowering the CAPE. The intensity of convection decreases, resulting in less supercooled water being transported to the freezing level and fewer ice particles forming, thereby increasing the total liquid water content. Thus, an increase in the aerosol loading suppresses the intensity of convective activity and CG lightning in the basin region.

scholarly journals Nlrp3 Inflammasome Activation in Bone Marrow-Residing Innate Immunity Cells Governs Circadian Changes in the Number of Circulating Hematopoietic Stem/Progenitor Cells in Peripheral Blood

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 1033-1033
Author(s):  
Mateusz Adamiak ◽  
Andrzej Ciechanowicz ◽  
Monika Cymer ◽  
Marta Skoda ◽  
Mariusz Z Ratajczak
Keyword(s):  
Nlrp3 Inflammasome ◽  
Early Morning ◽  
Sterile Inflammation ◽  
Circadian Oscillation ◽  
Inflammasome Activation ◽  
Hematopoietic Stem ◽  
Circadian Changes ◽  
Late Night ◽  
Circulating Cells ◽  
Nlrp3 Inflammasome Activation

Background. The number of hematopoietic stem/progenitor cells (HSPCs) in peripheral blood (PB) undergoes a circadian oscillation, with the peak occurring in the early morning hours and the nadir at night, and, as nicely demonstrated, this peak has been attributed to the enhanced tonus of the vegetative nervous system in the early morning hours (Nature 2008, 452, 442-447). Moreover, our group has demonstrated that release of HSPCs from bone marrow (BM) into PB is regulated during stress- or pharmacology-induced mobilization by activation of three ancient serum proteolytic cascades, the complement cascade (ComC), the coagulation cascade (CoaC), and the fibrynolytic cascade (FibC) (Stem Cell Rev. 2018; 14:677-685). Since it is known that the ComC, CoaC, and FibC show circadian activation at late night/early morning hours due to deep sleep hypoxia, regulation of the circadian oscillation of HSPC numbers in PB becomes more complex. Moreover, as we recently demonstrated, an important role in egress of HSPCs from BM into PB is played by purinergic signaling involving adenosine triphosphate (ATP) released from cells, which, as signaling mediators in the extracellular space, activate the Nlrp3 inflammasome in hematopoietic cells (Leukemia 2019; 33:815-825). Activation of the Nlrp3 inflammasome induces a state of sterile inflammation in the BM microenvironment and activates the ComC, CoaC, and FibC. Hypothesis. Since Nlrp3 inflammasome activation regulates egress of HSPCs from BM into PB by inducing BM sterile inflammation and activation of the ComC, CoaC, and FibC undergoes circadian activation, we became interested in whether Nlrp3 protein complex orchestrates circadian changes in the number of HSPCs circulating in PB.Materials and Methods. To address this important question, we studied the circadian oscillation in the number of circulating HSPCs in mice. Mice were accustomed to alternating periods of 12 hours light and 12 hours darkness. Light was turned on at 6 AM (ZT0), and the numbers of circulating white blood cells (WBCs), Sca-1+kit+Lin- HSCs, Sca-1+Lin-CD45+ HSCs, clonogenic CFU-GM progenitors, and non-hematopoietic Sca-1+Lin-CD45- cells (VSELs) were measured at 7 AM (ZT1), 11 AM (ZT5), 7 PM (ZT13), and 3 AM (ZT21). At the same time points, we evaluated expression of the Nlrp3 inflammasome at the mRNA level; Nlrp3 activation by measuring Nlrp3 inflammasome activation markers, such as interleukin-1beta, interleukin-18, and Hmgb1, at the mRNA and protein levels; ComC activation (by C5a ELISA); CoaC activation (by thrombin/antithrombin ELISA); and FibC activation (by plasmin/antiplasmin complex ELISA). To confirm the role of the Nlrp3 inflammasome in the circadian oscillation of HSPCs released into PB, we inhibited its activity by employing the specific small-molecule inhibitor MCC950. Results. We observed circadian changes in the expression and activation of the Nlrp3 inflammasome, with a peak in the early morning hours at ZT1 that preceded the peak in the number of circulating HSPCs at ZT5. This increase in activation of the Nlrp3 inflammasome and the number of circulating cells in WT animals was preceded by an increase in C5a concentration in PB at ZT1 as well as activation of the CoaC and FibC at ZT21. As expected, inhibition of the Nlrp3 inflammasome by MCC950 inhibited circadian oscillation of circulating HSPCs in PB. Conclusions. Our study confirms circadian activation of the Nlrp3 inflammsome due to the ComC, CoaC, and FibC in mice at late-night/early-morning hours preceding the release of HSPCs from BM into PB. The fact that we observed significant decrease in circadian changes in the number of circulating cells in PB in mice exposed to an Nlrp3 inflammasome inhibitor confirms its pivotal role in executing circadian release of HSPCs from BM into PB. Moreover, the fact that mice exposed to an Nlrp3 inhibitor show defective activation of the ComC and normal activation of the the CoaC and FibC indicates that, of the ancient proteolytic cascades tested, the ComC is the major player regulating Nlrp3 inflammasome-dependent circadian egress of HSPCs. Disclosures No relevant conflicts of interest to declare.

scholarly journals Characteristics of Diurnal Rainfall over Peatland Area of South Sumatra, Indonesia

2020 ◽  
Vol 5 (4) ◽  
pp. 136
Author(s):  
Puad Maulana Mandailing ◽  
Wijaya Mardiansyah ◽  
Muhammad Irfan ◽  
Arsali Arsali ◽  
Iskhaq Iskandar
Keyword(s):  
Seasonal Variation ◽  
Early Morning ◽  
Temporal Variations ◽  
In Situ Observation ◽  
Peak Time ◽  
The South ◽  
Night Time ◽  
Late Night ◽  
Diurnal Rainfall

The peak time of rainfall occurrence over an area has certain characteristics in which the difference in time and intensity of rainfall varies depending on its location and distance from the sea. This variation can be determined based on the phase and amplitude obtained using harmonic analysis. In this study, combined data from in-situ observation, satellite remote sensing and reanalysis were used to analyze spatial and temporal variations of peak rainfall events over peatland area of the South Sumatra Province. The results show that most of the South Sumatra Province has a diurnal peak of rainfall during afternoon ranging from 16.00 to 19.00 Western Indonesian Time. In addition, the results also indicate that the analysis on the in situ data revealed seasonal variation both in amplitude and time of maximum diurnal rainfall, while the reanalysis data only indicated a weak seasonal variation on the amplitude of the diurnal rainfall. Furthermore, spatial analysis shows that the time of maximum diurnal rainfall has spatial variation. Over the ocean, the time of maximum diurnal rainfall occurs during night time/early morning. Over the lowland or coastal area, the time of maximum diurnal rainfall occurs during afternoon, while over the high altitude (mountain) it occurs during late night.

scholarly journals Image Processing of Radar Mosaics for the Climatology of Convection Initiation in South China

2020 ◽  
Vol 59 (1) ◽  
pp. 65-81 ◽  
Author(s):  
Lanqiang Bai ◽  
Guixing Chen ◽  
Ling Huang
Keyword(s):  
South China ◽  
Numerical Models ◽  
Early Morning ◽  
Moist Convection ◽  
Late Night ◽  
Morning Peak ◽  
Spatial Modes ◽  
Triggering Mechanisms ◽  
Deep Moist Convection ◽  
Convection Initiation

AbstractA dataset of convection initiation (CI) is of great value in studying the triggering mechanisms of deep moist convection and evaluating the performances of numerical models. In recent years, the data quality of the operationally generated radar mosaics over China has been greatly improved, which provides an opportunity to retrieve a CI dataset from that region. In this work, an attempt is made to reveal the potential of applying a simple framework of objective CI detection for the study of CI climatology in China. The framework was tested using radar mosaic maps in South China that were accessible online. The identified CI events were validated in both direct and indirect ways. On the basis of a direct manual check, nearly all of the identified CI cells had an organized motion. The precipitation echoes of the cells had a median duration of approximately 2.5 h. The CI occurrences were further compared with rainfall estimates to ensure physical consistency. The diurnal cycle of CI occurrence exhibits three major modes: a late-night-to-morning peak at the windward coasts and offshore, a noon-to-late-afternoon peak on the coastal land, and an evening-to-early-morning peak over the northwestern highland. These spatial modes agree well with those of rainfall, indirectly suggesting the reliability of the CI statistics. By processing radar mosaic maps, such a framework could be applied for studying CI climatology over China and other regions.

scholarly journals Circadian Variation of Migraine Attack Onset: A Review of Clinical Studies

2019 ◽  
Vol 2019 ◽  
pp. 1-9 ◽  
Author(s):  
Daniel Baksa ◽  
Kinga Gecse ◽  
Sahel Kumar ◽  
Zsuzsanna Toth ◽  
Zsofia Gal ◽  
...  
Keyword(s):  
Migraine Attack ◽  
Circadian Variation ◽  
Early Morning ◽  
Sleep Stages ◽  
Shift Workers ◽  
Late Night ◽  
Diurnal Distribution ◽  
Pubmed Search ◽  
Migraine Triggers ◽  
The Moment

Several studies suggested that migraine attack onset shows a circadian variation; however, there has not been an overview and synthesis of these findings. A PubMed search with keywords “migraine” AND “circadian” resulted in ten studies directly investigating this topic. Results of these studies mostly show that migraine attacks follow a monophasic 24-hour cyclic pattern with an early morning or late night peak while other studies reported an afternoon peak and also a biphasic 24-hour cycle of attacks. The identified studies showed methodological variation including sample size, inclusion of medication use, comorbidities, and night or shift workers which could have contributed to the contradictory results. Several theories emerged explaining the diurnal distribution of migraine attacks suggesting roles for different phenomena including a morning rise in cortisol levels, a possible hypothalamic dysfunction, a circadian variation of migraine triggers, sleep stages, and a potentially different setting of the circadian pacemaker among migraineurs. At the moment, most studies show an early morning or late night peak of migraine attack onset, but a significant amount of studies reveals contradictory results. Further studies should investigate the arising hypotheses to improve our understanding of the complex mechanism behind the circadian variation of migraine attacks that can shed light on new targets for migraine therapy.

scholarly journals The European lightning location system EUCLID – Part 2: Observations

2016 ◽  
Vol 16 (2) ◽  
pp. 607-616 ◽  
Author(s):  
Dieter Roel Poelman ◽  
Wolfgang Schulz ◽  
Gerhard Diendorfer ◽  
Marina Bernardi
Keyword(s):  
Diurnal Cycle ◽  
Lightning Activity ◽  
European Continent ◽  
Peak Current ◽  
Location System ◽  
European Cooperation ◽  
Lightning Detection ◽  
Lightning Location System ◽  
Cg Lightning

Abstract. Cloud-to-ground (CG) lightning data from the European Cooperation for Lightning Detection (EUCLID) network over the period 2006–2014 are explored. Mean CG flash densities vary over the European continent, with the highest density of about 6 km−2 yr−1 found at the intersection of the borders between Austria, Italy and Slovenia. The majority of lightning activity takes place between May and September, accounting for 85 % of the total observed CG activity. Furthermore, the thunderstorm season reaches its highest activity in July, while the diurnal cycle peaks around 15:00 UTC. A difference between CG flashes over land and sea becomes apparent when looking at the peak current estimates. It is found that flashes with higher peak currents occur in greater proportion over sea than over land.

Socio-Spatial Variations in Commuting Patterns in Suburban Beijing

2019 ◽  
Vol 45 (4) ◽  
pp. 523-543 ◽  
Author(s):  
Wei Zheng ◽  
Cecilia Wong ◽  
Miao Qiao
Keyword(s):  
Cultural Context ◽  
Latent Class ◽  
Spatial Scales ◽  
Spatial Variations ◽  
Statistical Testing ◽  
Metropolitan Region ◽  
Gis Mapping ◽  
Rapid Urbanization ◽  
Time Distance ◽  
Commuting Patterns

With rapid urbanization and suburbanization in China, there is clear evidence of the decoupling of home-work locations in cities which is in contrast to the socialist danwei system where workers were housed in workplace compounds. This paper examines the diverse commuting patterns of suburban neighbourhoods in the Beijing metropolitan region. The research first examines the relationship between the characteristics of commutes in terms of time, distance, and mode, and the socio-economic attributes of residents. The analysis allows us to examine how different socio-economic groups, via latent class analysis, are often spatially concentrated in marginalized neighbourhoods, and further disadvantaged in their commuting experience. The socio-spatial variations in commuting patterns are analysed via GIS mapping analysis, statistical testing, and multiple regression analysis. Major variations were found in the commuting patterns in terms of time, distance and mode across different socioeconomic groups and across various suburban neighbourhood types. The results from regression models further suggest that personal resources have the strongest influence on commuting time but less so on distance, regardless of the type of neighbourhoods in which they live. The findings call for integrative planning and major transport measures, at different spatial scales, to shape commuting behaviour. Despite the unique institutional and cultural context of China, the lessons learnt from the need to have integrative strategic planning are relevant to other cities, and especially those in the developing world which are undergoing rapid urbanization.

Long-acting somatostatin analogue (Sandostatin) reduces late night insulinopenic ketogenesis in diabetic teenagers

1987 ◽  
Vol 116 (4_Suppla) ◽  
pp. S45-S53 ◽  
Author(s):  
R.S.R. Aarsen ◽  
G.J. Bruining ◽  
W.F.A. Grose ◽  
R. van Strik ◽  
S.W.J. Lamberts ◽  
...  
Keyword(s):  
Blood Glucose ◽  
Insulin Pump ◽  
Movement Analysis ◽  
Early Morning ◽  
Insulin Pump Therapy ◽  
Rank Test ◽  
Somatostatin Analogue ◽  
Late Night ◽  
Free Insulin ◽  
Long Acting

Abstract. Ten diabetic teenagers were admitted into our hospital for two nights, separated by one week. In a double-blind cross-over randomized study they received either 50 μg of the new long-acting somatostatin analogue Sandostatin sc or placebo. All patients were between 12 and 16 years of age, C-peptide negative with a duration of diabetes of at least four years. They had either conventional therapy or insulin pump therapy. Insulin doses and diets were kept unchanged. Blood samples were taken half hourly from 17.00 h until 09.30 h the next morning from an indwelling venous catheter. Hormonal and metabolic profiles on the two nights were evaluated by means of a distribution free time sequential co-movement analysis and by the paired Wilcoxon's signed rank test. After Sandostatin was given at 22.00 h, GH levels were significantly suppressed during 4 h. During that period blood glucose was slightly but significantly lower than after placebo. The free-insulin profiles from both nights were very comparable. Co-movement analysis showed a significant correlation between glucose and free insulin variations with a 30-min backward shift of the glucose curve. However, after Sandostatin administration this relation was lost in the period between 22.00 and 07.00 h, indicating a different effect of insulin on glucose levels during the nights Sandostatin was given. Early morning glucose rises were associated with free insulin levels below 20 mU/l. This association was not altered during the Sandostatin nights. Glucagon was not suppressed by Sandostatin except at 120 min after injection, and remained unchanged during the rest of the observation period. Triglyceride levels as well as 3-OH-butyrate values were significantly lower after Sandostatin. Plasma levels of FFA, free glycerol, alanine and cortisol were not significantly reduced. It is concluded that a single sc injection of 50 μg of Sandostatin given at 22.00 h is a potent GH inhibitor and lowers blood glucose concentrations for up to 4 h after injection. Early morning blood glucose rise is not prevented, but overnight hepatic ketogenesis as reflected by 3-OH--butyrate levels appears suppressed by Sandostatin up to the next morning injection of insulin.

scholarly journals A critical look at spatial scale choices in satellite-based aerosol indirect effect studies

2010 ◽  
Vol 10 (23) ◽  
pp. 11459-11470 ◽  
Author(s):  
B. S. Grandey ◽  
P. Stier
Keyword(s):  
Radiative Forcing ◽  
Spatial Scales ◽  
Cloud Droplet ◽  
Spatial Variations ◽  
Opposite Pattern ◽  
Cloud Properties ◽  
Methodological Errors ◽  
Albedo Effect ◽  
Moderate Resolution ◽  
Moderate Resolution Imaging Spectroradiometer

Abstract. Analysing satellite datasets over large regions may introduce spurious relationships between aerosol and cloud properties due to spatial variations in aerosol type, cloud regime and synoptic regime climatologies. Using MODerate resolution Imaging Spectroradiometer data, we calculate relationships between aerosol optical depth τa derived liquid cloud droplet effective number concentration Ne and liquid cloud droplet effective radius re at different spatial scales. Generally, positive values of dlnNedlnτa are found for ocean regions, whilst negative values occur for many land regions. The spatial distribution of dlnredlnτa shows approximately the opposite pattern, with generally postive values for land regions and negative values for ocean regions. We find that for region sizes larger than 4° × 4°, spurious spatial variations in retrieved cloud and aerosol properties can introduce widespread significant errors to calculations of dlnNedlnτa and dlnredlnτa. For regions on the scale of 60° × 60°, these methodological errors may lead to an overestimate in global cloud albedo effect radiative forcing of order 80% relative to that calculated for regions on the scale of 1° × 1°.

scholarly journals Cloud-to-Ground Lightning Distribution and Its Relationship with Orography and Anthropogenic Emissions in the Po Valley

2014 ◽  
Vol 53 (12) ◽  
pp. 2651-2670 ◽  
Author(s):  
Laura Feudale ◽  
Agostino Manzato
Keyword(s):  
The United States ◽  
Lightning Activity ◽  
Anthropogenic Emissions ◽  
Target Area ◽  
Mountain Areas ◽  
Weekly Cycle ◽  
Po Valley ◽  
Mountainous Regions ◽  
Area Of Interest ◽  
Cg Lightning

AbstractThe main object of this work is to study the lightning climatology in the Po Valley in Italy and how it varies in time (interannual, annual, weekly, and daily time scales) and space (sea coast, plains, and mountain areas) and how that is related to topographic characteristics and anthropogenic emissions. Cloud-to-ground (CG) lightning in the target area is analyzed for 18 yr of data (about 7 million records). It is found that the Julian Prealps of the Friuli Venezia Giulia region are one of the areas of maximum CG lightning activity across all of Europe. During spring lightning activity is more confined toward the mountainous regions, whereas during summer and even more during autumn the lightning activity involves also the coastal region and the Adriatic Sea. This is due to different triggering mechanisms acting in different topographic zones and during different periods of the year and times of the day. In analogy to previous studies of lightning done in the United States, a weekly cycle is also identified in the area of interest, showing that on Friday the probability of thunderstorms reaches its maximum. After conducting a parallel analysis with monitoring stations of atmospheric particulates (diameter ≤ 10 μm: PM10) and sounding-derived potential instability, the results presented herein seem to support the hypothesis that the weekly cycle in the thunderstorm activity may be due to anthropogenic emissions.

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