scholarly journals On some characteristics of the field intensity of atmospherics ant at Calcutta due to local active monsoon clouds

MAUSAM ◽  
2022 ◽  
Vol 46 (2) ◽  
pp. 163-168
Author(s):  
A. B.   BHATTACHARYA ◽  
B. K. DATTA ◽  
R. BHATTACHARYA
Keyword(s):  
Seasonal Variation ◽  
Field Intensity ◽  
Seasonal Variations ◽  
Cloud Amount ◽  
Intensity Level ◽  
Local Rainfall

The paper examines some characteristics of the field intensity level of atmospherics at three harmonically related frequencies due to local active monsoon clouds. Seasonal variations of the ratio of afternoon maximum to morning minimum as well as that of the afternoon minimum to morning minimum of atmospherics and the local rainfall have been critically analysed. The differences of the two ratios exhibit a pronounced seasonal variation, having minimum values during the monsoon months and also the significance ratio at such times decreases with the increase of rainfall. which. in turn. is related to local sferics. The results further indicate how the overhead cloud amount in okta contributes significantly over the intensity level of different frequencies and width of atmospherics.  

scholarly journals Evaluation of cloud fraction and its radiative effect simulated by IPCC AR4 global models against ARM surface observations

2012 ◽  
Vol 12 (4) ◽  
pp. 1785-1810 ◽  
Author(s):  
Y. Qian ◽  
C. N. Long ◽  
H. Wang ◽  
J. M. Comstock ◽  
S. A. McFarlane ◽  
...  
Keyword(s):  
Seasonal Variation ◽  
Probability Distribution ◽  
Vertical Structure ◽  
Cloud Amount ◽  
Cloud Fraction ◽  
Department Of Energy ◽  
The Arctic ◽  
Radiative Fluxes ◽  
The Tropics ◽  
Ipcc Ar4

Abstract. Cloud Fraction (CF) is the dominant modulator of radiative fluxes. In this study, we evaluate CF simulated in the IPCC AR4 GCMs against ARM long-term ground-based measurements, with a focus on the vertical structure, total amount of cloud and its effect on cloud shortwave transmissivity. Comparisons are performed for three climate regimes as represented by the Department of Energy Atmospheric Radiation Measurement (ARM) sites: Southern Great Plains (SGP), Manus, Papua New Guinea and North Slope of Alaska (NSA). Our intercomparisons of three independent measurements of CF or sky-cover reveal that the relative differences are usually less than 10% (5%) for multi-year monthly (annual) mean values, while daily differences are quite significant. The total sky imager (TSI) produces smaller total cloud fraction (TCF) compared to a radar/lidar dataset for highly cloudy days (CF > 0.8), but produces a larger TCF value than the radar/lidar for less cloudy conditions (CF < 0.3). The compensating errors in lower and higher CF days result in small biases of TCF between the vertically pointing radar/lidar dataset and the hemispheric TSI measurements as multi-year data is averaged. The unique radar/lidar CF measurements enable us to evaluate seasonal variation of cloud vertical structures in the GCMs. Both inter-model deviation and model bias against observation are investigated in this study. Another unique aspect of this study is that we use simultaneous measurements of CF and surface radiative fluxes to diagnose potential discrepancies among the GCMs in representing other cloud optical properties than TCF. The results show that the model-observation and inter-model deviations have similar magnitudes for the TCF and the normalized cloud effect, and these deviations are larger than those in surface downward solar radiation and cloud transmissivity. This implies that other dimensions of cloud in addition to cloud amount, such as cloud optical thickness and/or cloud height, have a similar magnitude of disparity as TCF within the GCMs, and suggests that the better agreement among GCMs in solar radiative fluxes could be a result of compensating effects from errors in cloud vertical structure, overlap assumption, cloud optical depth and/or cloud fraction. The internal variability of CF simulated in ensemble runs with the same model is minimal. Similar deviation patterns between inter-model and model-measurement comparisons suggest that the climate models tend to generate larger biases against observations for those variables with larger inter-model deviation. The GCM performance in simulating the probability distribution, transmissivity and vertical profiles of cloud are comprehensively evaluated over the three ARM sites. The GCMs perform better at SGP than at the other two sites in simulating the seasonal variation and probability distribution of TCF. However, the models remarkably underpredict the TCF at SGP and cloud transmissivity is less susceptible to the change of TCF than observed. In the tropics, most of the GCMs tend to underpredict CF and fail to capture the seasonal variation of CF at middle and low levels. The high-level CF is much larger in the GCMs than the observations and the inter-model variability of CF also reaches a maximum at high levels in the tropics, indicating discrepancies in the representation of ice cloud associated with convection in the models. While the GCMs generally capture the maximum CF in the boundary layer and vertical variability, the inter-model deviation is largest near the surface over the Arctic.

Global mapping of seasonal variations in tides from tide gauge and satellite altimeter data

2021 ◽  
Author(s):  
Inger Bij de Vaate ◽  
Henrique Guarneri ◽  
Cornelis Slobbe ◽  
Martin Verlaan
Keyword(s):  
Seasonal Variation ◽  
Sea Level ◽  
Seasonal Variations ◽  
Large Scale ◽  
Arctic Region ◽  
The Arctic ◽  
Altimeter Data ◽  
Tide Gauges ◽  
Tidal Constituents ◽  
The Arctic Region

&lt;p&gt;The existence of seasonal variations in major tides has been recognized since decades. Where Corkan (1934) was the first to describe the seasonal perturbation of the M2 tide, many others have studied seasonal variations in the main tidal constituents since. However, most of these studies are based on sea level observations from tide gauges and are often restricted to coastal and shelf regions. Hence, observed seasonal variations are typically dominated by local processes and the large-scale patterns cannot be clearly distinguished. Moreover, most tide models still perceive tides as annually constant and seasonal variation in tides is ignored in the correction process of satellite altimetry. This results in reduced accuracy of obtained sea level anomalies. &lt;/p&gt;&lt;p&gt;To gain more insight in the large-scale seasonal variations in tides, we supplemented the clustered and sparsely distributed sea level observations from tide gauges by the wealth of data from satellite altimeters. Although altimeter-derived water levels are being widely used to obtain tidal constants, only few of these implementations consider seasonal variation in tides. For that reason, we have set out to explore the opportunities provided by altimeter data for deriving seasonal modulation of the main tidal constituents. Different methods were implemented and compared for the principal tidal constituents and a range of geographical domains, using data from a selection of satellite altimeters. Specific attention was paid to the Arctic region where seasonal variation in tides was expected to be significant as a result of the seasonal sea ice cycle, yet data availability is particularly limited. Our study demonstrates the potential of satellite altimetry for the quantification of seasonal modulation of tides and suggests the seasonal modulation to be considerable. Already for M2 we observed changes in tidal amplitude of the order of decimeters for the Arctic region, and centimeters for lower latitude regions.&lt;/p&gt;&lt;p&gt;&amp;#160;&lt;/p&gt;&lt;div&gt;Corkan, R. H. (1934). An annual perturbation in the range of tide. &lt;em&gt;Proceedings of the Royal Society of London. Series A, Containing Papers of a Mathematical and Physical Character&lt;/em&gt;, &lt;em&gt;144&lt;/em&gt;(853), 537-559.&lt;/div&gt;

scholarly journals Effect of Seasonal Variation on Clinical Outcome in Patients with Chronic Conditions: Analysis of the Commonwealth Scientific and Industrial Research Organization (CSIRO) National Telehealth Trial (Preprint)

2017 ◽  
Author(s):  
Ahmadreza Argha ◽  
Andrey Savkin ◽  
Siaw-Teng Liaw ◽  
Branko George Celler
Keyword(s):  
Seasonal Variation ◽  
Length Of Stay ◽  
Clinical Outcome ◽  
Seasonal Variations ◽  
Chronic Conditions ◽  
Hospital Admissions ◽  
Australian Capital Territory ◽  
Home Telemonitoring ◽  
The Impact ◽  
At Home

BACKGROUND Seasonal variation has an impact on the hospitalization rate of patients with a range of cardiovascular diseases, including myocardial infarction and angina. This paper presents findings on the influence of seasonal variation on the results of a recently completed national trial of home telemonitoring of patients with chronic conditions, carried out at five locations along the east coast of Australia. OBJECTIVE The aim is to evaluate the effect of the seasonal timing of hospital admission and length of stay on clinical outcome of a home telemonitoring trial involving patients (age: mean 72.2, SD 9.4 years) with chronic conditions (chronic obstructive pulmonary disease coronary artery disease, hypertensive diseases, congestive heart failure, diabetes, or asthma) and to explore methods of minimizing the influence of seasonal variations in the analysis of the effect of at-home telemonitoring on the number of hospital admissions and length of stay (LOS). METHODS Patients were selected from a hospital list of eligible patients living with a range of chronic conditions. Each test patient was case matched with at least one control patient. A total of 114 test patients and 173 control patients were available in this trial. However, of the 287 patients, we only considered patients who had one or more admissions in the years from 2010 to 2012. Three different groups were analyzed separately because of substantially different climates: (1) Queensland, (2) Australian Capital Territory and Victoria, and (3) Tasmania. Time series data were analyzed using linear regression for a period of 3 years before the intervention to obtain an average seasonal variation pattern. A novel method that can reduce the impact of seasonal variation on the rate of hospitalization and LOS was used in the analysis of the outcome variables of the at-home telemonitoring trial. RESULTS Test patients were monitored for a mean 481 (SD 77) days with 87% (53/61) of patients monitored for more than 12 months. Trends in seasonal variations were obtained from 3 years’ of hospitalization data before intervention for the Queensland, Tasmania, and Australian Capital Territory and Victoria subgroups, respectively. The maximum deviation from baseline trends for LOS was 101.7% (SD 42.2%), 60.6% (SD 36.4%), and 158.3% (SD 68.1%). However, by synchronizing outcomes to the start date of intervention, the impact of seasonal variations was minimized to a maximum of 9.5% (SD 7.7%), thus improving the accuracy of the clinical outcomes reported. CONCLUSIONS Seasonal variations have a significant effect on the rate of hospital admission and LOS in patients with chronic conditions. However, the impact of seasonal variation on clinical outcomes (rate of admissions, number of hospital admissions, and LOS) of at-home telemonitoring can be attenuated by synchronizing the analysis of outcomes to the commencement dates for the telemonitoring of vital signs. CLINICALTRIAL Australian New Zealand Clinical Trial Registry ACTRN12613000635763; https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=364030&isReview=true (Archived by WebCite at http://www.webcitation.org/ 6xLPv9QDb)

Difference of seasonal variation between glycated albumin and glycated haemoglobin

2018 ◽  
Vol 55 (5) ◽  
pp. 583-587 ◽  
Author(s):  
Karin Tanaka ◽  
Shu Meguro ◽  
Masami Tanaka ◽  
Junichiro Irie ◽  
Yoshifumi Saisho ◽  
...  
Keyword(s):  
Seasonal Variation ◽  
Plasma Glucose ◽  
Seasonal Variations ◽  
Glycated Albumin ◽  
Rank Correlation ◽  
Correlation Coefficients ◽  
Glycated Haemoglobin ◽  
Spearman Rank Correlation ◽  
Spearman Rank ◽  
Average Temperature

Background Glycated albumin reflects 2–3-week glycaemic controls, and in addition to glycated haemoglobin, it has been used as a glycaemic control indicator. We presumed that glycated albumin also has seasonal variations and is related to temperature, similar to glycated haemoglobin. Methods The subjects were diabetic outpatients from April 2007 to March 2013. This resulted in the enrolment of 2246 subjects and the collection of a total of 53,968 measurements. Mean glycated haemoglobin, glycated albumin, and plasma glucose were calculated for each month over six years. The associations of the measures with each other and the average temperature for each month in Tokyo were assessed using Spearman rank correlation coefficients. Results Plasma glucose was highest in January and lowest in May. Glycated haemoglobin was highest in March and lowest in September. Glycated albumin was highest in May and lowest in December. Glycated albumin tended to have a disjunction with plasma glucose in winter. Glycated haemoglobin had seasonal variation, but glycated albumin did not. Plasma glucose and glycated haemoglobin showed significant negative correlations with temperature (rs = −0.359, P < 0.001, rs = −0.449, P < 0.001, respectively), but glycated albumin did not. However, glycated albumin was inter-correlated with plasma glucose (rs = 0.396, P < 0.001) and glycated haemoglobin (rs = 0.685, P < 0.001), and glycated haemoglobin was inter-correlated with plasma glucose (rs = 0.465, P < 0.001). Conclusion Glycated albumin and glycated haemoglobin showed different seasonal variations from each other over the six-year study period. Thus, further studies to identify factors that contribute to glycated albumin are needed.

Seasonal variations of mode-1 M2 internal tides observed by satellite altimetry

2021 ◽  
Author(s):  
Zhongxiang Zhao
Keyword(s):  
Seasonal Variation ◽  
Seasonal Variations ◽  
Internal Tide ◽  
Spatial Filtering ◽  
Internal Tides ◽  
Mapping Technique ◽  
Phase Variable ◽  
Model Errors ◽  
Tropical Zone ◽  
Variable Amplitude

&lt;p&gt;The seasonal variations of M&lt;sub&gt;2&lt;/sub&gt; internal tides is investigated using 25 years of satellite altimetric sea surface height measurements from 1992--2017. The satellite data are divided into four seasonal subsets, from which four seasonal M&lt;sub&gt;2&lt;/sub&gt; internal tide models are constructed. This study employs a new mapping technique that combines along-track spatial filtering, harmonic analysis, plane wave analysis, and two-dimensional spatial filtering. The vector mean of the four seasonal models yields the seasonal-mean model, which is equivalent to the 25-year-coherent model constructed directly using all the data. The seasonal models have larger errors than the seasonal-mean model, because the seasonally-subsetted data sets are short. Two seasonally-variable models are derived: The first model is a step function of the four seasonal models (phase-variable, amplitude-variable); The second model is same as the first one but that the amplitude is from the seasonal-mean model (phase-variable, amplitude-invariable). All these models are evaluated using independent CryoSat-2 data. Each seasonal model reduces most variance in its own season and least variance in its opposite season. Based on globally-integrated variance reductions, the two seasonally-variable models reduce 13% and 23% more variance than the seasonal models, respectively. The seasonal-mean model can reduce 27% more variance, thanks to its small model errors. However, the seasonally-variable models are better than the seasonal-mean model in the tropical zone, where the seasonal signals are larger than model errors. The satellite results reveal that M&lt;sub&gt;2&lt;/sub&gt; internal tides are subject to seasonal variation in varying degrees and that the seasonal variation is a function of location. Large variations in amplitude and phase mainly occur in the tropical zone. The seasonal phase variations are mainly caused by the seasonal variations of ocean stratification and internal tide speed. Significant amplitude variations are usually associated with strong internal tides such as from the Luzon and Lombok Straits, and in the Amazon River plume, the western Pacific and the Arabian Sea. At higher latitudes such as the North Pacific and North Atlantic Oceans, the seasonal variations are weak but detectable. The seasonally-variable models can partly account for the seasonal variations of internal tides, in particular, in the tropical zone. &amp;#160;A major challenge is the large model errors, which will be further reduced with the accumulation of new altimeter missions and data (e.g., SWOT).&lt;/p&gt;

scholarly journals Seasonal variation of the principal tidal constituents in the Bohai Sea

Ocean Science ◽  
2020 ◽  
Vol 16 (1) ◽  
pp. 1-14 ◽  
Author(s):  
Daosheng Wang ◽  
Haidong Pan ◽  
Guangzhen Jin ◽  
Xianqing Lv
Keyword(s):  
Seasonal Variation ◽  
Harmonic Analysis ◽  
Sea Level ◽  
Seasonal Variations ◽  
Eddy Viscosity ◽  
Bohai Sea ◽  
Phase Lag ◽  
Vertical Eddy Viscosity ◽  
Tidal Constituents ◽  
Vertical Eddy

Abstract. The seasonal variation of tides plays a significant role in water level changes in coastal regions. In this study, seasonal variations of four principal tidal constituents, M2, S2, K1, and O1, in the Bohai Sea, China, were studied by applying an enhanced harmonic analysis method to two time series: 1-year sea level observations at a mooring station (named E2) located in the western Bohai Sea and 17-year sea level observations at Dalian. At E2, the M2 amplitude and phase lag have annual frequencies, with large values in summer and small values in winter, while the frequencies of S2 and K1 amplitudes are also nearly annual. In contrast, the O1 amplitude increases constantly from winter to autumn. The maxima of phase lags appear twice in 1 year for S2, K1, and O1, taking place near winter and summer. The seasonal variation trends estimated by the enhanced harmonic analysis at Dalian are different from those at E2, except for the M2 phase lag. The M2 and S2 amplitudes show semi-annual and annual cycles, respectively, which are relatively significant at Dalian. The results of numerical experiments indicate that the seasonality of vertical eddy viscosity induces seasonal variations of the principal tidal constituents at E2. However, the tested mechanisms, including seasonally varying stratification, vertical eddy viscosity, and mean sea level, do not adequately explain the observed seasonal variations of tidal constituents at Dalian.

scholarly journals Seasonal variation of anti-resa/Pf155 Plasmodium falciparum antibodies in three localities from the state of Amapá, Brazil

1994 ◽  
Vol 36 (3) ◽  
pp. 237-243 ◽  
Author(s):  
Rosely S. Malafronte ◽  
Jorge Luis Valdívia ◽  
Clóvis R. Nakaie ◽  
Judith K. Kloetzel
Keyword(s):  
Plasmodium Falciparum ◽  
Seasonal Variation ◽  
Seasonal Variations ◽  
Fluorescent Antibody ◽  
Geometric Mean ◽  
The State ◽  
Indirect Fluorescent Antibody ◽  
Blood Smears ◽  
Short Rains

Anti-RESA/Pf155 antibodies were assayed in sera of individuals from three localities (Laranjal do Jari, Vila Padaria and Vila Paraíso) in the State of Amapá, Brazil, during the long-rains and short-rains seasons. All of these had negative blood smears for malaria. Most of the sera collected were positive in Indirect Fluorescent Antibody (IFA) with P. falciparum parasites, with no seasonal variation. A high percentage of these sera (62% to 100%) was RESA positive by Modified Indirect Fluorescent Antibody (MIFA), with a significant (p < 0.05) increase of geometric mean titers during the short-rains season, when the transmission of the disease is highest. ELISA with three repetitive RESA peptides (EENV)3 (4x3), (EENVEHDA)2 (8x2) and (DDEHVEEPTVA)2(11x2) did not reveal statistically significant seasonal variations, although a small enhancement of positivity was observed in V. Padaria (15.3 to 38.8%) in the short-rains season with the 8x2 peptides, and with 4x3 and 8x2 peptides in V. Paraíso, with a decrease in 11x2. MIFA titers appeared to be correlated mainly to the peptide 4x3 and it was the immunodominant in the three localities.

Seasonal variation in Sarcocystis species infections in goats in northern Iraq

Parasitology ◽  
2004 ◽  
Vol 130 (2) ◽  
pp. 151-156 ◽  
Author(s):  
M. BARHAM ◽  
H. STÜTZER ◽  
P. KARANIS ◽  
B. M. LATIF ◽  
W. F. NEISS
Keyword(s):  
Small Intestine ◽  
Seasonal Variation ◽  
Infection Rate ◽  
Seasonal Variations ◽  
Winter Season ◽  
Morphological Characteristics ◽  
Sarcocystis Species ◽  
Patent Period ◽  
Northern Iraq

We investigated the prevalence of sarcocystosis in 826 goats slaughtered in the winter season from November to April in northern Iraq. The prevalence of macrocysts was on average 34%, with only 20% infected animals in November, but 46% in February. The infection rate in 1-, 3- and 6-year-old goats was 4%, 48%, and 83%, respectively. The highest specificity of infection was in the oesophagus (99%) and the lowest in the diaphragm (3%). Grossly, we identified 2 forms of macroscopic sarcocysts, fat and thin, with different morphological characteristics. The prevalence of microcysts was 97% and no effects of age, sex and seasonal variations were observed. Development of microcysts in the small intestine of dogs and cats has also been investigated. The pre-patent period in experimentally infected dogs was 12–14 days and the patent period lasted 64–66 days. A dog shed about 155 million sporocysts, but no sporocysts were shed by cats that had been fed the same infected tissues, thus identifying the microcysts as Sarcocystis capracanis.

Seasonal Changes in General Condition and Lipid Content of Cod from Inshore Waters

1967 ◽  
Vol 24 (3) ◽  
pp. 607-612 ◽  
Author(s):  
P. M. Jangaard ◽  
H. Brockerhoff ◽  
R. D. Burgher ◽  
R. J. Hoyle
Keyword(s):  
Seasonal Variation ◽  
Nova Scotia ◽  
Lipid Content ◽  
General Condition ◽  
Seasonal Variations ◽  
Seasonal Changes ◽  
Oil Content ◽  
Gadus Morhua ◽  
Male Fish ◽  
Inshore Waters

The seasonal variations in lipid content and general "condition" of cod, Gadus morhua L., from an inshore population have been determined.Four female and four male fish were chosen from 20 live cod brought in monthly from Terence Bay, Halifax County, Nova Scotia, the fish were pooled and the lipid content determined on the flesh, livers, and gonads. The flesh lipids varied from 0.57% to 0.74% and the oil content of the livers from 15% to 75%.The general "condition" of the fish as expressed by [Formula: see text], the liver condition by [Formula: see text], and the fat content of the liver all showed seasonal variation with maxima in the fall and minima in the spring. KF varied from 0.79 to 1.05 and KL from 1.0 to 4.5. No seasonal variation in the amount of flesh lipids could be detected.

P2653Seasonal variations of myocardial infarction and sex-specific differences in Germany

2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
K Keller ◽  
L Hobohm ◽  
T Munzel ◽  
M A Ostad
Keyword(s):  
Myocardial Infarction ◽  
Seasonal Variation ◽  
Mortality Rate ◽  
Hospital Mortality ◽  
Seasonal Variations ◽  
The United States ◽  
Summer Season ◽  
Recurrent Event ◽  
Acute Mi ◽  
The Impact

Abstract Background Ischemic heart disease (IHD) is the most common cause of death with an increasing frequency worldwide. It accounts for approximately 20% of all deaths in Europe and the United States of America. Approximately 1/3 of the IHD patients present with sudden cardiac death. The acute presentation of IHD myocardial infarction (MI) is a life-threatening, serious health problem, which causes substantially morbidity and mortality. It is well established that the onset of MI follows a circadian and seasonal periodicity. Seasonal variation regarding the incidence and the short-term mortality of acute MI was frequently reported, but data about sex-specific differences are sparse. Purpose Thus, our objectives were to investigate seasonal variations of myocardial infarction. Methods We analyzed the impact of seasons on incidence and in-hospital mortality of patients with acute MI in Germany from 2005 to 2015. We included all MI patients (ICD code I21) with an acute MI (, but not those MI patients with a recurrent event in the first 28 days after a previous MI (ICD code I22)), who were hospitalized in Germany between 2005 and 2015, in this analysis (source: RDC of the Federal Statistical Office and the Statistical Offices of the federal states, DRG Statistics 2005–2015, own calculations). Results The nationwide sample comprised 3,008,188 hospitalizations of patients with MI (2005–2015). The annual incidence was 334.7 per 100.000 population. Incidence inclined from 316.3 to 341.6 per 100.000 population per year (β 0.17 [0.10 to 0.24], P<0.001), while in-hospital mortality rate decreased from 14.1% to 11.3% (β −0.29 [−0.30 to −0.28, P<0.001). Overall, 377,028 (12.5%) patients died in-hospital. Seasonal variation of both incidence and in-hospital mortality were of substantial magnitude. Seasonal incidence (86.1 vs. 79.0 per 100.000 population per year, P<0.001) and in-hospital mortality (13.2% vs. 12.1%, P<0.001) were higher in the winter than in the summer saeson. Risk to die in winter was elevated (OR 1.080 (95% CI 1.069–1.091), P<0.001) compared to summer season independently of sex, age and comorbidities. Reperfusion treatment with drug eluting stents and coronary artery bypass graft were more often used in summer. We observed sex-specific differences regarding the seasonal variation of in-hospital mortality: males showed lowest mortality in summer, while females during fall. Low temperature dependency of mortality seems more pronounced in males. Conclusions Incidence of acute MI increased 2005–2015, while in-hospital mortality rate decreased. Seasonal variations of incidence and in-hospital mortality were of substantial magnitude with lowest incidence and lowest mortality in the summer season. Additionally, we observed sex-specific differences regarding the seasonal variation of the in-hospital mortality. Acknowledgement/Funding This study was supported by the German Federal Ministry of Education and Research (BMBF 01EO1503)

Sign in / Sign up

Export Citation Format

Share Document