scholarly journals The Role of Weather during the Greek–Persian “Naval Battle of Salamis” in 480 B.C.

Atmosphere ◽  
2020 ◽  
Vol 11 (8) ◽  
pp. 838 ◽  
Author(s):  
Christos Zerefos ◽  
Stavros Solomos ◽  
Dimitris Melas ◽  
John Kapsomenakis ◽  
Christos Repapis

The Battle of Salamis in 480 B.C. is one of the most important naval battles of all times. This work examines in detail the climatically prevailing weather conditions during the Persian invasion in Greece. We perform a climatological analysis of the wind regime in the narrow straits of Salamis, where this historic battle took place, based on available station measurements, reanalysis and modeling simulations (ERA5, WRF) spanning through the period of 1960–2019. Our results are compared to ancient sources before and during the course of the conflict and can be summarized as follows: (i) Our climatological station measurements and model runs describing the prevailing winds in the area of interest are consistent with the eyewitness descriptions reported by ancient historians and (ii) The ancient Greeks and particularly Themistocles must have been aware of the local wind climatology since their strategic plan was carefully designed and implemented to take advantage of the diurnal wind variation. The combination of northwest wind during the night and early morning, converging with a south sea breeze after 10:00 A.M., formed a “pincer” that aided the Greeks at the beginning of the clash in the morning, while it brought turmoil to the Persian fleet and prevented them to escape to the open sea in the early afternoon hours.

2020 ◽  
Vol 12 (18) ◽  
pp. 7633
Author(s):  
Barbara Skowera ◽  
Zbigniew Zuśka ◽  
Alicja Baranowska

The aim of the study was to assess the temporal variability of tropospheric ozone pollution. The research was carried out for the agricultural region of central-eastern Poland, an area covering the Lublin Voivodeship. One-hour averages of automatic measurements of tropospheric ozone concentration in 2015–2017 were used for the study. The data were obtained from three measuring stations belonging to the Chief Inspectorate of Environmental Protection in Poland. The stations were located as part of the Air Quality Monitoring System in rural communes in the north-western, central and southern parts of the Lublin Voivodeship. Statistical analysis of the data showed that the tropospheric ozone concentrations were significantly dependent on weather conditions during the years of the study. At each monitoring station, the one-hour average O3 concentrations showed a clear structure over the course of the day: they were higher in the late morning and early afternoon than in the early morning and at night. The highest O3 concentrations were observed at the Florianka measurement station, located in Roztocze National Park. This area had high forest cover and was located at the highest elevation above sea level of the three measuring stations. In the light of climate change and increasing O3 concentrations, further scientific research on atmospheric air pollution is crucial, especially in agricultural areas associated with food production.


2019 ◽  
Vol 161 (2) ◽  
pp. 529-538
Author(s):  
Eva Maria Schöll ◽  
Manuel Polo Aparisi ◽  
Sabine Marlene Hille

AbstractEnvironmental conditions affect incubation behavior, but whilst the effect of ambient temperature is studied and still controversially discussed, the role of precipitation is unknown. Here, we analyzed the effect of local ambient temperature and precipitation on incubation behavior of female Great Tits (Parus major) and accounted for diurnal patterns of weather conditions. We monitored the incubation behavior of females using temperature data loggers, thus identifying periods of staying inside nest boxes incubating, and leaving nest boxes (off-bout). In total, 685 single off-bouts were analyzed between the first 8 days of incubation directly after clutches were completed. Our study showed that whilst precipitation had no effect on incubation behavior, number and duration of off-bouts were negatively related to ambient temperature, which varied throughout the day. We showed that females took longer off-bouts during low-temperature early mornings, which may result from the need to forage after fasting during the night. Thus, foraging in the early morning seemed to outcompete energy requirements during these cold temperature periods. In addition, females spent less time off the nest as incubation progressed. Our results emphasize that patterns of incubation behavior cannot be understood without taking into account varying temperature conditions throughout the day.


2010 ◽  
Vol 138 (6) ◽  
pp. 2426-2433 ◽  
Author(s):  
H. Bellenger ◽  
Y. N. Takayabu ◽  
T. Ushiyama ◽  
K. Yoneyama

Abstract The role of air–sea interaction in the diurnal variations of convective activity during the suppressed and developing stages of an intraseasonal convective event is analyzed using in situ observations from the Mirai Indian Ocean cruise for the Study of the Madden–Julian oscillation (MJO)-convection Onset (MISMO) experiment. For the whole period, convection shows a clear average diurnal cycle with a primary maximum in the early morning and a secondary one in the afternoon. Episodes of large diurnal sea surface temperature (SST) variations are observed because of diurnal warm layer (DWL) formation. When no DWL is observed, convection exhibits a diurnal cycle characterized by a maximum in the early morning, whereas when DWL forms, convection increases around noon and peaks in the afternoon. Boundary layer processes are found to control the diurnal evolution of convection. In particular, when DWL forms, the change in surface heat fluxes can explain the decrease of convective inhibition and the intensification of the convection during the early afternoon.


2021 ◽  
pp. bmjmilitary-2020-001686
Author(s):  
Iain T Parsons ◽  
R M Gifford ◽  
M J Stacey ◽  
L E Lamb ◽  
M K O'Shea ◽  
...  

For most individuals residing in Northwestern Europe, maintaining replete vitamin D status throughout the year is unlikely without vitamin D supplementation and deficiency remains common. Military studies have investigated the association with vitamin D status, and subsequent supplementation, with the risk of stress fractures particularly during recruit training. The expression of nuclear vitamin D receptors and vitamin D metabolic enzymes in immune cells additionally provides a rationale for the potential role of vitamin D in maintaining immune homeostasis. One particular area of interest has been in the prevention of acute respiratory tract infections (ARTIs). The aims of this review were to consider the evidence of vitamin D supplementation in military populations in the prevention of ARTIs, including SARS-CoV-2 infection and consequent COVID-19 illness. The occupational/organisational importance of reducing transmission of SARS-CoV-2, especially where infected young adults may be asymptomatic, presymptomatic or paucisymptomatic, is also discussed.


2015 ◽  
Vol 72 (7) ◽  
pp. 2806-2821 ◽  
Author(s):  
Yu Du ◽  
Richard Rotunno

The characteristics of thermally driven diurnally periodic wind signals off the east coast of China are studied using hourly model data for the period June 2006–11 simulated with a mesoscale model. Analysis of these model data indicates low-level diurnally periodic wind signals propagate eastward off the southeast coast, whereas diurnal wind variations off the northeast coast are nearly in phase. It is found that a simple 2D linear land–sea-breeze model with friction can capture this main difference in propagation character with respect to latitude. Idealized simulations using a simplified version of the mesoscale model that includes surface heating and terrain are found to explain certain features not captured by the present linear theory such as the absolute time phase and cross-coast location of the maximum amplitude of the diurnally periodic winds.


2015 ◽  
Vol 28 (20) ◽  
pp. 8093-8108 ◽  
Author(s):  
Cathryn E. Birch ◽  
Malcolm J. Roberts ◽  
Luis Garcia-Carreras ◽  
Duncan Ackerley ◽  
Michael J. Reeder ◽  
...  

Abstract There are some long-established biases in atmospheric models that originate from the representation of tropical convection. Previously, it has been difficult to separate cause and effect because errors are often the result of a number of interacting biases. Recently, researchers have gained the ability to run multiyear global climate model simulations with grid spacings small enough to switch the convective parameterization off, which permits the convection to develop explicitly. There are clear improvements to the initiation of convective storms and the diurnal cycle of rainfall in the convection-permitting simulations, which enables a new process-study approach to model bias identification. In this study, multiyear global atmosphere-only climate simulations with and without convective parameterization are undertaken with the Met Office Unified Model and are analyzed over the Maritime Continent region, where convergence from sea-breeze circulations is key for convection initiation. The analysis shows that, although the simulation with parameterized convection is able to reproduce the key rain-forming sea-breeze circulation, the parameterization is not able to respond realistically to the circulation. A feedback of errors also occurs: the convective parameterization causes rain to fall in the early morning, which cools and wets the boundary layer, reducing the land–sea temperature contrast and weakening the sea breeze. This is, however, an effect of the convective bias, rather than a cause of it. Improvements to how and when convection schemes trigger convection will improve both the timing and location of tropical rainfall and representation of sea-breeze circulations.


2014 ◽  
Vol 10 (1) ◽  
pp. 39-47
Author(s):  
B.E. Bergstrom ◽  
J.H. Foreman ◽  
C.R. Foreman ◽  
A.M. Barger

Sodium bicarbonate and other alkalinising solutions (‘milkshakes’) have been given to horses surreptitiously before exercise to provide exogenous buffering effects. After an initial positive blood test, some accused horse trainers claim that their horses ‘naturally test high’, so some jurisdictions allow a secured quarantine in which the horse is tested multiple times. The objective of this experiment was to determine the intra- and inter-day variability of plasma total CO2 (tCO2) and other plasma strong ions in a group of sedentary horses housed similarly to a quarantine period. The hypothesis was that plasma tCO2 would not remain constant over a multi-day monitoring interval, but would vary measurably during that interval. Eight sedentary (unconditioned) horses were studied for 2 weeks. Horses were acclimated to a climate-controlled indoor environment and an alfalfa-only diet for a minimum of 10 days prior to sampling. Horses were sampled 3 times daily for 5 consecutive days at 7:00, 11:00 and 15:00 h. Blood samples were collected directly into 10 ml heparinised evacuated glass tubes by jugular venipuncture using a double-ended 0.91 mm needle. Samples were chilled until concentrations of plasma tCO2, Na+, K+, and Cl-, were determined within 1-3 h of sampling using an automated serum chemistry analyzer which was calibrated daily using commercial reagents obtained from the manufacturer as well as externally-obtained NIST-traceable calibrating solutions. Mean results documented mild variations in mean plasma tCO2 (range 28.9-31.6 mmol/l), but individual horses’ plasma tCO2 ranged over 4-7 units. Results showed that there was considerable intra- and inter-individual variability in plasma tCO2. Mean pooled tCO2 and measured strong ion difference (SIDm) differed by time-of-day, with both late morning and early afternoon values lower than early morning values (P<0.001). There was a strong positive linear relationship between plasma SIDm and tCO2 (r=0.75, P<0.001).


2018 ◽  
Vol 46 (4) ◽  
pp. 579-608 ◽  
Author(s):  
Philippe Bontems ◽  
Céline Nauges

Abstract We develop a theoretical model that describes risk-averse farmers’ decisions when facing production risk due to uncertain weather conditions and when irrigation water can be traded on a market. We focus on the role of initial water allocations granted to irrigated farms at the start of the season. The presence of water markets makes the future water price uncertain and hence the value of initial water allocations uncertain. We analyse the properties of this background risk and study how initial water allocations impact farmers’ land allocation decisions between an irrigated crop and a non-irrigated crop, both characterised by random expected net returns. We then extend the model by permitting irrigation water to be traded ex-ante at a known price (forward market). Finally, we illustrate our main theoretical findings using simulations. We calibrate distributions of the random variables based on observed data from the Murray–Darling Basin in Australia where a water market has been in place for several decades.


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