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Itinerario ◽  
2021 ◽  
pp. 1-26
Author(s):  
Manuel Perez-Garcia ◽  
Li Wang ◽  
Omar Svriz-Wucherer ◽  
Nadia Fernández-de-Pinedo ◽  
Manuel Diaz-Ordoñez

Abstract This paper introduces an innovative method applied to global (economic) history using the tools of digital humanities through the design and development of the GECEM Project Database (www.gecem.eu; www.gecemdatabase.eu). This novel database goes beyond the static Excel files frequently used by conventional scholarship in early modern history studies to mine new historical data through a bottom-up process and analyse the global circulation of goods, consumer behaviour, and trade networks in early modern China and Europe. Macau and Marseille, as strategic entrepôts for the redistribution of goods, serve as the main case study. This research is framed within a polycentric approach to analyse the connectivity of south Chinese and European markets with trade zones of Spain, France, South America, and the Pacific.


MAUSAM ◽  
2021 ◽  
Vol 48 (2) ◽  
pp. 257-272
Author(s):  
U.C. MOHANTY ◽  
AKHILESH GUPTA

ABSTRACT. The paper presents a state-of-art review of different objective techniques available for tropical cyclone track prediction. A brief description of current theories of tropical cyclone motion is given. Deterministic models with statistical and dynamical methods have been discussed. Recent advances in the understanding of cyclone structure and motion aspects have led to improved prediction of tropical cyclones. There has been considerable progress in the field of prediction by dynamical methods. High resolution Limited Area Models (LAM) as well as Global Circulation Models (GCM) are now being used extensively by most of the leading operational numerical weather prediction (NWP) centres in the world The major achievements towards improvement of such models have come from improved horizontal resolution of the models, inclusion of physical processes, use of synthetic and other non-conventional data in the data assimilation schemes and nudging method for initial matching of analysed cyclone centres with corresponding observations. A brief description of further improvement in deterministic approach for prediction of tropical cyclone tracks is outlined.  


2021 ◽  
Author(s):  
Daniel Thompson McCoy ◽  
Paul R Field ◽  
Michelle Frazer ◽  
Mark D. Zelinka ◽  
Gregory Elsaesser ◽  
...  

2021 ◽  
pp. 105-108
Author(s):  
Т.Р. Кильматов ◽  
А.Д. Черепанова

В работе на основе базы данных температуры поверхности воды в северной части Тихого океана на климатическом масштабе 1980 - 2019 годы с временным шагом один год исследована зависимость скорости изменения температуры от широты. В летний (август) период отмечается устойчивая зависимость темпов роста средней зональной температуры поверхности в направлении от тропиков к субарктике. Характерная скорость роста температуры в тропических широтах 0,011 0C/год, в субтропиках 0,021 0C/год, в субарктических акваториях выше 400N имеем 0,027 0C/год. В зимний сезон (февраль) такой тенденции не наблюдается. Представлены количественные оценки возможного влияния температурных трендов на глобальную циркуляцию. Рост поверхностной температуры увеличивает вертикальную стратификацию и уменьшает вертикальный обмен вод, относительное ослабление вертикальной скорости не превышает 0,01 % за десятилетие, что представляет незначительным. Представлена количественная оценка уменьшения геострофической составляющей горизонтальной скорости течения продолжения Куросио на восток вследствие климатического сглаживания перепада температуры воды южнее и севернее струи. The change of sea surface temperature (SST) in the North Pacific Ocean on the climatic scale 1980 - 2019 is considered. The rate of temperature change as a function of latitude with the one year time step and the 10 degrees spatial step is investigated. The latitudinal time series for summer and winter are separated. The summer (August) period has the climatic stable dependence of the surface temperature growth rate in the direction from the tropics to the subarctic area. The characteristic rate of temperature rise in tropical latitudes is 0.011 0C / year; in the subtropics is 0.021 0C / year; in subarctic waters above 40 0N this is 0.027 0C / year. The winter season (February) does not have this tendency. The quantitative estimates of the temperature trends influence on global circulation are presented. The SST growth enhances vertical stratification and decreases the vertical water exchange. The estimation of the relative vertical speed decrease is not more than 0.01% / decade. The quantitative assessment of the weakening of the geostrophic horizontal velocity in the Kuroshio extension due to the climatic smoothing of the SST south - north gradient is presented.


2021 ◽  
pp. 13-33
Author(s):  
Francis Egenti Nzerem ◽  
Eucharia C. Nwachukwu

Abstract The human circulatory system is one of the admirable rhythms of nature. The heart and the vasculature are constitutive structures. The vasculature consists of arterial and venous appurtenances which are arranged in an idealized network capable of enhancing circulation. The crux of this study is the representation of the cardiovascular system as a network in which electrical constraints apply. As a network, the system is amenable to graph analytic treatment; as edge-nodal parameters ensue, topological constraints apply. In virtue of cardiac auto-rhythmicity, electrical impulses are driven through the vessels to the body cells. As a rule, the vessels must elicit a modicum of resistance. This work weaponized the elements of graph theory and electrical properties of the heart in elucidating the flow mechanism associated with the cardio-vascular system. The voltage drop across the connecting vessels (idealized as wires) was carefully depicted and analyzed by the method of matrices. When the cardiac function is within physiological definition a vascular compartment may be a liability in the event of poor circulation. Therefore the knowledge of vascular resistive capacities, which this work portrayed, is a sine-qua-non to the assessment of flow integrity of the system under consideration. MSC 2010 No.: 05C21, 92C42, 92B25. Keywords: Cardiovascular, Network, Matrices, Flow, Circuit, Edges and Nodes, Wave propagation, Bifurcation.


MAUSAM ◽  
2021 ◽  
Vol 57 (1) ◽  
pp. 111-118
Author(s):  
P. GOSWAMI ◽  
A. MANDAL ◽  
H. C. UPADHYAYA ◽  
FREDERIC HOURDIN

&  m".kdfVca/kh; pØokr lewps fo’o esa vf/kdka’k rVorhZ {ks=ksa esa xaHkhj vkSj fodjky Mj mRiUu djrs jgrs gSaA blfy, m".kdfVca/kh; pØokrksa ds laca/k esa vf/kd lVhd vkSj yEch vof/k ds iwokZuqeku dh ek¡x c<+rh tk jgh gSA ;|fi dkQh le; ls lhfer {ks= fun’kZ ¼,y- ,- ,e-½ m".kdfVca/kh; pØokrksa ds xfrdh; iwokZuqeku ds fy, ijEijkxr lk/ku jgs gSa fQj Hkh bl ckr ls Hkh badkj ugh fd;k tk ldrk gS fd pØokrksa dh xfrdh; izÑfr ds izLrqrhdj.k esa HkweaMyh; ifjlapj.k fun’kkZsa ¼th- lh- ,e-½ ds mi;ksx ds Qy Lo:Ik dkQh lq/kkj vk;k gSA mnkgj.k ds fy, caxky dh [kkM+h ds dqN pØokr rks caxky dh [kkM+h esa gh fodflr gksrs gSa fdarq cgqr ls pØokr [kkM+h ds iwoZ dh rjQ cus fuEu nkc {ks= ds l?ku gksus vkSj [kkM+h dh vksj c<+us ds dkj.k curs gSa ftlls ;g Li"V gS fd pØokr ds iwokZuqeku ds fy, pØokr ds mRiUu gksus ds foLr`r {ks= dks 'kkfey djus dh vko’;drk gSA bl 'kks/k&i= esa geus crk;k gS fd ,y- ,- ,e- vkSj th- lh- ,e- dh la;qDr fo’ks"krk rqyukRed :Ik ls uohu Js.kh ds HkweaMyh; ekWMyksa ¼th- lh- ,e-½ ls pØokr ds ekxZ vkSj mldh rhozrk tSls dqN vR;ar egRoiw.kZ y{k.kksa  ds laca/k eas yEch vof/k ds vkSj vf/kd lVhd rjg ds iwokZuqeku nksuksa miyC/k djk ldrs gSaA lkr pØokrksa ls lacaf/kr fofHkUu LFkkuksa] _rqvksa] o"kZ vkSj mudh rhozrk] izfr:fir ekxksZa vkSj pØokrksa ds ySaMQky ds LFkyksa ds ik¡p fnuksa ls Hkh vf/kd le; igys dh mudh vkjafHkd voLFkkvksa vkSj muds laca/k esa leqnz lrg rkieku ¼,l- ,l- Vh-½ ds ekfld tyok;q foKku ds 48 ?kaVs igys tkjh fd, x, gSaA buesa rkRdkfyd izpkyukRed iwokZuqeku ds leku gh =qfV;k¡ ikbZ xbZ gSaA Tropical cyclones pose a serious and growing threat to many coastal areas world over; there is increasing demand for better accuracy as well as longer range for tropical cyclone forecasts. While the traditional tool for dynamical forecasting of tropical cyclones has been Limited Area Models (LAM), there are reasons to believe that use of Global Circulation Models (GCM) may result in improved representation of cyclone dynamics. Over Bay of Bengal, for example, while some cyclones develop in situ, many result from intensification of low pressure system that travel from the east, implying need for consideration of a large domain. We show here that a relatively new class of Global Circulation Models (GCM), combining the advantages of LAMs and GCMs, can provide both longer range and better accuracy for such critical parameters like track and intensity. For seven cyclones representing different locations, seasons, years and strength, simulated tracks and land-fall locations show, with initial condition more than 5 days ahead and only monthly climatology of sea surface temperature (SST), errors comparable to those from current operational forecast 48 hours in advance.  


Abstract The Weddell Sea supplies 40–50% of the Antarctic BottomWaters that fill the global ocean abyss, and therefore exerts significant influence over global circulation and climate. Previous studies have identified a range of different processes that may contribute to dense shelf water (DSW) formation and export on the southern Weddell Sea continental shelf. However, the relative importance of these processes has not been quantified, which hampers prioritization of observational deployments and development of model parameterizations in this region. In this study a high-resolution (1/12°) regional model of the southern Weddell Sea is used to quantify the overturning circulation and decompose it into contributions due to multi-annual mean flows, seasonal/interannual variability, tides, and other sub-monthly variability. It is shown that tides primarily influence the overturning by changing the melt rate of the Filchner-Ronne Ice Shelf (FRIS). The resulting ~0.2 Sv decrease in DSW transport is comparable to the magnitude of the overturning in the FRIS cavity, but small compared to DSW export across the continental shelf break. Seasonal/interannual fluctuations exert a modest influence on the overturning circulation due to the relatively short (8-year) analysis period. Analysis of the transient energy budget indicates that the non-tidal, sub-monthly variability is primarily baroclinically-generated eddies associated with dense overflows. These eddies play a comparable role to the mean flow in exporting dense shelf waters across the continental shelf break, and account for 100% of the transfer of heat onto the continental shelf. The eddy component of the overturning is sensitive to model resolution, decreasing by a factor of ~2 as the horizontal grid spacing is refined from 1/3° to 1/12°.


2021 ◽  
Author(s):  
Samuel Clifford ◽  
Pauline Waight ◽  
Jada Hackman ◽  
Stephane Hue ◽  
Charlotte M Gower ◽  
...  

Background: The ability of SARS-CoV-2 vaccines to protect against infection and onward transmission determines whether immunisation can control global circulation. We estimated effectiveness of BNT162b2 and ChAdOx1 vaccines against acquisition and transmission of the Alpha and Delta variants in a prospective household study in England. Methods: Adult index cases in the community and their household contacts took oral-nasal swabs on days 1, 3 and 7 after enrolment. Swabs were tested by RT-qPCR with genomic sequencing conducted on a subset. We used Bayesian logistic regression to infer vaccine effectiveness against acquisition and transmission, adjusted for age, vaccination history and variant. Findings: Between 2 February 2021 and 10 September 2021 213 index cases and 312 contacts were followed up. After excluding households lacking genomic proximity (N=2) or with unlikely serial intervals (N=16), 195 households with 278 contacts remained of whom 113 (41%) became PCR positive. Delta lineages had 1.64 times the risk (95% Credible Interval: 1.15-2.44) of transmission than Alpha; contacts older than 18 years were 1.19 times (1.04-1.52) more likely to acquire infection than children. Effectiveness of two doses of BNT162b2 against transmission of Delta was 31% (-3%, 61%) and 42% (14%, 69%) for ChAdOx1, similar to their effectiveness for Alpha. Protection against infection with Alpha was higher than for Delta, 71% (12%,95%) vs 24% (-2%, 64%) respectively for BNT162b2 and 26% (-39%, 73%) vs 14% (-5%, 46%) respectively for ChAdOx1. Interpretation: BNT162b2 and ChAdOx1 reduce transmission of the Delta variant from breakthrough infections in the household setting though their protection against infection is low. Funding: This study was funded by the UK Health Security Agency (formerly Public Health England) as part of the COVID-19 response.


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