Indian summer monsoon onset forecast skill in the UK Met Office initialized coupled seasonal forecasting system (GloSea5-GC2)

Accurate and precise forecasting of the Indian monsoon is important for the socio-economic security of India, with improvements in agriculture and associated sectors from prediction of the monsoon onset. In this study we establish the skill of the UK Met Office coupled initialized global seasonal forecasting system, GloSea5-GC2, in forecasting Indian monsoon onset. We build on previous work that has demonstrated the good skill of GloSea5 at forecasting interannual variations of the seasonal mean Indian monsoon using measures of large-scale circulation and local precipitation. We analyze the summer hindcasts from a set of three springtime start-dates in late April/early May for the 20-year hindcast period (1992-2011). The hindcast set features at least fifteen ensemble members for each year and is analyzed using five different objective monsoon indices. These indices are designed to examine large and local-scale measures of the monsoon circulation, hydrological changes, tropospheric temperature gradient, or rainfall for single value (area-averaged) or grid-point measures of the Indian monsoon onset. There is significant correlation between onset dates in the model and those found in reanalysis. Indices based on large-scale dynamic and thermodynamic indices are better at estimating monsoon onset in the model rather than local-scale dynamical and hydrological indices. This can be attributed to the model's better representation of large-scale dynamics compared to local-scale features. GloSea5 may not be able to predict the exact date of monsoon onset over India, but this study shows that the model has a good ability at predicting category-wise monsoon onset, using early, normal or late tercile categories. Using a grid-point local rainfall onset index, we note that the forecast skill is highest over parts of central India, the Gangetic plains, and parts of coastal India - all zones of extensive agriculture in India. El Niño Southern Oscillation (ENSO) forcing in the model improves the forecast skill of monsoon onset when using a large-scale circulation index, with late monsoon onset coinciding with El Niño conditions and early monsoon onset more common in La Niña years. The results of this study suggest that GloSea5's ensemble-mean forecast may be used for reliable Indian monsoon onset prediction a month in advance despite systematic model errors

FE ANALYSIS OF A COUPLED ENERGETIC-STATISTICAL SIZE EFFECT IN PLAIN CONCRETE BEAMS WITH VARYING MATERIAL PROPERTIES

Abstract: The numerical FE investigations of a coupled energetic-statistical size effect in unnotched concrete beams of similar geometry under quasi-static three point bending were performed within elasto-plasticity with non-local softening. The stochastic FE analyses were carried out with three different beam sizes. Deterministic calculations were performed with the uniform distribution of a uniaxial tensile strength. In statistical calculations cross-correlated random fields were used to describe the spatial fluctuation of material randomness. Stochastic simulations were made with varying uniaxial tensile strength, initial fracture energy and elastic modulus. The effect of independently and simultaneously varying material parameter was investigated

Historical context of parasitological studies in tropical area, malaria as an example

Review paper deals with the historical analysis of intellectual activity of some famous parasitologists working in tropics on malaria in the XIX/XX century: A. Laveran (1845–1922), R. Ross (1857–1932), P. Manson (1844–1922), B. Grassi (1854–1925), and other Nobelprize researchers: P. H. Müller (1899–1965) and J. W. von Jauregg (1857–1940). Those chief investigations are interpreted from the point of view of the so−called anthropology of knowledge based on L. Fleck's (1896–1961) philosophy and sociology of science. Parasitological investigations, especially in the field of malaria, were undertaken in the developed economically countries in answer to the social demands. It was connected with development of colonies and the needs of stabilization of epidemiological situation in tropics. To mid of the eigthies of 19th century the lack of positive effects resulted from the theoretical barriers and conservative thinking style of the European academic society. It caused that great parasitological discoveries of the etiological agents of parasitic diseases (like plasmodia, life cycle in malaria) took place behind university circles. They were done by the physicians — general practitioners — in the colony areas. Doctors A. Laveran, P. Manson and R. Ross were not restricted by traditional standards and the obliging normative concepts in the academic naturalism. Those medical men worked out a new impulse for parasitology and supported an idea based on the rule that each disease should be assigned with the materialistic biological factor (pathogen). In the years 1800–1900 the old and a new concepts were competed in the natural sciences and medicine. Near year 1900 a new way in the context of modern interpretations was brought into general use. It was proved experimentally that etiological theory of parasitic disease was more practically usuful. It resulted in the formation of the effective prophylactic theory as well as the development of research in the field of chemotherapy. For that reason this thinking style was accepted by the state authorities and armies interested in possessing colonies. The governments organized and financed scientific institutes of tropical medicine and the hygienic parasitological journals. Also the researchers (A. Laveran, R. Ross, P. Manson) were rewarded for their epoch−making investigations in tropical disease problems. At the same time the progress in parasitology was prompted and the old theories in old thinking style were eliminated as false because of their practical uselessness. Their followers lost status of authorities. This analysis proved that external factors of science, i.e. social needs in historic periods play real role in the promoting of changes of scientific standards in the perception of new standards. Social needs form the broad social−cultural context of scientific activity and they influence seriously the way of thinking and investigations practice

Stochastic Modelling of Temperature Variations with a View Towards Weather Derivatives

Daily average temperature variations are modelled with a mean-reverting Ornstein-Uhlenbeck process driven by a generalized hyperbolic Levy process and having seasonal mean and volatility. It is empirically demonstrated that the proposed dynamics fits Norwegian temperature data quite successfully, and in particular explains the seasonality, heavy tails and skewness observed in the data. The stability of mean-reversion and the question of fractionality of the temperature data are discussed. The model is applied to derive explicit prices for some standardized futures contracts based on temperature indices and options on these traded on the Chicago Mercantile Exchange (CME).Temperature modelling, stochastic processes, Levy processes, mean-reversion, seasonality, fractionality, temperature futures and options,