Recent upper layer cooling and freshening in the Norwegian Sea

Several time series of temperature and salinity in the Norwegian Sea indicate a general upper layer decrease in both variables. The observations indicate that this change began in about the middle of the 1960s. Time series at Ocean Weather Station "M" (OWS"M"), from Russian surveys in the southem Norwegian Sea as well as Scottish and Faroese observations in the Faroe-Shetland Channel and around the Faroes, all have similar trends and show that this is a phenomenon which affects wide areas in the Norwegian Sea. The reason for this trend is an increased supply of freshwater in the East Icelandic Current. As a result, both temperature and salinity is now at a lower level than during the "Great Salinity Anomaly'' ("GSA") in the 1970s both at 400 m depth at OWS "M" and in the 200- 500 m layer in the southem Norwegian Sea as observed in the Russian time series. The forcing may be increased production of Arctic surface water in the Greenland Sea when the deep convection is reduced, or more probably, increased export of freshwater from the Arctic Ocean. There is fairly good correlation between the wind stress curl over the Greenland Sea and the Russian time series of temperature and salinity, averaged between 200 and 500 m depth and between O and 3.5°E along 63°N in the Norwegian Sea. Considerably increased supply of Arctic Water from the East Icelandic Current during a period around 1978, clearly reinforced the "GSA" in the Nordic Seas. This also explains the coinciding variation in Atlantic and Arctic waters in the Faroe-Shetland Channel during the "GSA"

On Double-Boundary Non-Crossing Probability for a Class of Compound Processes with Applications

We develop an efficient method for computing the probability that a non-decreasing, pure jump (compound) stochastic process stays between arbitrary upper and lower boundaries (i.e., deterministic functions, possibly discontinuous) within a finite time period. The compound process is composed of a process modelling the arrivals of certain events (e.g., demands for a product in inventory systems, customers in queuing, or claims/capital gains in insurance/dual risk models), and a sequence of independent and identically distributed random variables modelling the sizes of the events. The events arrival process is assumed to belong to the wide class of point processes with conditional stationary independent increments which includes (non-)homogeneous Poisson, binomial, negative binomial, mixed Poisson and doubly stochastic Poisson (i.e., Cox) processes as special cases. The proposed method is based on expressing the non-exit probability through Chapman-Kolmogorov equations, re-expressing them in terms of a circular convolution of two vectors which is then computed applying fast Fourier transform (FFT). We further demonstrate that our FFT-based method is computationally efficient and can be successfully applied in the context of inventory management (to determine an optimal replenishment policy), ruin theory (to evaluate ruin probabilities and related quantities) and double-barrier option pricing or simply computing non-exit probabilities for Brownian motion with general boundaries

A review of the physical and biological conditions in the Barents Sea

Management strategies for the fish stocks in the Barents sea. Proceedings of the 8th Norwegian-Russian Symposium. Bergen, 15-16 June 199

Theoretical models, problems of design, technology and rational use of dead-weight pressure-gauge tester

The investigation is concerned with corrugated waveguides. The object to be attained is investigation of the processes of light distribution, radiation, reflection and generation in corrugated waveguides. The analysis of the processes of excitation of the corrugated waveguide by Gaussian light beam in noncollinear geometry, light reflection from the waveguide surface, as well as process of noncollinear reflection of waveguide modes has been first analyzed. The possibility of one-dimensional light output from the corrugated waveguide, possibility of creating narrow-band laser mirrors and filter based on corrugated waveguides as well as laser with a low dispersion of radiation have been shownAvailable from VNTIC / VNTIC - Scientific & Technical Information Centre of RussiaSIGLERURussian Federatio

Trees with product-form random weights

We consider growing random recursive trees in random environment, in which at each step a new vertex is attached according to a probability distribution that assigns the tree vertices masses proportional to their random weights.The main aim of the paper is to study the asymptotic behavior of the mean numbers of outgoing vertices as the number of steps tends to infinity, under the assumption that the random weights have a product form with independent identically distributed factors

Trees with product-form random weights

We consider growing random recursive trees in random environment, in which at each step a new vertex is attached according to a probability distribution that assigns the tree vertices masses proportional to their random weights.The main aim of the paper is to study the asymptotic behavior of the mean numbers of outgoing vertices as the number of steps tends to infinity, under the assumption that the random weights have a product form with independent identically distributed factors