Search results for "Latitude"

Instantaneous distribution of global and diffuse radiation on horizontal surfaces

1991

Abstract The aim of this paper is to obtain a general expression for estimating both the instantaneous global and diffuse radiations on horizontal surfaces from the respective daily values. The proposed expression is a modified Gaussian distribution with two parameters which take into account its width and the asymmetries between morning and afternoon hours. The performance of the method has been tested by comparing the theoretical hourly results with the experimental data of six actinometric stations with different geographical location and climatic conditions. The comparison has shown that the method here proposed is accurate for both the diffuse and global radiation.

Influence of the Madden-Julian Oscillation on Southern African summer rainfall

2007

Rain-causing mechanisms over Southern Africa (south of 15˚S) involve both tropical and temperate dynamics. Most studies focused on the synoptical timescale, while the intraseasonal (20-120 days) variability has more been neglected to date. This study aims at determining whether the dominant mode of intraseasonal variability in the Tropics, namely the Madden-Julian Oscillation (MJO), has a significant impact on Southern African rainfall and associated atmospheric dynamics. The examination of outgoing longwave radiation (OLR) over Southern Africa shows indeed significant intraseasonal fluctuations at the 30-60 day timescale, i.e. in the pe- riods that are typically reminiscent of the MJO. In ord…

Probabilistic Forecast for Northern New Zealand Seismic Process Based on a Forward Predictive Kernel Estimator

2011

In seismology predictive properties of the estimated intensity function are often pursued. For this purpose, we propose an estimation procedure in time, longitude, latitude and depth domains, based on the subsequent increments of likelihood obtained adding an observation one at a time. On the basis of this estimation approach a forecast of earthquakes of a given area of Northern New Zealand is provided, assuming that future earthquakes activity may be based on the smoothing of past earthquakes.

DIURNAL RAINFALL VARIATION IN MALAYA1

1968

ABSTRACT In low latitudes, where seasonal differences of climate are small and usually limited to factors such as winds and precipitation, the weather is largely controlled by diurnal processes. The diurnal variation of rainfall is the most important result of these processes and it is a characteristic part of the climate. In Malaya, diurnal rainfall regimes show seasonal variations, which are closely related to the system of the southeast Asian monsoons. The seasonal variations differ according to location, and three regional types can be recognized, which are found, respectively, at the west coast, the east coast, and at inland stations. Singapore, because of its extreme location at the s…

Spatial, seasonal and long-term variability of phytoplankton photosynthesis in lakes

1994

Pour une véritable théorie de la latitude managériale et du gouvernement des entreprises.

1996

Le problème du contrôle des dirigeants et la notion de gouvernement des entreprises font l'objet depuis longtemps de travaux, souvent liés à des théories de l'organisation parmi les plus connues (théorie des coûts de transaction, théorie de l'agence…). Mais il semble que ces analyses, notamment parce qu'elles sont trop centrées sur les relations avec les actionnaires et négligent l'examen de la « latitude managériale », ne puissent qu'incomplètement rendre compte du statut et du comportement effectif des dirigeants. L'auteur propose ici de suivre diverses pistes pour dépasser cette situation en enrichissant les approches réductrices aujourd'hui dominantes.

Representative major element compositions of clinopyroxenes and phlogopites from ultrapotassic rocks from Nangqian basin (Eastern Tibet)

2020

Representative major element compositions (in wt%) of clinopyroxenes and phlogopites from Nangqian ultrapotassic rocks. In-situ major-element compositions of mineral phases were obtained using the JEOL JXA-8230 Electron Microprobe at ISTerre, University Grenoble Alpes. Analytical conditions were 15 kV accelerating voltage and 12 nA beam current. The ZAF procedure was applied to reduce the raw data. The microprobe was calibrated using natural and synthetic standards. An X-ray element map of a calcite-bearing aggregate was acquired using 15 kV accelerating voltage and 10 nA beam current.

Sample details on OSL data for aeolian sediments in north-eastern part of European Sand Belt

2019

A compilation of previously published and unpublished absolute age (OSL and TL) determinations of aeolian sediments from the north-eastern part of European Sand Belt. Contains age, error, sampling depth, location etc. and a reference to data source. Coordinates of sampling locations for contemporary publications are taken from field observations (GPS), but older ones - published schematic maps. Data set is created according to schema of DATED-1 database (https://doi.org/10.1594/PANGAEA.848117).

Mixed support for an alignment between phenotypic plasticity and genetic differentiation in damselfly wing shape

2023

The relationship between genetic differentiation and phenotypic plasticity can provide information on whether plasticity generally facilitates or hinders adaptation to environmental change. Here, we studied wing shape variation in a damselfly (Lestes sponsa) across a latitudinal gradient in Europe that differed in time constraints mediated by photoperiod and temperature. We reared damselflies from northern and southern populations in the laboratory using a reciprocal transplant experiment that simulated time-constrained (i.e. northern) and unconstrained (southern) photoperiods and temperatures. After emergence, adult wing shape was analysed using geometric morphometrics. Wings from individu…

Persistence of temperature and precipitation: from local to global anomalies

2021

Using detrended fluctuation analysis (DFA) we find that all continents are persistent in temperature. The scaling exponents of the southern hemisphere (SH) continents, i.e., South America (0.77) and Oceania (0.72) are somewhat higher than scaling exponents of Europe (0.70), Asia (0.69) and North America (0.64), but the scaling of Africa is by far the highest (0.86). The reason for this is the location of Africa near the equator. The scaling exponents of the precipitation are much smaller, i.e. between 0.55 (Europe) and 0.68 (North America). The scaling exponent of Europe is near that of the random noise (0.5), while the other continents are slightly persistent in precipitation. We also show…