Search results for "Sunshine duration"
showing 10 items of 12 documents
A 350 year drought reconstruction from Alpine tree ring stable isotopes
2010
[1] Climate reconstructions based on stable isotopes in tree rings rely on the assumption that fractionation-controlling processes are strongly linked to meteorological variables. In this context, we investigated the climate sensitivity of 350 years of carbon and oxygen isotope ratios of tree ring cellulose from European larch obtained at a high-elevation site in the Swiss Alps (∼2100 m above sea level). Unlike tree ring width and maximum latewood density, which contain only summer temperature information at this site, we found that our stable isotope series reveal additionally to temperature a striking sensitivity to precipitation (mainly for carbon) and sunshine duration (mainly for oxyge…
Studies on the impact of winter climate on rubber and wheat cultivation in the mountains of southern China, applying a fuzzy cluster analysis
1992
Data from climatic stations in China, located south of 30° N and > 400 m above sea-level, were analysed in order to study the relationship with winter climate, on the one hand, and with rubber and winter wheat cultivation, on the other. Three relevant agroclimatic parameters were investigated for January, namely mean temperature, precipitation total and sunshine duration. By applying a fuzzy cluster analysis, three agroclimatic regions were found in winter; the boundaries coincide with the macro-scale topography of southern China. In one case the boundary even corresponds with the position of the Kunming quasi-stationary front. Winter climate in the three agroclimatic regions was found to s…
A simple model for computing diffuse solar radiation
1989
In this paper a very simple model for predicting the daily diffuse solar radiation at any Italian location using as input few extensively measured meteorological parameters is proposed. In fact the daily diffuse radiation D, MJ.m−2.day−1, here is correlated with only the relative sunshine duration sS and the noon altitude of the sun on the 15th of the month hn, degrees, by the following equation: D=7(sS−(sinhn)1.55 . The validity of this formula is verified using monthly mean daily data from four Italian stations displaced at various latitudes or altitudes or geographical situations (inland or coastal site). The test results show that the deviations between the measured and the computed val…
Spanish Stock Returns: Where is the Weather Effect?
2003
Psychological studies support the existence of an influence of weather on mood. Saunders (1993) and Hirshleifer and Shumway (2001) argue that the weather could affect the behaviour of market traders and, therefore, it should be reflected in the stock returns. This paper investigates the possible relation between weather and market index returns in the context of the Spanish market. In 1989, this market changed its open outcry trading system into a computerised and decentralised trading system. Therefore, it is possible to check the influence of weather variables (sunshine hours and humidity levels) on index returns in an open outcry trading system, and to compare it with a screen traded env…
Cloudiness and Sunshine
1988
Records on mean monthly and annual cloudiness are contained in the climate tables (see Appendix). Despite regional gaps of data sources, the attempt was nevertheless made to work out some principal observations on cloudiness.
Validation of a very simple model for computing global solar radiation in the European, African, Asian and North American areas
1990
Abstract In a previous paper Coppolino has proposed a very simple model for predicting the monthly mean daily global solar radiation G (MJm −2 day −1 ) at any Italian location using as input only the sunshine duration s (hours) and the noon altitude of the sun on the 15th of the month h n (degrees). The correlation suggested is G = 7.8 s 0.5 (sin h n ) 1.15 . Herein the validity of this model is verified by extending its application to dat from 24 stations displaced at various latitudes, altitudes above sea level and geographical situations in the European, African, Asian and North American areas. Furthermore the validity of this model to fit the data of the tested stations is compared with…
A new model for estimating diffuse solar radiation in Italy from clearness index and minimum air mass
1990
The aim of this study is: (a) to propose a new simple model for estimating the monthly mean daily diffuse radiation D, MJ m−2 day−1, using as input only the clearness index Kt and minimum air mass and (b) to develop a map of diffuse solar radiation incident on a horizontal surface in Italy. The correlation herein suggested is D = 5.6 Kt−0.55 (sin hn)1.58 where hn is the noon altitude of the sun on the 15th of the month, in degrees, and Kt = G/H0; G and H0 are the monthly mean daily global and extraterrestrial solar radiation respectively. This equation is applied to Adrano, Palermo, Macerata and Genova stations, provided with measured data of global and diffuse radiation, and the relative c…
Seasonal variation of BMI at admission in German adolescents with anorexia nervosa.
2018
Objective Recent preliminary studies indicated a seasonal association of BMI at admission to inpatient treatment for anorexia nervosa (AN), indicating lower BMI in the cold season for restrictive AN. An impaired thermoregulation was proposed as the causal factor, based on findings in animal models of AN. However, findings regarding seasonality of BMI and physical activity levels in the general population indicate lower BMI and higher physical activity in summer than in winter. Therefore, we aimed to thoroughly replicate the findings regarding seasonality of BMI at admission in patients with AN in this study. Method AN subtype, age- and gender-standardized BMI scores (BMI-SDS) at admission, …
Estimation of daily average values of the Ångström turbidity coefficient β using a Corrected Yang Hybrid Model
2013
This paper aims to test a method for estimating daily values of atmospheric turbidity from non-specialized data, such as those obtained from agro-meteorological stations. This method allows estimating the spatial and temporal evolution of aerosols concentration in more places than just those in which direct measurements are available. The method is based on the Corrected Yang Hybrid Model (CYHM). The data used in the determination of errors between measured and estimated values of the daily Angstrom turbidity coefficient β were recorded in Valencia, Spain, during 2009 and 2011. These data were global solar irradiance, direct solar irradiance, temperature, relative humidity and Aerosol Optic…
Spanish Stock Returns: Rational or Weather-Influenced?
2002
Psychological studies support the existence of an influence of weather on mood. It could affect the behaviour of market traders, as suggested by some authors, and this should be reflected by the stock returns. This paper investigates the possible relation between weather and market index returns in the context of the Spanish market, in order to test the above hypothesis. In 1989, this market changed its open outcry trading system into a computerised and decentralised trading system. Therefore, it is possible to check the influence of weather variables (sunshine hours and humidity levels) on index returns in an open outcry trading system, and to compare it with a screen traded environment. T…