Next Article in Journal
Association Between Socioeconomic Factors and the Choice of Dentifrice and Fluoride Intake by Children
Previous Article in Journal
Trichloroethylene and Cancer: Systematic and Quantitative Review of Epidemiologic Evidence for Identifying Hazards
Article Menu

Export Article

Open AccessArticle
Int. J. Environ. Res. Public Health 2011, 8(11), 4272-4283; doi:10.3390/ijerph8114272

Estimation of Effective Day Length at Any Light Intensity Using Solar Radiation Data

1
Shimonoseki Junior College, 1-1 Sakurayama-cho, Shimonoseki City, 750-8508, Japan
2
Toshiwa-kai Hospital, 5-8-1 Kanayama, Nakaku, Nagoya City, 460-0022, Japan
*
Author to whom correspondence should be addressed.
Received: 16 September 2011 / Revised: 19 October 2011 / Accepted: 4 November 2011 / Published: 10 November 2011
View Full-Text   |   Download PDF [505 KB, uploaded 19 June 2014]   |  

Abstract

The influence of day length on living creatures differs with the photosensitivity of the creature; however, the possible sunshine duration (N0) might be an inadequate index of the photoperiod for creatures with low light sensitivity. To address this issue, the authors tried to estimate the effective day length, i.e., the duration of the photoperiod that exceeds a certain threshold of light intensity. Continual global solar radiation observation data were gathered from the baseline surface radiation network (BSRN) of 18 sites from 2004 to 2007 and were converted to illuminance data using a luminous efficiency model. The monthly average of daily photoperiods exceeding each defined intensity (1 lx, 300 lx, … 20,000 lx) were calculated [defined as Ne(lux)]. The relationships between the monthly average of global solar radiation (Rs), N0, and Ne(lux) were investigated. At low light intensity (10,000 lx), Ne(lux) and Rs showed a logarithmic relationship. Using these relationships, empirical models were derived to estimate the effective day length at different light intensities. According to the validation of the model, the effective day length for any light intensity could be estimated with an accuracy of less than 11% of the mean absolute percentage error (MAPE) in the estimation of the monthly base photoperiod. Recently, a number of studies have provided support for a link between day length and some diseases. Our results will be useful in further assessing the relationships between day length and these diseases.
Keywords: solar radiation; effective day length; luminous efficiency; light intensity; circadian rhythm solar radiation; effective day length; luminous efficiency; light intensity; circadian rhythm
This is an open access article distributed under the Creative Commons Attribution License (CC BY 3.0).

Scifeed alert for new publications

Never miss any articles matching your research from any publisher
  • Get alerts for new papers matching your research
  • Find out the new papers from selected authors
  • Updated daily for 49'000+ journals and 6000+ publishers
  • Define your Scifeed now

SciFeed Share & Cite This Article

MDPI and ACS Style

Yokoya, M.; Shimizu, H. Estimation of Effective Day Length at Any Light Intensity Using Solar Radiation Data. Int. J. Environ. Res. Public Health 2011, 8, 4272-4283.

Show more citation formats Show less citations formats

Related Articles

Article Metrics

Article Access Statistics

1

Comments

[Return to top]
Int. J. Environ. Res. Public Health EISSN 1660-4601 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert
Back to Top