Home
Back
Sunshine Hours Formula:
| From: | To: |
Sunshine hours represent the duration of direct solar radiation reaching the Earth's surface during a specific period, typically measured in hours per day. This measurement is crucial for meteorological studies, agriculture, solar energy planning, and climate research.
The calculator uses the standard conversion formula:
Where:
Explanation: The Campbell-Stokes recorder measures sunshine duration by focusing sunlight through a glass sphere to burn a trace on a specially designed card. The reading is then converted to actual sunshine hours using the 0.1 multiplication factor.
Details: Accurate sunshine hour data is essential for weather forecasting, agricultural planning (crop growth and development), solar energy system design, tourism industry planning, and understanding climate patterns and changes.
Tips: Enter the sunshine recorder reading obtained from the Campbell-Stokes instrument. The reading should be a positive number representing the measured value from the sunshine recorder card.
Q1: What is a Campbell-Stokes sunshine recorder?
A: It's a meteorological instrument that measures sunshine duration using a glass sphere to focus sunlight onto a calibrated card, creating burn marks that indicate periods of sunshine.
Q2: Why multiply by 0.1?
A: The 0.1 factor converts the recorder reading (which represents tenths of hours) into actual hours of sunshine duration.
Q3: What are typical sunshine hour values?
A: Values vary by location and season, ranging from 0-12 hours per day in most regions, with higher values in tropical areas and during summer months.
Q4: How accurate is this measurement method?
A: The Campbell-Stokes recorder provides reliable measurements with an accuracy of approximately ±0.1 hours when properly calibrated and maintained.
Q5: Are there modern alternatives to Campbell-Stokes recorders?
A: Yes, electronic sunshine sensors and pyranometers are now commonly used, offering automated data collection and higher temporal resolution.