1. What is the Sun Zenith Angle?

The sun zenith angle is the angle between the sun's rays and the vertical direction (directly overhead). It represents how high the sun is in the sky, with 0° being directly overhead and 90° at the horizon.

2. How Does the Calculator Work?

The calculator uses the sun zenith angle formula:

Where:

• \( \phi \) — Latitude in degrees (-90° to 90°)
• \( \delta \) — Solar declination in degrees (-90° to 90°)
• \( H \) — Hour angle in degrees (-180° to 180°)

Explanation: This formula calculates the angle between the sun's position and the zenith (directly overhead point) based on geographic location, time of year, and time of day.

3. Importance of Zenith Angle Calculation

Details: Zenith angle calculation is crucial for solar energy systems, agriculture, photography, and understanding seasonal variations in sunlight intensity and duration.

4. Using the Calculator

Tips: Enter latitude between -90° and 90°, declination between -90° and 90°, and hour angle between -180° and 180°. All values must be valid numbers within these ranges.

5. Frequently Asked Questions (FAQ)

Q1: What is solar declination?
A: Solar declination is the angle between the rays of the sun and the plane of the earth's equator, varying between approximately -23.45° and +23.45° throughout the year.

Q2: How is hour angle calculated?
A: Hour angle is 0° at solar noon, negative before noon, and positive after noon. It changes by 15° per hour (360° per 24 hours).

Q3: What does a zenith angle of 90° mean?
A: A zenith angle of 90° means the sun is at the horizon (sunrise or sunset).

Q4: How does latitude affect zenith angle?
A: Higher latitudes generally have larger zenith angles (sun lower in the sky) compared to equatorial regions.

Q5: What are practical applications of zenith angle calculation?
A: Solar panel positioning, architectural design, agricultural planning, and calculating solar radiation intensity.