irradiance
noun
ir·ra·di·ance
i-ˈrā-dē-ən(t)s 
1
2
: the density of radiation incident on a given surface usually expressed in watts per square centimeter or square meter
Examples of irradiance in a Sentence
Recent Examples on the Web
Solar irradiance is the amount of power that falls on the surface of the earth, measured in watts per square meter (W/m2).
—
Ian Dexter Palmer, Forbes.com, 10 Sep. 2025
Solar power works for missions close to the sun, but by the time a spacecraft gets to Jupiter, the available solar irradiance drops below 4 percent of that on Earth.
—IEEE Spectrum, 25 Aug. 2025
The scientists focused on a particular type of irradiance — which includes both direct sunlight and sunlight scattered by the atmosphere — and which is most relevant to prevalent flat-plate photovoltaic systems.
—Sharon Udasin, The Hill, 6 Jan. 2025
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Ian Dexter Palmer, Forbes.com, 10 Sep. 2025
Solar power works for missions close to the sun, but by the time a spacecraft gets to Jupiter, the available solar irradiance drops below 4 percent of that on Earth.
—IEEE Spectrum, 25 Aug. 2025
The scientists focused on a particular type of irradiance — which includes both direct sunlight and sunlight scattered by the atmosphere — and which is most relevant to prevalent flat-plate photovoltaic systems.
—Sharon Udasin, The Hill, 6 Jan. 2025
Cite this Entry
“Irradiance.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/irradiance. Accessed 15 Sep. 2025.
Copy CitationMedical Definition
irradiance
noun
ir·ra·di·ance
ir-ˈād-ē-ən(t)s
: the density of radiation incident on a given surface usually expressed in watts per square centimeter or square meter
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