Black Body Radiation

Black-body radiation is the thermal electromagnetic emission of an idealized perfect absorber and emitter, with a spectrum that depends only on temperature. The total emitted flux follows the Stefan-Boltzmann law, M = sigma * T^4, where sigma = 5.67e-8 W/m2/K^4, and the peak wavelength follows Wien’s displacement law (lambda_max * T = 2.898e-3 m*K). The Planck function gives the spectral distribution. The sea surface radiates nearly as a black body in the infrared with emissivity near 0.98, so satellite infrared radiometers invert measured radiance through Planck’s law to retrieve sea surface temperature.