The Relation Between the Radial Temperature Profile in the Chromosphere and the Solar Spectrum at Centimeter,Millimeter, Submillimeter,and Infrared Wavelengths

Solar observations from millimeter to ultraviolet wavelengths show that there is a temperature minimum between photosphere and chromosphere. Analyses based on semi-empirical models locate this point at about 500 km above the photosphere. The consistency of these models has been tested by means of millimeter to infrared observations. We show that variations of the theoretical radial temperature profile near the temperature minimum impact the brightness temperature at centimeter, submillimeter, and infrared wavelengths, but the millimeter wavelength emission remains unchanged. We found a region between 500 and 1000 km above the photosphere that remains hidden to observations at the frequencies that we studied here.