Detection of stratospheric HNO3 and NO2 response to short-term solar ultraviolet variability
It is pointed out that variations in the solar ultraviolet irradiance with a period equal to or approximately one-half of the rotation period of the sun are currently observed by satellite monitoring. Information regarding the response of stratospheric species to solar ultraviolet variability is indispensable for an understanding of the photochemical behavior of the middle atmosphere. Relations are considered between LIMS (limb infrared monitor of the stratosphere) measurements of HNO3 and NO2, and the SBUV (solar backscatter ultraviolet) measurements of short-term variations in 205-nm radiation. It is found that the response of HNO3 is much stronger than, but in the opposite sense to the ozone response, while the NO2 response is in the opposite sense to the HNO3 response. Model calculations predict large variations in HNO3 over the 11-yr solar cycle.