SOT: HOP46
2007-11-21T12:04:00 to 2007-11-21T12:34:00
Science Goal: Synoptic SOT Irradiance Scans
Program: Irradiance Scan DO NOT MODIFY! FG: all waves 4kx2k 1x1 repeat 2
Target: Active Region
xcen=-196 ycen=215
Instrument: SOT
HOP/JOP: 46
Description:
The total solar irradiance varies by about 0.1% over the course of the solar cycle, primarily due to the influence of magnetic structures such as sunspots and faculae on the photospheric spectral irradiance. Short-term irradiance variation (on the scale of days-to- months) is well understood to be due to the balance of sunspots and facular areas as they cross the disk. However on the decadal scale of the solar cycle, questions remain as to why the irradiance variation can lead and/or lag the active region count over the course of the cycle. Explanations ranging from changes in the solar diameter in response to magnetic flux storage in the convection zone to changes in the surface area of the photosphere due to F-mode modulation have been put forward. Seeing-free observations of both granulation and magnetic flux on a large range of scales are now possible with the SOT SP/FG instrument combination.
