Global structure of the out-of-ecliptic solar wind

We use the observed photospheric field maps and the wind speed observed from Ulysses to study the out‐of‐ecliptic solar wind. The model calculates the wind speed from the rate of magnetic flux tube expansion factors using a conversion function that is determined by least squares fit of all currently available data from Ulysses. Using the best fit conversion function, we investigate the global solar wind covering a 36‐year period from 1968 through 2003. The results complement and expand upon earlier studies conducted with interplanetary scintillation and other in situ spacecraft observations. The rotationally averaged wind speed is a function of two parameters: the heliolatitude and the phase of the solar cycle. The out‐of‐ecliptic solar wind has a recurrent stable structure, and the average wind speed varies like a sine square of latitude profile spanning more than 5 years during the declining phase and solar minimum in each solar cycle. Ulysses has observed this stable structure in its first polar orbit in 1992–1997. Near solar maximum the structure of the out‐of‐ecliptic solar wind is in a transient state lasting 2–3 years when the stable structure breaks down during the disappearance and reappearance of the polar coronal holes.