Current solar wind prediction is based on the Wang & Sheeley empirical
relationship between the solar wind speed observed at 1 AU and the rate of
magnetic flux tube expansion (FTE) between the photosphere and the inner
corona, where FTE is computed by coronal models that take the photospheric flux
density synoptic maps as their inner boundary conditions to extrapolate the
photospheric magnetic fields to deduce the coronal and the heliospheric
magnetic field configuration. Since these synoptic maps are among the most
widely-used of all solar magnetic data products, the uncertainties in the model
predictions that are caused by the uncertainties in the synoptic maps are
worthy of study. However, such an estimate related to synoptic map construction
was not available until Bertello et al. (Solar Physics, 289, 2014) obtained the
spatial standard deviation synoptic maps; 98 Monte-Carlo realizations of the
spatial standard deviation maps for each photospheric synoptic maps. In this
paper, we present an estimate of uncertainties in the solar wind speed
predicted at 1 AU by the CSSS model due to the uncertainties in the
photospheric synoptic maps. We also present a comparison of the coronal hole
locations predicted by the models with the STEREO/SECCHI EUV synoptic maps. In
order to quantify the extent of the uncertainties involved, we compared the
predicted speeds with the OMNI solar wind data during the same period (taking
the solar wind transit time into account) and obtained the root mean square
error between them. To illustrate the significance of the uncertainty estimate
in the solar wind prediction, we carried out the analysis for three Carrington
rotations, CR 2102, CR 2137 and CR 2160 at different phases of the solar cycle.
The uncertainty estimate is critical information necessary for the current and
future efforts of improving the solar wind prediction accuracies.
