seriesDashStyle

Specifies the line style of the polarsplinearea series line. May be one of the following:

Solid
ShortDash
ShortDot
ShortDashDot
ShortDashDotDot
Dot
Dash
LongDash
DashDot
LongDashDot
LongDashDotDot

seriesSettings: {
    polarsplinearea: {
        seriesDashStyle: "ShortDot"
    }
}

This setting is demonstrated in the following example.