// creates duplicate list in ascending order
List<WindRosePlotDataRecord> SortedList = _Rows.OrderByDescending(o => o.Parameter).ToList(); 

// creates duplicate list in descending order
List<WindRosePlotDataRecord> SortedList = _Rows.OrderByDescending(o => o.Parameter).ToList(); 
            
// sort-in-place in ascending order
_Rows.Sort((x, y) => x.Parameter.CompareTo(y.Parameter));  

// sort-in-place in descending order
_Rows.Sort((x, y) => y.Parameter.CompareTo(x.Parameter));  // we switched x and y in CompareTo