def compute_windspeed(uas, vas):
    """Compute absolute wind speed from horizontal components."""
    sfc_wind = (uas ** 2 + vas ** 2) ** .5
    sfc_wind.var_name = 'sfcWind'
    sfc_wind.long_name = 'Daily-Mean Near-Surface Wind Speed'
    sfc_wind.standard_name = 'wind_speed'
    comment = 'near-surface (usually, 10 meters) wind speed.'
    sfc_wind.attributes['comment'] = comment
    return sfc_wind