#ozone_layer__ozonelayer__ozonosphere  a layer in the stratosphere (at approximately 20 miles) that contains a concentration of ozone sufficient to block most ultraviolet radiation from the sun
  supertype:  layer  a relatively thin sheetlike expanse or region lying over or under another
  part of:  stratosphere
  part:  ozone_hole__ozonehole  an area of the ozone layer (near the poles) that is seasonally depleted of ozone

No statement uses or specializes ozone_layer; click here to add one.