Variations of the plasma pressure in a magnetic flux tube can produce MHD waves evolving into shocks. In the case of a low plasma beta. plasma pressure pulses in the magnetic flux tube generate MHD slow shocks propagating along the tube. For converging magnetic field lines. https://safeersappliancers.shop/product-category/samsung-rf56m9540sr-family-hub-91cm-frost-free-american-fridge-freezer/