Magnetic force microscopy and spin-polarized scanning electron microscopy are used to study the relationship between the reproduced noise properties and the recorded magnetization structures of longitudinal recording media. Magnetically continuous areas cross-linked between the neighboring recorded bits are observed when the linear recording density is increased to greater than 100 kFCI (Flux Change per Inch). The magnetization transition for a randomly oriented medium tends to form an intermittent magnetization transition with a size similar to that of magnetic clusters. This process is related to the relatively high DC-erased noise characteristics. High Cr content in CoCr-alloy media and magnetic anisotropy along the circumferential direction contribute to reducing medium noise possibly through the reduction in size and/or the oriented magnetic distribution of the magnetic clusters.