By adopting a 2D time-dependent wave code, we investigate how mode-converted waves at the Ion-Ion Hybrid (IIH) resonance and compressional waves propagate in 2D density structures with a wide range of field-aligned wavenumbers to background magnetic fields. The simulation results show that the mode-converted waves have continuous bands across the field line consistent with previous numerical studies. These waves also have harmonic structures in frequency domain and are localized in the field-aligned heavy ion density well. Our results thus emphasize the importance of a field-aligned heavy ion density structure for ultra-low frequency wave propagation, and suggest that IIH waves can be localized in different locations along the field line.

1. INTRODUCTION
 2. NUMERICAL RESULTS
 3. DISCUSSION
 ACKNOWLEDGMENTS
 REFERENCES

• Eun-Hwa Kim(Princeton Center for Heliophysics and Princeton Plasma Physics Laboratory, Princeton University, Princeton, NJ 08543-0451, USA) Corresponding Author
• Jay R. Johnson(Princeton Center for Heliophysics and Princeton Plasma Physics Laboratory, Princeton University, Princeton, NJ 08543-0451, USA)
• Dong-Hun Lee(School of Space Research, Kyung Hee University, Yongin 17104, Korea)