Add Princess Elizabeth Land data

[weiji14]

Add in bed elevation data at Princess Elizabeth Land, East Antarctica collected using the “Snow Eagle 601” aero geophysical platform; a BT-67 airplane operated by the Polar Research Institute of China for the Chinese National Antarctic Research Expedition (CHINARE) program

References:

• Cui, X., Jeofry, H., Greenbaum, J. S., Guo, J., Li, L., Lindzey, L. E., Habbal, F. A., Wei, W., Young, D. A., Ross, N., Morlighem, M., Jong, L. M., Roberts, J. L., Blankenship, D. D., Bo, S., & Siegert, M. J. (2020). Bed topography of Princess Elizabeth Land in East Antarctica [Preprint]. Cryosphere – Radar measurements. https://doi.org/10.5194/essd-2020-126
• ICECAP-2 consortium processed airborne ice thickness data from the Princess Elizabeth Land, East Antarctica at https://doi.org/10.5281/zenodo.3815063
• ICECAP-2 consortium bed elevation model for Princess Elizabeth Land, East Antarctica at https://doi.org/10.5281/zenodo.3666087