- An extended ground surface frost number method for mapping permafrost: frostnum/cop
The method, originally developed by Hu et al. (2020), was an extension of the surface ground frost index model (Nelson and Outcalt, 1983), which exclusively relied on satellite temperature data (LST) and calibration using permafrost distribution maps within specific sub-regions of the study area. In Cao et al. (2023), improvements were made to the frostnum/cop method by refining the objective functions to alleviate issues related to parametric equifinality. The R code for this method is available in our Github repository, and the release (v1.0-essd) associated with mapping ground-frost zones in the Tibetan Plateau for the year 2010 can be accessed at https://doi.org/10.5281/zenodo.8301453.
- Hu J, Zhao S, Nan Z*, Wu X, Sun X. A novel approach for mapping permafrost in a large area using subregion maps and satellite data. Permafrost and Periglacial Processes. 2020, 31(4): 548-560. doi:10.1002/ppp.2068.
- Cao Z, Nan Z*, Hu J, Chen Y, Zhang Y. A new 2010 permafrost distribution map over the Qinghai-Tibet Plateau based on subregion survey maps: a benchmark for regional permafrost modeling. Earth System Science Data. 2023, 15(9): 3905-3930. doi:10.5194/essd-15-3905-2023.
- Nelson F E, Outcalt S I. A frost index number for spatial prediction of ground-frost zones. Proceedings of 4th International Conference on Permafrost,Vol.1. Washington, DC: National Academy Press, 1983.907-911.
- SCSG-based interpolation method for cloudy-sky LSTs associated with ISPRS P&RS paper (Chen et al. 2023)
We have devised an innovative approach for retrieving missing cloudy-sky MODIS LST data, leveraging the solar-cloud-satellite geometry. Through a case study conducted over the Tibetan Plateau, we have demonstrated a high level of interpolation accuracy. The R code for this method is readily accessible on our GitHub repository. For further details, please refer to the following publication:
Chen Y, Nan Z*, Cao Z, Ou M, Feng K. “A stepwise framework for interpolating land surface temperature under cloudy conditions based on solar-cloud-satellite geometry.” ISPRS Journal of Photogrammetry and Remote Sensing, 2023.
- Modified Noah LSM v3.4.1 associated with a manuscript submitted to Earth’s Future(2022EF002652: Qinghai-Tibet Plateau permafrost at risk in the late 21st century).
This release corresponds to the version used in the simulation conducted for the manuscript published on Earth’s Future. Key improvements in the modified Noah LSM codes include a revised thermal roughness scheme specific for the sparse vegetation commonly found on the Tibetan Plateau (QTP), an enhanced parameterization for thermal and hydraulic conductivities to accommodate the coarse-grained soils and ground-ice prevalent in the QTP region, and an expansion of the simulation depth to depths exceeding 15 meters accommodating vertical soil heterogeneity. The download link for the source codes is available for access.