The freeze/thaw status of the near-surface soil is the water-ice phase transition that occurred at the top soil layer. It is an important indicator as a giant on-off “switch” of the land surface processes including water, energy, and carbon exchanges between the land surface and atmosphere. The freeze/thaw status is an essential variable for understanding how the ecosystem responds to and affects global changes. This dataset is based on the AMSR-E, AMSR2 passive microwave brightness temperature data and MODIS optical remote sensing data. The freeze-thaw discriminant function algorithm and downscaling algorithm are used to generate the global near-surface soil freeze-thaw status with a spatial resolution of grids at 0.05° from 2002 to 2017. The dataset can be used for the analysis of the spatial distribution and trend changes of global freeze-thaw cycles, such as the freeze/thaw onset dates and duration. It provides data support for understanding the interaction mechanism between the land surface freeze-thaw cycle and the land-atmosphere exchanges under the context of global changes.

File naming and required software

YYYYDOY_ PP_ StateRR. h5
YYYY: 4 characters, year
DOY: 3 characters, day of year
PP: 2 characters, product name (FT stands for frozen / unfrozen status)
RR: 2 characters, spatial resolution of data grid (0.05 °)

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Cite as:

Zhao, T., Zhang, Z. (2019). 2002-2017 Global AMSR-E/2 Near-surface Freeze/Thaw state (0.05°). A Big Earth Data Platform for Three Poles, DOI: 10.11888/Geocry.tpdc.270283. CSTR: 18406.11.Geocry.tpdc.270283. (Download the reference： RIS | Bibtex )

Related Literatures:

1. Zhao, T., Shi, J., Hu, T., Zhao, L., Zou, D., Wang, T., ... & Wang, P. (2017). Estimation of high‐resolution near‐surface freeze/thaw state by the integration of microwave and thermal infrared remote sensing data on the Tibetan Plateau. Earth and Space Science, 4(8), 472-484.( View Details | Bibtex)

2. Hu, T., Zhao, T., Shi, J., Wu, S., Liu, D., Qin, H., & Zhao, K. (2017). High-resolution mapping of freeze/thaw status in china via fusion of MODIS and AMSR2 data. Remote Sensing, 9(12), 1339.( View Details | Bibtex)

Using this data, the data citation is required to be referenced and the related literatures are suggested to be cited.

Support Program

CASEarth:Big Earth Data for Three Poles（grant No. XDA19070000） (No:XDA19000000)

Second Tibetan Plateau Scientific Expedition Program

o Strategic Priority ResearchProgram of the Chinese Academy of Sciences: Grant No. XDA19070204 (No:XDA19070204) [XDA19070204]

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