A long term global daily soil moisture dataset derived from AMSR-E and AMSR2 released by the National Tibetan Plateau Data Center (TPDC) (https://data.tpdc.ac.cn) has recently realized near-real-time daily updating. The current product can provide global daily soil moisture data two days after the passage of a satellite.

Based on AMSR-E/AMSR 2 Brightness Temperature (TB), this product uses a completely independently developed algorithm to retrieve the global surface soil moisture on a daily scale, with its accuracy being equivalent to that of SMAP soil moisture products. Moreover, this product, featuring long-term and high temporal and spatial consistency, can provide global surface soil moisture information for nearly 23 years (2002/07/27~ now).

This product is also the first data product of the National Tibetan Plateau Data Center (TPDC) to realize daily dynamic update, which indicates that the TPDC can provide more timely and faster data services.

The following figure shows the latest global soil moisture distribution map on April 7-8, 2024 and the average soil moisture after two days of integration. Based on data products of two consecutive days, soil moisture observation in most areas of the world can be realized.

Figure 1 Spatial distribution of global soil moisture on April 7 (top left), 8 (top right) and April 7-8 (average), 2024.

Figure 2 presents the daily time series of the soil moisture dataset in four grids from July 27, 2002 to April 8, 2024 in different climate zones around the world. It is apparent that the dataset is stable on these grids with obvious seasonal variation. Meanwhile, there are distinctive differences between different climatic zones across different grids.

Figure 2 Long term daily soil moisture change curve of global typical grids

In addition, in response to users’ needs, this product update has added data in tif format. Figure 3 shows the information of soil moisture files in the data center server, including nc and tif formats for downloading.

Figure 3 Soil moisture files in nc format (left) and tif format (right) on the data center server.

This dataset was published in Scientific Data (IF= 8.501) in the form of a data paper in early 2021 by Professor Lu Hui from the Department of Earth System Science (DESS), Tsinghua University (corresponding author) and Dr. Yao Panpan from the Institute of Aerospace Information Innovation under the Chinese Academy of Sciences (first author). The paper has drawn high attention and been downloaded many times (more than 19,000 views and over 2,300 downloads). Meanwhile, it has supported a national special project, “the Second Tibetan Plateau Scientific Expedition and Research”, and a national key research and development plan project, “Research and Development of Global Sea-Land-Air-Ice Water Cycle Coupling Model and the Attribution of Extreme Hydrological Events”.

Paper information: Yao, P.P., Lu, H., Shi, J.C., Zhao, T.J., Yang K., Cosh, M.H., Gianotti, D.J.S., & Entekhabi, D. (2021). A long term global daily soil moisture dataset derived from AMSR-E and AMSR2 (2002-2019). Scientific Data, 8, 143 (2021).

Data information: Yao Panpan and Lu Hui. (2020). A long term global daily soil moisture dataset derived from AMSR-E and AMSR2 (2002-the present), the National Tibetan Plateau Data Center (TPDC), DOI: 10.11888/Soil.tpdc.270960. CSTR: 18406.11.Soil.tpdc.270960.

Data link: https://data.tpdc.ac.cn/zh-hans/data/c26201fc-526c-465d-bae7-5f02fa49d738