China HydroMeteorology Research Group
Published November 26, 2025 | Version V1.0
Dataset Open

CHM_Ssd: A New High-Resolution Sunshine duration Dataset for Mainland China

Authors/Creators

  • 1. ROR icon Beijing Normal University

Description

1.  Dataset information

Dataset name: CHM_Ssd

Summary: CHM_Ssd, an innovative and comprehensive long-term daily Sunshine duration (Ssd) dataset with a spatial resolution of 0.1° and data collected from 1961 to 2024 in mainland China. 

Content of the data set:

(1)  Metadata for CHM_Ssd.docx: This document provides detailed information about the dataset.

(2)  CHM_Ssd_01_daily_1961_2024.zip: Compressed file containing gridded daily sunshine duration (Ssd) fields at 0.1° spatial resolution for the period 1961–2024 (NetCDF format; “01” = 0.1°, “daily” = interpolated daily data, “1961_2024” = years).

To facilitate downloading, we have split the data into nc data every ten years.

CHM_Ssd_1961_1969.nc

CHM_Ssd_1970_1979.nc

CHM_Ssd_1980_1989.nc

CHM_Ssd_1990_1999.nc

CHM_Ssd_2000_2009.nc

CHM_Ssd_2010_2019.nc

CHM_Ssd_2020_2024.nc

2.  Brief calculation introduction

The dataset utilizes high-density meteorological station data and follows a structured framework based on the China Hydro-Meteorology dataset (CHM; https://zenodo.org/communities/chm/records?q=&l=list&p=1&s=10). To ensure data integrity, rigorous quality control was applied and missing values were removed to facilitate reliable interpolation.

Key meteorological variables—Ssd—were interpolated to a 0.1° spatial resolution using angular distance weighting (ADW). This method incorporates both angular and distance weighting, improving robustness against outliers. We interpolated the basic meteorological variables (Ssd), and in the interpolation process adopted ADW interpolation, which considers angle weight in addition to the distance weight function, making it more robust to outliers. We interpolated meteorological elements to 0.1° spatial resolution, which is consistent with CHM_Drought (https://zenodo.org/records/14634774) and CHM_PRE (https://zenodo.org/records/15735374). The ADW approach employed a modified Shepard’s algorithm, which integrates the correlation decay distance (CDD). CDD defines the distance at which inter-station correlation falls below 1/e, roughly equivalent to a 0.05 significance level in large samples (Ssd≈480). Using CDD to constrain the number of stations per grid cell enhances interpolation accuracy.

3.  Details of the variables in the file

Each NetCDF file contains the following four variables:

(1) lat: Latitude dimension, measured in degrees (°).

(2) lon: Longitude dimension, measured in degrees (°).

(3) time: Time dimension, measured in days since January 1, 1961.

(4) Ssd: Daily Sunshine duration (time, lat, lon).

4.  Authors and contacts

 Qi Zhang (qizhang@qhnu.edu.cn)

Chiyuan Miao (miaocy@bnu.edu.cn)

Jinlong Hu (hujl98@mail.bnu.edu.cn)

Files

Files (21.5 GB)

Name Size Download all
md5:17b470244e31af2c78e9575599034489
3.0 GB Download
md5:cb3174a319ef70717c335dfd0187ada2
3.4 GB Download
md5:7f994447f1b1992bdab39370d985e592
3.4 GB Download
md5:fde255bba2d928f298f7218b9663cff8
3.4 GB Download
md5:2df38096ca678ba30f7d7c6c40d0d0a6
3.4 GB Download
md5:ff8004ab9bd173b4420144625998117d
3.4 GB Download
md5:259940d9ea6f5dad06aeeb727da60fcf
1.7 GB Download

Additional details

Dates

Submitted
2025-11-26
Initial submission

References

  • Zhang, Q., Miao, C., Su, J., Gou, J., Hu, J., Zhao, X., & Xu, Y. (2025). A new high-resolution multi-drought-index dataset for mainland China. Earth System Science Data, 17(3), 837–853. https://doi.org/10.5194/essd-17-837-2025
  • Hu, J., Miao, C., Su, J., Zhang, Q., Gou, J., & Sun, Q. (2025). An upgraded high-precision gridded precipitation dataset for the Chinese mainland considering spatial autocorrelation and covariates. Earth System Science Data, 17(8), 3987–4004. https://doi.org/10.5194/essd-17-3987-2025
  • Han, J., Miao, C., Gou, J., Zheng, H., Zhang, Q., & Guo, X. (2023). A new daily gridded precipitation dataset for the Chinese mainland based on gauge observations. Earth System Science Data, 15(7), 3147–3161. https://doi.org/10.5194/essd-15-3147-2023