Brief description of observation datasets used in the RDAS
ECMWF Reanalysis v5 – Land (ERA5-Land) (Muñoz Sabater, 2019) is a reanalysis dataset provided by European Centre for Medium-Range Weather Forecasts (ECMWF). It has been produced by replaying the land component of the ECMWF ERA5 climate reanalysis which combines model data wit observations from across the world into a globally complete and consistent dataset using the laws of physics (ECMWF, 2024). It has spatial resolution of approximately 9km grid spacing at hourly data scale. The data is available from Climate Data Store (CDS) platform at https://cds.climate.copernicus.eu/datasets/reanalysis-era5-land?tab=download .
In RDAS, gridded ERA5-land dataset was processed at daily, monthly, seasonal and annual scales for administrative levels 1 and 2 for countries of South Asian Region from 1950 to 2023. The variables processed are total precipitation (tp), temperature (t2m) (daily maximum temperature, daily minimum temperature and daily average temperature).
ECMWF Reanalysis v5 (ERA5) (Hersbach et al., 2018) is the fifth generation ECMWF reanalysis. It combines model data with observations from across the world into a globally complete and consistent dataset using the laws of physics using data assimilation. It has spatial resolution of approximately 0.25 degrees grid spacing at hourly data. The data is available from Climate Data Store (CDS) platform at https://cds.climate.copernicus.eu/datasets/reanalysis-era5-single-levels?tab=download .
In RDAS, ERA5 land was processed at daily, monthly, seasonal and annual scales for administrative levels 1 and 2 for countries of South Asian Region from 1980 to 2023. The variables processed are total precipitation (tp), temperature (t2m) (daily maximum temperature, daily minimum temperature and daily average temperature).
Climate Hazards Group InfraRed Precipitation with Station data (CHIRPS) (Funk et al., 2014) is a rainfall data set ranging from 1981 to near-present. It is published by Climate Hazards Center (CHC), University of California, Santa Barbara. It incorporates climatology, CHPclim, 0.05° resolution satellite imagery, and in-situ station data to create gridded rainfall time series for trend analysis and seasonal drought monitoring (CHC, 2024). It has spatial resolution of 0.05 x 0.05 degree spatial resolution at various time scale including daily scale. The data is available from CHC platform at https://data.chc.ucsb.edu/products/CHIRPS-2.0/ .
In RDAS, CHIRPS version 2.0 was processing at daily, monthly, seasonal and annual scales for administrative levels 1 and 2 for countries of South Asian Region. Precipitation was processed from 1981 to 2023.
Multi-Source Weighted-Ensemble Precipitation (MSWEP) (Beck et al., 2019) is a global precipitation product by GloH20. This product merges gauge, satellite, and reanalysis data to obtain the highest quality precipitation estimates at every location. It has with a 3‑hourly 0.1° resolution available from 1979 to ~3 hours from real-time (GloH20, 2024). MSWEP tends to exhibit better performance than other precipitation products in both densely gauged and ungauged (Beck et al., 2019, 2017a, 2017b). The dataset is available at https://www.gloh2o.org/mswep/ via registration.
In RDAS, daily version of the MSWEP version 2.80 data was processed. It was processing at daily, monthly, seasonal and annual scales for administrative levels 1 and 2 for countries of South Asian Region. Precipitation was processed from 1979 to 2023.
Asian Precipitation - Highly-Resolved Observational Data Integration Towards Evaluation (APHRODITE) (Yatagai et al., 2012) of Water Resources dataset is a daily precipitation dataset with high-resolution grids for Asia. It is created with data obtained from a rain-gauge-observation network. The data is produced by Research Institute for Humanity and Nature (RIHN) and the Meteorological Research Institute of Japan Meteorological Agency (MRI/JMA). Spatial resolution of data is 0.25 degree. The dataset is available at http://aphrodite.st.hirosaki-u.ac.jp/download/ via registration.
In RDAS, APHRODITE (versions V1101 and V1101EX_R1 for daily precipitation and V1808 for temperature) was processed at daily, monthly, seasonal and annual scales for administrative levels 1 and 2 for countries of South Asian Region. Two variables (precipitation and daily average temperature) were processed from 1951 to 2015.
Global Precipitation Climatology Centre (GPCC) (Markus et al., 2022) is a daily global land-surface precipitation totals based on precipitation data provided by national meteorological and hydrological services, regional and global data collections as well as WMO GTS-data. The data is operated by Global Precipitation Climatology Centre at Deutscher Wetterdienst (DWD). The spatial resolution of data is 1.0 degree at daily scale. The dataset is available at https://opendata.dwd.de/climate_environment/GPCC/html/fulldata-daily_v2022_doi_download.html.
In RDAS, GPCC Full Data Daily Version 2022 was processed at daily, monthly, seasonal and annual scales for administrative levels 1 and 2 for countries of South Asian Region. It was processed from 1982 to 2020.
Climate Research Unit (CRU) Time Series (TS) (Harris et al., 2020) consists of gridded monthly fields of precipitation, daily maximum and minimum temperatures. It was published by University of Anglia. It is a widely used climate dataset on a 0.5° latitude by 0.5° longitude grid over all land domains of the world except Antarctica. It is derived by the interpolation of monthly climate anomalies from extensive networks of weather station observations. The dataset is available at https://crudata.uea.ac.uk/cru/data/hrg/index.htm#current .
In RDAS, CRU TS version 4.07 was processed. Daily data for CRU is not available and therefore, is processed at monthly, seasonal and annual scale. It was processed from 1901 to 2022.
India Meteorological Department (IMD) New High Spatial Resolution gridded dataset (Pai et al., 2014) is a daily gridded dataset over India, with temperature and precipitation variables. This data product is of 0.25 x 0.25 degree spatial resolution. Daily rainfall records from 6955 rain gauge stations in India were used to prepare the dataset. Data is prepared and published by Climate Prediction Group at India Meteorological Department. The dataset is available at https://www.imdpune.gov.in/lrfindex.php inside Gridded dataset achieve section.
In RDAS, IMD precipitation and temperature dataset was processed at daily, monthly, seasonal and annual scale for states and districts of India from 1951 to 2023.
| Datasets | Version used in RDAS | Full Form | Published by | Available year in RDAS | Available variables in RDAS | ||
| rainfall | Temperature | Resolution | |||||
| ERA5-land | xx | ECMWF Reanalysis v5 - land | European Centre for Medium-Range Weather Forecasts (ECMWF) | 1950-2023 | pr | tmax, tmin, tmean |
~9km |
| ERA5 | xx | ECMWF Reanalysis v5 | European Centre for Medium-Range Weather Forecasts (ECMWF) | 1980-2023 | pr | Tmax ,tmin, tmean |
0.25° |
| CHIRPS | V2.0 | Climate Hazards Group InfraRed Precipitation with Station data (CHIRPS) | Climate Hazards Center (CHC), University of California, Santa Barbara | 1981-2023 | pr | xx | 0.05° |
| MSWEP | V2.80 | Multi-Source Weighted-Ensemble Precipitation (MSWEP) | GloH20 | 1979-2023 | pr | xx | 0.1° |
| APHRODITE | V1101 and V1101EX_R1 for daily precipitation V1808 for temperature |
Asian Precipitation - Highly-Resolved Observational Data Integration Towards Evaluation | Research Institute for Humanity and Nature (RIHN) and the Meteorological Research Institute of Japan Meteorological Agency (MRI/JMA) | 1951-2015 | pr | tavg | 0.25° |
| GPCC | V2022_100 | Global Precipitation Climatology Centre (GPCC) | Global Precipitation Climatology Centre at Deutscher Wetterdienst (DWD) | 1982-2020 | pr | xx | 1° |
| CRU | V4.07 | Climate Research Unit (CRU) | University of East Anglia | 1901-2022 | pr | tmx, tmn, tmp |
0.5° |
| IMD | xx | MD New High Spatial Resolution Dataset | India Meteorological Department | 1951-2023 | pr | tmax, tmin |
0.25° |
Table B: Reference and original data link for datasets used in RDAS
| Datasets | Reference | Link |
| ERA5-land | (Muñoz Sabater, 2019) | https://cds.climate.copernicus.eu/datasets/reanalysis-era5-land?tab=overview |
| ERA5 | (Hersbach et al., 2018) | https://cds.climate.copernicus.eu/datasets/reanalysis-era5-single-levels?tab=overview |
| CHIRPS | (Funk et al., 2014) | https://data.chc.ucsb.edu/products/CHIRPS-2.0/ |
| MSWEP | (Beck et al., 2019) | https://www.gloh2o.org/mswep/ |
| APHRODITE | (Yatagai et al., 2012) | http://aphrodite.st.hirosaki-u.ac.jp/download/ |
| GPCC | (Markus et al., 2022) | https://opendata.dwd.de/climate_environment/GPCC/html/fulldata-daily_v2022_doi_download.html |
| CRU | (Harris et al., 2020) | https://crudata.uea.ac.uk/cru/data/hrg/index.htm#current |
| IMD | (Pai et al., 2014) | https://www.imdpune.gov.in/lrfindex.php |