Data processing and figures for the chapter Global Climate in the report State of Climate in 2024 (Bulletin of the American Meteorological Society).
The pre-processed data used in this study are saved in the folder data.
The river discharge and runoff data are the results from the GloFASv4 (Global Flood Awareness System) historical run, extracted from the Copernicus Early Warning Data Store. The simulation spans from 1979 up until present, with 3 arc-minute spatial resolution and daily temporal resolution. It is produced by forcing the calibrated LISFLOOD-OS hydrological model with the meteorology from ERA5. Apart from that, the GloFAS subfolder contains two of the LISFLOOD static maps —upstream area and local drainage direction— that were used in the analysis.
The subfolder teleconnections contains the time series of the ENSO ONI index and the PDO:
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The El Niño-Sourthern Oscillation (ENSO) ONI index was retrieved from https://origin.cpc.ncep.noaa.gov/products/analysis_monitoring/ensostuff/ONI_v5.php.
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The Pacific Decadal Oscillation (PDO) was retrieved from: https://www.ncei.noaa.gov/pub/data/cmb/ersst/v5/index/ersst.v5.pdo.dat
The folders notebook and src contain the code used to download, pre-process and post-process the data.
Three Python scripts were developed to download and pre-process the GloFAS simuation, i.e., aggregate the daily simulations to annual or monthly time series. The functions can be found in this folder; for the explanation on how to use it, please go to the Wiki of the repository.
The results of the pre-processing of the GloFAS results are saved in the data folder. The original files downloaded from the EWDS were too large (250 GB approximately) to be saved in the repository.
To define the river outlets into the four oceans (Atlantic, Pacific, Indian and Arctic), I used the GloFAS static maps that define the catchment area and local drainage directions (LDD). I screened the model pixels which have at least 5,000 km2 catchment area and are sinks in the LDD (value 5). That selection included the outlets of endorheic catchments, which were removed from the final set of river outlets. Each river outlet was assigned to an ocean using as reference the marine areas from Natural Earth. The final selection of river outlets includes 1310 points.
Figure 1. River outlets selected to compute the discharge into the oceans. Colours represent the ocean basins.