DOI: 10.5281/zenodo.14287505
title: Dataset - Snowfall decrease in recent years undermines glacier health and meltwater resources in the Northwestern Pamirs

description: Data and model outputs needed to reproduce the findings of the study published in Communications Earth and Environment:

"Snowfall decrease in recent years undermines glacier health and meltwater resources in the Northwestern Pamirs". A. Jouberton, T. E. Shaw, E. Miles, M. Kneib, S. Fugger, P. Buri, M. McCarthy, A. Kayumov, H. Navruzshoev, A. Halimov, K. Kabutov, F. Homidov, F. Pellicciotti.

This repository includes the reconstructed meteorological forcing time-series at key locations in the Kyzylsu catchment, the model outputs and post-processing scripts to generate Figures 2-8, and in-situ observations collected from June 2021 to September 2023 which were used for the climate reanalysis downscaling (meteorological data) and model evaluation (snow depth, surface albedo, ablation measurements, stream water levels). If you use this dataset, please cite the associated article (https://doi.org/10.1038/s43247-025-02611-8).This work was made possible with funding from the Swiss National Science Foundation (ASCENT Project 189890, Understanding snow, glacier and rivers response to climate in High Mountain Asia). It was also supported by the ERC Consolidator RAVEN project No. 772751, Rapid mass losses of debris-covered glaciers in High Mountain Asia. Fieldwork funding support for the repeated visits to Tajikistan was also received from the Swiss Polar Institute Flagship Programme PAMIR (SPI-FLAG-2021-001) and the Swiss National Science Foundation (HOPE Project 183633, High-elevation precipitation in High Mountain Asia). We would like to thank Firdavs Vosidov, Ubaydullo Ubaydulloev, Tojiddin Rasulzoda and Iskandarov Handullo from the Center for the Research of Glaciers, Tajik National Academy of Sciences (CRG-TAS), for their invaluable support over multiple field campaigns at the study site. We thank Nazrialo Sheralizoda, current director of CRG-TAS, and Tomas Saks from the University of Fribourg for their support in enabling and coordinating the ongoing collaborative monitoring and measurements at the site. 

----------ContentsThis repository is organized into eight folders, some of which have READ-ME files that further document their contents. 

1) InSitu-data

In-situ hydro-meteorological data collected at Kyzylsu catchment from June 2021 to September 2023The files included in the "InSitu-data" folder are:    "AWS_Kyzylsu_15min_2021-06-28_2023-09-12.csv"   "AWS_ridge_15min_2022-09-20_2023-09-05.csv"   "CampLakeLevel_Kyzylsu_2021-09-18_2022-06-21.csv"   "LR_Kyzylsu_2021-07-01_2023-09-13.csv"   "Pluviostation_Kyzylsu_2021-06-28_2023-09-13.csv"   "SnowDepth_Kyzylsu_2021-09-19_2023-09-05.csv"    "Stakes_2021-07_2023-09_melt_summary.csv"   "StreamGauge#3_Kyzylsu_2021-07-02_2023-09-04.csv"   "Ta_Kyzylsu_2021-06-28_2023-09-13.csv"Their content is explained in InSitu-data/READ-ME.txt

2) Remote_sensing_data

     "00_rgi60": Contains the RGI 6.0 outlines used in this work.     "Country_boundaries": Contains the data of the boundaries used in Figure 8     "Reanalysis": Contains the precipitation anomaly given by ERA5-Land between 2000-2018 and 2018-2023 over Tajikistan. This is the data used to generate Figure 8 of the paper.      "Snow_cover": Contains the snow cover data derived from MODIS, Landsat-5/7/8/9 and Sentinel-2 used in Figure 3 and for the model evaluation.More READ-MEs are included in these sub-folders, which further document their content.

3) Reconstructed_forcing

Reconstructed forcing at selected key locations in the Kyzylsu catchment. These are ERA5-Land time series after statistical downscaling and bias-correction using in-situ meteorological data from June 2021 to September 2023 (provided in folder "InSitu_data"). 

- Time resolution: hourly- Period: 01/10/1999 00:00:00 to 30/09/2023 23:00:00

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Coordinates (WGS84) of the selected key points: 

AWS3900m: 39.10003°N, 71.43205°E, 3899 m a.s.l.AWSonGlacier: 39.09697°N, 71.41769°E, 3579 m a.s.l.Pluviometer: 39.11507°N, 71.41184°E, 3372 m a.s.l.Tlogger2100m: 39.15813°N, 71.54635°E, 2130 m a.s.l.

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Variables:

- Time: date- FF: wind speed [m s-1]- LWIN: incoming longwave radiation [W m-2]- PP: total precipitation [mm]  - RH: relative humidity [%]- TA:  air temperature [°C]- PRESS: atmospheric pressure [hPa]- SAD1: incoming radiation UV/VIS waveband diffuse [W m-2] - SAD2: incoming radiation NIR waveband diffuse [W m-2] - SAB1: incoming radiation UV/VIS waveband direct [W m-2] - SAB2: incoming radiation NIR waveband direct [W m-2] - PARD: incoming PAR radiation beam direct [W m-2] - PARB: incoming PAR radiation diffuse [W m-2] 

4) Spatial_inputsThe Spatial_inputs folder contains the spatial information needed by the Post_processing scripts to generate the figures and numbers of the manuscript. 

5) Documentation

This folder contains the documentation of the model output variables: their name, description and units. 

6) Model_outputs

The "Model_outputs" folder contains all of the model outputs generated while running the land-surface model Tethys-Chloris (T&C) from October 1st 1999 to September 30th 2023 at hourly resolution at the Kyzylsu catchment. 

The files included in this folder are described in alphabetical order.

-------------------------------------------------------------------------"dtm_Kyzylsu_100m.m" Matlab files which contains all of the spatial inputs require to run T&C.

DTM: the reference surface elevationGLA: glacier maskVEG_CODE: the land-cover codeDEB_MAP: distributed supraglacial debris thicknessMASK: catchment maskPSAN: soil content in sandPORG: soil content in organic matterPCAL: soil content in claySOIL_TH: soil thicknesscellsize: model spatial resolutionGLA_ID: glacier RGI IDsAacc: Accumulation in river network-------------------------------------------------------------------------"Final_reached_step_Kyzylsu.m" Matlab workspace saved at the end of the simulation period.-------------------------------------------------------------------------"INITIAL_CONDITIONS_Kyzylsu.m"Script which initialises the values of the variables of the model at the start of the simulation periods.-------------------------------------------------------------------------"OUTPUT_Kyzylsu_AVG.dat"Aggregated catchment-wide average of model outputs, at hourly resolution. The variable description can be found in Documentation/Variable_Spatial_20200924.pdf, replacing "_tg" with "_spatial".-------------------------------------------------------------------------"OUTPUT_Kyzylsu_PIXEL_[point_of_interest].dat"Model output at selected tracked point location of interest.The variable description can be found in Documentation/T&C_Variable_LIST_PlotScale_20200924.pdf, note that "_S" is sometimes added at the end of the variable name.-------------------------------------------------------------------------"OUTPUT_Kyzylsu_SNOALB_[hh].mat"Simulated distributed surface albedo. The output are bi-weekly, and hh corresponds to the number of hours since the start of the simulation period.------------------------------------------------"OUTPUT_Kyzylsu_SNOWMAP_[hh].mat"Simulated distributed surface albedo. The outputs are daily, and hh corresponds to the number of hours since the start of the simulation period.

Variables:- DTM : surface elevation model [m]- Ice_spatial_daily: Ice water equivalent content [mm]- ros_spatial_daily: Snow density [kg/m^3]- Smelt_spatial_daily: Snow melt [mm/h]- SND_spatial_daily: Snow depth [m]- SSN_spatial_daily: Snow surface sublimation [mm/h]- x_cell: x-dimension (UTM 42N)- y_cell: y-dimension (UTM 42N)------------------------------------------------"OUTPUT_Kyzylsu_SPATIAL_[hh].mat"Simulated distributed variables. The outputs are monthly, and hh corresponds to the number of hours since the start of the simulation date.

The description and units of the 130 variables stored in each of these output files can be found here:Documentation/Variable_Spatial_20200924.pdf------------------------------------------------"OUTPUT_MANAGER_DIST_LABEL.m"Matlab script which creates the output files when running T&C.------------------------------------------------"PARAMETERS_SOIL.m"Matlab function which defines the soil parameters (but also parameters related to supraglacial properties).------------------------------------------------"TC_distributed_launcher.m"Matlab script which is the main launcher of the T&C simulations. In is adapted to be able to run on a HPC.Note that it includes other study sites, but only s = 2 (Kyzylsu) is relevant for this work. It is only provided for references and is not designed to run with the data and folder hierarchy of he zenodo repository. For any questions about its use, please contact achille.jouberton@gmail.com 

7) Post_processing

The Matlab codes (version R2022b) included in the folder "Post_processing" are the scripts which generate Figure 2 to 8 of the manuscript and compute some of the key numbers given in the manuscript.

It requires the following folders to be in the same working directory:Post-processing, InSitu_data, Model_outputs, Remote_sensing_data and Spatial_inputs

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"Distributed_outputs_analysis.m"Postprocesses the distributed model outputs, and generates Figures 3, 4, 5, 6 and 7 of the manuscriptIt also includes the model evaluation against MODIS, Landsat-5/7/8/9 and Sentinel-2 snow cover maps.

"Pointscale_outputs_analysis.m"Postprocesses the point-scale model outputs, and generates Figure 2 of the manuscript.It also generates all Supplementary Figures related to the model comparison against:- meteorological observations- measured snow depth and surface albedo- mass balance from ablation stakes- water level at the proglacial stream of Koshkul Glacier

"Tajikistan_MODIS_E5_analysis.m"Generates Figure 8 of the manuscript.

"Postprocessing_functions"Folder containing Matlab scripts and functions needed by the postprocessing scripts described above.

8) Figures

In this folder are stored the figures created by the post_processing scripts.