Data from: Snow-cover seasonality in Kyrgyzstan: Variation and change over 20 years (2001-2021) as observed by the MODIS Terra snow product
Data files
Jan 17, 2025 version files 46.89 MB
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datadryad_archive.zip
46.89 MB
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README.md
2.52 KB
Abstract
Snow seasonality is expected to change as a result of planetary warming. Yet, how the timings of snow seasons have already shifted in mountain environments can be counterintuitive. Here, we updated our 2018 analyses of snow seasonality in Kyrgyzstan (KG) using more data and improved methods. Using two decades of MODIS snow-cover data, we investigated trends in four snow seasonality metrics: First Date of Snow (FDoS); Last Date of Snow (LDoS); Duration of the Snow Season (DoSS); and Snow-Covered Days (SCD). Our novel but conservative nonparametric approach analyzed trends within elevation ranges at two administrative levels: oblast and rayon. To attenuate the risk of false-positive trends, we reported as “notable” only those significant (p<0.05) nonparametric trends that were also (i) strongly asymmetric (at least twice as many significant pixels in one direction) within a elevational range of the oblast or rayon and (ii) covering at least 5% of the elevation range in oblast or rayon and more than 10 pixels. We used both simple and advanced snow-cover metrics, with the latter exploiting the within-composite chronobyte detail available in the MOD10A2.061 product. We found notable trends to earlier FDoS below 3000 m in western KG and more SCD between 1500-3500 m in western KG. We also found the expected notable trends towards earlier LDoS at both oblast and rayon levels. In northwestern KG, DoSS was notably longer <3000 m, but notably shorter at 3500-4000 m. In our 2018 analyses, we found at the national level 160% more area trending to earlier FDoS than to earlier LDoS. Our comprehensive updated trend analysis was designed to be more conservative. It revealed more area (106-130%) trending to earlier FDoS than earlier LDoS, reinforcing the counterintuitive finding of longer snow seasons starting earlier at lower elevations.
README: Data from: Snow-cover seasonality in Kyrgyzstan: Variation and change over 20 years (2001-2021) as observed by the MODIS Terra snow product
https://doi.org/10.5061/dryad.95x69p8wb
Description of the data and file structure
These data support the analyses and findings described in the following open access article: Henebry GM, MA Tomaszewska. 2025. Snow-cover seasonality in Kyrgyzstan: Variation and change over 20 years (2001-2021) as observed by the MODIS Terra snow product. Environmental Research Letters.** **https://doi.org/10.1088/1748-9326/ad9c98.
There are two subdirectories, one for the spreadsheets (.xlsx) and another for the GeoTIFF images (*.tiff).
Files and variables
File: datadryad_archive.zip
Description:
In the IMAGES subdirectory there are two subdirectories (ASCM and SSCM). ASCM contains advanced snow cover metrics and SSCM contains simple snow cover metrics, both derived from the Terra snow cover product (MOD10A2.V061). Within each of these two subdirectories, there are 8 GeoTIFF images containing significant trends (positive or negative) for each of four snow cover metrics: First Date of Snow (FDoS); Last Date of Snow (LDoS); Duration of Snow Season (DoSS); and Snow-Covered Days (SCD).
In the XLS subdirectory there are four files that contain the pixel count information for each snow cover seasonality metric derived from MODIS Terra snow cover product (MOD10A2.V061) using either the advanced snow cover metrics (ASCM) or simple snow cover metrics (SSCM) at either the administrative level of oblast (province) or rayon (county).
Pix_count_ASCM_pos_neg_oblast_masked_KGZ_proj_elevation_notable_005_MK_ERL_119043_R2.xlsx
Pix_count_ASCM_pos_neg_rayon_masked_KGZ_proj_elevation_notable_005_MK_ERL_119043_R2.xlsx
Pix_count_SSCM_pos_neg_oblast_masked_KGZ_proj_elevation_notable_005_MK_ERL_119043_R2.xlsx
Pix_count_SSCM_pos_neg_rayon_masked_KGZ_proj_elevation_notable_005_MK_ERL_119043_R2.xlsx
Code/software
To view a xlsx file, use any software capable of reading the xlsx format.
To view a GeoTIFF file, use any software capable of reading the GeoTIFF format, but be aware that these image files range from 4-6 MB each.
Access information
Other publicly accessible locations of the data:
- none
Data was derived from the following sources:
- MOD10A2.v061: https://doi.org.10.5067/MODIS/MOD10A2.061