DOI: 10.5061/dryad.95x69p8wb
title: Data from: Snow-cover seasonality in Kyrgyzstan: Variation and change over 20 years (2001-2021) as observed by the MODIS Terra snow product

description: 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&lt;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 &lt;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.
description: # 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](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. ](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](https://doi.org.10.5067/MODIS/MOD10A2.061)