Changing snow seasonality in the highlands of Kyrgyzstan
Few studies have examined changing snow seasonality in Central Asia. Here, we analyzed changes in the seasonality of snow cover across Kyrgyzstan (KGZ) over 14 years from 2002/03–2015/16 using the most recent version (v006) of MODIS Terra and Aqua 8 day snow cover composites (MOD10A2/MYD10A2). We fo...
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| Format: | Article |
| Language: | English |
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IOP Publishing
2018-01-01
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| Series: | Environmental Research Letters |
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| Online Access: | https://doi.org/10.1088/1748-9326/aabd6f |
| _version_ | 1797748272465444864 |
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| author | Monika A Tomaszewska Geoffrey M Henebry |
| author_facet | Monika A Tomaszewska Geoffrey M Henebry |
| author_sort | Monika A Tomaszewska |
| collection | DOAJ |
| description | Few studies have examined changing snow seasonality in Central Asia. Here, we analyzed changes in the seasonality of snow cover across Kyrgyzstan (KGZ) over 14 years from 2002/03–2015/16 using the most recent version (v006) of MODIS Terra and Aqua 8 day snow cover composites (MOD10A2/MYD10A2). We focused on three metrics of snow seasonality—first date of snow, last date of snow, and duration of snow season—and used nonparametric trends tests to assess the significance and direction of trends. We evaluated trends at three administration scales and across elevation. We used two techniques to assure that our identification of significant trends was not resulting from random spatial variation. First, we report only significant trends (positive or negative) that are at least twice as prevalent as the converse trends. Second, we use a two-stage analysis at the national scale to identify asymmetric directional changes in snow seasonality. Results show that more territory has been experiencing earlier onset of snow than earlier snowmelt, and roughly equivalent areas have been experiencing longer and shorter duration of snow seasons in the past 14 years. The changes are not uniform across KGZ, with significant shifts toward earlier snow arrival in western and central KGZ and significant shifts toward earlier snowmelt in eastern KGZ. The duration of the snow season has significantly shortened in western and eastern KGZ and significantly lengthened in northern and southwestern KGZ. Duration is significantly longer where the snow onset was significantly earlier or the snowmelt significantly later. There is a general trend of significantly earlier snowmelt below 3400 m and the area of earlier snowmelt is 15 times greater in eastern than western districts. Significant trends in the Aqua product were less prevalent than in the Terra product, but the general trend toward earlier snowmelt was also evident in Aqua data. |
| first_indexed | 2024-03-12T16:02:31Z |
| format | Article |
| id | doaj.art-56900fd8ebdf47e4a765e6985fd92953 |
| institution | Directory Open Access Journal |
| issn | 1748-9326 |
| language | English |
| last_indexed | 2024-03-12T16:02:31Z |
| publishDate | 2018-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| series | Environmental Research Letters |
| spelling | doaj.art-56900fd8ebdf47e4a765e6985fd929532023-08-09T14:33:33ZengIOP PublishingEnvironmental Research Letters1748-93262018-01-0113606500610.1088/1748-9326/aabd6fChanging snow seasonality in the highlands of KyrgyzstanMonika A Tomaszewska0https://orcid.org/0000-0003-3641-323XGeoffrey M Henebry1https://orcid.org/0000-0002-8999-2709Geospatial Sciences Center of Excellence , South Dakota State University, Brookings, SD 57007, United States of AmericaGeospatial Sciences Center of Excellence , South Dakota State University, Brookings, SD 57007, United States of America; Department of Natural Resource Management , South Dakota State University, Brookings, SD 57007, United States of America; Author to whom any correspondence should be addressed.Few studies have examined changing snow seasonality in Central Asia. Here, we analyzed changes in the seasonality of snow cover across Kyrgyzstan (KGZ) over 14 years from 2002/03–2015/16 using the most recent version (v006) of MODIS Terra and Aqua 8 day snow cover composites (MOD10A2/MYD10A2). We focused on three metrics of snow seasonality—first date of snow, last date of snow, and duration of snow season—and used nonparametric trends tests to assess the significance and direction of trends. We evaluated trends at three administration scales and across elevation. We used two techniques to assure that our identification of significant trends was not resulting from random spatial variation. First, we report only significant trends (positive or negative) that are at least twice as prevalent as the converse trends. Second, we use a two-stage analysis at the national scale to identify asymmetric directional changes in snow seasonality. Results show that more territory has been experiencing earlier onset of snow than earlier snowmelt, and roughly equivalent areas have been experiencing longer and shorter duration of snow seasons in the past 14 years. The changes are not uniform across KGZ, with significant shifts toward earlier snow arrival in western and central KGZ and significant shifts toward earlier snowmelt in eastern KGZ. The duration of the snow season has significantly shortened in western and eastern KGZ and significantly lengthened in northern and southwestern KGZ. Duration is significantly longer where the snow onset was significantly earlier or the snowmelt significantly later. There is a general trend of significantly earlier snowmelt below 3400 m and the area of earlier snowmelt is 15 times greater in eastern than western districts. Significant trends in the Aqua product were less prevalent than in the Terra product, but the general trend toward earlier snowmelt was also evident in Aqua data.https://doi.org/10.1088/1748-9326/aabd6fsnowmelttrend analysisremote sensingsnow cover |
| spellingShingle | Monika A Tomaszewska Geoffrey M Henebry Changing snow seasonality in the highlands of Kyrgyzstan Environmental Research Letters snowmelt trend analysis remote sensing snow cover |
| title | Changing snow seasonality in the highlands of Kyrgyzstan |
| title_full | Changing snow seasonality in the highlands of Kyrgyzstan |
| title_fullStr | Changing snow seasonality in the highlands of Kyrgyzstan |
| title_full_unstemmed | Changing snow seasonality in the highlands of Kyrgyzstan |
| title_short | Changing snow seasonality in the highlands of Kyrgyzstan |
| title_sort | changing snow seasonality in the highlands of kyrgyzstan |
| topic | snowmelt trend analysis remote sensing snow cover |
| url | https://doi.org/10.1088/1748-9326/aabd6f |
| work_keys_str_mv | AT monikaatomaszewska changingsnowseasonalityinthehighlandsofkyrgyzstan AT geoffreymhenebry changingsnowseasonalityinthehighlandsofkyrgyzstan |