Machine Learn. doi:10.1038/NGEO1068, Schmitt, A., Wendleder, A., and Hinz, S. (2015). Trends in Heat Wave Related Indices in pakistan. Glaciological characteristics of the ablation zone of Baltoro glacier In all cases, lake areas expanded faster than they contracted. (2017). For a better distinction of shadows and clouds from lakes, we added the blue and shortwave infrared bands. PlanetScope (2020). Glaciers are shown in pale blue, snow in light blue to . J. Geo. The residual standard error of all linear regressions was between 1,397m2 and 1923m2 and the p-value was between 0.029 and 0.037 (95% confidence level), indicating a significant correlation. The side-by-side comparison is a very tedious thing as the brain cannot freeze-frame and virtually overlay the images, Dr Paul explains. As the mean daytime temperature during summer is close to the freezing point at 5,400m a.s.l., most of the precipitation deposits as snow above this elevation (Mayer et al., 2006). Change 56, 137152. The reference datasets varied in their spatial coverage (Table 4; Supplementary Figure S1) but were consistently selected from 2019, as this year had the lowest cloud coverage and the highest number of coincident pairs between PlanetScope and Sentinel/TerraSAR-X. Climate Change Indicators: Glaciers This indicator examines the balance between snow accumulation and melting in glaciers, and it describes how glaciers in the United States and around the world have changed over time. SPI (A) and STI (B) from 2016 to 2020 for the monthly precipitation and temperature, color-coded for the seasonal distribution: January, February, and March (JFM) in dark blue, April and May (AM) in light blue, June to September (JJAS) in orange, and October to December (OND) in red. Each sector is specified by its altitude range (m a.s.l.). The SAR data of Sentinel-1 (Vincent et al., 2019) and TerraSAR-X (Eineder and Fritz, 2009) bridge the gaps of the optical data, which are brought about by cloud cover during the westerly disturbances in April and the monsoon season from the end of May until the end of July. TE calculated the seasonal and trend components and wrote Section 3.5 and Section 4.6. A combination of linear regression and the Hausdorff distance are used to harmonize between SAR- and optical-derived lake areas, producing a consistent and internally robust time series dynamics. The training data were selected from the classification results of an index approach. 146, 19992049. The Era5 Global Reanalysis. The five-year study period showed that the total lake area varied from year to year, with the largest total lake area in 2018 (5.783km2) and the smallest lake area in 2017 (3.563km2). We used a multi-sensor time series with an acquisition every two to fourdays based on optical data from PlanetScope and Sentinel-2 and SAR data from Sentinel-1 and TerraSAR-X. 5, 58. doi:10.3389/feart.2017.00058, Miles, E. S., Willis, I., Buri, P., Steiner, J. F., Arnold, N. S., and Pellicciotti, F. (2018). Arrive in Islamabad and transfer to our group hotel. It is notable that the reference datasets of July 7, August 6, and August 21 (all 2019) had a higher RSE. Two previous studies have classified the supraglacial lakes on the Baltoro Glacier, but only for one to three scenes per year. The main feature of MAJA is the use of multi-temporal information contained in the time series to better estimate aerosol optical thickness and correct atmospheric effects (Hagolle et al., 2017). . TABLE 1. Lett. The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. Glob. These changes would be hard to observe by other methods, such as by comparing side-by-side images of a glacier taken at different times. doi:10.3189/172756406781812087, McFeeters, S. K. (1996). Monthly means of the total lake area (data), model fit, seasonal components, linear trend, and residuals for 2016 to 2020. doi:10.1016/j.gloplacha.2016.04.008, Watson, C. S., King, O., Miles, E. S., and Quincey, D. J. 1 a). Glacial Lakes in the Himalayas: a Review on Formation and Expansion Processes. Full article: Changes in glacier surface cover on Baltoro glacier Creative Commons Attribution License (CC BY). Remote Sensing 102, 122139. Additionally, warmer springs lead to greater lake drainage later in the same year as more meltwater causes redevelopment of the subsurface drainage system (Liu et al., 2015). 52, 463470. It appears then that the stronger and earlier precipitation in 20182020 caused an increase in the lake area. Glacier Change, Concentration, and Elevation Effects in the Karakoram Himalaya, Upper Indus basin. 62, 467485. The Supplementary Material for this article can be found online at: https://www.frontiersin.org/articles/10.3389/feart.2021.725394/full#supplementary-material. (2012). (2000). The third (3,8804,030m a.s.l. doi:10.1126/science.1215828, PubMed Abstract | CrossRef Full Text | Google Scholar, Bookhagen, B., and Burbank, D. W. (2006). The background image is a Sentinel-2 RGB (B2, B3, B4) composite acquired on July 22, 2019. Misclassifications like ice-covered surfaces of the tributaries Yermanendu and Biarchedi Glacier and ice sails were manually removed. Distribution and Interannual Variability of Supraglacial Lakes on Debris-Covered Glaciers in the Khan Tengri-Tumor Mountains, central Asia. Overview of the sensor characteristics and acquisition parameters. The initiative has assembled comprehensive datasets going back decades for scientists to understand exactly how these sensitive components of our environment are changing. Evolution of Supra-glacial Lakes across the greenland Ice Sheet. As turbid water and ice had similar spectral reflectance, the Liligo Lake was consistently misclassified as ice. Published today in The Cryosphere journal, these new animations provide a novel look at glacier dynamics, revealing changes over a much longer time and at a much larger scale than ever before. Supraglacial lakes are located from the terminus up to Concordia. Sci. Changes in glacier surface cover on Baltoro glacier, Karakoram, north The number and cumulative area of lakes are divided into two categories: lakes with an area smaller and larger than 0.01km2. The second, third, and fourth sectors had the greatest number of lakes, with a maximum number in the second sector (100120) and a decrease towards the fourth sector (6090). Ice velocity and climate variations for Baltoro Glacier, Pakistan 430, 427438. The probability density represents the distribution of lake areas and differs each year. Mass balance models can include such debris-dependent surface properties, but due to a lack of empirical data, it is difficult to readily include their impact on glacier melt rates. The Glaciers of Pakistan - An Overview | Epic Backpacker Tours to form the main glacier. 122, 1270212712. Surface Pond Energy Absorption across Four Himalayan Glaciers Accounts for 1/8 of Total Catchment Ice Loss. PD processed the MAJA corrected Sentinel-2 data. The beautiful coincidence point of Siachen and Baltoro glaciers (75 km doi:10.1002/2017JD027414, Mlg, N., Ferguson, J., Bolch, T., and Vieli, A. The authors acknowledge the use of TerraSAR-X data (DLR 2019-2020), Sentinel-1 and 2 data (ESA 2019-2020) provided by DLR PAC/LTA, PlanetScope data (Planet 2019-2020), and ERA5-Land provided by Copernicus Climate Change Service (C3S) Climate Data Store (CDS). doi:10.3390/w9060405. Glob. High-resolution Ndvi from Planets Constellation of Earth Observing Nano-Satellites: A New Data Source for Precision Agriculture. In 2012, the Karakoram region had a glacierized area of 18,000km2 (Collier et al., 2015; Bolch et al., 2012), and approximately 1822% of it was covered with supraglacial debris (Collier et al., 2015; Scherler et al., 2011; Hewitt, 2011). Random Forests. Using this approach, it was possible to discriminate between the classes debris, ice, and lake. For every scene, an individual threshold for the differentiation between the reflectance of ice and lake was automatically calculated using the unimodal threshold determination (Rosin, 2001). Prominent Midlatitude Circulation Signature in High Asia's Surface Climate during Monsoon. glaciology of Himalayas In Himalayas: Drainage of the Himalayas Karakoram Range, for example, the Baltoro Glacier moves about 6 feet (2 metres) per day, while others, such as the Khumbu, move only about 1 foot (30 cm) daily. (2012), 4.5% in Sundal et al. Baltoro Glacier is a river of ice in Pakistan | Earth | EarthSky Our study showed that the supraglacial lakes filled between mid-April to mid-June and drained between mid-June to mid-September. Environ. FIGURE 10. The ablation of debris-covered glaciers is very heterogeneous with minimal lowering beneath thick debris near the terminus and maximal downwasting in the upper ablation zone near the equilibrium line where thin debris dominates (Benn et al., 2017). Toward Monitoring Surface and Subsurface Lakes on the greenland Ice Sheet Using sentinel-1 Sar and Landsat-8 Oli Imagery. (2017). Modelling the Feedbacks between Mass Balance, Ice Flow and Debris Transport to Predict the Response to Climate Change of Debris-Covered Glaciers in the Himalaya. San Francisco, CA: Planet Labs, Inc. https://assets.planet.com/docs/Planet_Combined_Imagery_Product_Specs_letter_screen.pdf. doi:10.1017/jog.2016.120, Miles, K. E., Willis, I. C., Benedek, C. L., Williamson, A. G., and Tedesco, M. (2017b). The majority of those lakes are supraglacial lakes located on the main glacier. Copernicus Climate Change Service (C3s) Climate Data Store (Cds). The equivalent disaggregated data for Yermanendu and Liligo Lakes can be found in Supplementary Figure S4. 2) In what way does the lake area change over the years? Here's everything you need to know about hiking to K2 base camp. Hence, the classification results on September 08, 2016, derived from Sentinel-1 are lower. Geografiska Annaler 41, 228230. Spatial, Seasonal and Interannual Variability of Supraglacial Ponds in the Langtang Valley of Nepal, 1999-2013. A thin debris cover of only a few centimeters leads to enhanced ablation compared to clean ice due to increased absorption of solar radiation (Ostrem, 1959; Nicholson and Benn, 2006). Wendleder et al. Although the five-year observation period is too short to derive a significant trend, the tendency for a possible increase in the supraglacial lake area is in line with the pronounced positive anomalies of the SPI and STI during the observation period. doi:10.1016/j.rse.2009.05.018, Thayyen, R. J., and Gergan, J. T. (2010). Day 5. Watson, C. S., Quincey, D. J., Carrivick, J. L., and Smith, M. W. (2016). Trekkers follow a rocky trail that winds up the mighty Baltoro Glacier, passing through a colossal amphitheater of sky-scraping summits - including seven of the 19 highest mountains on the planet - en route to the base of the world's second highest peak. (2012). Lett. Lett. There are also two ice-dammed lakes located south of the main trunk, namely, Liligo and Yermanendu Lakes. Hydrology of Debris-Covered Glaciers in High Mountain Asia. AW, AS, CM, and MB designed the research. Variability in image coverage impeded a direct comparison of the classification accuracy from optical imagery of different dates. It combines the results of many different random decision trees taking the majority votes for each decision tree. Roth, A. 4) How does the seasonal evolution vary over the years? Res. Overview of the used classes, features, and training data for the random forest classifier. As the seasonal lake evolution shows a larger area for 2018, 2019, and 2020, a connection between lake evolution and climate cannot be identified, even though the climate data show a tendency to larger precipitation and higher temperatures in terms of amplitude and time. Context 1 . Located in the Gilgit-Baltistan region of Pakistan, it runs through part of the Karakoram mountain range, which is home to second highest mountain on earth, K2 (8,611M) and three other 8000 meter peaks. The total lake area was lowest in 2017 (3.563km2) and the highest values in 2018 (5.783km2). FIGURE 7. The outliers were characterized by their local minimum in the time series and could be detected with the Hausdorff distance (Hausdorff, 1914). These studies have found that supraglacial debris delays glacier response to warming and leads to surface lowering and ice cliff backwasting rather than frontal recession (Rowan et al., 2015; Thompson et al., 2016; Brun et al., 2018). Rowan, A. V., Egholm, D. L., Quincey, D. J., and Glasser, N. F. (2015). The second study mapping supraglacial lakes on Baltoro Glacier used a U-Net model with EfficientNet backbone based on PlanetScope data (Qayyum et al., 2020). FIGURE 2. Thus, larger lakes comprised a larger percentage of the total lake area through time. Structure and Evolution of the Drainage System of a Himalayan Debris-Covered Glacier, and its Relationship with Patterns of Mass Loss. In 2020, most of the lake areas were concentrated around the median value. Since SAR sensors distinguish only between wet and dry and thus are not sensitive to seasonal turbidity variations, we selected one validation date for each SAR sensor and each pass direction. The uncertainty of the linear trend component was derived as follows: with r being the standard deviation of the de-trended residuals, n the number of months, and the first-order autocorrelation of the residuals. 33, 15. (2009), and 4.0% in Selmes et al. FIGURE 1. During the harmonization of the lake area, not all SAR-derived areas were corrected due to the absence of any significant associations between the predictor and the outcome variables. Consequently, the seasonal evolution could not be sampled with the same high temporal resolution as it was possible for the other years (Supplementary Figure S5). Stoch Environ. doi:10.1029/98jd00995, Wendleder, A., Friedl, P., and Mayer, C. (2018). doi:10.1659/MRD-JOURNAL-D-11-00020.1, Houborg, R., and McCabe, M. (2016). AW analyzed the data and results and wrote the manuscript. Using the neighboring water level change for interpolation was not possible because each lake had its own characteristic pattern of water level rise and fall, and in addition, cloud coverage often affected large parts of the scene and thus also the neighboring lakes. This mountain range is home to some of the highest peaks in the world, including the famous K2. The Baltoro Glacier is situated in the northern part of Pakistan near the border to India and China (Figure 1). (2018). Geophys. The number of lakes varied from year to year without any clear trend, with a minimum of 379 in 2020 and a maximum of 553 in 2016 (Table 3). Baltoro glacier has undergone a long series of scientific investigations since the first observations by W.M. 63, 88105. Formation Conditions of Supraglacial Lakes on Debris-Covered Glaciers in the Himalaya. The advantage of the presented approach is the usage of a dense multi-temporal and multi-sensor summertime series. Revealing glacier flow with animated satellite images - Phys.org Res., 2330. doi:10.1029/2018GL079678, Miles, K. E., Hubbard, B., Irvine-Fynn, T. D. L., Miles, E. S., Quincey, D. J., and Rowan, A. V. (2020). Higher precipitation tends to intensify both lake filling and drainage. doi:10.5194/tc-11-2247-2017, Bolch, T., Kulkarni, A., Kb, A., Huggel, C., Paul, F., Cogley, J. G., et al. J. Geophys. Xie, F., Liu, S., Wu, K., Zhu, Y., Gao, Y., Qi, M., et al. (A) Distribution of the number of lakes along the altitude divided into seven sectors. (1998). However, the seasonal evolution of supraglacial lakes and thus their potential for influencing mass balance and ice dynamics have not yet been sufficiently analyzed. This metric is defined as the maximum distance between the original curve and a simplified line between preceding and subsequent measurements. For the sake of simplicity, we implemented the random forest classifier for all four sensors but with different classification classes and training data. The lake area ranged between 500m2 to 440,000m2. doi:10.3189/002214309790794913, Reynolds, J. M. (2006). Multi-source and Multi-Temporal Image Fusion on Hypercomplex Bases. Risk Assess. Therefore, the undulating patterns in Figure 7 can be explained by higher precipitation resulting in short-term lake fluctuations. Mihalcea, C., Mayer, C., Diolaiuti, G., DAgata, C., Smiraglia, C., Lambrecht, A., et al. doi:10.5194/tc-4-115-2010, Thompson, S., Benn, D. I., Mertes, J., and Luckman, A. Spatial Distribution of Debris Thickness and Melting from Remote-Sensing and Meteorological Data, at Debris-Covered Baltoro Glacier, Karakoram, pakistan. (2018) calculated the NDWI based on the green and the near-infrared band for the Landsat-8 Operational Land Imager (OLI) Level-2 data. Habercker, P. (1987). Fly to Skardu or drive to Chilas. Data availability reduced the number of observations available in 2016. doi:10.3390/rs9121306, Davies, E. R. (2005). https://tandemx-science.dlr.de/pdfs/TX-GS-DD-3302_Basic-Products-Specification-Document_V1.9.pdf. Anderson, L. S., and Anderson, R. S. (2019). 48, 4957. Location of the study area, and schematic map of the Baltoro basin Remote Sensing 9, 831927. The number of lakes with a size of 1,0002,000m2 ranged between 15 and 57, whereas those between 2,000 and 3,000m2 varied from 80 to120; otherwise, as the lake size increased, the number of lakes decreased, with the exception of a peak in the size bin of 10,00020,000m2. From mid-July, Liligo Lake was fed by the meltwater of the Liligo Glacier and hence, the turbidity increased. More reason for you to put it on your must visit list. Previous studies have tended to use only optical data and hence have been unable to monitor lake dynamics during the cloudy and rainy seasons. Supraglacial debris distribution is important when calculating glacier mass balance, as such debris layers . The largest aggregated lake area was found in 2018 with 5.783km2, followed by 2019 with 4.703km2, and 2020 with 4.606km2. Role of Geophysics in Glacial hazard Assessment. (2019). If the water is able to drain to the glacier bed, it can support basal sliding and hence higher glacier velocities (Sakai and Fujita, 2006; Sakai, 2012; Watson et al., 2016; Benn et al., 2017; Miles E. S. et al., 2017; Miles et al., 2020). Scientists have sought to understand what is regulating the flow speeds of glaciers in order to project how meltwater will contribute to the region's water resources and to sea level rise. Our data suggest that warmer spring seasons (AprilMay) with higher precipitation rates lead to increased formation of supraglacial lakes. However, to better understand the seasonal evolution of supraglacial lakes and the relationship between lake growth and climate, a continuous time series covering a period of several years is essential. Baltoro is one of the longest glaciers in the world outside the polar region. Maja Algorithm Theoretical Basis Document. Res. doi:10.3390/rs8090768, Huo, D., Bishop, M. P., and Bush, A. doi:10.3390/rs12060943, Selmes, N., Murray, T., and James, T. D. (2011). McKee, T. B., Doesken, N. J., and Kleist, J. Grundzge der Mengenlehre. NDI stands for normalized difference index, GLCM for gray level co-occurrence matrix, and ROI for region of interest. Santer, B. D., Wigley, T. M. L., Boyle, J. S., Gaffen, D. J., Hnilo, J. J., Nychka, D., et al. Dyn. (2007). The data are available on a 0.1 by 0.1 grid and were downloaded from the Copernicus Climate Change Service (C3S) Climate Data Store (CDS) (Muoz-Sabater, 2019). Conway in 1892 . J. T stands for threshold derived with the unimodal threshold determination (Rosin, 2001). This was 24weeks in advance of other years. Number of lakes, cumulative area of lakes in km2, percentage of seasonal and permanent lakes at the end of the ablation season, and date and area in km2 at maximum lake area for each summer season from 2016 to 2020. Vincent, P., Bourbigot, M., Johnsen, H., and Piantanida, R. (2019). and the fast changes affecting the glacial surface. The percentage of lake area (as a component of overall glacier area) rose by 3.3% between 2017 and 2018. Glaciol. Everything required to do it both images and software is freely available, so I recommend trying this at home.. For the Sentinel-2 data, the MAJA atmospheric correction was used. For our study of glacial lake dynamics, we selected the Baltoro Glacier in the eastern Karakoram. As detailed in The Cryosphere, Dr Paul created the animations in simple gif format using satellite images freely available from the US Geological Survey. Geosci. In the case of the SAR sensors, the classifications derived from descending passes, i.e., glacier velocity parallel to the SAR line of sight, provided better results. Planet Imagery Product Specification. Additionally, the mapping of the inundated area gives an indication of the lake bathymetry, as shown in Figures 6D,E for the Yermanendu Lake in 2018 and 2020. (Godwin Austen region) and at 5,500m a.s.l. Spatially Variable Response of Himalayan Glaciers to Climate Change Affected by Debris Cover. doi:10.1016/j.earscirev.2012.03.008, Benn, D. I., Thompson, S., Gulley, J., Mertes, J., Luckman, A., and Nicholson, L. (2017). Glacial Lakes Mapping Using Multi Satellite Planetscope Imagery and Deep Learning. K2 & BALTORO GLACIER TREK - KARAKORAM - One World Trekking For the accuracy assessment, a reference dataset was manually mapped based on the RGB composite and the NDWI (McFeeters, 1996) calculated with the green and near-infrared band of PlanetScope data. Details. Overall, the probability density data reinforce the observation of there being great year-to-year variability. J. Glaciol. The greater the contribution of glacier meltwater, the more turbid the lake, as is the case at Liligo Lake around the middle or end of July. Miles K. E. et al. doi:10.1080/01431169608948714. 9, 123. Hagolle, O., Huc, M., Desjardins, C., Auer, S., and Richter, R. (2017). Important place names are indicated. The sensor characteristics and acquisition parameters are summarized in Table 1 and the data availability is visualized in Figure 2. doi:10.1080/20014422.1959.11907953. (2012). The Baltoro Glacier is the world's largest glacier, and one of the longest outside the polar regions. From a scientific point of view, the key motivation for this research was to understand the highly variable behaviour of the glaciers in the Karakoram. Res. For the semi-automated classification, the data needed to be atmospherically corrected, radiometrically calibrated, and orthorectified. Qayyum et al. J. Glaciol. 114, 156174. 3) What does the spatial lake distribution look like? 31, 188200. Photographs of McCall Glacier, Alaska, 1958 and 2003 Sources: Post, 1958; 2 Nolan, 2003 3 Web update: August 2016 Figure 1. FIGURE 3. The spatial distribution of lakes (Figure 6; Supplementary Figures S2,S3) was highly variable between each of the observation periods. Remote Sensing 10, 1681. doi:10.3390/rs10111681, Winkler, K., Gessner, U., and Hochschild, V. (2017). Geophys. (2020). Evatt, G. W., Mayer, C., Mallinson, A., Abrahams, I. D., Heil, M., and Nicholson, L. (2017). TABLE 3. Snow . Rising air temperatures and changes in precipitation patterns provoke an increase in the supraglacial lakes in number and total area. Nevertheless, glacier expansion in the Karakoram has occurred on a temporal scale less than the estimated response time of Baltoro Glacier. Debris-covered glaciers are characterized by the presence of ice sails (Mayer et al., 2006; Evatt et al., 2017), ice cliffs, and supraglacial lakes. 4 to 5 hour trek. shows the greatest variation, with a total relative area increase of 3.3% between 2017 and 2018. Cryosphere 10, 11051124. As both ascending and descending acquisitions were acquired with the same incidence angle of 35, we cannot determine which incidence angle would be more suitable. Seasonal Surface Velocities of a Himalayan Glacier Derived by Automated Correlation of Unmanned Aerial Vehicle Imagery. Planet. AS helped with the methodology. The probability density of 2019 had a negative skew indicating that most of the lake areas were larger than the median. to an altitude of 3410 m a.s.l. Dr Paul said, The most interesting insight is to really see how the glaciers flow and how the individual parts of the glaciers such as the tributary streams interact.. doi:10.1016/j.rse.2018.08.020, Weatherhead, E. C., Reinsel, G. C., Tiao, G. C., Meng, X.-L., Choi, D., Cheang, W.-K., et al. According to our definition, a negative distance indicated a local minimum. Since the lake dynamics are highly variable, the linear interpolation could produce differences. TerraSAR-X Ground Segment Basic Product Specification Document; Doc: TX-GS-DD-3302. Remote Sensing | Free Full-Text | Impacts of Climate and - MDPI The rise of the median lake area from 1.2 in 2016 to 1.71.9 in 20182020 is clearly visible. Overview of Baltoro Glacier, Pakistan, with the glacier boundaries (blue) and the sectors (red) used for the supraglacial lake area analyzed in Sections 4.2 and 4.3. Baltoro glacier, one of the world's largest debris-covered glaciers, drains the south flank of the Karakoram range (35 8 35 0 -35 8 56 0 N, 76 8 04 0 -76 8 46 0 E) as a tributary to the Indus. Hence, 2018 was affected by higher temperatures leading to an intensified contribution of snow and glacier meltwater at an altitude of about 4,400m a.s.l. Available at: https://public.wmo.int/en/media/news/march-3rd-warmest-record-many-contrasts (Accessed 05 29, 2021). Most of the Himalayan glaciers are in retreat, at least in part because of climate change. The sixth and seventh (higher-elevation) sectors consistently had the lowest number of lakes (<50). Day 4. As SAR signals are able to penetrate clouds, they provide relevant information during the rainy seasons and especially during the period of lake onset. The interquartile ranges of 2016 and 2018 showed a larger variation of lake areas than in 2020. The basin is 400 km 2 larger, but the area of the glacier slightly smaller, and barely 42 % of the whole. We present a summertime series of supraglacial lake evolution on Baltoro Glacier in the Karakoram from 2016 to 2020. A significant increase for both indices above 1.0 is observed from 2016 to 2018 and in summer 2019, which represents moderate surpluses.

Street Shopping In Winslow Az Downtown, $2,000 A Week For Life Scratch-off, How To Ask For Salary Increment Politely, Articles H