MODIS Snow and Sea Ice Products

Hall, Dorothy K.; Riggs, George A.; Salomonson, V. V.

doi:10.1007/978-3-540-37293-6_9

Cited by 119 publications

(132 citation statements)

References 51 publications

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“…The apparent AWS albedo measurements were subsequently compared to satellite-derived albedo from MODIS (Moderate Resolution Imaging Spectroradiometer) and Landsat sensors. MODIS albedo (α MOD ) was derived from the MODIS daily snow product (MOD10A1) processed by the National Snow and Ice Data Center (Hall et al, 2007;Stroeve et al, 2006). MOD10A1 provides daily estimates of the snow cover, snow fraction and albedo of snow surfaces at 500 m spatial resolution based on the Terra overpass (i.e., around 10:30 Local Solar Time (LST) at the Equator) with viewing angle closest to nadir.…”

Section: Temporal Albedo Evolutionmentioning

confidence: 99%

Albedo over rough snow and ice surfaces

2014

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Abstract. Both satellite and ground-based broadband albedo measurements over rough and complex terrain show several limitations concerning feasibility and representativeness. To assess these limitations and understand the effect of surface roughness on albedo, firstly, an intrasurface radiative transfer (ISRT) model is combined with albedo measurements over different penitente surfaces on Glaciar Tapado in the semiarid Andes of northern Chile. Results of the ISRT model show effective albedo reductions over the penitentes up to 0.4 when comparing the rough surface albedo relative to the albedo of the flat surface. The magnitude of these reductions primarily depends on the opening angles of the penitentes, but the shape of the penitentes and spatial variability of the material albedo also play a major role.Secondly, the ISRT model is used to reveal the effect of using albedo measurements at a specific location (i.e., apparent albedo) to infer the true albedo of a penitente field (i.e., effective albedo). This effect is especially strong for narrow penitentes, resulting in sampling biases of up to ±0.05. The sampling biases are more pronounced when the sensor is low above the surface, but remain relatively constant throughout the day. Consequently, it is important to use a large number of samples at various places and/or to locate the sensor sufficiently high in order to avoid this sampling bias of surface albedo over rough surfaces.Thirdly, the temporal evolution of broadband albedo over a penitente-covered surface is analyzed to place the experiments and their uncertainty into a longer temporal context. Time series of albedo measurements at an automated weather station over two ablation seasons reveal that albedo decreases early in the ablation season. These decreases stabilize from February onwards with variations being caused by fresh snowfall events. The 2009/2010 and 2011/2012 seasons differ notably, where the latter shows lower albedo values caused by larger penitentes. Finally, a comparison of the ground-based albedo observations with Landsat and MODIS (Moderate Resolution Imaging Spectroradiometer)-derived albedo showed that both satellite albedo products capture the albedo evolution with root mean square errors of 0.08 and 0.15, respectively, but also illustrate their shortcomings related to temporal resolution and spatial heterogeneity over small mountain glaciers.

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Section: Temporal Albedo Evolutionmentioning

confidence: 99%

Albedo over rough snow and ice surfaces

2014

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“…MOD02QKM and MOD10L2 scenes covering western North America were obtained for the end of the ablation season (15 August-15 October) between 2000(NASA, 2012Hall et al, 2012). Between two and four scenes were analysed per day, which represents about 1830 scenes over the study period.…”

Section: Mod02qkm Classificationmentioning

confidence: 99%

An approach to derive regional snow lines and glacier mass change from MODIS imagery, western North America

et al. 2013

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Abstract. We describe a method to calculate regional snow line elevations and annual equilibrium line altitudes (ELAs) from daily MODIS imagery (MOD02QKM) on large glaciers and icefields in western North America. An automated cluster analysis of the cloud-masked visible and near-infrared bands at 250 m resolution is used to delineate glacier facies (snow and ice) for ten glacierized regions between 2000-2011. For each region and season, the maximum observed value of the 20th percentile of snowcovered pixels (Z S(20) ) is used to define a regional ELA proxy (ELA est ). Our results indicate significant increases in the regional ELA proxy at two continental sites (Peyto Glacier and Gulkana Glacier) over the period of observation, though no statistically significant trends are identified at other sites. To evaluate the utility of regional ELA proxies derived from MOD02QKM imagery, we compare standard geodetic estimates of glacier mass change with estimates derived from historical mass balance gradients and observations of Z S(20) at three large icefields. Our approach yields estimates of mass change that more negative than traditional geodetic approaches, though MODIS-derived estimates are within the margins of error at all three sites. Both estimates of glacier mass change corroborate the continued mass loss of glaciers in western North America. Between 2000 and 2009, the geodetic change approach yields mean annual rates of surface elevation change for the Columbia, Lillooet, and Sittakanay icefields of −0.29 ± 0.05, −0.26 ± 0.05, and −0.63 ± 0.17 m a −1 , respectively. This study provides a new technique for glacier facies detection at daily timescales, and contributes to the development of regional estimates of glacier mass change, both of which are critical for studies of glacier contributions to streamflow and global sea level rise.

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“…NDSI is insensitive to most clouds except when ice-containing clouds are present, exhibiting a similar spectral signature to snow. Hence, some MOD35/MYD35_L2 cloud mask images presented conservative over-masking of snow cover on cloudy and foggy days (Hall et al, 2006).…”

Section: Modis Data Processingmentioning

confidence: 98%

“…This, in combination with coarse-resolution cloud cover masks resulted in 5-10 % of the images being omitted from analysis. Problems in snow detection arise when spectral characteristics important in the use of the normalised difference snow index (NDSI) make it difficult to discriminate between snow and specific cloud types (Hall et al, 2006). NDSI is insensitive to most clouds except when ice-containing clouds are present, exhibiting a similar spectral signature to snow.…”

Section: Modis Data Processingmentioning

confidence: 99%

Monitoring ice break-up on the Mackenzie River using MODIS data

2016

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Abstract. The aim of this study was to develop an approach for estimating ice break-up dates on the Mackenzie River (MR) using more than a decade of MODIS Level 3 500 m snow products (MOD/MYD10A1), complemented with 250 m Level 1B radiance products (MOD/MYD02QKM) from the Terra and Aqua satellite platforms.The analysis showed break-up began on average between days of year (DOYs) 115 and 125 and ended between DOYs 145 and 155 over 13 ice seasons (2001)(2002)(2003)(2004)(2005)(2006)(2007)(2008)(2009)(2010)(2011)(2012)(2013), resulting in an average melt duration of ca. 30-40 days. Thermal processes were more important in driving ice break-up south of the MR confluence with the Liard River, while dynamically driven break-up was more important north of the Liard.A comparison of the timing of ice disappearance with snow disappearance from surrounding land areas of the MR with MODIS Level 3 snow products showed varying relationships along the river. Ice-off and snow-off timing were in sync north of the MR-Liard River confluence and over sections of the MR before it enters the Mackenzie Delta, but ice disappeared much later than snow on land in regions where thermal ice break-up processes dominated.MODIS observations revealed that channel morphology is a more important control of ice break-up patterns than previously believed with ice runs on the MR strongly influenced by channel morphology (islands and bars, confluences and channel constriction).Ice velocity estimates from feature tracking were able to be made in 2008 and 2010 and yielded 3-4-day average ice velocities of 1.21 and 1.84 m s −1 respectively, which is in agreement with estimates from previous studies.These preliminary results confirm the utility of daily MODIS data for monitoring ice break-up processes along the Mackenzie River. The addition of optical and synthetic aperture radar data from recent and upcoming satellite missions (e.g. Sentinel-1/2/3 and RADARSAT Constellation) would improve the monitoring of ice break-up in narrower sections of the MR.

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MODIS Snow and Sea Ice Products

Cited by 119 publications

References 51 publications

Albedo over rough snow and ice surfaces

Albedo over rough snow and ice surfaces

An approach to derive regional snow lines and glacier mass change from MODIS imagery, western North America

Monitoring ice break-up on the Mackenzie River using MODIS data

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