scholarly journals Interim guidelines for operational implementation of SAR applications for lake ice monitoring and mapping: break-up and freeze-up

2014 ◽  
Author(s):  
T Geldsetzer ◽  
J J van der Sanden
Keyword(s):  
Lake Ice ◽  
Break Up

Lake ice phenology changes in the northern hemisphere

2021 ◽  
Author(s):  
Yubao Qiu ◽  
Xingxing Wang ◽  
Matti Leppäranta ◽  
Bin Cheng ◽  
Yixiao Zhang
Keyword(s):  
Remote Sensing ◽  
North America ◽  
Northern Hemisphere ◽  
Ice Cover ◽  
Passive Microwave ◽  
Lake Area ◽  
Lake Ice ◽  
Northern Tibetan Plateau ◽  
Break Up ◽  
Ice Phenology

<p>Lake-ice phenology is an essential indicator of climate change impact for different regions (Livingstone, 1997; Duguay, 2010), which helps understand the regional characters of synchrony and asynchrony. The observation of lake ice phenology includes ground observation and remote sensing inversion. Although some lakes have been observed for hundreds of years, due to the limitations of the observation station and the experience of the observers, ground observations cannot obtain the lake ice phenology of the entire lake. Remote sensing has been used for the past 40 years, in particular, has provided data covering the high mountain and high latitude regions, where the environment is harsh and ground observations are lacking. Remote sensing also provides a unified data source and monitoring standard, and the possibility of monitoring changes in lake ice in different regions and making comparisons between them. The existing remote sensing retrieval products mainly cover North America and Europe, and data for Eurasia is lacking (Crétaux et al., 2020).</p><p>Based on the passive microwave, the lake ice phenology of 522 lakes in the northern hemisphere during 1978-2020 was obtained, including Freeze-Up Start (FUS), Freeze-Up End (FUE), Break-Up Start (BUS), Break-Up End (BUE), and Ice Cover Duration (ICD). The ICD is the duration from the FUS to the BUE, which can directly reflect the ice cover condition. At latitudes north of 60°N, the average of ICD is approximately 8-9 months in North America and 5-6 months in Eurasia. Limited by the spatial resolution of the passive microwave, lake ice monitoring is mainly in Northern Europe. Therefore, the average of ICD over Eurasia is shorter, while the ICD is more than 6 months for most lakes in Russia. After 2000, the ICD has shown a shrinking trend, except northeastern North America (southeast of the Hudson Bay) and the northern Tibetan Plateau. The reasons for the extension of ice cover duration need to be analyzed with parameters, such as temperature, the lake area, and lake depth, in the two regions.</p>

scholarly journals Sensitivity of lake freeze-up and break-up to climate change: a physically based modeling study

1995 ◽  
Vol 21 ◽  
pp. 387-393 ◽  
Author(s):  
Glen E. Liston ◽  
Dorothy K. Hall
Keyword(s):  
Air Temperature ◽  
Model Performance ◽  
Atmospheric Forcing ◽  
Lake Ice ◽  
Temperature Changes ◽  
Wind Speeds ◽  
Great Slave Lake ◽  
Physically Based ◽  
Speed Up ◽  
Break Up

To assess the response of lake Freeze-up and break-up dates to changes in atmospheric forcing, a physically based computational model of the coupled lake, lake-ice, snow and atmosphere system has been developed. Model performance is validated using meteorological and lake-ice observations from Great Slave Lake in northern Canada (1991/92) and St Mary Lake in Glacier National Park, Montana, (1992/93). Model integrations with modified atmospheric forcing indicate that air-temperature changes of ±4°C can delay or speed up the freeze-up and break-up dates by as much as 4 weeks for St Mary Lake, and 2 weeks for Great Slave Lake. For both lakes, break-up date is more sensitive to air-temperature changes than is freeze-up. Changes of ±3/10 cloud-cover fraction produce a shifting of break-tip dates by 1 week. Changes in wind speeds of ± 3 m s−1 modify the maximum ice depth of the lakes by 5–10 cm. For Great Slave Lake, lower wind speeds produced a surface temperature low enough to delay the onset of break-up by 2 weeks.

scholarly journals Fritz Müller’s legacy on Axel Heiberg Island, Nunavut, Canada

2000 ◽  
Vol 31 ◽  
pp. 1-9
Author(s):  
Peter Adams
Keyword(s):  
Faculty Member ◽  
Mass Balance ◽  
Early Years ◽  
Glacier Mass Balance ◽  
Personal Account ◽  
Lake Ice ◽  
Glacier Terminus ◽  
Mcgill University ◽  
Break Up ◽  
Axel Heiberg Island

AbstractFritz Müller (1926–80) was the leader of the Jacobsen-McGill Arctic Research Expeditions to Axel Heiberg Island, Nunavut, Canada. He was a faculty member at McGill University, Montreal, Canada, from 1959 to 1970. Thereafter, he was Chair of Geography at Eidgenossische Techmsche Hochschule, Zürich, Switzerland. He conducted research on Axel Heiberg Island, mainly in the vicinity of Expedition Fiord, from 1959 until his death in 1980. This paper is a personal account of Müller’s work by one of his students, with a commentary on his contributions to Arctic science. The personal account focuses on the early years of the expeditions. The commentary includes discussion of glacier mass-balance records and lake-ice break-up from 1959 to the present, glacier-terminus records from 1948 to the present and other research focused on the region.

scholarly journals The Impact of the NAO on the Delayed Break-Up Date of Lake Ice over the Southern Tibetan Plateau

2018 ◽  
Vol 31 (22) ◽  
pp. 9073-9086 ◽  
Author(s):  
Yong Liu ◽  
Huopo Chen ◽  
Huijun Wang ◽  
Yubao Qiu
Keyword(s):  
Water Vapor ◽  
Tibetan Plateau ◽  
North Atlantic ◽  
Vapor Transport ◽  
Water Vapor Transport ◽  
Freezing Process ◽  
Lake Ice ◽  
Break Up ◽  
The Impact ◽  
Ice Phenology

The changing characteristics of lake ice phenology over the Tibetan Plateau (TP) are investigated using historical satellite retrieved datasets during 2002–15 in this study. The results indicate that the freezing process mainly starts in December, and the ice melting process generally occurs in April for most lakes. However, the changes in lake ice phenology have varied depending on the location in recent years, with delayed break-up dates and prolonged ice durations in the southern TP, but no consistent changes have occurred in the lakes in the northern TP. Further analysis presents a close connection between the variation in the lake ice break-up date/ice duration over the southern TP and the winter North Atlantic Oscillation (NAO). The positive NAO generally excites an anomalous wave activity that propagates southward from the North Atlantic to North Africa and, in turn, strengthens the African–Asian jet stream at its entrance. Because of the blocking effect of the TP, the enhanced westerly jet can be divided into two branches and the south branch flow can deepen the India–Myanmar trough, which further strengthens the anomalous cyclonic circulation and water vapor transport. Therefore, the increased water vapor transport from the northern Indian Ocean to the southern region of the TP can increase the snowfall over this region. The increased snow cover over the lake acts as an insulating layer and lowers the lake surface temperature in the following spring by means of snow–ice feedback activity, resulting in a delayed ice break-up date and the increased ice duration of the lakes over the southern TP in recent years.

scholarly journals Sensitivity of lake freeze-up and break-up to climate change: a physically based modeling study

1995 ◽  
Vol 21 ◽  
pp. 387-393 ◽  
Author(s):  
Glen E. Liston ◽  
Dorothy K. Hall
Keyword(s):  
Air Temperature ◽  
Model Performance ◽  
Atmospheric Forcing ◽  
Lake Ice ◽  
Temperature Changes ◽  
Wind Speeds ◽  
Great Slave Lake ◽  
Physically Based ◽  
Speed Up ◽  
Break Up

To assess the response of lake Freeze-up and break-up dates to changes in atmospheric forcing, a physically based computational model of the coupled lake, lake-ice, snow and atmosphere system has been developed. Model performance is validated using meteorological and lake-ice observations from Great Slave Lake in northern Canada (1991/92) and St Mary Lake in Glacier National Park, Montana, (1992/93). Model integrations with modified atmospheric forcing indicate that air-temperature changes of ±4°C can delay or speed up the freeze-up and break-up dates by as much as 4 weeks for St Mary Lake, and 2 weeks for Great Slave Lake. For both lakes, break-up date is more sensitive to air-temperature changes than is freeze-up. Changes of ±3/10 cloud-cover fraction produce a shifting of break-tip dates by 1 week. Changes in wind speeds of ± 3 m s−1 modify the maximum ice depth of the lakes by 5–10 cm. For Great Slave Lake, lower wind speeds produced a surface temperature low enough to delay the onset of break-up by 2 weeks.

Long-term changes in lake ice cover in Finland*

2006 ◽  
Vol 37 (4-5) ◽  
pp. 347-363 ◽  
Author(s):  
Johanna Korhonen
Keyword(s):  
Time Series ◽  
19Th Century ◽  
Ice Cover ◽  
Ice Thickness ◽  
Lake Ice ◽  
Early 19Th Century ◽  
Long Term Changes ◽  
Break Up ◽  
Thickness Measurements

The freeze-up and break-up records of almost ninety lakes, and ice thickness of about thirty lakes, were analysed in order to identify long-term changes in the ice regime in Finland. The longest time series of break-up and freeze-up of ice in lakes are available from the early 19th century, while the earliest ice thickness measurements started in the 1910s. The analysis showed that there is a significant change towards earlier ice break-up in Finland except in the very north from the late 19th century to the present time. There is also a significant trend towards later freeze-up and thus also towards a shorter ice cover duration for the longest time series. However, for most lakes, for which data are not available prior to 1900, there are no significant trends. The ice thickness seems to have increased over the last 40 years, although there are significant trends only in half of the investigated lakes and significant decrease in the maximum ice thickness was found in four lakes in southern Finland. The increased ice thickness is most likely due to heavy snow on the ice and production of snow ice.

scholarly journals Monitoring the Ice Phenology of Qinghai Lake from 1980 to 2018 Using Multisource Remote Sensing Data and Google Earth Engine

2020 ◽  
Vol 12 (14) ◽  
pp. 2217 ◽  
Author(s):  
Miaomiao Qi ◽  
Shiyin Liu ◽  
Xiaojun Yao ◽  
Fuming Xie ◽  
Yongpeng Gao
Keyword(s):  
Google Earth ◽  
Qinghai Lake ◽  
Small Scale ◽  
Surface Reflectance ◽  
Lake Area ◽  
Lake Ice ◽  
Noaa Avhrr ◽  
Break Up ◽  
Freeze Duration ◽  
Ice Phenology

Lake ice, one of the most direct lake physical characteristics affected by climate change, can reflect small-scale environmental changes caused by the atmosphere and hydrology, as well as large-scale climate changes such as global warming. This study uses National Oceanic and Atmospheric Administration, Advanced Very High Resolution Radiometer (NOAA AVHRR), MOD09GQ surface reflectance products, and Landsat surface reflectance Tier 1 products, which comprehensively used RS and GIS technology to study lake ice phenology (LIP) and changes in Qinghai Lake. Over the past 38 years, freeze-up start and freeze-up end dates were gradually delayed by a rate of 0.16 d/a and 0.19 d/a, respectively, with a total delay by 6.08 d and 7.22 d. The dates of break-up start and break-up end showed advancing trends by −0.36 d/a and −0.42 d/a, respectively, which shifted them earlier by 13.68 d and 15.96 d. Overall, ice coverage duration, freeze duration, and complete freeze duration showed decreasing trends of −0.58 d/a, −0.60 d/a, and −0.52 d/a, respectively, and overall decreased by 22.04 d, 22.81 d, and 9.76 d between 1980 and 2018. The spatial pattern in the freeze–thaw of Qinghai Lake can be divided into two areas; the west of the lake area has similar spatial patterns of freezing and ablation, while, in the east of the lake area, freezing and ablation patterns are opposite. Climate factors were closely related to LIP, especially the accumulated freezing degree-day (AFDD) from October to April of the following year. Furthermore, freeze-up start time was more sensitive to changes in wind speed and precipitation.

scholarly journals Validation of lake surface state in the HIRLAM v.7.4 numerical weather prediction model against in situ measurements in Finland

2019 ◽  
Vol 12 (8) ◽  
pp. 3707-3723 ◽  
Author(s):  
Laura Rontu ◽  
Kalle Eerola ◽  
Matti Horttanainen
Keyword(s):  
Water Temperature ◽  
Numerical Weather Prediction ◽  
Surface State ◽  
Weather Prediction ◽  
Objective Analysis ◽  
Ice Thickness ◽  
Lake Surface ◽  
Lake Ice ◽  
Numerical Weather ◽  
Break Up

Abstract. The High Resolution Limited Area Model (HIRLAM), used for the operational numerical weather prediction in the Finnish Meteorological Institute (FMI), includes prognostic treatment of lake surface state since 2012. Forecast is based on the Freshwater Lake (FLake) model integrated into HIRLAM. Additionally, an independent objective analysis of lake surface water temperature (LSWT) combines the short forecast of FLake to observations from the Finnish Environment Institute (SYKE). The resulting description of lake surface state – forecast FLake variables and analysed LSWT – was compared to SYKE observations of lake water temperature, freeze-up and break-up dates, and the ice thickness and snow depth for 2012–2018 over 45 lakes in Finland. During the ice-free period, the predicted LSWT corresponded to the observations with a slight overestimation, with a systematic error of +0.91 K. The colder temperatures were underrepresented and the maximum temperatures were too high. The objective analysis of LSWT was able to reduce the bias to +0.35 K. The predicted freeze-up dates corresponded well to the observed dates, mostly within the accuracy of a week. The forecast break-up dates were far too early, typically several weeks ahead of the observed dates. The growth of ice thickness after freeze-up was generally overestimated. However, practically no predicted snow appeared on lake ice. The absence of snow, presumably due to an incorrect security coefficient value, is suggested to be also the main reason for the inaccurate simulation of the lake ice melting in spring.

scholarly journals The fate of lake ice in the North American Arctic

2011 ◽  
Vol 5 (4) ◽  
pp. 869-892 ◽  
Author(s):  
L. C. Brown ◽  
C. R. Duguay
Keyword(s):  
Snow Cover ◽  
North American ◽  
Climate Model ◽  
Regional Climate ◽  
Ice Cover ◽  
Lake Ice ◽  
The North ◽  
North American Arctic ◽  
Break Up ◽  
Perennial Ice

Abstract. Lakes comprise a large portion of the surface cover in northern North America, forming an important part of the cryosphere. The timing of lake ice phenological events (e.g. break-up/freeze-up) is a useful indicator of climate variability and change, which is of particular relevance in environmentally sensitive areas such as the North American Arctic. Further alterations to the present day ice regime could result in major ecosystem changes, such as species shifts and the disappearance of perennial ice cover. The Canadian Lake Ice Model (CLIMo) was used to simulate lake ice phenology across the North American Arctic from 1961–2100 using two climate scenarios produced by the Canadian Regional Climate Model (CRCM). Results from the 1961–1990 time period were validated using 15 locations across the Canadian Arctic, with both in situ ice cover observations from the Canadian Ice Database as well as additional ice cover simulations using nearby weather station data. Projected changes to the ice cover using the 30-year mean data between 1961–1990 and 2041–2070 suggest a shift in break-up and freeze-up dates for most areas ranging from 10–25 days earlier (break-up) and 0–15 days later (freeze-up). The resulting ice cover durations show mainly a 10–25 day reduction for the shallower lakes (3 and 10 m) and 10–30 day reduction for the deeper lakes (30 m). More extreme reductions of up to 60 days (excluding the loss of perennial ice cover) were shown in the coastal regions compared to the interior continental areas. The mean maximum ice thickness was shown to decrease by 10–60 cm with no snow cover and 5–50 cm with snow cover on the ice. Snow ice was also shown to increase through most of the study area with the exception of the Alaskan coastal areas.

Intra- and inter-annual changes in chemistry of Australian glacial lakes

2012 ◽  
Vol 63 (6) ◽  
pp. 513 ◽  
Author(s):  
Ken Green
Keyword(s):  
Biological Activity ◽  
Chemical Characteristics ◽  
Biogeochemical Processes ◽  
Lake Ice ◽  
Nutrient Deposition ◽  
Order Of Magnitude ◽  
Spring Temperatures ◽  
Ionic Pulse ◽  
Annual Changes ◽  
Break Up

The chemical characteristics of five seasonally ice-covered lakes in the Snowy Mountains were measured monthly from 2006 to 2009. Although N and P concentrations were significantly higher in rainfall than snowfall, concentrations peaked in lakes in winter rather than summer. This was linked to continuous winter nutrient flow into the lakes from melting snowpack and continued biogeochemical processes in unfrozen soil at a time when biological activity beneath the lake ice was depressed. In contrast to high altitude lakes elsewhere, there was no spring ionic pulse of nutrients. Lake pH fluctuated throughout the ice-free period between 6.9 and 6.5, falling to 6.1–6.0 beneath ice cover, before rising abruptly after ice break-up. Earlier ice break-up in recent years has resulted in an earlier increase in pH, and decrease in concentrations of NH3-N and NOx-N. In years with least snowfall and early ice break-up, winter peaks of NH3-N were lowest whereas both PO4-P and NOx-N showed winter peaks of various concentrations in medium years rather than extreme years. Rising winter and/or spring temperatures resulting in changes in precipitation from snow to rain could lead to increased nutrient deposition, with rain carrying an order of magnitude more nutrients than does snow.

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