scholarly journals Bridging perspectives from remote Sensing and Inuit communities on changing Sea-ice cover in the Baffin Bay region

2006 ◽  
Vol 44 ◽  
pp. 433-438 ◽  
Author(s):  
Walter N. Meier ◽  
Julienne Stroeve ◽  
Shari Gearheard
Keyword(s):  
Remote Sensing ◽  
Sea Ice ◽  
Local Level ◽  
Indigenous Communities ◽  
Passive Microwave ◽  
Regional Variability ◽  
Sea Ice Extent ◽  
Baffin Bay ◽  
Inuit Knowledge ◽  
Arctic Summer

AbstractPassive microwave imagery indicates a decreasing trend in Arctic Summer Sea-ice extent Since 1979. The Summers of 2002–05 have exhibited particularly reduced extent and have reinforced the downward trend. Even the winter periods have now Shown decreasing trends. At the local level, Arctic residents are also noticing changes in Sea ice. In particular, indigenous elders and hunters report changes Such as earlier break-up, later freeze-up and thinner ice. The changing conditions have profound implications for Arctic-wide climate, but there is also regional variability in the extent trends. These can have important ramifications for wildlife and indigenous communities in the affected regions. Here we bring together observations from remote Sensing with observations and knowledge of Inuit who live in the Baffin Bay region. Weaving the complementary perspectives of Science and Inuit knowledge, we investigate the processes driving changes in Baffin Bay Sea-ice extent and discuss the present and potential future effects of changing Sea ice on local activities.

Hypertemporal analysis of remotely sensed sea-ice data for climate change studies

1995 ◽  
Vol 19 (2) ◽  
pp. 216-242 ◽  
Author(s):  
Joseph M. Piwowar ◽  
Ellsworth F. LeDrew
Keyword(s):  
Climate Change ◽  
Remote Sensing ◽  
Sea Ice ◽  
Historical Record ◽  
Passive Microwave ◽  
Electromagnetic Spectrum ◽  
Large Area ◽  
Sea Ice Extent ◽  
The North ◽  
Arctic Ice

Climatologists have speculated that a spatially coherent pattern of high-latitude temperature trends could be an early indicator of climatic change. The sensitivity of sea ice to the temperature of the overlying air suggests the possibility that trends in Arctic ice conditions may be useful proxy indicators of general climatic changes. Aspects of the north-polar ice pack which have been identified as key parameters to be monitored include ice extent, concentration, type, thickness and motion dynamics. In spite of the considerable interannual, regional and seasonal variations exhibited by these data, there may be some evidence of an emerging trend towards decreasing ice extent and concentration. Collecting data in such a remote and harsh environment to support these analyses is only possible through satellite remote sensing. Remote sensing in the microwave portion of the electromagnetic spectrum is particularly relevant for polar applications because microwaves are capable of penetrating the atmosphere under virtually all conditions and are not dependent on the sun as a source of illumination. In particular, analyses of passive microwave imagery can provide us with daily information on sea-ice extent, type, concentration, dynamics and melt onset. A historical record of Arctic imagery from orbiting passive microwave sensors starting from 1973 provides us with an excellent data source for climate change studies. The development of analysis tools to support large area monitoring is integral to advancing global change research. The critical need is to create techniques which highlight the space-time relationships in the data rather than simply displaying voluminous quantities of data. In particular, hypertemporal image analysis techniques are required to help find anticipated trends and to discover unexpected or anomalous temporal relationships. Direct hypertemporal classification, principal components analysis and spatial time-series analysis are identified as three primary techniques for enhancing change in temporal image sequences. There is still a need for the development of new tools for spatial- temporal modelling.

scholarly journals Brief communication: lack of agreement in remote sensing detection of cyclonic drift caused by Atlantic weather in Antarctic sea ice

2021 ◽  
Author(s):  
Wayne de Jager ◽  
Marcello Vichi
Keyword(s):  
Remote Sensing ◽  
Sea Ice ◽  
Alternative Methods ◽  
Polar Regions ◽  
Sea Ice Concentration ◽  
Sea Ice Extent ◽  
Ice Dynamics ◽  
Antarctic Sea Ice ◽  
Ice Drift ◽  
The Impact

Abstract. Sea-ice extent variability, a measure based on satellite-derived sea ice concentration measurements, has traditionally been used as an essential climate variable to evaluate the impact of climate change on polar regions. However, concentration- based measurements of ice variability do not allow to discriminate the relative contributions made by thermodynamic and dynamic processes, prompting the need to use sea-ice drift products and develop alternative methods to quantify changes in sea ice dynamics that would indicate trends in Antarctic ice characteristics. Here, we present a new method to automate the detection of rotational drift features in Antarctic sea ice at daily timescales using currently available remote sensing ice motion products from EUMETSAT OSI SAF. Results show that there is a large discrepancy in the detection of cyclonic drift features between products, both in terms of intensity and year-to-year distributions, thus diminishing the confidence at which ice drift variability can be further analysed. Product comparisons showed that there was good agreement in detecting anticyclonic drift, and cyclonic drift features were measured to be 1.5–2.2 times more intense than anticyclonic features. The most intense features were detected by the merged product, suggesting that the processing chain used for this product could be injecting additional rotational momentum into the resultant drift vectors. We conclude that it is therefore necessary to better understand why the products lack agreement before further trend analysis of these drift features and their climatic significance can be assessed.

scholarly journals Comparison of sea-ice extent and ice-edge location estimates from passive microwave and enhanced-resolution scatterometer data

2008 ◽  
Vol 48 ◽  
pp. 65-70 ◽  
Author(s):  
Walter N. Meier ◽  
Julienne Stroeve
Keyword(s):  
Sea Ice ◽  
Resolution Enhancement ◽  
Passive Microwave ◽  
Sea Ice Concentration ◽  
Sea Ice Extent ◽  
Local Conditions ◽  
Enhanced Resolution ◽  
Edge Location ◽  
Ice Conditions ◽  
Ice Edge

AbstractPassive microwave sea-ice concentration fields provide some of the longest-running and most consistent records of changes in sea ice. Scatterometry-based sea-ice fields are more recently developed data products, but now they provide a record of ice conditions spanning several years. Resolution enhancement techniques applied to scatterometer fields provide much higher effective resolutions (~10 km) than are available from standard scatterometer and passive microwave fields (25–50 km). Here we examine ice-extent fields from both sources and find that there is general agreement between scatterometer data and passive microwave fields, though scatterometer estimates yield substantially lower ice extents during winter. Comparisons with ice-edge locations estimated from AVHRR imagery indicate that enhanced scatterometer data can sometimes provide an improved edge location, but there is substantial variation in the results, depending on the local conditions. A blended product, using both scatterometer and passive microwave data, could yield improved results.

scholarly journals Biomarker characterization of the North Water Polynya, Baffin Bay: Implications for local sea ice and temperature proxies

2021 ◽  
Author(s):  
David J. Harning ◽  
Brooke Holman ◽  
Lineke Woelders ◽  
Anne E. Jennings ◽  
Julio Sepúlveda
Keyword(s):  
Sea Ice ◽  
The Arctic ◽  
Sea Ice Extent ◽  
Baffin Bay ◽  
The North ◽  
North Water Polynya ◽  
Lipid Biomarker ◽  
North Water ◽  
Order Of Magnitude ◽  
Insight Into

Abstract. The North Water Polynya (NOW, Greenlandic Inuit: Pikialasorsuaq), Baffin Bay, is the largest polynya and one of the most productive regions in the Arctic. This area of thin to absent sea ice is a critical moisture source for local ice sheet sustenance and coupled with the inflow of nutrient-rich Arctic Surface Water, supports a diverse community of Arctic fauna and indigenous people. Although paleoceanographic records can provide critical insight into the NOW’s past behavior, it is critical that we fully understand the modern functionality of the paleoceanographic proxies beforehand. In this study, we analyzed lipid biomarkers, including algal highly-branched isoprenoids and sterols for sea ice extent and pelagic productivity, and algal alkenones and archaeal GDGTs for ocean temperature, in a suite of modern surface sediment samples from within and around the NOW. Our data show that all highly-branched isoprenoids exhibit strong correlations with each other and show highest concentrations within the NOW, which suggests a spring/autumn sea ice diatom source rather than a combination of sea ice and open water diatoms as seen elsewhere in the Arctic. Sterols are also highly concentrated in the NOW and exhibit an order of magnitude higher concentration here compared to sites south of the NOW, consistent with the order of magnitude higher primary productivity observed within the NOW relative to surrounding waters in spring/summer months. Finally, our temperature calibrations for alkenones, GDGTs and OH-GDGTs reduce the uncertainty present in global temperature calibrations, but also identify some additional variables that may be important in controlling their local distribution, such as salinity, nutrients, and dissolved oxygen. Collectively, our datasets provide new insight into the utility of these lipid biomarker proxies in high-latitude settings and will help provide a refined perspective on the Holocene development of the NOW with their application in downcore reconstructions.

scholarly journals Comparison of Passive Microwave Data with Shipborne Photographic Observations of Summer Sea Ice Concentration along an Arctic Cruise Path

2019 ◽  
Vol 11 (17) ◽  
pp. 2009 ◽  
Author(s):  
Qingkai Wang ◽  
Peng Lu ◽  
Yongheng Zu ◽  
Zhijun Li ◽  
Matti Leppäranta ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Sea Ice ◽  
Moving Average ◽  
Open Water ◽  
Arctic Sea Ice ◽  
Passive Microwave ◽  
Sea Ice Concentration ◽  
Melt Ponds ◽  
Ice Concentration ◽  
Arctic Navigation

Arctic sea ice concentration (SIC) has been studied extensively using passive microwave (PM) remote sensing. This technology could be used to improve navigation along vessel cruise paths; however, investigations on this topic have been limited. In this study, shipborne photographic observation (P-OBS) of sea ice was conducted using oblique-oriented cameras during the Chinese National Arctic Research Expedition in the summer of 2016. SIC and the areal fractions of open water, melt ponds, and sea ice (Aw, Ap, and Ai, respectively) were determined along the cruise path. The distribution of SIC along the cruise path was U-shaped, and open water accounted for a large proportion of the path. The SIC derived from the commonly used PM algorithms was compared with the moving average (MA) P-OBS SIC, including Bootstrap and NASA Team (NT) algorithms based on Special Sensor Microwave Imager/Sounder (SSMIS) data; and ARTIST sea ice, Bootstrap, Sea Ice Climate Change Initiative, and NASA Team 2 (NT2) algorithms based on Advanced Microwave Scanning Radiometer 2 (AMSR2) data. P-OBS performed better than PM remote sensing at detecting low SIC (< 10%). Our results indicate that PM SIC overestimates MA P-OBS SIC at low SIC, but underestimates it when SIC exceeds a turnover point (TP). The presence of melt ponds affected the accuracy of the PM SIC; the PM SIC shifted from an overestimate to an underestimate with increasing Ap, compared with MA P-OBS SIC below the TP, while the underestimation increased above the TP. The PM algorithms were then ranked; SSMIS-NT and AMSR2-NT2 are the best and worst choices for Arctic navigation, respectively.

scholarly journals The anomalous sea‐ice extent in Hudson bay, Baffin bay and the Labrador sea during three simultaneous NAO and ENSO episodes

1996 ◽  
Vol 34 (2) ◽  
pp. 313-343 ◽  
Author(s):  
L.A. Mysak ◽  
R.G. Ingram ◽  
J. Wang ◽  
A. van der Baaren
Keyword(s):  
Sea Ice ◽  
Labrador Sea ◽  
Hudson Bay ◽  
Sea Ice Extent ◽  
Baffin Bay

Springtime atmospheric energy transport and the control of Arctic summer sea-ice extent

2013 ◽  
Vol 3 (8) ◽  
pp. 744-748 ◽  
Author(s):  
Marie-Luise Kapsch ◽  
Rune Grand Graversen ◽  
Michael Tjernström
Keyword(s):  
Sea Ice ◽  
Energy Transport ◽  
Sea Ice Extent ◽  
Atmospheric Energy ◽  
Atmospheric Energy Transport ◽  
Arctic Summer

scholarly journals Antarctic summer sea ice concentration and extent: comparison of ODEN 2006 ship observations, satellite passive microwave and NIC sea ice charts

2008 ◽  
Vol 2 (4) ◽  
pp. 623-647 ◽  
Author(s):  
B. Ozsoy-Cicek ◽  
H. Xie ◽  
S. F. Ackley ◽  
K. Ye
Keyword(s):  
Sea Ice ◽  
Linear Trend ◽  
Passive Microwave ◽  
The Arctic ◽  
Poor Correlation ◽  
Sea Ice Concentration ◽  
Sea Ice Extent ◽  
Antarctic Sea Ice ◽  
Ice Concentration ◽  
Ice Edge

Abstract. Antarctic sea ice cover has shown a slight increase in overall observed ice extent as derived from satellite mapping from 1979 to 2008, contrary to the decline observed in the Arctic regions. Spatial and temporal variations of the Antarctic sea ice however remain a significant problem to monitor and understand, primarily due to the vastness and remoteness of the region. While satellite remote sensing has provided and has great future potential to monitor the variations and changes of sea ice, uncertainties remain unresolved. In this study, the National Ice Center (NIC) ice edge and the AMSR-E (Advanced Microwave Scanning Radiometer – Earth Observing System) ice extent are examined, while the ASPeCt (Antarctic Sea Ice Process and Climate) ship observations from the Oden expedition in December 2006 are used as ground truth to verify the two products during Antarctic summer. While there is a general linear trend between ASPeCt and AMSR-E ice concentration estimates, there is poor correlation (R2=0.41) and AMSR-E tends to underestimate the low ice concentrations. We also found that the NIC sea ice edge agrees well with ship observations, while the AMSR-E shows the ice edge further south, consistent with its poorer detection of low ice concentrations. The northward extent of the ice edge at the time of observation (NIC) had mean values varying from 38 km to 102 km greater on different days for the area as compared with the AMSR-E sea ice extent. For the circumpolar area as a whole in the December period examined, AMSR-E therefore underestimates the area inside the ice edge at this time by up to 14% or, 1.5 million km2 less area, compared to the NIC ice charts. These differences alone can account for more than half of the purported sea ice loss between the pre 1960s and the satellite era suggested earlier from comparative analysis of whale catch data with satellite derived data. Preliminary comparison of satellite scatterometer data suggests better resolution of low concentrations than passive microwave, and therefore better fidelity with ship observations and NIC charts of the area inside the ice edge during Antarctic summer.

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