Search Results - "Yackel, John J"

Trends and variability in summer sea ice cover in the Canadian Arctic based on the Canadian Ice Service Digital Archive, 1960-2008 and 1968-2008 by Tivy, Adrienne, Howell, Stephen E. L., Alt, Bea, McCourt, Steve, Chagnon, Richard, Crocker, Greg, Carrieres, Tom, Yackel, John J.

“…The Canadian Ice Service Digital Archive (CISDA) is a compilation of weekly ice charts covering Canadian waters from the early 1960s to present. The main…”
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Comparing L- and C-band synthetic aperture radar estimates of sea ice motion over different ice regimes by Howell, Stephen E.L., Komarov, Alexander S., Dabboor, Mohammed, Montpetit, Benoit, Brady, Michael, Scharien, Randall K., Mahmud, Mallik S., Nandan, Vishnu, Geldsetzer, Torsten, Yackel, John J.

“…Estimating sea ice motion from synthetic aperture radar (SAR) imagery at C-band is the most reliable approach because of its high spatial resolution and ever…”
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Ku-, X- and C-band measured and modeled microwave backscatter from a highly saline snow cover on first-year sea ice by Nandan, Vishnu, Geldsetzer, Torsten, Islam, Tanvir, Yackel, John. J., Gill, Jagvijay P.S., Fuller, Mark. C., Gunn, Grant, Duguay, Claude

“…In this study, we inter-compare observed and modeled Ku-, X- and C-band microwave backscatter for two snow temperature conditions for a highly saline snow…”
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Multifrequency Microwave Backscatter From a Highly Saline Snow Cover on Smooth First-Year Sea Ice: First-Order Theoretical Modeling by Nandan, Vishnu, Geldsetzer, Torsten, Yackel, John J., Islam, Tanvir, Gill, Jagvijay P. S., Mahmud, Mallik

“…A theoretical understanding of a multifrequency microwave approach to understand complex microwave interactions from a highly saline snow cover on a relatively…”
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Snow Property Controls on Modeled Ku-Band Altimeter Estimates of First-Year Sea Ice Thickness: Case Studies From the Canadian and Norwegian Arctic by Nandan, Vishnu, Scharien, Randall K., Geldsetzer, Torsten, Kwok, Ronald, Yackel, John J., Mahmud, Mallik S., Rosel, Anja, Tonboe, Rasmus, Granskog, Mats, Willatt, Rosemary, Stroeve, Julienne, Nomura, Daiki, Frey, Markus

“…Uncertainty in snow properties impacts the accuracy of Arctic sea ice thickness estimates from radar altimetry. On first-year sea ice (FYI), spatiotemporal…”
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Physical length scales of wind-blown snow redistribution and accumulation on relatively smooth Arctic first-year sea ice by Moon, Woosok, Nandan, Vishnu, Scharien, Randall K, Wilkinson, Jeremy, Yackel, John J, Barrett, Andrew, Lawrence, Isobel, Segal, Rebecca A, Stroeve, Julienne, Mahmud, Mallik, Duke, Patrick J, Else, Brent

“…Snow thickness measurements over relatively smooth Arctic first-year sea ice, obtained near Cambridge Bay in the Canadian Arctic (2014, 2016 and 2017) and near…”
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Diurnal Scale Controls on C-Band Microwave Backscatter From Snow-Covered First-Year Sea Ice During the Transition From Late Winter to Early Melt by Yackel, John J., Gill, Jagvijay P. S., Geldsetzer, Torsten, Fuller, Mark Christopher, Nandan, Vishnu

“…Diurnal observations of coincident in situ physical-, electrical-, and surface-based C-band microwave scattering properties of a 16-cm saline snow cover on…”
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C‐band backscatter from a complexly‐layered snow cover on first‐year sea ice by Fuller, M. Christopher, Geldsetzer, Torsten, Gill, Jagvijay P. S, Yackel, John J, Derksen, Chris

“…We present a case study of observed and modelled C‐band microwave backscatter signatures for a complexly‐layered snow cover on smooth, land‐fast, first‐year…”
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Changing sea ice melt parameters in the Canadian Arctic Archipelago: Implications for the future presence of multiyear ice by Howell, Stephen E. L., Tivy, Adrienne, Yackel, John J., Else, Brent G. T., Duguay, Claude R.

“…Estimates of annual sea ice melt onset, freeze onset, and melt duration are made within the Canadian Arctic Archipelago (CAA) using SeaWinds/QuikSCAT data from…”
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Origins and Levels of Seasonal Forecast Skill for Sea Ice in Hudson Bay Using Canonical Correlation Analysis by Tivy, Adrienne, Howell, Stephen E. L., Alt, Bea, Yackel, John J., Carrieres, Thomas

“…Canonical correlation analysis (CCA) is used to estimate the levels and sources of seasonal forecast skill for July ice concentration in Hudson Bay over the…”
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Observations of sea surface fCO2 distributions and estimated air-sea CO2 fluxes in the Hudson Bay region (Canada) during the open water season by Else, Brent G. T., Papakyriakou, Tim N., Granskog, Mats A., Yackel, John J.

“…The lack of baseline estimates of air‐sea CO2 exchange in Arctic and sub‐Arctic regions represents a major shortfall in our ability to understand how climate…”
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Application of a SeaWinds/QuikSCAT sea ice melt algorithm for assessing melt dynamics in the Canadian Arctic Archipelago by Howell, Stephen E. L., Tivy, Adrienne, Yackel, John J., Scharien, Randall K.

“…A remotely sensed sea ice melt algorithm utilizing SeaWinds/QuikSCAT (QuikSCAT) data is developed and applied to sea ice the Canadian Arctic Archipelago (CAA)…”
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Application of satellite remote sensing techniques for estimating air-sea CO2 fluxes in Hudson Bay, Canada during the ice-free season by ELSE, Brent G. T, YACKEL, John J, PAPAKYRIAKOU, Tim N

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Incidence Angle Dependence of HH-Polarized C- and L-Band Wintertime Backscatter Over Arctic Sea Ice by Mahmud, Mallik S., Geldsetzer, Torsten, Howell, Stephen E. L., Yackel, John J., Nandan, Vishnu, Scharien, Randall K.

“…Synthetic aperture radar (SAR) incidence angle has a significant effect on the microwave backscatter from sea ice. This paper investigates the incidence angle…”
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Estimating melt onset over Arctic sea ice from time series multi-sensor Sentinel-1 and RADARSAT-2 backscatter by Howell, Stephen E.L., Small, David, Rohner, Christoph, Mahmud, Mallik S., Yackel, John J., Brady, Michael

“…Information on the timing of melt onset over sea ice is important for understanding the Arctic's changing climate. The daily temporal resolution of passive…”
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A spectral mixture analysis approach to quantify Arctic first-year sea ice melt pond fraction using QuickBird and MODIS reflectance data by Yackel, John J., Nandan, Vishnu, Mahmud, Mallik, Scharien, Randall, Kang, Jason W., Geldsetzer, Torsten

“…Melt ponds play a significant role in the summer decay of sea ice due to the fact that their albedo is significantly lower than surrounding snow and sea ice…”
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Landfast sea ice break out patterns in the northern Bering Sea observed from C-band Synthetic Aperture Radar by Jensen, David A., Nandan, Vishnu, Mahoney, Andrew R., Yackel, John J., Resler, Lynn M.

“…•Break outs influenced by coastal orientation to ocean/wind currents and ice advection.•Stronger mechanical and weaker thermodynamic drivers influence…”
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Sensitivity of C-band synthetic aperture radar polarimetric parameters to snow thickness over landfast smooth first-year sea ice by Gill, Jagvijay P.S., Yackel, John J., Geldsetzer, Torsten, Fuller, M. Christopher

“…C-band linear and polarimetric parameters derived from synthesis and decomposition of Radarsat-2 SAR data are analyzed and evaluated with respect to snow…”
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Geophysical and atmospheric controls on Ku-, X- and C-band backscatter evolution from a saline snow cover on first-year sea ice from late-winter to pre-early melt by Nandan, Vishnu, Scharien, Randall, Geldsetzer, Torsten, Mahmud, Mallik, Yackel, John J., Islam, Tanvir, Gill, Jagvijay P.S., Fuller, Mark C., Gunn, Grant, Duguay, Claude

“…This study investigates changes in Ku-, X- and C-band microwave backscatter, co-polarized ratio and dual-frequency ratios, to changes in in-situ measured snow…”
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Physical, dielectric, and C band microwave scattering properties of first-year sea ice during advanced melt by Scharien, Randall K., Geldsetzer, Torsten, Barber, David G., Yackel, John J., Langlois, A.

“…This paper investigates the influence of solar heating and intermittent cloud cover on the physical and dielectric properties of naturally snow‐free, warm…”
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