The monitoring of katabatic wind-coastal polynya interaction using AVHRR imagery

1994 ◽  
Vol 6 (4) ◽  
pp. 537-540 ◽  
Author(s):  
Jeremy H. Cotton ◽  
Kelvin J. Michael
Keyword(s):  
High Resolution ◽  
Katabatic Wind ◽  
Thermal Imagery ◽  
Katabatic Winds ◽  
Coastal Polynya ◽  
The Antarctic ◽  
Avhrr Imagery ◽  
Very High

Coastal polynyas, which form around the Antarctic coast due to persistent katabatic winds, play an important role in enhancing air-sea interaction. This paper discusses how thermal imagery from the Advanced Very High Resolution Radiometer (AVHRR) can be used to track the direction of katabatic winds, and hence facilitate research into air-sea interaction.

scholarly journals Observations of the Antarctic ice sheet with the Seasat scatterometer: relation to katabatic-wind intensity and direction

1993 ◽  
Vol 39 (132) ◽  
pp. 385-396
Author(s):  
M. Ledroit ◽  
F. Remy ◽  
J.-F. Minster
Keyword(s):  
Incidence Angle ◽  
Ice Sheet ◽  
Katabatic Wind ◽  
Katabatic Winds ◽  
Antarctic Ice Sheet ◽  
Scatter Coefficient ◽  
Low Incidence ◽  
Ocean Wind ◽  
Wind Intensity ◽  
The Antarctic

AbstractThe Seasat A satellite scatterometer radar, initially designed to measure ocean-wind intensity and direction, also provided observations on the Antarctic ice sheet. The signal of the back-scatter coefficient decreases strongly from 10 to −20 dB when the incidence angle of the observations increases from 0° to 65°. An additional 5 dB signal is found, which is correlated with the direction and intensity of katabatic winds, independent of the incidence angle and polarization of the signal. By using simplified models of the volume-scattering within the snowpack (which is mostly sensitive to snow grain-size) and surface-scattering from the air-snow interface (which depends on roughness), it is evident that the signal of the scatterometer could result from the effects of snow dunes at low incidence angle, and of micro-roughness and volume back-scatter at incidence angles greater than 25°. The instrument therefore provides a means of measuring the direction and intensity of katabatic winds.

Orographic clouds in north Victoria Land from AVHRR images

Polar Record ◽  
1996 ◽  
Vol 32 (183) ◽  
pp. 317-324 ◽  
Author(s):  
Giuseppe Zibordi ◽  
Massimo Frezzotti
Keyword(s):  
High Resolution ◽  
Satellite Imagery ◽  
Meteorological Data ◽  
Spectral Features ◽  
Katabatic Winds ◽  
Victoria Land ◽  
Avhrr Data ◽  
Orographic Clouds ◽  
Temporal Occurrence ◽  
Very High

ABSTRACTOrographic clouds over north Victoria Land, East Antarctica, have been observed in Advanced Very High Resolution Radiometer (AVHRR) satellite imagery. These occasional clouds are discussed through analysis of their spectral features in AVHRR data. Temporal occurrence, spatial extension, and direction of the clouds are also discussed in relation to meteorological data for two periods characterised by katabatic winds, in December 1992 and January 1993.

Documenting Complex Surface Temperature Patterns from Advanced Very High Resolution Radiometer (AVHRR) Imagery of Saginaw Bay, Lake Huron

1998 ◽  
Vol 24 (3) ◽  
pp. 582-594 ◽  
Author(s):  
Judith Wells Budd ◽  
W. Charles Kerfoot ◽  
Ann L. Maclean
Keyword(s):  
High Resolution ◽  
Surface Temperature ◽  
Complex Surface ◽  
Lake Huron ◽  
Saginaw Bay ◽  
Avhrr Imagery ◽  
Very High

scholarly journals On the Sea-Ice Regime of the Ross Sea, Antarctica

1986 ◽  
Vol 32 (110) ◽  
pp. 54-59 ◽  
Author(s):  
Andrew P. Sturman ◽  
Mark R. Anderson
Keyword(s):  
Sea Ice ◽  
Ross Sea ◽  
Minor Role ◽  
Oceanic Circulation ◽  
Katabatic Winds ◽  
Coastal Polynya ◽  
Convergence And Divergence ◽  
Ice Regime ◽  
The Antarctic ◽  
Dominant Influence

Abstract A study is made of the sea-ice regime of the Ross Sea, Antarctica, using ESMR passive microwave data and supporting information. Inferences are made of the processes responsible for observed spatial and temporal sea-ice variations. Air flow appears to have a dominant influence on sea-ice distribution and movement, with oceanic circulation playing a more minor role. This is particularly so with coastal polynya development, where katabatic winds are important. It has been possible to identify broad areas of ice convergence and divergence by assimilating the rather limited oceanic and atmospheric information with observed sea-ice variations. In spite of some basic physical similarities of the Weddell and Ross Seas, it is apparent that the major differences in their sea-ice regimes are due to the differing roles of oceanic and atmospheric circulation in each area. The Antarctic Peninsula plays a key role in these differences. Suggestions for further research are also considered.

scholarly journals Temperature and Wind Climate of the Antarctic Peninsula as Simulated by a High-Resolution Regional Atmospheric Climate Model

2015 ◽  
Vol 28 (18) ◽  
pp. 7306-7326 ◽  
Author(s):  
Jan Melchior van Wessem ◽  
Carleen H. Reijmer ◽  
Willem Jan van de Berg ◽  
Michiel R. van den Broeke ◽  
Alison J. Cook ◽  
...  
Keyword(s):  
High Resolution ◽  
Surface Temperature ◽  
Antarctic Peninsula ◽  
Climate Model ◽  
Katabatic Wind ◽  
Near Surface ◽  
Climate Gradients ◽  
Climate Maps ◽  
The Antarctic ◽  
Regional Atmospheric Climate Model

Abstract The latest polar version of the Regional Atmospheric Climate Model (RACMO2.3) has been applied to the Antarctic Peninsula (AP). In this study, the authors present results of a climate run at 5.5 km for the period 1979–2013, in which RACMO2.3 is forced by ERA-Interim atmospheric and ocean surface fields, using an updated AP surface topography. The model results are evaluated with near-surface temperature and wind measurements from 12 manned and automatic weather stations and vertical profiles from balloon soundings made at three stations. The seasonal cycle of near-surface temperature and wind is simulated well, with most biases still related to the limited model resolution. High-resolution climate maps of temperature and wind showing that the AP climate exhibits large spatial variability are discussed. Over the steep and high mountains of the northern AP, large west-to-east climate gradients exist, while over the gentle southern AP mountains the near-surface climate is dominated by katabatic winds. Over the flat ice shelves, where katabatic wind forcing is weak, interannual variability in temperature is largest. Finally, decadal trends of temperature and wind are presented, and it is shown that recently there has been distinct warming over the northwestern AP and cooling over the rest of the AP, related to changes in sea ice cover.

Determination of the Influence of Wind on the Keweenaw Current in the Lake Superior Basin as Identified by Advanced Very High Resolution Radiometer (AVHRR) Imagery

1999 ◽  
Vol 25 (4) ◽  
pp. 625-641 ◽  
Author(s):  
Diane M. Van Luven ◽  
Jacqueline E. Huntoon ◽  
Ann L. Maclean
Keyword(s):  
High Resolution ◽  
Lake Superior ◽  
Avhrr Imagery ◽  
Very High

scholarly journals On the Sea-Ice Regime of the Ross Sea, Antarctica

1986 ◽  
Vol 32 (110) ◽  
pp. 54-59 ◽  
Author(s):  
Andrew P. Sturman ◽  
Mark R. Anderson
Keyword(s):  
Sea Ice ◽  
Ross Sea ◽  
Minor Role ◽  
Oceanic Circulation ◽  
Katabatic Winds ◽  
Coastal Polynya ◽  
Convergence And Divergence ◽  
Ice Regime ◽  
The Antarctic ◽  
Dominant Influence

AbstractA study is made of the sea-ice regime of the Ross Sea, Antarctica, using ESMR passive microwave data and supporting information. Inferences are made of the processes responsible for observed spatial and temporal sea-ice variations. Air flow appears to have a dominant influence on sea-ice distribution and movement, with oceanic circulation playing a more minor role. This is particularly so with coastal polynya development, where katabatic winds are important. It has been possible to identify broad areas of ice convergence and divergence by assimilating the rather limited oceanic and atmospheric information with observed sea-ice variations. In spite of some basic physical similarities of the Weddell and Ross Seas, it is apparent that the major differences in their sea-ice regimes are due to the differing roles of oceanic and atmospheric circulation in each area. The Antarctic Peninsula plays a key role in these differences. Suggestions for further research are also considered.

An assessment of UK Meteorological Office numerical weather prediction analyses and forecasts for the Antarctic

1997 ◽  
Vol 9 (1) ◽  
pp. 100-109 ◽  
Author(s):  
S. Leonard ◽  
J. Turner ◽  
S. Milton
Keyword(s):  
Numerical Weather Prediction ◽  
Weather Prediction ◽  
Forecast Model ◽  
Snow Accumulation ◽  
Katabatic Wind ◽  
Good Representation ◽  
Katabatic Winds ◽  
Total Cloud Amount ◽  
Numerical Weather ◽  
The Antarctic

The performance of the UK Meteorological Office operational numerical weather prediction system in the Antarctic is examined. The analysis/forecast model currently has a reasonable representation of the atmospheric circulation, although there are some problems. During the first three days of the forecasts the katabatic winds in the coastal region become too strong compared to those in the initial fields, which results in coastal easterly winds that are too strong. However, the pattern of katabatic winds across the continent is broadly correct, suggesting that there are no major errors in the model orography used. The forecast tropospheric temperatures are generally too cold, although positive errors are found inland of the coast in the region of descent associated with the katabatic wind circulation. The mean forecast low pressure centres within the circumpolar trough are in approximately the correct locations, although the depth of the centres is too deep. During January there is good agreement between the model total cloud amount over the Antarctic and the estimates of total cloud cover from in situ observations. However, in July the model has too much cloud. There is no significant change in the amount of cloud during the first three days of the forecasts. The model has a good representation of the broadscale field of snow accumulation across the Antarctic. A comparison of various 6 hour forecast model fields against observations confirms the errors noted in the three-day forecasts when compared against analyses

scholarly journals Relief and decay of flow stripes on Byrd Glacier, Antarctica

1993 ◽  
Vol 17 ◽  
pp. 255-261 ◽  
Author(s):  
G. Casassa ◽  
H. H. Brecher
Keyword(s):  
High Resolution ◽  
Aerial Photographs ◽  
Polar Ice ◽  
Ice Shelf ◽  
Lateral Shear ◽  
Ross Ice Shelf ◽  
Avhrr Data ◽  
Shelf Margin ◽  
Avhrr Imagery ◽  
Very High

Curvilinear flow stripes appear on aerial photographs and satellite imagery of polar ice. On Byrd Glacier, Antarctica, flow stripes are especially prominent and can be detected on AVHRR imagery down to the ice shelf margin. Aerial photographs of Byrd Glacier (Brecher, 1986) are used to determine photogrammetrically the relief associated with flow stripes on two transverse profiles separated by a distance of 65 km. Two kinds of stripes are found, topographic and textural flow stripes. Topographic flow stripes are associated with a ridge-trough topography with double amplitudes of 7 m to 45 m and slopes of 1–7 %. The valleys of the topographic flow stripes appear bright in the photographs and correspond to snow-covered areas, while ridges appear in general as dark stripes that correspond to bare ice areas with abundant crevasses. Textural flow stripes correspond to bands of distinct crevasse pattern which are not associated with topography. The photogrammetric information is correlated with the brightness pattern across flow stripes that appears on Advanced Very High Resolution Radiometer (AVHRR) data. Flow stripes decay rapidly on the AVHRR imagery over the first 40 km downstream from Byrd Glacier and some persist for nearly 400 km to the front of the Ross Ice Shelf. Velocity was measured across a transect on the upstream photogrammetric profile. There are no velocity discontinuities across the boundaries of flow stripes, which shows that lateral shear between flow stripes is not a valid mechanism for explaining their persistence.

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