scholarly journals Extracting tidal variability of sea ice concentration from AMSR-E passive microwave single-swath data: a case study of the Ross Sea

2013 ◽  
Vol 40 (3) ◽  
pp. 547-552 ◽  
Author(s):  
Stefanie Mack ◽  
Laurie Padman ◽  
John Klinck
Keyword(s):  
Sea Ice ◽  
Ross Sea ◽  
Passive Microwave ◽  
Sea Ice Concentration ◽  
Ice Concentration ◽  
Tidal Variability

scholarly journals Summer and early-fall Sea-ice concentration in the Ross Sea: comparison of in Situ ASPeCt observations and satellite passive microwave estimates

2006 ◽  
Vol 44 ◽  
pp. 303-309 ◽  
Author(s):  
Margaret A. Knuth ◽  
Stephen F. Ackley
Keyword(s):  
Sea Ice ◽  
Satellite Data ◽  
Ross Sea ◽  
Passive Microwave ◽  
Sea Ice Concentration ◽  
Point Sampling ◽  
Continuous Sampling ◽  
Ice Concentration ◽  
Observation Protocol

AbstractSea-ice conditions were observed using the AsPeCt observation protocol on three cruises in the Ross Sea spanning the Antarctic Summer Season (APIs, December 1999–February 2000; Anslope 1, March–April 2003; Anslope 2, February–April 2004). An additional dataset was analyzed from helicopter video Surveys taken during the APIs cruise. The helicopter video was analyzed using two techniques: first, as an AsPeCt dataset where it was Sampled visually for ice concentration, floe Sizes and ice type on a point basis at 11 km intervals; Second, computerized image processing on a Subset of nine helicopter flights to obtain ice concentration on a continuous basis (1 S intervals) for the entire flight. This continuous Sampling was used to validate the point-sampling methods to characterize the ice cover; the ‘AsPeCt Sampling’ on the helicopter video and the use of the AsPeCt protocol on the Ship Surveys. The estimates for average ice concentration agreed within 5% for the continuous digitized data and point Sampling at 11 km intervals in this comparison. The Ship and video in Situ datasets were then compared with ice concentrations from SsM/I passive microwave Satellite data derived using the Bootstrap and NAsA-Team algorithms. Less than 50% of the variance in Summer ice concentration observed in Situ was explainable by Satellite microwave data. The Satellite data were also inconsistent in measurement, both underestimating and overestimating the concentration for Summer conditions, but improved in the fall period when conditions were colder. This improvement was in the explainable variance of >70%, although in Situ concentration was underestimated (albeit consistently) by the Satellite imagery in fall.

scholarly journals Modeling the effect of Ross Ice Shelf melting on the Southern Ocean in quasi-equilibrium

2018 ◽  
Vol 12 (9) ◽  
pp. 3033-3044 ◽  
Author(s):  
Xiying Liu
Keyword(s):  
Southern Ocean ◽  
Sea Ice ◽  
Ross Sea ◽  
Global Ocean ◽  
Freshwater Flux ◽  
Quasi Equilibrium ◽  
Ice Shelf ◽  
Sea Ice Concentration ◽  
Ross Ice Shelf ◽  
Ice Concentration

Abstract. To study the influence of basal melting of the Ross Ice Shelf (BMRIS) on the Southern Ocean (ocean southward of 35∘ S) in quasi-equilibrium, numerical experiments with and without the BMRIS effect were performed using a global ocean–sea ice–ice shelf coupled model. In both experiments, the model started from a state of quasi-equilibrium ocean and was integrated for 500 years forced by CORE (Coordinated Ocean-ice Reference Experiment) normal-year atmospheric fields. The simulation results of the last 100 years were analyzed. The melt rate averaged over the entire Ross Ice Shelf is 0.25 m a−1, which is associated with a freshwater flux of 3.15 mSv (1 mSv = 103 m3 s−1). The extra freshwater flux decreases the salinity in the region from 1500 m depth to the sea floor in the southern Pacific and Indian oceans, with a maximum difference of nearly 0.005 PSU in the Pacific Ocean. Conversely, the effect of concurrent heat flux is mainly confined to the middle depth layer (approximately 1500 to 3000 m). The decreased density due to the BMRIS effect, together with the influence of ocean topography, creates local differences in circulation in the Ross Sea and nearby waters. Through advection by the Antarctic Circumpolar Current, the flux difference from BMRIS gives rise to an increase of sea ice thickness and sea ice concentration in the Ross Sea adjacent to the coast and ocean water to the east. Warm advection and accumulation of warm water associated with differences in local circulation decrease sea ice concentration on the margins of sea ice cover adjacent to open water in the Ross Sea in September. The decreased water density weakens the subpolar cell as well as the lower cell in the global residual meridional overturning circulation (MOC). Moreover, we observe accompanying reduced southward meridional heat transport at most latitudes of the Southern Ocean.

scholarly journals A Method to Determine the Margins of High Sea Ice Concentration Using AMSR-E Passive Microwave Imagery

2017 ◽  
Vol 05 (06) ◽  
pp. 15-25
Author(s):  
Shugang Zhang ◽  
Shixuan Liu ◽  
Shuwei Zhang ◽  
Shizhe Chen
Keyword(s):  
Sea Ice ◽  
Passive Microwave ◽  
Sea Ice Concentration ◽  
Ice Concentration

Intercomparisons of sea ice concentration from SSM/I and AVHRR data of the Ross Sea

1995 ◽  
Vol 53 (3) ◽  
pp. 145-152 ◽  
Author(s):  
G. Zibordi ◽  
M. Van Woert ◽  
G.P. Meloni ◽  
I. Canossi
Keyword(s):  
Sea Ice ◽  
Ross Sea ◽  
Sea Ice Concentration ◽  
Ice Concentration ◽  
Avhrr Data

scholarly journals The 2018 North Greenland polynya observed by a newly introduced merged optical and passive microwave sea-ice concentration dataset

2019 ◽  
Vol 13 (7) ◽  
pp. 2051-2073 ◽  
Author(s):  
Valentin Ludwig ◽  
Gunnar Spreen ◽  
Christian Haas ◽  
Larysa Istomina ◽  
Frank Kauker ◽  
...  
Keyword(s):  
Sea Ice ◽  
Growth Yield ◽  
Thermal Infrared ◽  
Passive Microwave ◽  
Pressure System ◽  
Sea Ice Concentration ◽  
Sea Ice Thickness ◽  
Ice Growth ◽  
Spatial Coverage ◽  
Ice Concentration

Abstract. Observations of sea-ice concentration are available from satellites year-round and almost weather-independently using passive microwave radiometers at resolutions down to 5 km. Thermal infrared radiometers provide data with a resolution of 1 km but only under cloud-free conditions. We use the best of the two satellite measurements and merge thermal infrared and passive microwave sea-ice concentrations. This yields a merged sea-ice concentration product combining the gap-free spatial coverage of the passive microwave sea-ice concentration and the 1 km resolution of the thermal infrared sea-ice concentration. The benefit of the merged product is demonstrated by observations of a polynya which opened north of Greenland in February 2018. We find that the merged sea-ice concentration product resolves leads at sea-ice concentrations between 60 % and 90 %. They are not resolved by the coarser passive microwave sea-ice concentration product. The benefit of the merged product is most pronounced during the formation of the polynya. Next, the environmental conditions during the polynya event are analysed. The polynya was caused by unusual southerly winds during which the sea ice drifted northward instead of southward as usual. The daily displacement was 50 % stronger than normal. The polynya was associated with a warm-air intrusion caused by a high-pressure system over the Eurasian Arctic. Surface air temperatures were slightly below 0 ∘C and thus more than 20 ∘C higher than normal. Two estimates of thermodynamic sea-ice growth yield sea-ice thicknesses of 60 and 65 cm at the end of March in the area opened by the polynya. This differed from airborne sea-ice thickness measurements, indicating that sea-ice growth processes in the polynya are complicated by rafting and ridging. A sea-ice volume of 33 km3 was produced thermodynamically.

Sensitivity of the Arctic sea ice concentration forecasts to different atmospheric forcing: a case study

2014 ◽  
Vol 33 (12) ◽  
pp. 15-23
Author(s):  
Qinghua Yang ◽  
Jiping Liu ◽  
Zhanhai Zhang ◽  
Cuijuan Sui ◽  
Jianyong Xing ◽  
...  
Keyword(s):  
Sea Ice ◽  
Arctic Sea Ice ◽  
The Arctic ◽  
Atmospheric Forcing ◽  
Sea Ice Concentration ◽  
Arctic Sea ◽  
Ice Concentration

scholarly journals Intercomparison of passive microwave sea ice concentration retrievals over the high-concentration Arctic sea ice

2007 ◽  
Vol 112 (C8) ◽  
Author(s):  
Søren Andersen ◽  
Rasmus Tonboe ◽  
Lars Kaleschke ◽  
Georg Heygster ◽  
Leif Toudal Pedersen
Keyword(s):  
Sea Ice ◽  
Arctic Sea Ice ◽  
Passive Microwave ◽  
High Concentration ◽  
Sea Ice Concentration ◽  
Arctic Sea ◽  
Ice Concentration
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