Aerial observations of the evolution of ice surface conditions during summer
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In the summer of 1998, a program of aerial photography was carried out at the main site of the Surface Heat Budget of the Arctic Ocean (SHEBA) program at altitudes ranging from 1220 to 1830 m as mentioned in this paper.Abstract:
[1] During spring and summer, the Arctic pack ice cover undergoes a dramatic change in surface conditions, evolving from a uniform, reflective surface to a heterogeneous mixture of bare ice, melt ponds, and leads. This transformation is accompanied by a significant decrease in areally averaged, integrated albedo. The key factors contributing to this reduction in albedo are the melting of the snow cover, the formation and growth of the melt ponds, and the increase in the open water fraction. To document these changes and enable quantification of the evolution of the ponds throughout the melt season, a program of aerial photography was carried out at the main site of the Surface Heat Budget of the Arctic Ocean (SHEBA) program. A modified square pattern, 50 km on a side, surrounding the SHEBA site was flown at altitudes ranging from 1220 to 1830 m. Twelve of these aerial survey photography flights were completed between 20 May and 4 October 1998. The flights took place at approximately weekly intervals at the height of the melt season, with occasional gaps as long as 3 weeks during August and September due to persistent low clouds and fog. In addition, flights on 17 May and 25 July were flown in a closely spaced pattern designed to provide complete photo coverage of a 10-km square centered on the SHEBA main site. Images from all flights were scanned at high resolution and archived on CD-ROMs. Using personal computer image processing software, we have measured ice concentration, melt pond coverage, statistics on size and shape of melt ponds, lead fraction, and lead perimeter for the summer melt season. The ponds began forming in early June, and by the height of the melt season in early August the pond fraction exceeded 0.20. The temporal evolution of pond fraction displayed a rapid increase in mid-June, followed by a sharp decline 1 week later. After the decline, the pond fraction gradually increased until mid-August when the ponds began to freeze. By mid-September the surface of virtually all of the ponds had frozen. The open water fraction varied between 0.02 and 0.05 from May through the end of July. In early August the open water fraction jumped to 0.20 in just a few days owing to ice divergence. Melt ponds were ubiquitous during summer, with number densities increasing from 1000 to 5000 ponds per square kilometer between June and August.read more
Citations
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Journal ArticleDOI
Sistema Integrado de Estimativa e Previsão de Precipitação para Bacias Hidrográficas da CESP
Augusto José Pereira Filho,Mírian Adelaide R.R. Costa Pinto,Laércio Manfredini,Fabiano Alves de Lima,Amarílio Costa e Carvalho Pinto,Carlos H. Moribe,Felipe Vemado,Ivon Wilson da Silva Júnior +7 more
TL;DR: In this article, a sistema de monitoramento e previsao de precipitacao is presented, with the aim of melhorar as estimativas de vazao afluentes aos seus reservatorios.
NOTES AND CORRESPONDENCE Application of Aerosondes to Melt-Pond Observations over Arctic Sea Ice
TL;DR: In this article, a UAV-based continuous observation of sea ice using a small robotic aircraft called the Aerosonde was made over the Arctic Ocean from Barrow, Alaska, on 20 and 21 July 2003.
Posted ContentDOI
Freshwater Sources and Sinks for Arctic Sea Ice in Summer
TL;DR: In this paper, the authors calculate the sources and sinks of fresh water produced during summer melt on Arctic sea ice and show that the total freshwater input to the system from snow melt, ice melt, and precipitation from 1 June to 9 August was equivalent to a layer of water 80 cm thick over the ice-covered and open ocean.
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Using Lomb-Scargle Analysis to Derive Empirical Orthogonal Functions from Gappy Meteorological Data
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Book ChapterDOI
Variability of Surface Temperature and Albedo
TL;DR: In this article, the spatial and temporal variability of surface temperature, including that of liquid water at high latitudes, are presented using mainly NOAA/AVHRR data from 1981 to 2008.
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Journal ArticleDOI
Surface Heat Budget of the Arctic Ocean
Taneil Uttal,Judith A. Curry,Miles G. McPhee,Donald K. Perovich,Richard E. Moritz,James A. Maslanik,Peter S. Guest,Harry L. Stern,James A. Moore,Rene Turenne,Andreas Heiberg,Mark C. Serreze,Donald P. Wylie,Ola Persson,Clayton A. Paulson,Christopher Halle,James H. Morison,Patricia A. Wheeler,Alexander Makshtas,Harold Welch,Matthew D. Shupe,Janet M. Intrieri,Knut Stamnes,Ronald W. Lindsey,Robert Pinkel,W. Scott Pegau,Timothy P. Stanton,Thomas C. Grenfeld +27 more
TL;DR: The Surface Heat Budget of the Arctic Ocean (SHEBA) project as discussed by the authors collected ocean, ice, and atmospheric datasets over a full annual cycle that could be used to understand the processes controlling surface heat exchanges.