Abstract
From 2002 through 2008 the secular rate of de-creasing sea ice area in the northern hemisphere accelerated by a factor of 18, whereas the secular rate of increasing sea ice area in the southern hemisphere accelerated by a factor of 16, relative to the rates from 1978 through 2007. These were derived from the daily sea ice area retrieved from the Scanning Multi-channel Microwave Radiometer – Special Sensor Microwave/Imager and the Advanced Microwave Scan- ning Radiometer for the Earth Observation Sys- tem. The “annual” cycle of northern and southern sea ice areas, the number of days between maxima and minima is 372.4, on average, a frequency modulation, with a recurrence interval of 61.7 years. Significant spectral power occurs at the quasi-4-day through 120-day frequencies. The frequency content and modulation of the daily time series’ are consistent inter-monthly to inter-seasonal frequencies of solar irradiance, atmospheric-oceanic Rossby waves, length-of- day, and polar motion. This suggests conserva-tion of angular momentum of the atmosphere – sea-ice – ocean system. The near 60-year modu- lation and analysis of the detrended daily time series of the Arctic and Antarctic sea ice areas suggest the accelerations shown by the secular trends are relatively short-lived and reversible within an interval of one-quarter (15-years) to one-half (30-years) of the modulation period.
Highlights
The sea ice areas at the polar oceans serve a vital function through surface albedo in the energy balance and climate system of Earth [1,2,3,4,5]
Comparison shows that the mean Arctic sea ice area decreasing by about 3%, the mean Antarctic sea ice area increasing by about 16%, and the mean Polar sea ice area is increasing by about 7%
The satellite instrument retrievals of daily northern and southern hemisphere sea ice areas were investigated for secular trends and periodic variations
Summary
The sea ice areas at the polar oceans serve a vital function through surface albedo in the energy balance and climate system of Earth [1,2,3,4,5]. 7 from late 1978 through late 1987, and the Defense Meteorological Satellite Program special sensor microwave/imager (SSM/I) which was flown on satellites F8, F11, F13 and F15 (F13 is till operational and F15 recently experienced anomalous behavior) began from mid-1987 and current is described in Cavalieri et al [7] In this investigation we will use the daily sea ice area (not extent) from the NASA TEAM algorithm, from the northern (Arctic) and southern hemisphere (Antarctic) since it covers the longer time interval from October 1978 through the end of December 2007. In addition to the SMMR-SSM/I time series of sea ice area we use daily sea ice area data from the Advanced Microwave Scanning Radiometer for the Earth Observation System (AMSR-E), derived through an algorithm developed by scientists Institute of Oceanography, University of Hamburg, Germany [11] This sensor, flown on the NASA-Aqua satellite, provides a dataset that covers the period from mid-2002 through 2008, for comparison with the SMMR-SSM/I data. We use the secular trends to detrend the daily Arctic, Antarctic and Global time series to investigate their frequency content
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have