Premium
Time variability in the annual cycle of sea ice thickness in the T ranspolar D rift
Author(s) -
Hansen E.,
Gerland S.,
Høyland K. V.,
Pavlova O.,
Spreen G.
Publication year - 2015
Publication title -
journal of geophysical research: oceans
Language(s) - English
Resource type - Journals
eISSN - 2169-9291
pISSN - 2169-9275
DOI - 10.1002/2015jc011102
Subject(s) - trough (economics) , amplitude , geology , sea ice , rift , geodesy , climatology , seismology , physics , optics , economics , macroeconomics , tectonics
The annual cycle of modal and mean sea ice thickness was derived from upward looking sonar ice thickness observations (1990–2011) in Fram Strait. The average annual peak‐to‐trough amplitude of the mode of 0.54 m is superimposed on interannual variability with peak‐to‐trough amplitudes of 0.73 m on time scales of 6–8 years, which again is superimposed on a long‐term trend of −0.55 m/decade over the observation period. The long‐term trend is stronger for April than for August, the average months of maximum and minimum modal thickness. As a result, the annual peak‐to‐trough modal thickness amplitude was reduced by 30% between the 1990s and the 2000s. The average annual peak‐to‐trough amplitude of the mean ice thickness of 1.20 m is also superimposed on interannual variability, with as much as 0.97 m thickness change over only 3 years. These two modes of variability are superimposed on a long‐term trend of −0.35 m/decade through the entire data set. In contrast to the modal thickness, the long‐term trend is weaker for the average month of maximum mean thickness (June), than for the average month of minimum (September). Therefore, the annual peak‐to‐trough amplitude of the mean ice thickness increased by 14% between the 1990s and the 2000s.