In this paper, the 1978–2022 series of northern (NHSI) and southern (SHSI) hemisphere sea ice extent are submitted to singular spectral analysis (SSA). The trends are quasi-linear, decreasing for NHSI (by 58,300 km2/yr) and increasing for SHSI (by 15,400 km2/yr). The amplitude of annual variation in the Antarctic is double that in the Arctic. The semi-annual components are in quadrature. The first three oscillatory components of both NHSI and SHSI, at 1, 1/2, and 1/3 yr, account for more than 95% of the signal variance. The trends are respectively 21 (Antarctic) and 4 times (Arctic) less than the amplitudes of the annual components. We next analyze variations in pole position (PM for polar motion, coordinates m1, m2) and length of day (lod). Whereas the SSA of the lod is dominated by the same first three components as sea ice, the SSA of the PM contains only the 1-yr forced annual oscillation and the Chandler 1.2-yr component. The 1-yr component of NHSI is in phase with that of the lod and in phase opposition with m1, while the reverse holds for the 1-yr component of SHSI. The semi-annual component appears in the lod and not in m1. The annual and semi-annual components of NHSI and SHSI are much larger than the trends, leading us to hypothesize that a geophysical or astronomical forcing might be preferable to the generally accepted forcing factors. The lack of modulation of the largest (SHSI) forced component does suggest an alternate mechanism. In Laplace’s theory of gravitation, the torques exerted by the Moon, Sun, and planets play the leading role as the source of forcing (modulation), leading to changes in the inclination of the Earth’s rotation axis and transferring stresses to the Earth’s envelopes. Laplace assumes that all masses on and in the Earth are set in motion by astronomical forces; more than variations in eccentricity, it is variations in the inclination of the rotation axis that lead to the large annual components of melting and re-freezing of sea-ice.
Posted onDecember 14, 2022| Comments Offon Arctic Report: primary productivity still high & sea ice flatline continues despite warmer temperatures
NOAAs annual Arctic Report Card is, for the most part, a valiant effort to turn good and ambiguous news into harbingers of climate change disaster. Primary productivity is up across most of the region (good news for wildlife) and despite Arctic temperatures being “twice as high” as the rest of the world in recent years, the summer sea ice ‘death spiral’ has failed to materialize.
Oddly, there is no bad news about polar bears (last mention was 2014). However, the media were told that the few hundred sea birds that died this year in the enormous Bering/Chukchi Sea region over the four months of summer in 2022 is a portend of climate change catastrophe–even though the authors of the NOAA report admit they have no conclusive evidence to explain the phenomenon. However, here are also some honest figures that are quite illuminating.
The graph at the bottom of this graphic, spread out rather than bunched up to make changes seem more dramatic, makes it much easier to see the lack of a declining trend in sea ice extent since 2007, and that winter (March) coverage has changed hardly at all.