The Greenland Ice Core Chronology 2005, 15–42 ka. Part 2: comparison to other records

A new Greenland Ice Core Chronology (GICC05) based on multi-parameter counting of annual layers has been obtained for the last 42 ka. Here we compare the glacial part of the new time scale, which is based entirely on records from the NorthGRIP ice core, to existing time scales and reference horizons covering the same period. These include the GRIP and NorthGRIP modelled time scales, the Meese-Sowers GISP2 counted time scale, the Shackleton–Fairbanks GRIP time scale (SFCP04) based on ¹⁴C calibration of a marine core, the Hulu Cave record, three volcanic reference horizons, and the Laschamp geomagnetic excursion event occurring around Greenland Interstadial 10. GICC05 is generally in good long-term agreement with the existing Greenland ice core chronologies and with the Hulu Cave record, but on shorter time scales there are significant discrepancies. Around the Last Glacial Maximum there is a more than 1 ka age difference between GICC05 and SFCP04 and a more than 0.5 ka discrepancy in the same direction between GICC05 and the age of a recently identified tephra layer in the NorthGRIP ice core. Both SFCP04 and the tephra age are based on ¹⁴C-dated marine cores and fixed marine reservoir ages. For the Laschamp event, GICC05 agrees with a recent independent dating within the uncertainties.     

Dimensional reduction of a fractured medium for a polymer EOR model

Computational Geosciences - Dimensional reduction strategy is an effective approach to derive reliable conceptual models to describe flow in fractured porous media. The fracture aperture is several...     

Modelling the height,temperature and relative humidity of a well-mixed planetary boundary layer over a water surface

A vertically integrated model of a developing boundary layer over a wet surface is presented, and the expected change in the relative humidity is discussed. For the case of cold air moving over a water surface of constant temperature, analytical solutions of the model equations are obtained, giving the height, temperature and relative humidity of the boundary layer as functions of the distance travelled by the air column. The relation to the problem of sea smoke is discussed.