Daily Archives: February 13, 2013

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Solar Cycle 24 heads south….

solar cycle 24 feb 13

Greenland resistant to melting despite warmer temperatures?

….”a relatively low contribution to Last Interglacial sea level rise from Greenland melting, ranging from 0.7 to 1.5 meters of sea level equivalent,”….

A. Quiquet1, C. Ritz1, H. J. Punge, and D. Salas y Mélia. Greenland ice sheet contribution to sea level rise during the last interglacial period: a modelling study driven and constrained by ice core data. Clim. Past, 9, 353-366, 2013
http://www.clim-past.net/9/353/2013/ doi:10.5194/cp-9-353-2013

Abstract. As pointed out by the forth assessment report of the Intergovernmental Panel on Climate Change, IPCC-AR4 (Meehl et al., 2007), the contribution of the two major ice sheets, Antarctica and Greenland, to global sea level rise, is a subject of key importance for the scientific community. By the end of the next century, a 3–5 °C warming is expected in Greenland. Similar temperatures in this region were reached during the last interglacial (LIG) period, 130–115 ka BP, due to a change in orbital configuration rather than to an anthropogenic forcing. Ice core evidence suggests that the Greenland ice sheet (GIS) survived this warm period, but great uncertainties remain about the total Greenland ice reduction during the LIG. Here we perform long-term simulations of the GIS using an improved ice sheet model. Both the methodologies chosen to reconstruct palaeoclimate and to calibrate the model are strongly based on proxy data. We suggest a relatively low contribution to LIG sea level rise from Greenland melting, ranging from 0.7 to 1.5 m of sea level equivalent, contrasting with previous studies. Our results suggest an important contribution of the Antarctic ice sheet to the LIG highstand.

Click here for full paper (Open Access).

Tropical Cyclones predicted to decrease 6 to 20%

This is just one of many other peer-reviewed papers demonstrating that global cyclone activity has decreased and is expected to further decline over the 21st century. If we are going to rely on unverified models, then at least consider model results like this that fly in the face of the elite.

K. J. Tory, S. S. Chand, R. A. Dare, and J. L. McBride. An assessment of a model-, grid- and basin-independent tropical cyclone detection scheme in selected CMIP3 global climate models. Journal of Climate 2013
doi: http://dx.doi.org/10.1175/JCLI-D-12-00511.1

A novel TC detection technique designed for coarse resolution models is tested and evaluated. The detector, based on the Okubo-Weiss-Zeta parameter (OWZP) is applied to a selection of CMIP3 models (CSIRO-Mk3.5, MPI-ECHAM5, GFDL2.0 and GFDL2.1) and the combined performance of the model and detector is assessed by comparison with observed TC climatology for the period 1970—2000. Preliminary TC frequency projections are made using the three better performing models by comparing the detected TC climatologies between the late 20th and the late 21st centuries. Very reasonable TC formation climatologies were detected in CSIRO-Mk3.5, MPI-ECHAM5 and GFDL2.1 for most basins, with the exception being the North Atlantic where a large under-detection was present in all models. The GFDL2.0 model was excluded from the projection study due to a systematic under-detection in all basins. The above detection problems have been reported in other published studies, which suggests model rather than detector limitations are mostly responsible. This study demonstrates that coarse resolution climate models do in general produce TC-like circulations with realistic geographical and seasonal distributions detectable by the OWZP TC detector. The preliminary projection results are consistent with the published literature, based on higher resolution studies, of a global reduction of TCs [Tropical Cyclones] between about 6—20%, with a much larger spread of results (about +20 to -50%) in individual basins.

Click here for full paper (fee).