PhD position: "Can models explain the natural climate variability? Testing the agreement between different methods of reconstructing climate variability since the Last Deglaciation"The range of natural climate variability is under discussion even for the most recent geological period, the Holocene. A wide array of scientific approaches is used today to understand the range and causes of climate variability in the past and thereby also a deeper understanding of the climate system.Job assignments This project aims to assess the coherency in climate variability between different methods of reconstructing the past climate. Our approach is to take advantage of the vast catalogue of existing proxy and model output data. Coupled atmosphere-ocean General Circulation Models (GCMs) are capable of providing reconstructions of the climate variability based on external forcing records (greenhouse gases, solar activity, volcanic eruptions). However, the results depend heavily on the ability of the model to reproduce the natural modes of variability of, for example, sea surface temperature (SST). GCMs forced with observed SST fields provide the response in atmospheric circulation to realistic SSTs, but usually only cover very limited time spans. Proxy records are substitutes for meteorological observations back in time, albeit with a large margin of uncertainty. The strength of proxy-based climate reconstructions lies in the fact that they include information on the spatial component of the reconstructed climate variability, similar to GCMs. Also, the proxy records themselves provide long-term data series for single sites, covering a range of environmental parameters, while often being limited in temporal resolution. The PhD student will work with GCM output, climate reconstructions, and proxy data. This includes post processing of large amounts of GCM output, climate reconstructions, and proxy records, as well as learning and developing statistical/mathematical tools for comparing the different types of data. An important part of the work will involve some level of programming to treat the data. Initially, the work will be based on the following data: coupled atmosphere-ocean GCM experiments covering the past 1200 years using different external forcing data, GCM experiments forced with observed SSTs (1870-2003) including isotope tracers (d18O, dD), climate reconstructions covering the past 500 years (mainly temperature reconstructions), proxy data for atmospheric circulation (peat, lake, and ice core records). Specific investigations include the representation in the different data sets of the modes of variability in the North Atlantic region (e.g. the North Atlantic Oscillation), and the variability (latitudinal and strength) of the Southern Hemisphere Westerlies, including their relation to variations in total solar irradiance. The work will be carried out in cooperation with palaeoclimatic research groups at the Department of Geology and within the framework of our strategic research area of Modelling the Regional and Global Earth System (MERGE), at Lund University. Eligibility/Entry Requirements The applicants are expected to hold a university degree (preferably MSc. or equivalent) in subjects like Earth Sciences, Environmental Physics, Meteorology, Climatology or related areas. The following qualifications represent additional and important merits for the position:
Regulations for Ph.D. positions will be found in SFS regulations 1998:80 (in Swedish). This position can only be appointed to a person eligible for postgraduate studies. Particular emphasis for admission shall be placed upon the applicants ability to successfully complete postgraduate studies, as indicated by academic qualifications and merits. Apart from postgraduate education, the successful applicant may be assigned other duties within undergraduate teaching, research, and administrative work according to special regulations. Type of employment: Limit of tenure, 4 years Extent: 100 % Location: Department of Geology, Lund First day of employment: 2012-09-01 Official Records Number: NPA 2012/161 More information, contact information for informal inquiries and link to online application see: http://admin.lu.se/o.o.i.s?id=22598&Dnr=456417&Type=E |
