Reconstruction of the Holocene (post Ice Age) environment in northern Fennoscandia

The aim of the project is to develop new statistical tools for making reconstructions of past environmental changes. An example is the reconstruction of temperature variation in the Finnish Lapland during the past 10000 years. Of special interest is the detection of statistically significant trends in century and millennium time scales. A short tutorial is found here. Another question studied is the discovery of underlying periodicities in the environmental variable time series. The project is joint work with the Environmental Change Research Unit (ECRU) of the Department of Ecology and Systematics Division of Hydrobiology of University of Helsinki.

Publications:

• P. Erästö and L. Holmström. Bayesian multiscale smoothing for making inferences about features in scatter plots. Journal of Computational and Graphical Statistics, 14(3): 569-589, 2005.
  
  
• J. Weckström, A. Korhola, P. Erästö and L. Holmström. Temperature patterns over the past eight centuries in northern Fennoscandia inferred from sedimentary diatoms. Submitted manuscript, 2005
  
  
• P. Erästö and L. Holmström. Selection of prior distributions and multiscale analysis in Bayesian temperature reconstructions based on fossil assemblages. Submitted manuscript, 2005
  
  
• P. Erästö and L. Holmström. Bayesian analysis of features in a scatter plot with dependent observations and errors in predictors. Submitted manuscript, 2005
  
  
• P. Erästö and L. Holmström. Bayesian analysis of trends in a two-dimensional scatter plot. In COMPSTAT'04 - 16th Symposium of IASC on Computational Statistics. Book of abstracts, page 254, Prague, Czech Republic, 2004. Czech Statistical Society.
  
  
• P. Erästö and L. Holmström. BSiZer for making Bayesian inferences about features in scatter plots. In 6th World Congress of the Bernoulli Society for Mathematical Statistics and Probability and 67th Annual Meeting of the Institute of Mathematical Statistics. Programme, Abstracts and Directory of Participants, pages 115 -- 116, Barcelona, Spain, 2004.
  
  
• P. Erästö and L. Holmström. Bayesian analysis of trends in a two-dimensional scatter plot. In In 20th Nordic Conference on Mathematical Statistics. Abstracts volume, Jyväskylä, Finland, 2004.
  
  
• P. Erästö and L. Holmström. Bayesian SiZer - a tool for parametric data analysis of scatter plots. In B. Fournier, R. Furrer, T. Gsponer, and E.-M. Restle, editors, Proceedings of the 13th European Young Statisticians Meeting (EYSM'03), Ovronnaz, Switzerland, September 21-26, 2003, 2003.
  
  
• P. Erästö and L. Holmström. Bayesian SiZer - a tool for inferring significant features in environmental reconstructions. In 9th International Paleolimnology Symposium, Abstracts Volume, Espoo, Finland, 2003.
  
  
• P. Erästö and L. Holmström. Bayesian SiZer - a tool for parametric data analysis of scatter plots. In Bulletin of the International Statistical Institute 54th Session, Proceedings (CD-ROM), August 13 -- 20, Berlin, Germany, 2003.
  
  
• L. Holmström and P. Erästö. Making inferences about past environmental change using smoothing in multiple time scales. Computational Statistics & Data Analysis, 41(2):289-309, 2002. (PostScript, 29 pages, 1329024 bytes)
  
  
• L. Holmström and Panu Erästö. Using the SiZer method in Holocene temperature reconstruction. Research Reports A36, Rolf Nevanlinna Institute, August 2001.
  
  
• P. Erästö, L. Holmström, A. Korhola, and J. Weckström. Sizer - a tool for inferring significant features in environmental reconstructions. In Past Climate Variability Through Europe and Africa, An International Conference. Abstracts, page 79, Centre des Congrès, Aix-en-Provence, France, August 27-31, 2001.
  
  
• A. Korhola, J. Weckström, K. Vasko, H. T. Toivonen, L. Holmström, and P. Erästö. Holocene climate records from aquatic organisms in Finnish Lapland: Comparison of various models and proxies. In Mikko Lahti, Linda Talve, symposium, Programme and abstracts, page 63, Turku/Åbo, Finland, June 6-8th, 2001.
  
  
• A. Korhola, J. Weckström, L. Holmström, and P. Erästö. A quantitative Holocene climatic record from diatoms in northern Fennoscandia. Quaternary Research, 54:284-294, 2000.
  
  
• L. Holmström, P. Erästö, P. Koistinen, J. Weckström, and A. Korhola. Using smoothing to reconstruct the Holocene temperature in Lapland. In E. Wegman and Y. Martinez, editors, Computing Science and Statistics, 32. Modeling the Fairfax Station, VA, USA, 2000. Interface Foundation of North America, Inc. Invited paper.