climatologist mann cleared of misconduct charges - Page 9

We update the Goddard Institute for Space Studies (GISS) analysis of global surface temperature change, compare alternative analyses, and address questions about perception and reality of global warming. Satellite-observed nightlights are used to identify measurement stations located in extreme darkness and adjust temperature trends of urban and peri-urban stations for non-climatic factors, verifying that urban effects on analyzed global change are small. Because the GISS analysis combines available sea surface temperature records with meteorological station measurements, we test alternative choices for the ocean data, showing that global temperature change is sensitive to estimated temperature change in polar regions where observations are limited. We suggest use of 12-month (and n×12) running mean temperature to fully remove the annual cycle and improve information content in temperature graphs. We conclude that global temperature continued to rise rapidly in the past decade, despite large year-to-year fluctuations associated with the El Nino-La Nina cycle of tropical ocean temperature. Record high global temperature during the period with instrumental data was reached in 2010.