RT Journal Article T1 Two approaches for determining extreme years of global atmospheric temperature A1 Calvo Fernández, Natalia A1 Ribera, P. A1 Gimeno, L. A1 Gallego, D. A1 García Herrera, Ricardo Francisco A1 Hernández, E. A1 Torre, L. de la A1 Nieto, R. AB Two different groups of indices have been defined to analyze the evolution of global temperature between 1958 and 1998. All the indices were evaluated at three different levels (850, 500 and 200 hPa), and averaged indices were calculated using the whole globe, continental areas and oceanic areas. The first group of indices analyzes the area of the world covered with higher and lower than normal temperatures, detecting a slight cooling in the 200 hPa level. The second group of indices studies the annual frequency of extreme events, and again, it is at 200 hPa where the most intense variation is detected. Finally, an analysis is performed to determine the regions most sensible to variations in the occurrence of extreme events. Tropical areas are mostly responsible of the variations detected in the second group of indices. PB Springer SN 0039-3169 YR 2004 FD 2004-04 LK https://hdl.handle.net/20.500.14352/51080 UL https://hdl.handle.net/20.500.14352/51080 LA eng NO © 2004 StudiaGeo s.r.o. DS Docta Complutense RD 9 abr 2025