The impact of the maximum convection location over eastern and central Equatorial Pacific over the intensity and positioning of the South American Low-Level Jet east of the Andes (SALLJ) during the austral summer was investigated. The Bonner criteria 1 was applied to the NCEPNCAR circulation fields during the El Niño of 1997/1998 and 2002/2003 to identify the SALLJ episodes. The composites of t...

The damages from climatic extremes have dramatically increased in the last decades in Europe, as likely outcomes of climate change: floods, droughts, heat waves and hailstorms have brought local as well as widespread damages to farmers, industry, infrastructures and society, to insurance and reinsurance companies; in this work we deal with the hailstorm hazard. The NCEP-NCAR Reanalysis (2.5 by ...

We are using a method to at least partially identify the impact of land-use changes by computing the difference between the trends of the surface temperature observations (which reflect all the sources of climate forcing, including surface effects) and the NCEPNCAR Reanalysis estimated surface temperatures (with trends only influenced by the assimilated atmospheric temperature trends). This dif...

[1] The surface of maximum wind (SMW) is used as a frame for examining spatial and temporal variability in the vertical position of fast upper tropospheric winds over the Northern Hemisphere during winter. At a given observation time in a gridded data set, the SMW is defined as the surface passing through the fastest analyzed wind above each grid node, with a vertical search domain restricted t...

The structure and variance of the equatorial zonal circulation, as characterized by the atmospheric mass flux in the equatorial zonal plane, is examined and intercompared in simulations from 9 CMIP3 coupled climate models with multiple ensemble members and the NCEPNCAR and ERA-40 reanalyses. The climate model simulations analyzed here include twentieth century (20C3M) and twenty-first century (...