There are number of web-based sites that provide the cabability to visualize, perform limited proceessing tasks and, somtimes download data. Some are designed for a specific data product while others are cabable of creating graphics and performing computations  on multible data sets. Common tasks include difference maps, correlations, composites, climate monitoring and deriving climate indices. Often generated graphical images can be downloaded using a variety of file image formats. Downsides of these tools include little, if any, ability to alter the preset graphical images or expand the available computational capabilities or add additional data sets.

Some sites that users may find useful for 'large scale' climate related work include.

• NOAA: Earth System Research Laboratory: http://www.esrl.noaa.gov/psd/ : Click "Products"
• KNMI: Royal Netherlands Meteorological Institute: Climate Explorer
• UMaine: Climate Change Institute: ClimateReanalyzer
• NASA: Goddard Space Flight Center: Giovanni
• NASA: Goddard Institute for Space Studies: Panoply