The International Atmospheric Circulation Reconstructions over the Earth (ACRE) Initiative

The Atmospheric Circulation Reconstructions over the Earth (ACRE) Initiative was established with the goal of encouraging and undertaking the research work needed to produce and use reanalyses for climate applications. ACRE works closely with the international surface weather and climate observations community particularly the International Surface Pressure Databank, the international RECLAIM, the International Environmental Data Rescue Organization, and NOAA's NCDC Climate Database Modernization Program. The first ACRE-facilitated reanalysis product, the 20CR Version 2 dataset, has global four-times-daily atmospheric and surface fields spanning 1871-2008. The 20CR generates global gridded wind, temperature, pressure, humidity, and other variables at 2° latitude by 2° longitude horizontal resolution and 28 vertical levels with an ensemble of 56 analyses for each 6-hourly time step. The 20CR also generates quality control information and other metadata about the ISPD observations.