Data Discovery and Access to The International Surface Pressure Databank

The International Surface Pressure Databank (ISPD) is the world's largest collection of atmospheric surface and sea level pressure observations. Comprised of sub-daily station, marine, and tropical cyclone best track pressure observations, the ISPD is a blend of many national and international data collections and currently spans the period 1755-2010. The motivation for its development is to facilitate the study of both the variations and gradients in surface air pressure which characterize the thermal and dynamic structures of the atmosphere. Version 2.0 of the ISPD was assimilated into the 20th Century Reanalysis Project (Compo et al. 2011, Quart. J. Roy. Meteor. Soc.) and is considered a valuable dataset to be used in future reanalysis and climate studies.

Data access and discovery to the ISPDv2 is provided by the Research Data Archive (RDA) at the National Center for Atmospheric Research (NCAR) and presents data users with various options in exploring and retrieving the data. A file content metadata harvesting system used in the archival of RDA data allows users to easily search and discover the ISPD. Each data file is interrogated by the system at the time of archival, and metadata databases are populated with the descriptive information gathered from the data file. The populated metadata databases are then used to drive dynamic web interfaces, data search tools, and data subsetting services. Within the ISPD dataset, users have the options to search across available data by parameter, examine the contents of individual data files, and browse summaries of the metadata gathered throughout a dataset. Included in the ISPD data is the quality control feedback information from the 20th Century Reanalysis, which informs users on the quality and estimated uncertainty in the observed values. Each record in the ISPD is assigned a unique identifier in the dataset and thus produces a traceable record for each observation.

The data are archived in both the native HDF5 and ASCII formats, and can be downloaded from the RDA web server. Users may either select a collection of files from default lists or use system-prepared lists based on user-specified constraints (e.g. time, space, observation type). The download options include direct file downloads through a web browser or via a system-prepared script to facilitate a more efficient transfer of data. Temporal, spatial, and parameter subsetting is also available; in this case the output option is ASCII.