Baseline Surface Radiation Network (BSRN/WCRP): New Precision Radiometry for Climate Research

Abstract

To support climate research, the World Climate Research Programme (WCRP) initiated a new radiometric network, the Baseline Surface Radiation Network (BSRN). The network aims at providing validation material for satellite radiometry and climate models. It further aims at detecting long-term variations in irradiances at the earth's surface, which are believed to play an important role in climate change. The network and its instrumentation are designed 1) to cover major climate zones, 2) to provide the accuracy required to meet the objectives, and 3) to ensure homogenized standards for a long period in the future. The limits of the accuracy are defined to reach these goals. The suitable instruments and instrumentations have been determined and the methods for observations and data management have been agreed on at all stations. Measurements of irradiances are at 1 Hz, and the 1-min statistics (mean, standard deviation, and extreme values) with quality flags are stored at a centralized data archive at the WCRP's World Radiation Monitoring Center (WRMC) in Zurich, Switzerland. The data are quality controlled both at stations and at the WRMC. The original 1-min irradiance statistics will be stored at the WRMC for 10 years, while hourly mean values will be transferred to the World Radiation Data Center in St. Petersburg, Russia. The BSRN, consisting of 15 stations, covers the earth's surface from 80°N to 90°S, and will soon be joined by seven more stations. The data are available to scientific communities in various ways depending on the communication environment of the users. The present article discusses the scientific base, organizational and technical aspects of the network, and data retrieval methods; shows various application possibilities; and presents the future tasks to be accomplished.

Downward longwave irradiance uncertainty under arctic atmospheres: Measurements and modeling

“…Investigations of calibration methods, instrument characterization and measurement techniques have led to a deeper understanding and dramatic improvements of pyrgeometer calibration and measure-ments [Philipona et al, 1995;Fairall et al, 1998]. The Baseline Surface Radiation Network (BSRN) [Ohmura et al, 1998] round-robin calibration experiment [Philipona et al, 1998] demonstrates that PIRs are stable and that calibration results of individual blackbody calibration sources used worldwide are within 2% of each other. Uncertainties of longwave irradiance measurements dropped due to these efforts from about 10% in the early 1990s [Dehne et al, 1993] to less than 2% in the last few years.…”

Comparison of aerosol optical depth from satellite (MODIS), sun photometer and broadband pyrheliometer ground-based observations in Cuba

“…The first step applies the standard procedures designed for Yanishevski-type actinometric instruments from the former Soviet Hydrometeorological Service (Kirilov et al, 1957). Data that pass this quality procedure are then evaluated following the standards set by the Baseline Solar Radiation Network, BSRN (Ohmura, 1998;Long andShi, 2006, 2008;Estevan et al, 2012).…”

An Efficient Method of Estimating Downward Solar Radiation Based on the MODIS Observations for the Use of Land Surface Modeling

“…For validation purpose, we collect ground measurements from the Baseline Surface Radiation Network (BSRN) sites [46]. BSRN is a project of the radiation panel of the Global Energy and Water Cycle Experiment (GEWEX) and its member sites whose latitudes range from 80°N to 90°S provide the most comprehensive coverage of the major geographical regions in the world.…”

“…These errors may be caused by multiple reasons. The measuring errors due to systematic problems such as the measurement "cosine response error" of pyranometers, which are widely used at BSRN sites [46], exists at all the BSRN sites and varies under different solar zenith angles. Beside the error induced by interpolation, the simplified radiative transfer processes and the assumptions of the calculating method, the spatial-temporal resolution and the uncertainty of the MODIS atmospheric products can all contribute to the errors of the estimated solar radiation, which is discussed in the below sections.…”