Small changes in the
radiation budget at the earth's surface can lead to large climatological
responses when persistent over time. With the increasing debate on
anthropogenic influences on climatic processes during the 1980s the need for
accurate radiometric measurements with higher temporal resolution was
identified, and it was determined that the existing measurement networks did
not have the resolution or accuracy required to meet this need. In 1988 the
WMO therefore proposed the establishment of a new international Baseline
Surface Radiation Network (BSRN), which should collect and centrally archive
high-quality ground-based radiation measurements in 1 min resolution. BSRN
began its work in 1992 with 9 stations; currently (status 2018-01-01), the
network comprises 59 stations (delivering data to the archive) and 9
candidates (stations recently accepted into the network with data forthcoming
to the archive) distributed over all continents and oceanic environments. The
BSRN database is the World Radiation Monitoring Center (WRMC). It is hosted at the
Alfred Wegener Institute (AWI) in Bremerhaven, Germany, and now offers more than
10 300 months of data from the years 1992 to 2017. All data are available at
The climate of our earth is decisively influenced by radiative processes.
Even small changes in the radiation budget at the earth's surface can lead to
large climatological responses when persistent over time
last access: 11 June 2018 last access: 11 June 2018
However, with the increasing debate on anthropogenic influences on climatic
processes since the 1980s – e.g., anthropogenic aerosol emission
Active (green star) and closed (red triangle) BSRN stations. Stations that measure both upward and downward radiative fluxes are circled in yellow. White circle: BSRN candidate stations. Please note that in the beginning of 2018 all four stations in India became active stations, and chinese station XIA received the status closed.
A central data archive for BSRN was developed under the direction of Atsumu
Ohmura at the Swiss Federal Institute of Technology (ETH) in Zurich
BSRN began its work in 1992 with 9 stations distributed globally, including
the Antarctic, Arctic, Atlantic and Pacific oceans, North America, Africa and
Europe. Currently (status 2018-01-01), the network comprises 59 stations
(delivering data to the archive) and 9 candidates (stations recently accepted
into the network with data forthcoming to the archive), collectively
representing all seven continents as well as island-based stations in the
Pacific, Atlantic, Indian and Arctic oceans (Fig. 1). Each BSRN station is
committed to measuring at least the following radiation fluxes (SI unit
W m The incoming solar radiation flux incident upon the
planet's surface. Downward solar radiation, downward shortwave radiation or
global horizontal irradiance are synonyms. SWD is measured with pyranometers,
which typically cover a spectral range between 250 and 3000 nm. The part of the global radiation incident on a surface
orthogonal (or “normal”) to the sun's beam, which originates from the solid
angle subtended by the sun's disk. It is also called direct normal
irradiance. Most BSRN stations use pyrheliometers which are automatically
aligned perpendicular to the sun's beams by means of sun trackers. The component of global radiation that is scattered
out of the solar beam by atmospheric constituents. It is also called diffuse
horizontal irradiance. DIF is measured with pyranometers mounted horizontally
that are shaded, e.g., by shadows cast by discs or balls, also using a sun tracker. This is the thermal emission of
the atmosphere incident on the planet's surface. The term thermal irradiation
is also used. LWD is measured with pyrgeometers that typically cover a
spectral range between 4000 and 40 000 nm. Pyrgeometers are also frequently
shaded to help mitigate solar leakage and help maintain a consistent
temperature between the sensor window and the instrument case. The part of the global radiation that is reflected by the surface. The thermal emission from the planet's surface.
Overview of the logical records (LR) contained in station-to-archive
files, as well as the number of stations submitting these data to the WRMC
(status December 2017). The last column states the standard title for BSRN
datasets archived within PANGAEA
Apart from the measurements mentioned above, many stations also offer
additional information such as spectral ultraviolet irradiance, synoptic
weather observations, radiosonde data (vertical profiles of temperature,
humidity, wind and ozone) and data on the ozone column thickness. An
up-to-date overview of all available measurements can be accessed here:
last access: 28 July 2018
The original submission format is the so-called station-to-archive file.
The relatively complex, strictly defined format of the station-to-archive
file is intended to encapsulate both the data and all relevant metadata
within a single ASCII file. Metadata records include the contact information,
calibration history, geographical characteristics of the station and
the types of instruments. The actual data within station-to-archive files are
divided into so-called logical records, which do not contain table
headers (no parameter names and units); see last access: 28 July 2018
BSRN stations and the years where short- and long-wave radiation data are available for each station.
Example of a PanPlot2
The methods for the initial stage of quality control are left up to the
individual station scientists (some scientists are responsible for more than
one station) and thus are not implemented uniformly across BSRN stations.
However, BSRN does maintain recommendations
Station scientists and users have the option of processing BSRN data using
software developed for the BSRN community and WRMC called the “BSRN
Toolbox” Although if the sun tracker
for DIR and DIF is completely off then DIR
Since the BSRN Toolbox is subject to the GNU General Public License, it is
freely available to everyone. With the help of the toolbox, BSRN station
scientists as well as data users can easily download and convert
station-to-archive files to user-friendly formats by clicking the option
“Data”, which splits station-to-archive files up into logical records
containing parameter names and units. In addition, quality checks can be
applied on BSRN files (downloaded from both ftp and PANGAEA) using the
option “Quality check”. All data can be visualized with the free software
PanPlot2
Some quality issues cannot be easily solved. One prominent example is
the case of zero-offsets: Thermophile radiometers are known to suffer a
negative bias due to infrared loss to the sky
Example of the PANGAEA download format of a monthly data file (January 2017) from station GVN (Neumayer, Antarctica).
A more thorough description of BSRN methods and quality control issues can be
found in
In
To be able to download the files, users should contact the WRMC staff
( last access: 28 July 2018 last access: 28 July 2018
The zip files which are publicly available at
PANGAEA itself offers comfortable ways to extract long periods of individual
variables via the so-called data warehouse
( last access: 28 July 2018 last access: 28 July 2018 last access: 28 July 2018
A list of all radiation instruments used in BSRN is available at
last access: 28 July 2018
In the 25 years of its existence, the Baseline Surface Radiation Network (BSRN) and its central archive have become an important component of global climate monitoring and climate research. Beginning as a contribution to the Global Energy and Water Cycle Experiment (GEWEX), the BSRN was later made part of the Global Climate Observing System (GCOS). Also, a formal cooperation agreement was established with the Network for the Detection of Atmospheric Composition Change (NDACC).
Validation of models last access: 28 July 2018
Neither the BSRN stations nor the archive receive direct financial grants for their involvement in the BSRN. Despite this fact it has succeeded in developing a network that is setting standards for ground-level radiation measurements through volunteer efforts by a global community of scientists and technicians who have agreed to define and maintain a common set of standards. A total of 12 of the 59 stations have unfortunately closed, are no longer maintained, are inactive or seek funding. Thanks to the BSRN, the data collected by these stations remain available. However, BSRN is now in the process of adding nine new stations into the network (four from India, two from Taiwan, one from Russia, one from the Azores and one from Australia). One of the challenges the BSRN faces will therefore be the tremendous effort to continue its collection of high-quality, high-temporal-resolution measurements with as many representative stations as possible. As a fundamental environmental variable, the importance of permanently archived, freely accessible and high-quality radiation data cannot be valued highly enough.
All authors except for HG, SS, RS, AD and AO are responsible for station maintenance, data quality, technical aspects of the article; whereas HG, SS, RS, AD, GK-L, AO took care of the data curation and support within the WRMC. All authors except for RS gave input to manuscript, in which the main work has been done by AD, CL, GK-L.
The authors declare that they have no conflict of interest.
First and foremost, we would like to express our gratitude to all BSRN scientists and technicians working tediously to keep the high quality of BSRN standards up. Your dedicated work of calibrating, maintaining and quality checking sensors, instruments and data – often working extra hours to do so – is greatly appreciated. Thanks as well to all the institutions supporting the BSRN cause! We would also like to thank Wolfgang Cohrs for his excellent work in keeping the ftp server up and running, as well as his work for the BSRN homepage. We are grateful for the excellent and very useful comments of the two reviewers – your input definitely helped improve this paper. Last but not least we are indebted to the current (Skalde Lübberstedt) and former (Bonnie Raffel, Friedrich Richter) WRMC data curators – committed students with a knack for data visualization and the mind set on “finding the needle in the data haystack”. This article is dedicated to co-author Rainer Sieger, architect of the BSRN data archive in PANGAEA, responsible for maintaining the BSRN Toolbox and a good friend, who passed away unexpectedly in 2017; and also to Ells Dutton, the original and long-serving BSRN project manager for the first two decades, who was essential in establishing BSRN as a leader in surface radiation measurements and improvements. Ells Dutton passed away suddenly in 2012. Edited by: David Carlson Reviewed by: Martin Wild and one anonymous referee