Integrated Surface Flux System (ISFS)

The Integrated Surface Flux System (ISFS) is designed to study exchange processes between the atmosphere and Earth's surface.

ISFS combines the capabilities of a network of surface weather stations with the ability to support intensive micrometeorological research at a single site. Investigators can configure ISFS resources to match the research objectives of each field project.

Multiple sites can be instrumented to measure near-surface wind, temperature, humidity, pressure, and precipitation in the network mode. As needed, scientists can also request measurements of momentum fluxes, sensible and latent heat fluxes, short-wave and long-wave radiation, soil temperature, soil moisture, and soil heat flux at each station.

In an intensive mode, multiple sensors can be deployed on an array of towers at a single site for a detailed examination of the atmospheric surface layer's turbulence structure. ISFS also supports user-supplied sensors with digital or analog outputs at data rates up to 2,000 samples/s.

ISFS integrates data from both network and intensive modes with a common data ingest, archival, and display system. Solar power, RF modems, and satellite data transmission provide sighting flexibility to permit ISFS to operate almost anywhere.

Data Products

Average statistics of all variables, including the second-order moments needed to compute fluxes and limited third-order moments, are a standard product of ISFS and are available in real-time for display.  Every data sample is archived to allow processing using spectral, wavelet, or conditional sampling methods. 

Project Archives

ISFS Project Documentation is available online and as a pdf document for most projects. For each project listed there is a link to the project report, table of variables, field logbook, data links, and a contact person.

The project reports contain a description of the field site, instrumentation configuration, and data processing steps. For some projects, there are also plots of weather conditions, fluxes, etc.

The field logbook has all information logged by ISF staff and visitors before, during, and after the field campaign. Each entry is indexed by time, location, type (e.g. sensor), and author.

Data available online include 5-minute average statistics (including 2nd and 3rd-order moments for turbulence variables) of all quantities measured. High-rate time series of every sample from each sensor are now a standard product. Data are formatted in NetCDF.

What's New


Standard ISFS sensors are available for the following measurements: momentum, sensible heat, water vapor, carbon dioxide, and pressure fluxes by eddy-correlation; vertical profiles of wind, temperature, and humidity; radiation fluxes; soil temperature, soil moisture, and soil heat fluxes; and precipitation including size distribution. The ISFS sensors are a mix of commercial instruments and in-house developments. Whenever possible, each sensor has a microprocessor that provides sensor output in calibrated engineering units through a serial communications link.

User-supplied or non-standard sensors can be readily accommodated by ISFS. Power and mounting are provided and the various data streams are easily integrated into the system.

See the Sensor List for a table of supported sensors.

Variable Names

Since many different variables can be measured at multiple sites, a naming convention, ISFS Variable Names, has been established to manage the profusion of variable names.

PI Interaction

We encourage our users to be involved with all aspects of the field measurements. To this end, we have a User Guide to describe all of the aspects of our field deployments.


When referencing the NCAR Integrated Surface Flux System (ISFS) in publications or proposals, please use the identifier 10.5065/D6ZC80XJ -- for example as a citation:

UCAR/NCAR - Earth Observing Laboratory. (1990). NCAR Integrated Surface Flux System (ISFS). UCAR/NCAR - Earth Observing Laboratory. Retrieved February 17, 2017

Please be careful of line breaks when cutting and pasting the above text, and feel free to reformat to fit your document. Additional citation styles are available at DataCite or CrossCite.

Additionally, please cite the First Use paper associated with this Facility/Instrument:

Sun, J., S.P. Burns, A.C. Delany, S.P. Oncley, T.W. Horst, and D.H. Lenschow, 2003: Heat Balance in the Nocturnal Boundary Layer during CASES-99. J. Appl. Meteor., 42 (11), 1649--1666. doi:10.1175/1520-0450(2003)042<1649:HBITNB>2.0.CO;2