ARM TR-026

> SKYRAD Handbook
>
> November 2004
>
> T. Stoffel
>
> Work supported by the U.S. Department of Energy,
>
> Office of Science, Office of Biological and Environmental Research

# Contents {#contents .Heading-Front}

[1. General Overview 1](#general-overview)

[2. Contacts 1](#contacts)

[3. Deployment Locations and History
1](#deployment-locations-and-history)

[4. Near-Real-Time Data Plots 1](#near-real-time-data-plots)

[5. Data Description and Examples 1](#data-description-and-examples)

[6. Data Quality 3](#data-quality)

[7. Instrument Details 3](#instrument-details)

# General Overview

The Sky Radiation (SKYRAD) collection of radiometers provides each
Atmospheric Radiation and Cloud Station (ARCS) with continuous
measurements of broadband shortwave (solar), longwave (infrared), and
ultra violet irradiances for downwelling components. These 1-minute data
are collected from a network of stations to help determine the total
radiative energy exchange within the Tropical Western Pacific and North
Slope of Alaska.

# Contacts

## Mentor

Tom Stoffel\
National Renewable Energy Laboratory\
1617 Cole Blvd.\
Golden, CO 80401-3393\
Phone: 303-384-6395\
Fax: 303-384-6391\
Email: [tom_stoffel@nrel.gov](mailto:Tom_Stoffel@nrel.gov)

Richard L. Hart, Scientific Associate\
Argonne National Laboratory\
Bldg. 203\
Argonne IL 60439\
Phone: 708-252-5839\
Fax: 708-252-9792\
Email: <hart@anler.er.anl.gov>

## Instrument Developer

This section is not applicable to this instrument.

# Deployment Locations and History 

The SKYRAD is operational at the North Slope of Alaska and Tropical
Western Pacific sites.

# Near-Real-Time Data Plots

[Barrow, Alaska Quicklooks](http://nanuna.gi.alaska.edu/nsadocs/)

[Atqasuk, Alaska Quicklooks](http://nanuna.gi.alaska.edu/atqdocs/)

# Data Description and Examples

See Near-Real-Time Data Plots, Section 4, and Data Quality Health and
Status, Section 6.1.

## Data File Contents

### Primary Variables and Expected Uncertainty

The following broadband irradiance measurements are available from the
SKYRAD platform: DOWNWELLING SHORTWAVE (0.3 TO 3.0 micrometers) Global
Hemispheric Irradiance measured by an unshaded pyranometer with a
hemispheric field of view. DIFFUSE SHORTWAVE (0.3 TO 3.0 micrometers)
Diffuse Hemispheric Irradiance measured by a shaded pyranometer with a
hemispheric field of view. DIRECT NORMAL SHORTWAVE (0.3 TO 3.0
micrometers) Direct Normal Irradiance measured by a solar tracking
pyrheliometer with a 5.7 degree field of view. DOWNWELLING LONGWAVE (4.0
to 50 micrometers) Irradiance measured by a shaded pyrgeometer with a
hemispheric field of view. ULTRA VIOLET IRRADIANCE UV-B measured by a
UV-Biometer with a hemispheric field of view.

#### Definition of Uncertainty

This section is not applicable to this instrument.

### Secondary/Underlying Variables

This section is not applicable to this instrument.

### Diagnostic Variables

This section is not applicable to this instrument.

### Data Quality Flags

[SKYRAD Data Object Design
Changes](http://science.arm.gov/tool/dod/showdod.php?Inst=skyrad) for
ARM netCDF file header descriptions.

### Dimension Variables

This section is not applicable to this instrument.

## Annotated Examples

This section is not applicable to this instrument.

## User Notes and Known Problems

This section is not applicable to this instrument.

## Frequently Asked Questions

This section is not applicable to this instrument.

# Data Quality

## Data Quality Health and Status

The following links go to current data quality health and status
results.

-   [DQ HandS](http://dq.arm.gov/) (Data Quality Health and Status)

-   [NCVweb](http://dq.arm.gov/ncvweb/ncvweb.cgi) for interactive data
    plotting using.

The tables and graphs shown contain the techniques used by ARM\'s data
quality analysts, instrument mentors, and site scientists to monitor and
diagnose data quality.

## Data Reviews by Instrument Mentor

This section is not applicable to this instrument.

## Data Assessments by Site Scientist/Data Quality Office

All DQ Office and most Site Scientist techniques for checking have been
incorporated within [DQ HandS](http://dq.arm.gov/) and can be viewed
there.

## Value-Added Procedures and Quality Measurement Experiments

Many of the scientific needs of the ARM Program are met through the
analysis and processing of existing data products into \"value-added\"
products or VAPs. Despite extensive instrumentation deployed at the ARM
CART sites, there will always be quantities of interest that are either
impractical or impossible to measure directly or routinely. Physical
models using ARM instrument data as inputs are implemented as VAPs and
can help fill some of the unmet measurement needs of the program.
Conversely, ARM produces some VAPs not in order to fill unmet
measurement needs, but instead to improve the quality of existing
measurements. In addition, when more than one measurement is available,
ARM also produces \"best estimate\" VAPs. A special class of VAP called
a Quality Measurement Experiment (QME) does not output geophysical
parameters of scientific interest. Rather, a QME adds value to the input
datastreams by providing for continuous assessment of the quality of the
input data based on internal consistency checks, comparisons between
independent similar measurements, or comparisons between measurement
with modeled results, and so forth. For more information, see the [VAPs
and QMEs web page](http://www.arm.gov/data/vaps.stm).

# Instrument Details

## Detailed Description

### List of Components

This section is not applicable to this instrument.

### System Configuration and Measurement Methods

This section is not applicable to this instrument.

### Specifications

This section is not applicable to this instrument.

## Theory of Operation

This section is not applicable to this instrument.

## Calibration

### Theory

This section is not applicable to this instrument.

### Procedures

This section is not applicable to this instrument.

### History

This section is not applicable to this instrument.

## Operation and Maintenance

### User Manual

This section is not applicable to this instrument.

### Routine and Corrective Maintenance Documentation

This section is not applicable to this instrument.

### Software Documentation

This section is not applicable to this instrument.

### Additional Documentation

This section is not applicable to this instrument.

## Glossary

See the [ARM Glossary](http://www.arm.gov/about/glossary.stm).

## Acronyms

See the [ARM Acronyms and
Abbreviations](http://www.arm.gov/about/acronyms.stm).

## Citable References

None.