About SWICS 1.1 Level 2 Data

Sensor Full Name Measured Species Measured Quantities Typical Energy (KeV/Q) Measurement Technique


Solar Wind Ion Composition Spectrometer 2.0 1 ≤ Z ≤ 30 M, Q, E 0.5 - 100 E/Q

The SWICS 1.1 Instrument on ACE

SWICS 1.1 is the SWICS instrument prior to August 23, 2011, when a radiation and age-induced hardware anomaly altered the instrument's operational state. It should not be confused with SWICS 2.0, the data set for the time period after the anomaly.

The Solar Wind Ion Composition Spectrometer (SWICS) on ACE is optimized for measurements of the chemical and isotopic composition of solar and interstellar matter. SWICS was designed to determine uniquely the chemical and ionic-charge composition of the solar wind, the temperatures and mean speeds of all major solar-wind ions, from H through Fe, at all solar wind speeds above 300 km/s (protons) and 170 km/s (Fe+16), and to resolve H and He isotopes of both solar and interstellar sources. SWICS measures the distribution functions of both the interstellar cloud and dust cloud pickup ions up to energies of 100 keV/e.

For more information about the SWICS and SWIMS instruments, visit the SWICS and SWIMS Home Page, at the University of Michigan.

SWICS 1.1 Data Description

The SWICS 1.1 dataset covers launch up to August 23, 2011, when a radiation and age-induced hardware anomaly altered the instrument's operational state.

The SWICS 1.1 dataset consists of a re-release of significantly improved time series measurements by ACE/SWICS of the elemental abundance, charge state composition, and kinetic properties of heavy ions in the solar wind. It is a major new version produced with completely redesigned analysis methods to account more rigorously for instrumental and statistical effects (Shearer et al. 2014). Rare elements are now identified more reliably and estimates of statistical error are provided.

For details, see the release notes for SWICS 1.1 level 2 data - provided by the instrument team. All users of SWICS data should read these notes.

All level 2 data records for all ACE instruments contain timing information in the same format. The format of the timing information is described here.

Important note: The data-collection cycles of the SWICS instrument are not synced with UTC, and they are not always exactly the same time-length. As a result, the timestamps of the SWICS 1.1 data records are NOT aligned with UTC hourly time boundaries. Also, they are NOT exactly 1 hour (2 hours) apart. Users should be careful combining these data with data from other data sets.

SWICS 1.1 level 2 data from the ACE Science Center are organized into yearly files.
Time resolutions: 1 hour, 2 hour, 1 day. Not all products are delivered at all time-resolutions: see this chart for details.

For all quantities except bulk and thermal velocity, we also provide estimates of statistical uncertainty due to limited count statistics. Note that these estimates do NOT include systematic error, which is discussed separately in the release notes.

SWICS 1.1 Data Quality Flags and estimates of statistical uncertainty are described in the Release notes for SWICS-SWIMS level 2 data - please read the release notes and do not ignore the data quality flags!

Download SWICS 1.1 level 2 data

Our Email Address: asc@srl.caltech.edu

Last Updated: 22 Jan. 2015

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