ACE Science Center News


March 2015
ACE Magnetometer spectrograms now online

March 2015
A major new release of the SWICS Level 2 data, using completely redesigned analysis methods

October 2012
The SWEPAM observations, in particular the proton density and to lesser extent the temperature, became increasing sparse starting in 2010 as the primary channel electron multiplier (CEM) detectors have aged. Now, many years past the original planned mission lifetime, these Ulysses spare detectors do not provide adequate gain to make good measurements. In response, the ACE science team has developed and implemented, starting Oct 23 2012, an innovative mission operations concept that more frequently repoints the ACE spacecraft's spin axis further away from the Sun. This allows other, stronger CEMs that have received significantly less total fluence to measure the solar wind; this operational improvement has significantly increased the frequency of good quality SWEPAM observations, back to levels not seen in several years.
For more details, please read this analysis by the SWEPAM team of The Effect of ACE Spacecraft Repointing on SWEPAM Calculated Moments

February 22, 2010
New Level 3 data product: SWEPAM/SWICS Level 3 Merged Solar Wind Proton Data

January 1, 2010
New Level 3 data product: ACE Magnetic Reconnection Exhaust List - identified using the MAG and SWEPAM data sets.

December 30, 2009
During the current solar minimum, ACE has measured the highest-intensities of cosmic rays since the dawn of the Space Age:

Washington Post and Scientific American articles.

January 27, 2009
Release of an extensive collection of ACE Level 3 summary plots, most with a new plot-browsing interface. All plots accessable from a single web-page.

October 1, 2008

July, 2008
ACE was featured in a Mission News item entitled Solar Shield Experiment Aims to Keep the Power On about an experimental system that forecasts the effects that Earth-bound space weather may have on the North American power grid. The system uses ACE real time solar wind and SOHO CME data to drive models at the Community Coordinated Modeling Center at Goddard.

June 23, 2008
Re-release of the SIS Level 2 data for the whole mission. Addition of intensities for Na, Al, Ar, Ca, and Ni. Release notes are accessable from the SIS Level 2 data documentation web page.

April 21, 2008
Re-release of the SWICS Level 2 data for the whole mission. Release notes are accessable from the SIS Level 2 data documentation web page.

April 27, 2007
Release of MAG data at 1-second resolution. Previously, highest available time-resolution for the MAG data was 16 seconds.

April 26, 2007
Re-release of the SIS Level 2 data for the whole mission. Release notes are accessable from the SIS Level 2 data documentation web page.

April 4, 2007
Re-release of the SWEPAM Level 2 data for Bartels rotations 2342 - 2361 (02/27/2005 thru 08/20/2006). Data have been reprocessed to incorporate updated instrument calibrations. Based on increased time at CEM voltage Level 2, the instrument geometric factors have been better defined, particularly for the off-axis CEMs. We also better account for changing CEM gains over time, based on weekly on-board calibrations.

Jan 19, 2007
The EPAM team identified a timing drift in the EPAM data. This timing drift was ~ 1 minute/year. The team has identified the source of this drift and fixed the problem. The entire entire EPAM hourly-averaged dataset has been regenerated. The 5-minute averages have not yet been regenerated.

April 13, 2006
The EPAM team has contributed an updated and time-corrected near-relativistic electron beam list to the ACE Level 3 Data. The time correction was required due to recent evidence of a slow ~ 1 minute/year timing drift. More details on the EPAM timing issue can be found at the EPAM home page

March 1, 2006
The SIS team has performed a new analysis of the appropriate energies at which to plot SIS intensities.

Feb 14, 2006
Re-release of the SWEPAM Level 2 data for Bartels rotations 2342 - 2348 (March - Sept 2005). Incorporates the new geometric factors for operation at CEM voltage level 2. Fills some data gaps.

Sept 30, 2005
A new and improved version of the SWICS-SWIMS level 2 data has been released. This data set includes solar wind temperatures, speeds, elemental abundances, and charge states. ACE Level 2 Data Main Page

August 31, 2005
New additions to the ACE Level 3 Data page, and the page has been reorganized.

May 12, 2005
A web services interface to ACE data is under development.

May 1, 2005
Due to failure of the valves that control gas flow through the instrument, active control of the SEPICA proportional counter is no longer possible. At this time, we do not expect to deliver any SEPICA data beyond Feb 4 2005, unless one of the valves opens by itself, as has happened a few times in the past.

Mar 21, 2005
Some MAG and SWEPAM Level 2 data have been re-released, to update instrument calibrations. Please see the instrument release notes for details:
SWEPAM Release Notes
MAG release notes

Dec 28, 2004
The ASC website has a new look! Let us know what you think...

Dec 23, 2004
Merged IMF, Solar Wind, and Energetic Particle Hourly Averages are now available. Hourly data from the MAG, SWEPAM, SWICS and EPAM instruments are merged into a single download.

Dec 15, 2004
New Level 3 (contributed) data items. Solar particle fluences over the Solar Cycle, and observations of the helium focusing cone with pickup ions by SWICS.

October 4, 2004
ULEIS level 2 data are now being delivered regularly to CDAWeb.