SUMER at MSSL : Spicule Studies

This is an overview of a group of spicule studies that were run by the SUMER team for Jay M. Pasachoff, Hopkins Observatory, Williamstown, MA. The studies were executed in April and May 2004 as part of SOHO Campaigns 7038 and 7052, "Dynamics of Chromospheric Spicules", in parts with cooperation from TRACE and SST (La Palma).

The list at the bottom shows all studies with various identification numbers, dates, start and end times, resulting numbers of images, coordinates, and exposure times. The links (where existent) lead to information pages with two-dimensional overview images and spectral information about the lines that were used for observation.

In a first approach, the three lines Si II 1533, C IV 1548, and Ne VIII 770 were analysed (continuum level subtracted, line intensity integrated, line center-of-gravity calculated relative to average position, line width calculated). The 2D images on the linked pages are basically in the form of "x-t-plots", which should be called t-y-plots in this case, because observation time runs from left to right, while the vertical dimension represents the north-south extension of the SUMER slit across the solar limb. In the May campaign, a variant is used which scans back and forth across a 20" strip first, and then keeps the slit position fixed in the middle of this strip for the remaining ~150 exposures.

Example: Strips rastered on 24 / 25 / 26 / 27 May 2004...
...before first time series:

...before second time series:
From left to right, resp.: Continuum, Si II, C IV, Ne VIII radiances

Gaps due to data faults or due to periodical half-detector exposures (SUMER data format 38) were filled by averaging neighbour exposures. - All studies use 30 seconds (April) or 25 seconds (May) exposure time on detector A, they keep SUMER slit 2 in a fixed position during the whole observation (or, in May, most of the observation), without using flatfield correction or rotation compensation, and they transmit the three above-mentioned lines in SUMER data format 8 (50 spectral pixels * 360 spatial pixels). - In some studies of the May campaign, there appears to be a detector fault in the middle of the slit. 

id-     | SUMER| SOHO | date in| start, end  | #   | solarX| solarY| expos.
number  | study| camp.| 2004   | time in UTC | imag| in "  | in "  | in s
-----------------------------------------------------------------------------
        |             |        |             |     |       |       |
s305905 | 2482 | 7038 | 16 Apr | 19:40-19:50 |  19 |     0 | -1010 | 30
s306301 | 2482 | 7038 | 20 Apr | 16:01-17:43 | 204 |  -300 |  -940 | 30
s306302 | 2482 | 7038 | 20 Apr | 20:01-21:44 | 204 |  -300 |  +940 | 30
s309701 | 2532 | 7052 | 24 May | 08:01-09:29 | 186 |  +250 |  +930 | 25
s309702 | 2532 | 7052 | 24 May | 10:31-11:59 | 186 |  +250 |  -930 | 25
s309801 | 2532 | 7052 | 25 May | 08:01-09:29 | 186 |  +250 |  +930 | 25
s309802 | 2532 | 7052 | 25 May | 10:31-11:59 | 186 |  +250 |  -930 | 25
s309901 | 2532 | 7052 | 26 May | 08:01-09:29 | 186 |  +250 |  +930 | 25
s309902 | 2532 | 7052 | 26 May | 10:31-10:59 |  58 |  +250 |  -930 | 25
s310001 | 2532 | 7052 | 27 May | 08:01-09:29 | 186 |  +250 |  +930 | 25
s310002 | 2532 | 7052 | 27 May | 10:31-11:59 | 186 |  +250 |  -930 | 25
        |      |      |        |             |     |       |       |

IED, 11 Mar 2005