Number: JOP013 JOINT CDS/MDI/SUMER PROGRAMME Temporal Variability in the Solar Transition Region Per Maltby & Olav Kjeldseth-Moe, ITA, University of Oslo, Richard A. Harrison, RAL, & Klaus Wilhelm, MPI-Ae Scientific Justification The quiet Sun is not quiet, particularly not in the transition region. A pervasive temporal variability has been observed, but the reported results differ videly. Apart from explosive events, microflares and temporal changes within 40 -- 60s in bright features in active regions (Porter et al. 1984), rapid changes have also been reported for the quiet Sun. Cheng (1991) found from HRTS time series observations that temporal fluctuations in chromospheric and transition region lines occur in all locations associated with or without strong magnetic fields. He reported changes ranging from 10 to 20 percent to a factor of 3 in a time period of 30 sec. Porter et al. (1987), on the other hand, found from SMM observations of the CIV resonance line 1548 A that some bright sites (individual 3" pixels) are short lived, lasting less than 2 minute, while others last for an hour. Based on a study of spectroheliograms from the Harvard experiment on Skylab (with time resolution of 5.5 min and spatial resolution of 5"x 5") Rabin and Dowdy (1992) found that the CIII line at 977 A showed significant variation in 93 percent of the spatial elements. From a total of 6 lines the amplitude of the fractional variability was highest (32 percent) for the OIV line at 554 A. In order to obtain a more quantitative and systematic treatment of the temporal variability in the quiet Sun, simultaneous observations in different transition region lines with high spatial, spectral and temporal resolution are required. The data reduction should include a search for solar oscillations as well as determinations of the fraction of the spatial elements that show significant variation above noise in transition region line intensity, line shift and line width. It seems very likely that the transition region variability depends on the magnetic field. Accordingly, since the supergranular nettwork may be followed from the photosphere into the transition region, nearly simultaneous observations of the photospheric magnetic field observations with high spatial resolution will give valuable information. The study may be extended to include several transition region lines and various degree of solar activity. References: Cheng, C.C. 1991 in Mechanisms of Chromospheric and Coronal Heating, eds. P. Ulmschneider, E.R. Priest, & R. Rosner (Springer), 77 Porter, J.G., Moore, R.L., Reichmann, E.J., Engvold, O., & Harvey, K.L. 1987, ApJ 323, 380 Porter, J.G., Toomre, J., & Gebbie, K.B. 1984, ApJ 283, 879 Rabin, D., & Dowdy, J.F. 1992, ApJ 398, 665 CDS-NIS Fe XVI 335.40, Mg IX 368.06, O IV 554.52, He I 584.33, O V 629.73 MDI Magnetic field observation of selected region SUMER C III 977.02, O VI 1031.91 CDS Study Detail Phase 1 ------- Spectrometer: Normal Incidence Slit: 90 x 240 arcseconds Raster Area: 90 x 240 arcseconds Step (DX,DY): 0 arcseconds, 0 arcseconds Raster Locations: 30 x 1 = 30 Exposure Time: 10 seconds Duration of Raster: 825 seconds Number of Rasters: 1 Total Duration: 825 seconds Line Selection: Mg IX 368.06, He I 584.33, O V 629.73 Bins Across Line: 60 Telemetry/Compression: truncate to 12 bits Phase 2 ------- Spectrometer: Normal Incidence Slit: 2 x 240 arcseconds Raster Area: 120 x 120 arcseconds Step (DX,DY): 2 arcseconds, 0 arcseconds Raster Locations: 60 x 1 = 60 Exposure Time: 20 seconds Duration of Raster: 1343 seconds Number of Rasters: 1 Total Duration: 1343 seconds Line Selection: Fe XVI 335.40, Mg IX 368.06, O IV 554.52, He I 584.33, O V 629.73 Bins Across Line: 21 Telemetry/Compression: Truncate to 12 bits Phase 3 ------- Spectrometer: Normal Incidence Slit: 2 x 240 arcseconds Raster Area: 6 x 120 arcseconds Step (DX,DY): 2 arcseconds, 0 arcseconds Raster Locations: 3 x 1 = 3 Exposure Time: 20 seconds Duration of Raster: 73 seconds Number of Rasters: 18 Total Duration: ~1300 seconds Line Selection: Fe XVI 335.40, Mg IX 368.06, O IV 554.52, He I 584.33, O V 629.73 Bins Across Line: 21 Telemetry/Compression: Truncate to 12 bits Phase 4 ------- Spectrometer: Normal Incidence Slit: 2 x 240 arcseconds Raster Area: 2 x 120 arcseconds Step (DX,DY): 0 arcseconds, 0 arcseconds Raster Locations: 295 x 1 = 295 Exposure Time: 20 seconds Duration of Raster: 6526 seconds Number of Rasters: 1 Total Duration: 6526 seconds Line Selection: Fe XVI 335.40, Mg IX 368.06, O IV 554.52, He I 584.33, O V 629.73 Bins Across Line: 21 Telemetry/Compression: Truncate to 12 bits Pointing: To pre-planned location Flags: No flag during this study Solar Feature Tracking: On (TBD) Frequency: Product Phase 1: 90 x 240 arcseconds slit raster Phase 2: 120 x 120 arcseconds raster (Start SUMER Item # 0) Phase 3: A 6 x 120 arcseconds raster run 18 times (TBD) (Start SUMER Item # 2) Phase 4: A 2 x 120 arcseconds raster run 295 times (TBD) Phase 2: 120 x 120 arcseconds raster (Start SUMER Item # 5) Phase 3: A 6 x 120 arcseconds raster run 18 times (TBD) (Start SUMER Item # 7) Phase 4: A 2 x 120 arcseconds raster run 295 times (TBD) Phase 1: 90 x 240 arcseconds slit raster Total duration 5 hours 33 minutes Joint Observation SUMER Parameter List for SUMER Study: JOP013 Item # 0 ------------------------------------------------- You have selected (Irrelevant points are not listed.): 1. Interruption mode: No interruption. 2. Slit 3 (up) with 1*120 arcsec^2. 3. Point to TO PRE-PLANNED LOCATION 4. Solar rotation: Standard compensation. 10. RSC integration time: 206.000 ms 11. RSC step size: 1.14000 arcsec 12. RSC group number: 2 13. Number of RSC images: 1 16. The total duration of the RSC activity will be approximately 20 s. 17. Your selection requires a mean telemetry rate of: 19.8835 kbit/s Bitrate: 10.0000 kbit/s Your item will run for approximately: 0.343333 minutes The range of the initial scan will be 114 arcsec and will be covered 1 time(s). Note that the memory monitoring and the run times are not very accurate. The run times just give the total exposure times with a margin of 1%. More detailed information can be provided by the SUMER Simulator. All items up to now will run for approximately: 0.343333 minutes You will use for this item: 0.0383250 MB out of which 0.00000 MB are for uncompressed images. You will have used in total: 0.0383250 MB out of which 0.00000 MB are for uncompressed images. Parameter List for SUMER Study: JOP013 Item # 1 ------------------------------------------------- You have selected (Irrelevant points are not listed.): 1. Interruption or flag mode: No interruption. 2. Slit 4 (centred) with 1*120 arcsec^2. 3. Point to TO PRE-PLANNED LOCATION SOHO roll angle: 0.00000 deg 4. Solar rotation: Standard compensation. 5. Binning (spectral) = 1 (spatial) = 1 6. Compression: 1. Bytescale_min_max (0.69 s). 7. Reference pixel 1: 810 on detector A Flat-field correction: OFF Ion(s) in band 1: O VI .... 1031.91 Angstroem Spectral window(s) (pixel): 50 8. Image format: Format #10 (50*120, B1); 1 time(s) 9. Spectrohelio mode: Spectrohelio 3 Integration time: 6.00000 s Step size: 1.14000 arcsec or 3 units. Step number: 105 Step mode: Normal steps Repetition number: 1 Staggering: 1 17. Your selection requires a telemetry rate of: 8.00000 kbit/s Bitrate: 10.0000 kbit/s This item will run for approximately: 10.8612 minutes and will cover a solar area defined by 120 px time(s) 119.700 arcsec^2 Note that the memory monitoring and the run times are not very accurate. The run times just give the total exposure times with a margin of 1%. More detailed information can be provided by the SUMER Simulator. All items up to now will run for approximately: 11.2046 minutes You will use for this item: 0.00000 MB out of which 0.00000 MB are for uncompressed images. You will have used in total: 0.00000 MB out of which 0.00000 MB are for uncompressed images. Parameter List for SUMER Study: JOP013 Item # 2 ------------------------------------------------- You have selected (Irrelevant points are not listed.): 1. Interruption or flag mode: No interruption. 2. Slit 4 (centred) with 1*120 arcsec^2. 3. Point to TO PRE-PLANNED LOCATION SOHO roll angle: 0.00000 deg 4. Solar rotation: Standard compensation. 5. Binning (spectral) = 1 (spatial) = 1 6. Compression: 1. Bytescale_min_max (0.69 s). 7. Reference pixel 1: 810 on detector A Flat-field correction: OFF Ion(s) in band 1: O VI .... 1031.91 Angstroem Spectral window(s) (pixel): 50 8. Image format: Format #10 (50*120, B1); 1 time(s) 9. Spectrohelio mode: Spectrohelio 3 Scans back and forth. Integration time: 6.00000 s Step size: 1.14000 arcsec or 3 units. Step number: 3 Step mode: Normal steps Repetition number: 50 Staggering: 1 17. Your selection requires a telemetry rate of: 8.00000 kbit/s Bitrate: 10.0000 kbit/s This item will run for approximately: 20.4929 minutes and will cover a solar area defined by 120 px time(s) 3.42000 arcsec^2 Note that the memory monitoring and the run times are not very accurate. The run times just give the total exposure times with a margin of 1%. More detailed information can be provided by the SUMER Simulator. All items up to now will run for approximately: 31.6975 minutes You will use for this item: 0.00000 MB out of which 0.00000 MB are for uncompressed images. You will have used in total: 0.00000 MB out of which 0.00000 MB are for uncompressed images. Parameter List for SUMER Study: JOP013 Item # 3 ------------------------------------------------- You have selected (Irrelevant points are not listed.): 1. Interruption or flag mode: No interruption. 2. Slit 4 (centred) with 1*120 arcsec^2. 3. Point to TO PRE-PLANNED LOCATION SOHO roll angle: 0.00000 deg 4. Solar rotation: Standard compensation. 5. Binning (spectral) = 1 (spatial) = 1 6. Compression: 1. Bytescale_min_max (0.69 s). 7. Reference pixel 1: 511 on detector A Flat-field correction: OFF Ion(s) in band 1: VIRTUAL .... 1045.13 Angstroem Spectral window(s) (pixel): 1024 8. Image format: Format #4 (1024*120, B1); 1 time(s) 9. Spectrohelio mode: Spectrohelio 3 Integration time: 100.000 s Step size: 0.00000 arcsec or 0 units. Image number: 1 17. Your selection requires a telemetry rate of: 9.83040 kbit/s Bitrate: 10.0000 kbit/s This item will run for approximately: 1.68480 minutes and will cover a solar area defined by 120 px time(s) 0.00000 arcsec^2 Note that the memory monitoring and the run times are not very accurate. The run times just give the total exposure times with a margin of 1%. More detailed information can be provided by the SUMER Simulator. All items up to now will run for approximately: 33.3823 minutes You will use for this item: 0.124217 MB out of which 0.00000 MB are for uncompressed images. You will have used in total: 0.124217 MB out of which 0.00000 MB are for uncompressed images. Parameter List for SUMER Study: JOP013 Item # 4 ------------------------------------------------- You have selected (Irrelevant points are not listed.): 1. Interruption or flag mode: No interruption. 2. Slit 4 (centred) with 1*120 arcsec^2. 3. Point to TO PRE-PLANNED LOCATION SOHO roll angle: 0.00000 deg 4. Solar rotation: Standard compensation. 5. Binning (spectral) = 1 (spatial) = 1 6. Compression: 1. Bytescale_min_max (0.69 s). 7. Reference pixel 1: 810 on detector A Flat-field correction: OFF Ion(s) in band 1: O VI .... 1031.91 Angstroem Spectral window(s) (pixel): 50 8. Image format: Format #10 (50*120, B1); 1 time(s) 9. Spectrohelio mode: Spectrohelio 1 Scan from East to West (SOHO in normal attitude). Integration time: 6.00000 s Step size: 0.00000 arcsec or 0 units. Image number: 1050 17. Your selection requires a telemetry rate of: 8.00000 kbit/s Bitrate: 10.0000 kbit/s This item will run for approximately: 107.588 minutes and will cover a solar area defined by 120 px time(s) 0.00000 arcsec^2 Note that the memory monitoring and the run times are not very accurate. The run times just give the total exposure times with a margin of 1%. More detailed information can be provided by the SUMER Simulator. All items up to now will run for approximately: 140.970 minutes You will use for this item: 0.00000 MB out of which 0.00000 MB are for uncompressed images. You will have used in total: 0.00000 MB out of which 0.00000 MB are for uncompressed images. Parameter List for SUMER Study: JOP013 Item # 5 ------------------------------------------------- You have selected (Irrelevant points are not listed.): 1. Interruption mode: No interruption. 2. Slit 3 (up) with 1*120 arcsec^2. 3. Point to TO PRE-PLANNED LOCATION 4. Solar rotation: Standard compensation. 10. RSC integration time: 206.000 ms 11. RSC step size: 1.14000 arcsec 12. RSC group number: 2 13. Number of RSC images: 1 16. The total duration of the RSC activity will be approximately 20 s. 17. Your selection requires a mean telemetry rate of: 19.8835 kbit/s Bitrate: 10.0000 kbit/s Your item will run for approximately: 0.343333 minutes The range of the initial scan will be 114 arcsec and will be covered 1 time(s). Note that the memory monitoring and the run times are not very accurate. The run times just give the total exposure times with a margin of 1%. More detailed information can be provided by the SUMER Simulator. All items up to now will run for approximately: 141.313 minutes You will use for this item: 0.0383250 MB out of which 0.00000 MB are for uncompressed images. You will have used in total: 0.0383250 MB out of which 0.00000 MB are for uncompressed images. Parameter List for SUMER Study: JOP013 Item # 6 ------------------------------------------------- You have selected (Irrelevant points are not listed.): 1. Interruption or flag mode: No interruption. 2. Slit 7 (centred) with 0.3*120 arcsec^2. 3. Point to TO PRE-PLANNED LOCATION SOHO roll angle: 0.00000 deg 4. Solar rotation: Standard compensation. 5. Binning (spectral) = 1 (spatial) = 1 6. Compression: 1. Bytescale_min_max (0.69 s). 7. Reference pixel 1: 810 on detector A Flat-field correction: OFF Ion(s) in band 1: C III .... 977.029 Angstroem Spectral window(s) (pixel): 50 8. Image format: Format #10 (50*120, B1); 1 time(s) 9. Spectrohelio mode: Spectrohelio 3 Integration time: 6.00000 s Step size: 0.760000 arcsec or 2 units. Step number: 158 Step mode: Normal steps Repetition number: 1 Staggering: 1 17. Your selection requires a telemetry rate of: 8.00000 kbit/s Bitrate: 10.0000 kbit/s This item will run for approximately: 16.2919 minutes and will cover a solar area defined by 120 px time(s) 120.080 arcsec^2 Note that the memory monitoring and the run times are not very accurate. The run times just give the total exposure times with a margin of 1%. More detailed information can be provided by the SUMER Simulator. All items up to now will run for approximately: 157.605 minutes You will use for this item: 0.00000 MB out of which 0.00000 MB are for uncompressed images. You will have used in total: 0.00000 MB out of which 0.00000 MB are for uncompressed images. Parameter List for SUMER Study: JOP013 Item # 7 ------------------------------------------------- You have selected (Irrelevant points are not listed.): 1. Interruption or flag mode: No interruption. 2. Slit 7 (centred) with 0.3*120 arcsec^2. 3. Point to TO PRE-PLANNED LOCATION SOHO roll angle: 0.00000 deg 4. Solar rotation: Standard compensation. 5. Binning (spectral) = 1 (spatial) = 1 6. Compression: 1. Bytescale_min_max (0.69 s). 7. Reference pixel 1: 810 on detector A Flat-field correction: OFF Ion(s) in band 1: C III .... 977.029 Angstroem Spectral window(s) (pixel): 50 8. Image format: Format #10 (50*120, B1); 1 time(s) 9. Spectrohelio mode: Spectrohelio 3 Scans back and forth. Integration time: 6.00000 s Step size: 0.760000 arcsec or 2 units. Step number: 3 Step mode: Normal steps Repetition number: 50 Staggering: 1 17. Your selection requires a telemetry rate of: 8.00000 kbit/s Bitrate: 10.0000 kbit/s This item will run for approximately: 20.4929 minutes and will cover a solar area defined by 120 px time(s) 2.28000 arcsec^2 Note that the memory monitoring and the run times are not very accurate. The run times just give the total exposure times with a margin of 1%. More detailed information can be provided by the SUMER Simulator. All items up to now will run for approximately: 178.098 minutes You will use for this item: 0.00000 MB out of which 0.00000 MB are for uncompressed images. You will have used in total: 0.00000 MB out of which 0.00000 MB are for uncompressed images. Parameter List for SUMER Study: JOP013 Item # 8 ------------------------------------------------- You have selected (Irrelevant points are not listed.): 1. Interruption or flag mode: No interruption. 2. Slit 7 (centred) with 0.3*120 arcsec^2. 3. Point to TO PRE-PLANNED LOCATION SOHO roll angle: 0.00000 deg 4. Solar rotation: Standard compensation. 5. Binning (spectral) = 1 (spatial) = 1 6. Compression: 1. Bytescale_min_max (0.69 s). 7. Reference pixel 1: 511 on detector A Flat-field correction: OFF Ion(s) in band 1: VIRTUAL .... 990.297 Angstroem Spectral window(s) (pixel): 1024 8. Image format: Format #4 (1024*120, B1); 1 time(s) 9. Spectrohelio mode: Spectrohelio 3 Integration time: 100.000 s Step size: 0.00000 arcsec or 0 units. Image number: 1 17. Your selection requires a telemetry rate of: 9.83040 kbit/s Bitrate: 10.0000 kbit/s This item will run for approximately: 1.68480 minutes and will cover a solar area defined by 120 px time(s) 0.00000 arcsec^2 Note that the memory monitoring and the run times are not very accurate. The run times just give the total exposure times with a margin of 1%. More detailed information can be provided by the SUMER Simulator. All items up to now will run for approximately: 179.783 minutes You will use for this item: 0.124217 MB out of which 0.00000 MB are for uncompressed images. You will have used in total: 0.124217 MB out of which 0.00000 MB are for uncompressed images. Parameter List for SUMER Study: JOP013 Item # 9 ------------------------------------------------- You have selected (Irrelevant points are not listed.): 1. Interruption or flag mode: No interruption. 2. Slit 7 (centred) with 0.3*120 arcsec^2. 3. Point to TO PRE-PLANNED LOCATION SOHO roll angle: 0.00000 deg 4. Solar rotation: Standard compensation. 5. Binning (spectral) = 1 (spatial) = 1 6. Compression: 1. Bytescale_min_max (0.69 s). 7. Reference pixel 1: 810 on detector A Flat-field correction: OFF Ion(s) in band 1: C III .... 977.029 Angstroem Spectral window(s) (pixel): 50 8. Image format: Format #10 (50*120, B1); 1 time(s) 9. Spectrohelio mode: Spectrohelio 1 Scan from East to West (SOHO in normal attitude). Integration time: 6.00000 s Step size: 0.00000 arcsec or 0 units. Image number: 1050 17. Your selection requires a telemetry rate of: 8.00000 kbit/s Bitrate: 10.0000 kbit/s This item will run for approximately: 107.588 minutes and will cover a solar area defined by 120 px time(s) 0.00000 arcsec^2 Note that the memory monitoring and the run times are not very accurate. The run times just give the total exposure times with a margin of 1%. More detailed information can be provided by the SUMER Simulator. All items up to now will run for approximately: 287.371 minutes You will use for this item: 0.00000 MB out of which 0.00000 MB are for uncompressed images. You will have used in total: 0.00000 MB out of which 0.00000 MB are for uncompressed images. Parameter List for SUMER Study: JOP013 Item # 10 ------------------------------------------------- You have selected (Irrelevant points are not listed.): 1. Interruption mode: No interruption. 2. Slit 3 (up) with 1*120 arcsec^2. 3. Point to TO PRE-PLANNED LOCATION 4. Solar rotation: Standard compensation. 10. RSC integration time: 206.000 ms 11. RSC step size: 1.14000 arcsec 12. RSC group number: 2 13. Number of RSC images: 1 16. The total duration of the RSC activity will be approximately 20 s. 17. Your selection requires a mean telemetry rate of: 19.8835 kbit/s Bitrate: 10.0000 kbit/s Your item will run for approximately: 0.343333 minutes The range of the initial scan will be 114 arcsec and will be covered 1 time(s). Note that the memory monitoring and the run times are not very accurate. The run times just give the total exposure times with a margin of 1%. More detailed information can be provided by the SUMER Simulator. All items up to now will run for approximately: 287.714 minutes You will use for this item: 0.0383250 MB out of which 0.00000 MB are for uncompressed images. You will have used in total: 0.0383250 MB out of which 0.00000 MB are for uncompressed images. At the end of the study you have to allow for approx. 0.530250 min to clear the memory.