Surges and filaments in active regions during SOHO campaigns

SCHMIEDER, B.; DENG, Y.Y.; RUDAWY, P.; NITTA, N.; MANDRINI, C.H.; FLETCHER, L.; MARTENS, P.; INNES, D.; MASON, H.

Isla de Guadalupe

Congreso; Solar Jets and Coronal Plumes,; 1998

ESA

JOP 33 is a SOHO JointObserving Program, in col­ laboration with Yohkoh and ground based observa­ tories (GBO's), dedicated to observejets and their signatures in the transition region with CDS and SUMER and in the chromosphere by GBO's . CDS observations provide large (4 ' x 4') and small (2' x 2') rasters in severa! diagnosticlines. JOP 17 has been adapted to observe dynamicalevents through the at­ mosphere, from the chromosphere to the corona,cov­ ering a largefield of view (240" x 240") and in 6 !ines withCDS; while spectralobservations in Lyman or N V lines with a high cadence are provided by SUMER.     During runs of these programs  we  observed  a surge and a fiare in active region(AR) 7968 on  June  9, 1996, and bright faculae, surges, a filament and  CDS bright knots in AR 8048 from June 3 to 5, 1997. From these observations, and from MDI data, we have been ableto understand sorne of the responses of the coro­ nal and chromospheric plasma to the evolution of the photospheric magnetic field in these  regions.  Emerg­ ing flux in an AR led to the formationof arch filament systems in the chromosphere, hot loops in the  tran­ sition region  and  sorne hotter  knots  and  X-ray  loopsin  the corona  as observed  by  SXT .     Frequent surges have been observedrelated  to para­ sitie or mixed polarities, but coronal jets have not yet been found. Their lack of detectioncould be the re­ sult of the low density in the jet plasma as mentioned by Schmieder et al. ( 1995).