GLOBAL ASYMMETRY OF THE SUN OBSERVED IN THE EXTREME ULTRAVIOLET RADIATION A. N. Zhukov ¹ ’ ², I. S. Veselovsky ², J.-F. Hochedez ¹, F. Clette ¹, O. A. Panasenco ², P. Cugnon ¹ ¹ Royal Observatory of Belgium Avenue Circulaire 3, B–1180 Brussels, Belgium ² Institute of Nuclear Physics, Moscow State University Moscow , Russia

Variations of integral intensity of full resolution SOHO/EIT images (1024×1024 pixels); January 1996 – February 2001, one image per day.

18–Nov– –Dec–1996 coronal holes: –8%; “quiet Sun”: +60%; active regions and bright points: +48%

171 Å Fe IX/X 18–Nov– Å He II 20–May– Å Fe XII 22–Sep– Å Fe XV 12–Apr–1999

MINMAX III III N I

MINMAX III III N I

RotationQSARCH Nov – Dec ’96 60 %48 %–8 % Apr ’99 8 %97 %–5 % Jan %96 %–8 % May 2000 –1 %105 %–4 % RotationQSARCH Nov – Dec ’96 28 %78 %–6 % Apr ’99 6 %97 %–3 % Jan %101 %–11 % May %103 %–6 % RotationQSARCH Nov – Dec ’96 69 %63 %–32 % Apr ’99 15 %102 %–17 % Jan %102 %–9 % May 2000 –3 %113 %–10 % RotationQSARCH Nov – Dec ’96 62 %69 %–31 % Apr ’99 4 %110 %–14 % Jan %111 %–11 % May 2000 –1 %112 %–11 % 195 Å171 Å 284 Å304 Å

Contributions of different solar structures to the variations of the solar disc integral intensity in the Fe XII line (195 Å).

Contributions of different solar structures to the variations of the solar disc integral intensity in the Fe IX/X line (171 Å).

Contributions of different solar structures to the variations of the solar disc integral intensity in the Fe XV line (284 Å).

Contributions of different solar structures to the variations of the solar disc integral intensity in the He II line (304 Å).

Variations of the average intensity of different solar structures in the Fe XII line (195 Å).

Variations of the average intensity of different solar structures in the Fe IX/X line (171 Å).

Variations of the average intensity of different solar structures in the Fe XV line (284 Å).

Variations of the average intensity of different solar structures in the He II line (304 Å).

CONCLUSIONS Variations of the integral intensity of the EUV “quiet Sun” exhibit rotational modulation, i. e. global longitudinal asymmetry. During the epoch of low solar activity the contribution of the “quiet Sun” to the rotational modulation of the integral solar disc intensity is comparable to the contribution of active regions and bright points. The average intensity of the “quiet Sun” exhibits the rotational modulation at least throughout half of the solar cycle observed by SOHO.