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Title: BEHAVIOR OF SOLAR CYCLES 23 AND 24 REVEALED BY MICROWAVE OBSERVATIONS

Journal Article · · Astrophysical Journal Letters
; ;  [1];  [2];  [3];  [4]
  1. NASA Goddard Space Flight Center, Greenbelt, Maryland, MD (United States)
  2. Jagielloninan University, Krakow (Poland)
  3. Nobeyama Solar Radio Observatory, Nobeyama (Japan)
  4. NASA Marshall Space Flight Center, Huntsville, AL (United States)

Using magnetic and microwave butterfly diagrams, we compare the behavior of solar polar regions to show that (1) the polar magnetic field and the microwave brightness temperature during solar minimum substantially diminished during the cycle 23/24 minimum compared to the 22/23 minimum. (2) The polar microwave brightness temperature (Tb) seems to be a good proxy for the underlying magnetic field strength (B). The analysis indicates a relationship, B = 0.0067Tb - 70, where B is in G and Tb in K. (3) Both the brightness temperature and the magnetic field strength show north-south asymmetry most of the time except for a short period during the maximum phase. (4) The rush-to-the-pole phenomenon observed in the prominence eruption (PE) activity seems to be complete in the northern hemisphere as of 2012 March. (5) The decline of the microwave brightness temperature in the north polar region to the quiet-Sun levels and the sustained PE activity poleward of 60{sup o}N suggest that solar maximum conditions have arrived at the northern hemisphere. The southern hemisphere continues to exhibit conditions corresponding to the rise phase of solar cycle 24.

OSTI ID:
22047833
Journal Information:
Astrophysical Journal Letters, Vol. 750, Issue 2; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 2041-8205
Country of Publication:
United States
Language:
English