POLAR FIELD REVERSAL OBSERVATIONS WITHHINODE

Diagnostics of Polar Field Reversal in Solar Cycle 23 Using a Flux Transport Dynamo Model

Motivated by observed anomalous features in cycle 23, as inferred from records of photospheric magnetic flux, we develop a flux transport dynamo–based scheme in order to investigate the physical cause of such anomalies. In this first study we focus on understanding anomalies occurring in the polar field evolutionary pattern in cycle 23, namely, why the polar reversal in cycle 23 was slow, why a...

Field observations on population fluctuations of chicory aphids 1970

Sustaining observations in the polar oceans.

Polar oceans present a unique set of challenges to sustained observations. Sea ice cover restricts navigation for ships and autonomous measurement platforms alike, and icebergs present a hazard to instruments deployed in the upper ocean and in shelf seas. However, the important role of the poles in the global ocean circulation provides ample justification for sustained observations in these reg...

Asymmetric Solar Polar Field Reversals

The solar polar fields reverse because magnetic flux from decaying sunspots moves towards the poles, with a preponderance of flux from the trailing spots. If there is a strong asymmetry in the sense that most activity is in the Northern Hemisphere, then that excess flux will move to the North Pole and reverse that pole first. If later on, there is more activity in the South, then that flux will...

Polar cap index comparisons with AMIE cross polar cap potential, electric field, and polar cap area

[1] The polar cap index (PCI) has been shown to be quite useful as an index of the electrodynamic processes within the high-latitude ionosphere. Here we use between 150 and 180 magnetometers to model the high-latitude electrodynamics with the assimilative mapping of ionospheric electrodynamics (AMIE) technique for all of 1997–2001. We compare AMIE calculations of the cross polar cap potential (...