Long term evolution of solar sector structure

The large-scale structure of the solar magnetic field during the past five sunspot cycles (representing by implication a much longer interval of time) has been investigated using the polarity (toward or away from the Sun) of the interplanetary magnetic field as inferred from polar geomagnetic observations. The polarity of the interplanetary magnetic field has previously been shown to be closely related to the polarity (into or out of the Sun) of the large-scale solar magnetic field. It appears that a solar structure with four sectors per rotation persisted through the past five sunspot cycles with a synodic rotation period near 27.0 days, and a small relative westward drift during the first half of each sunspot cycle and a relative eastward drift during the second half of each cycle. Superposed on this four-sector structure there is another structure with inward field polarity, a width in solar longitude of about 100° and a synodic rotation period of about 28 to 29 days. This 28.5 day structure is usually most prominent during a few years near sunspot maximum. Some preliminary comparisons of these observed solar structures with theoretical considerations are given.     

Environmental toxicology: population modeling of cod larvae shows high sensitivity to loss of zooplankton prey

Two factors determine whether pollution is likely to affect a population indirectly through loss of prey: firstly, the sensitivity of the prey to the pollutants, and secondly, the sensitivity of the predator population to loss of prey at the given life stage. We here apply a statistical recruitment model for Northeast Arctic cod to evaluate the sensitivity of cod cohorts to loss of zooplankton prey, for example following an oil spill. The calculations show that cod cohorts are highly sensitive to possible zooplankton biomass reductions in the distribution area of the cod larvae, and point to a need for more knowledge about oil-effects on zooplankton. Our study illustrates how knowledge about population dynamics may guide which indirect effects to consider in environmental impact studies.     

Follow-up Ephemerides and the Accuracy of Preliminary Orbits

The accuracy of follow-up ephemerides and orbits of asteroids based on a short arc is investigated. The geocentric distance and its time derivative are the essential parameters determining the accuracy of predicted positions. The consequences for the optimal observing strategies are discussed. The node and inclination of the orbital plane are restricted enough to be useful for a preliminary sorting of candidates for linking.     

The alkali metal atmospheres on the Moon and Mercury: Explaining the stable exospheres by heavy Rydberg Matter clusters

Despite recent progress in the modeling of alkali atmospheres like those around the Moon and Mercury, many problems still exist. It is proposed that Rydberg Matter (RM) clusters containing Na and K atoms are the main part of the alkali atmospheres of the Moon and Mercury, forming large clouds. RM clusters are studied in the laboratory with laser fragmentation and laser spectroscopy methods. Due to the very large collision cross sections of Rydberg atoms and RM clusters, the atmospheres are not collision free, as normally assumed based on the low densities of free alkali atoms. The non-escaping radial density variation for the Na atoms, observed, e.g., on the Moon, and the Maxwellian velocity distributions observed on Mercury are caused by a true atmosphere with collisional equilibration; this process is not possible in an exosphere. Fast alkali atoms are released from the RM clusters already at large heights by solar photons and charged particle impact. The kinetic temperatures derived for the atmospheres agree with the quantized energy release. The cluster model predicts that the rate of loss from the surface is much smaller than for a purely atomic model, since the transient storage is in the RM cluster form in the atmosphere and not at the surface. The conductance of the atmosphere is of the order of 100 S due to the facile collisional ionization of the RM clusters. The apparent depletion of K in the atmosphere of Mercury is explained.     

Diffuse interstellar bands (DIB): co-planar doubly excited He and metal atoms embedded in Rydberg Matter

The interpretation of the more than 300 diffuse interstellar bands (DIBs) is one of the most long-standing problems in interstellar spectra since the two first bands were reported in 1921. We now predict the frequencies of 260 diffuse interstellar bands (DIBs) using the Rydberg Matter model we have developed previously. These transitions involve mainly He atoms, but other two-electron atoms like Ca and other metals can take part in the absorption processes. Approximately 70% of the total intensity of the DIBs is due to absorption in doubly excited states and 30% in singly excited He atoms. The doubly excited states are in inverted states while the He atoms are thermal. The possibilities to observe DIBs in the UV and NIR ranges are discussed and band positions are predicted.     

Well Development by Jetting Using Coiled Tubing and Simultaneous Pumping

During flow testing of a deep, 1927-m, gravel packed screen completed well, it became apparent that well development was needed to increase productivity. A hydrojetting system using coiled tubing in combination with simultaneous pumping was developed and tested and found to be successful. To verify whether the jetting improved the well, the results of a pumping test conducted before and after the jetting operation are compared. In addition, flowmeter logging and hydraulic properties obtained from pumping tests conducted during the jetting operation were also used to verify the improvements. Hydrojetting in combination with simultaneous pumping proved to be an effective cleaning method. After 100 min of pumping, around 110 m less drawdown and 15 L/s higher average flow rate were obtained compared to the values before the jetting operation. The skin factor was positive before the jetting operation and negative thereafter, thus providing additional evidence of improvements of the well. The flowmeter data also confirmed the improvements and were valuable in optimizing the jetting operation. It was also found, from the short-term pumping tests conducted during the jetting operation, that the Hantush–Jacob method for leaky confined aquifers is a valuable indicator of the well development. The combination of methods used for the well development in this case can easily be applied on other deep well projects to obtain a controlled and time-efficient well development.