Short term Variability of the Sun Earth System: An Overview of Progress Made during the CAWSES II Period

This paper presents an overview of results obtained during the CAWSES II period on the short term variability of the Sun and how it affects the near Earth space environment. CAWSES II was planned to examine the behavior of the solar terrestrial system as the solar activity climbed to its maximum phase in solar cycle 24. After a deep minimum following cycle 23, the Sun climbed to a very weak maximum in terms of the sunspot number in cycle 24 (MiniMax24), so many of the results presented here refer to this weak activity in comparison with cycle 23. The short term variability that has immediate consequence to Earth and geospace manifests as solar eruptions from closed field regions and high speed streams from coronal holes. Both electromagnetic (flares) and mass emissions (coronal mass ejections, CMEs) are involved in solar eruptions, while coronal holes result in high speed streams that collide with slow wind forming the so called corotating interaction regions (CIRs). Fast CMEs affect Earth via leading shocks accelerating energetic particles and creating large geomagnetic storms. CIRs and their trailing high speed streams (HSSs), on the other hand, are responsible for recurrent small geomagnetic storms and extended (days) of auroral zone activity, respectively. The latter lead to the acceleration of relativistic magnetospheric killer electrons. One of the major consequences of the weak solar activity is the altered physical state of the heliosphere that has serious implications for the shock-driving and storm causing properties of CMEs. Finally, a discussion is presented on extreme space weather events prompted by the 2012 July 23 super storm event that occurred on the backside of the Sun. Many of these studies were enabled by the simultaneous availability of remote-sensing and in situ observations from multiple vantage points with respect to the Sun Earth line.Comment: 85 pages, 30 figures, 2 tables, Accepted for publication in Progress in Earth and Planetary Science on April 13, 201

Criteria of interplanetary parameters causing intense magnetic storms (Dst less than -100nT)

Ten intense storms occurred during the 500 days of August 16, 1978 to December 28, 1979. From the analysis of ISEE-3 field and plasma data, it is found that the interplanetary cause of these storms are long-duration, large and negative IMF B sub Z events, associated with interplanetary duskward-electric fields greater than 5 mV/m. Because a one-to-one relationship was found between these interplanetary events and intense storms, it is suggested that these criteria can, in the future, be used as predictors of intense storms by an interplanetary monitor such as ISEE-3. These B sub Z events are found to occur in association with large amplitudes of the IMF magnitude within two days after the onset of either high-speed solar wind streams or of solar wind density enhancement events, giving important clues to their interplanetary origin. Some obvious possibilities will be discussed. The close proximity of B sub Z events and magnetic storms to the onset of high speed streams or density enhancement events is in sharp contrast to interplanetary Alfven waves and HILDCAA events previously reported, and thus the two interplanetary features corresponding geomagnetic responses can be thought of as being complementary in nature. An examination of opposite polarity B sub Z events with the same criteria show that their occurrence is similar both in number as well as in their relationship to interplanetary disturbances, and that they lead to low levels of geomagnetic activity

Bruce T. Tsurutani Receives 2009 John Adam Fleming Medal

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/95226/1/eost17116.pd

An intercomparison of plasma turbulence at three comets: Grigg-Skjellerup, Giacobini-Zinner, and Halley

We examine and intercompare the LF plasma wave turbulence at three comets: Grigg-Skjellerup (GS), Giacobini-Zinner (GZ), and Halley (H). All three have power spectral peaks at the local ion cyclotron frequency (the pump wave) at approx. 10(exp -2) Hz, and a power-law fall-off at higher frequencies that suggest the development of turbulent cascades. The power laws for the three comets are approximately f(exp -1.9), f(exp -1.9) and f(exp -2.1), respectively. However, other than the similarities in the power spectra, we find the magnetic field turbulence is considerably different at the three comets. Phase steepening is demonstrated to occur at the trailing edges of the GS waves. This is probably due to nonlinear steepening plus dispersion of the left-hand mode components. A coherency analysis of GZ turbulence indicates that it is primarily composed of righthanded mode components, i.e., the turbulence is 'whistlermode.' This too can be explained by nonlinear steepening plus dispersion of the magnetosonic waves. At the level of GS and GZ turbulence development when the spacecraft measurements were made, classical three-wave processes, such as the decay or modulation instabilities do not appear to play important roles. It is most likely that the nonlinear steepening and dispersive time scales are more rapid than three-wave processes, and the latter had not had time to develop for the relatively 'new' turbulence. The wave turbulence at Halley is linearly polarized. The exact nature of this turbulence is still not well understood at this time. Several possibilities are suggested, based on our preliminary analyses

Dayside Ionospheric Superfountain

The Dayside Ionospheric Super-fountain modified SAMI2 code predicts the uplift, given storm-time electric fields, of the dayside near-equatorial ionosphere to heights of over 800 kilometers during magnetic storm intervals. This software is a simple 2D code developed over many years at the Naval Research Laboratory, and has importance relating to accuracy of GPS positioning, and for satellite drag

NORAD Tracking of the February 2022 Starlink Satellites (and the Possible Immediate Loss of 32 Satellites)

The North American Aerospace Defense Command (NORAD) tracking of the SpaceX Starlink satellite launch on February 03, 2022 is reviewed. Of the 49 Starlink satellites released into orbit, 38 were eventually lost. Thirty-two of the satellites were never tracked by NORAD. There have been three articles written proposing physical mechanisms to explain the satellite losses. It is argued that none of the proposed mechanisms can explain the immediate loss of 32 of the 49 satellites. The non-availability of telemetry data from the lost satellites has hindered the search for a physical mechanism to explain the density increase observed in a short time interval.Comment: 23 pages, 5 figures, 1 table. arXiv admin note: text overlap with arXiv:2210.0790

Plasma-Based Detector of Outer-Space Dust Particles

A report presents a concept for an instrument to be flown in outer space, where it would detect dust particles - especially those associated with comets. The instrument would include a flat plate that would intercept the dust particles. The anticipated spacecraft/dust-particle relative speeds are so high that the impingement of a dust particle on the plate would generate a plasma cloud. Simple electric dipole sensors located equidistantly along the circumference of the plate would detect the dust particle indirectly by detecting the plasma cloud. The location of the dust hit could be estimated from the timing of the detection pulses of the different dipoles. The mass and composition of the dust particle could be estimated from the shapes and durations of the pulses from the dipoles. In comparison with other instruments for detecting hypervelocity dust particles, the proposed instrument offers advantages of robustness, large collection area, and simplicity

Uplift of Ionospheric Oxygen Ions During Extreme Magnetic Storms

Research reported earlier in literature was conducted relating to estimation of the ionospheric electrical field, which may have occurred during the September 1859 Carrington geomagnetic storm event, with regard to modern-day consequences. In this research, the NRL SAMI2 ionospheric code has been modified and applied the estimated electric field to the dayside ionosphere. The modeling was done at 15-minute time increments to track the general ionospheric changes. Although it has been known that magnetospheric electric fields get down into the ionosphere, it has been only in the last ten years that scientists have discovered that intense magnetic storm electric fields do also. On the dayside, these dawn-to-dusk directed electric fields lift the plasma (electrons and ions) up to higher altitudes and latitudes. As plasma is removed from lower altitudes, solar UV creates new plasma, so the total plasma in the ionosphere is increased several-fold. Thus, this complex process creates super-dense plasmas at high altitudes (from 700 to 1,000 km and higher)