D=+Rob Sheldon+rsheldon@bu.edu+im.bu.edu++Wed Jun 5 16:18:31 MDT 1996 C=Just a quick thought as to Bob's paradox. If the electrons are being C=energized by a Second order Fermi process, which, say is time dependent, C=then the initial turning on of such a process will cause a DECREASE C=in the high energy electrons, followed by an INCREASE as the lower C=energy particles diffuse up to higher energy. Thus a single process C=might explain both effects seen in the prediction filters. ---------------------------------------------------------------------- D=+Laurent Desorgher and Paul Buehler+Desorgher@psi.ch+psw222.psi.ch++Mon May 6 06:18:55 MDT 1996 C=We are actually working on the analyses of data measured with the Radiation C=environment monitor(REM). REM measures omnidirectional flux with energies C=above 1 MeV, and protons with energies above 30 MeV. Since June 94, C=one of these instruments orbits the earth aboard the UK Strv1b satellite C=on a nearly equatorial(7 deg. incl.) Geostationnary Transfer Orbit, covering C=L values from 1 to 6.5. C= C=Especially the outer belt electronfluxes are highly variable and comparison C=with e fluxes measured at high magnetic latitudes would certainly help C=to understand better some of the observed features. C= C=> C= During the main phase of a storm we always observe a strong decrease C=of the e flux. C= C=> C= After this strong decrease ,there is a strong increase of the e flux C=in the beginning of the recovery phase. C= C=> C= The rest of the recovery phase the e fluxs follow slow varaitions C=wich depend of the L values. C= C= We would like to participate in the investigation of the loss C=mechanisms and are open for discussions. Please put us on the list. C= C=Laurent Desorgher and Paul Buehler ---------------------------------------------------------------------- D=+Ioannis Daglis+daglis@linax2.mpae.gwdg.de+143.233.41.3++Mon Apr 29 11:30:27 MDT 1996 C=A short answer to question Nr. 2: C=(What particles account for the increase in ring current strength if the in situ C= measurements show a flux decrease? ) C= C=The particles accounting for the increase in ring current strength C=are ions in the energy range ~20-300 keV, i.e. the "core" energy range C=of the ring current. It is my understanding (e.g. comment of Finn C=Soeraas) that the observed losses refer to energies above 400 keV. C=So is this question still a question? C=Please put me on the list! C=Ioannis Daglis ---------------------------------------------------------------------- D=+Robert McPherron+rmcpherr@igpp.ucla.edu+mcppc.igpp.ucla.edu++Thu Apr 25 17:11:32 MDT 1996 C=I would like to remind every one of a result that Dan Baker, myself and others obtained using linear prediction filters. Starting with several years of relativistic electron fluxes at synchronous orbit we derived impulse response functions relating the log flux to various posible causes (solar wind vleocity, magnetic activity indices). The response function starts with a depression on day zero, injection for two subsequent days, then exponential decay. I have never been certain of the interpretation of the decrease on day zero. My first though that it was an artifact of detrending the data before calculating correlation fucntions. It is evident that the flux before an injection will be lower than after (by definition). If trends are removed the flux before will be negative relative to the trend. Dan Baker argued that from his earlier superposed epoch analysis that this was a real physical effect. I agree it is a persistent feature of the response functions we get whatever input we use. ---------------------------------------------------------------------- D=+Margy Kivelson+mkivelson@igpp.ucla.edu+kivpc.igpp.ucla.edu++Wed Apr 24 12:25:34 MDT 1996 C=Rob's comment (below) reminds me of an old paper of mine: C=Kivelson, M. G., S. M. Kaye, and D. J. Southwood, C=The physics of plasma injection events, in Dynamics of the C=Magnetosphere, (S. I. Akasofu, Editor), C=D. Reidel, Dordrecht, Holland, 1979 C=In this paper, we point out that "injection" can result from transport, C=from crossing a separatrix between "forbidden' and "allowed" regions, C=or from "in situ" acceleration. What one notes in the data is that C=new particles appear in the energy range to which the detector is C=responding, and these can be locally accelerated as well as transported, C=or they could have been there all along, and the s/c has entered the C=region in which the particles are present. These processes are all relevant C=to the study suggested. Separatrices move with increasing E, so C=particles disappear from regions in which they had been present. C=Evidently temporal variations in B produce both transport and local C=acceleration. We need some way of working out the global distribution C=from the available data. Karen's thought that we should correlate C=with data from other spacecraft is relevant here. ---------------------------------------------------------------------- D=+Rob Sheldon+rsheldon@ceppad.bu.edu+ceppad.bu.edu++Mon Apr 22 16:27:48 MDT 1996 C=Just a comment about ion transport and loss processes: C= People generally lump transport processes into one of two categories, C= convection or diffusion. Injections during storms are generally treated C= examples of convective transport. (Though recently Margaret Chen has C= been showing how random convective transport looks like an "enhanced" C= diffusion.) Whereas slow transport (such as Starfish electrons) is C= treated as diffusion. In actuality, one needs to track both at the C= same time, though there are two asymptotic regimes where one or the C= other dominates. For ions < 30 keV, electric fields dominate the motion C= and "convection" is of greater importance. For ions > 100 keV, it is C= the magnetic fields (and fluctuations of them) that dominate, so C= diffusion is of greater importance. However, during a storm, these C= asymptotic regimes are not as clear cut as above, which leads to a C= wide energy range of enhanced "convective-diffusion". C= Meanwhile the loss processes are pretty much fixed -- pitch angle C= diffusion into the loss cone, radial diffusion into the atmosphere or C= out the frontside magnetopause, Coulomb drag and Charge exchange. So C= my gut feeling is that given a reasonable transport and loss model, C= one can plug in the boundary conditions to find the sources and sinks C= of energetic particles. e.g. it isn't a mystery, its a PDE. ---------------------------------------------------------------------- D=+Geoff Reeves+reeves@lanl.gov+brewer.lanl.gov++Mon Apr 15 17:02:09 MDT 1996 C=Greetings Everyone, C= C=You are getting this message because you are listed as an active C=participant in the Global Loss of Particles in the Early Phase of Storms C=science trust. The web page for this science thrust is at C=http://leadbelly.lanl.gov/cgi-bin/CCR_forms/science_thrusts/science.cgi/4a. C=Each time someone posts a message to the Global Loss web page you will C=get an e-mail (like this one) with the text of the message. If you do C=not want to be an active participant then I can take your name off the C=list. You can still participate in the discussion on the web page but C=you won't get e-mail each time someone posts a comment. C= C=Well, enough with the logistics. I'd like to get the ball rolling on C=this topic. I realize that we're not really ready to look at the Polar C=data but we can start looking at other data to try to identify candidate C=intervals. I'm going to try to bring geosynchronous and GPS data to the C=CEPPAD meeting next week. Dan, maybe you can bring some SAMPEX line C=plots too. Even if we can't find a candidate event I'd like to start a C=list of questions we'd like to answer with this study. ---------------------------------------------------------------------- D=+Finn Soraas+finn.soraas@fi.uib.no+rapid.fi.uib.no++Tue Mar 19 04:11:35 MST 1996 C=Dear Geoff C=

C=Referring to your Web page on the study of loss processes on energetic ions in C=the main phase of the storm. I am very interested in this matter as I did some C=research on it many years ago. C=

C= I then, together with Leo Davis, did a study of the long time behavior of C=energetic protons in the magnetosphere using the Explorer 25 satellite. The C=results were published in (F. Soraas and Davis L.R., 1968:report X-612-68-328. C=Goddard Space Flight Center). C=

C=The time variations in the protons in the energy range 100 -1700 keV, L-range 2 C=-6.5 were investigated for a time span of 1/2 year. The data was corrected for C=adiabatic variations using a realistic model for the disturbance field. Three C=basic large scale time variations were located in the 100-1700 keV protons: C=

C=a. Adiabatic redistribution of the proton population, which varies directly C=with the magnetic field variations and during which the three particle C=invariants are conserved. C=

C=b.Rapid non-adiabatic variations occurring in the main phase of geomagnetic C=storms, during which the low energy proton intensities are enhanced and the high C=energy intensities are depleted. These variations penetrate deeper into the C=magnetosphere as the size of the storm increases. C=

C=c. A slow non-adiabatic post-storm variations, during which both low and high C=energy intensities recovered towards the pre-storm levels, low energy C=intensities decay, and high energy intensities increase during this period. C=

C=A model involving large scale electric fields was invoked to explain the C=observations. We assumed a soft spectrum of protons in the tail region and that C=these protons were drifted toward the earth by an electric field. As they moved C=to regions with higher B value they were energized, resulting in a net increase C=in the intensity of the low energy protons. At the same time higher energy C=protons which were trapped at a particular radial distance can be come untrapped C=and drift by the electric field toward the front of the magnetosphere causing C=these energies to be depleted at a particular radial distance. C=

C=

C=The flux decrease took place mainly for energies above 400 keV, depending on C=L-value and the size of the storm. C=

C=I have wanted to continue these earlier investigations. For the time being I am C=together with a student performing a long time study of ions observed with the C=MICS instrument on CRRES. It observe, however, only protons with energies below C=426 keV. C=

C=I feel it is essential to be able to study energies from a few keV and up in the C=MeV range. Data from the POLAR satellite could prove to be important in such a C=study. It should however be combined by a satellite measuring over a range of C=L-values in the equatorial plane. C=

C=It should also be useful to investigate some of the CRRES data covering ions C=over a larger energy interval during storms. C=

C=If you are interested I can send you a copy of my old paper. C=

C=I want to congratulate you with the CCR pages which are very useful. C=

C=I would like to join the team, investigating the global loss ............. C=

C=Best regards C=

C=

C=Finn ---------------------------------------------------------------------- D=+Karen Lewis Hirsch+hirsch@bu.edu+uss-enterprise.bu.edu++Fri Mar 15 20:29:44 MST 1996 C=Will it be necessary to wait for cluster or use other satellites to seperate spatial from temporal variations in the energetic particle flux? What efforts have been made to coordinate with other groups, possibly even on other satellites, whose data would be pertinant in delineating the difference in spatial vs temporal effects. ----------------------------------------------------------------------