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Theoretical storm variability in the ionosphere
1789
COMPARISON OF MODEL ELECTRON DENSITIES WITH MILLSTONE HILL OBSERVATIONS DURING UNDISTURBED PERIODS AND THE GEOMAGNETIC STORMS OF MARCH 16-23 AND APRIL 6-12 1990 A. V. Pavlov* and M. J. Buonsanto** VZMtRAN, The Russian Academy of Science, Troitsk, Moscow Region.142092, Russia, **Haystack Observatory, Massachusetts Institute of Technology, Westford, Massachusetts, U.S.A.
ABSTRACT of ?;mfL’ ar Millstone Hili are compared with results Irom the IZYIH.U time-.dependent mathematical model ot the Earth’s ionosphere and plasmasphere during Yarch 16-.LI3 and April 6-12, 1991. Satisfactory aqreement between the model and the data is obtained durins the quiet intervals provided in MIS-86 atomic osyen densities are included in the that 3-50% increases nqreement 1s obtained durlnq the storm periods when model. Good model/data in daytime vibrationally cscited 6:, brings about tactors of 2 -3 reductions ‘on April 10 are :;rnFll. Estremeiy low ?imFS! and bmEL! and hiqb ion temperatures cspiained by the large i_!O-100 mk/m) electric rields on this day. Yodel calculations are carried out usinq different expressions ior O&-O collision frequency and the best agreement between the measured and modeled NmFL’ is obtained when the C&DARinterim standard formula for the O--O collision frequency vibrational distribution of X, is hiqhly non-Boltzmann is used. I’be calcuiated assumption results a~ vibrational levels I,_‘. and the Boltzmann distribution in errors or 10.40% in calculated 3mF2 durinq the storm-time neriods. Yeasurements
THEORETICAL STORM VARIABILITY
IN THE IONOSPHERE
J. J. Sojka and R. W. Schunk Center for Atmospheric and Space Sciences, Utah State University, Logan, UT84322-4405
U.S.A.
ABSTRACT aspects of ionospheric storms are well understood qualitatively. inclndlnq neqative storm phase. positive storm phase. storm enhanced density, dusk are dependent not only upon rhe srorm etftect, etc. Ye know that these effects ulrect maqnetosherlc drivers. but also on the subsequent and otten deLayed thermospneric response. Since no t.wo storms are identical. the resultlnq perturbations experienced by the ionosphere are numerous and complex. With the aid of a physical ionospheric model, we will discuss strategies by whlcb regional storm effects may be integrated into an empirical ionospheric model. Such simulations do not provide absolute parameters.1 .e._VW2, I~mf2. et.c. .tor every storm. but specity quantitatively bow the ionosphere would resoond to specific storm Inputs. Hence, the challenge is how t.o monitor or specify the storm inputs or drivers in a way that will enable the empirical formulations to be “storm” modified, where the storm modification would be derived from a parametrization of t.he physical model simulations. tie will discuss the storm responses in different regions of the ionosphere. ?lany
COMPARISON OF MODEL ELECTRON DENSITIES WITH MILLSTONE HILL OBSERVATIONS DURING UNDISTURBED PERIODS AND THE GEOMAGNETIC STORMS OF MARCH 16-23 AND APRIL 6-12 1990 A. V. Pavlov* and M. J. Buonsanto** VZMtRAN, The Russian Academy of Science, Troitsk, Moscow Region.142092, Russia, **Haystack Observatory, Massachusetts Institute of Technology, Westford, Massachusetts, U.S.A.
ABSTRACT of ?;mfL’ ar Millstone Hili are compared with results Irom the IZYIH.U time-.dependent mathematical model ot the Earth’s ionosphere and plasmasphere during Yarch 16-.LI3 and April 6-12, 1991. Satisfactory aqreement between the model and the data is obtained durins the quiet intervals provided in MIS-86 atomic osyen densities are included in the that 3-50% increases nqreement 1s obtained durlnq the storm periods when model. Good model/data in daytime vibrationally cscited 6:, brings about tactors of 2 -3 reductions ‘on April 10 are :;rnFll. Estremeiy low ?imFS! and bmEL! and hiqb ion temperatures cspiained by the large i_!O-100 mk/m) electric rields on this day. Yodel calculations are carried out usinq different expressions ior O&-O collision frequency and the best agreement between the measured and modeled NmFL’ is obtained when the C&DARinterim standard formula for the O--O collision frequency vibrational distribution of X, is hiqhly non-Boltzmann is used. I’be calcuiated assumption results a~ vibrational levels I,_‘. and the Boltzmann distribution in errors or 10.40% in calculated 3mF2 durinq the storm-time neriods. Yeasurements
THEORETICAL STORM VARIABILITY
IN THE IONOSPHERE
J. J. Sojka and R. W. Schunk Center for Atmospheric and Space Sciences, Utah State University, Logan, UT84322-4405
U.S.A.
ABSTRACT aspects of ionospheric storms are well understood qualitatively. inclndlnq neqative storm phase. positive storm phase. storm enhanced density, dusk are dependent not only upon rhe srorm etftect, etc. Ye know that these effects ulrect maqnetosherlc drivers. but also on the subsequent and otten deLayed thermospneric response. Since no t.wo storms are identical. the resultlnq perturbations experienced by the ionosphere are numerous and complex. With the aid of a physical ionospheric model, we will discuss strategies by whlcb regional storm effects may be integrated into an empirical ionospheric model. Such simulations do not provide absolute parameters.1 .e._VW2, I~mf2. et.c. .tor every storm. but specity quantitatively bow the ionosphere would resoond to specific storm Inputs. Hence, the challenge is how t.o monitor or specify the storm inputs or drivers in a way that will enable the empirical formulations to be “storm” modified, where the storm modification would be derived from a parametrization of t.he physical model simulations. tie will discuss the storm responses in different regions of the ionosphere. ?lany