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Testing different models to calculate the peak height at Tucuman
Pergamon
Adv. Space Res. Vol. 15,No. 2,pp.(2)153-(2)154,199~ copyright 8 1994COSPAR Printed in GreatBritain. All d tsrwervcd. P $7.00+ 0.00 0273-1177/9
TESTING DIFFERENT MODELS TO CALCULATE THE PEAK HEIGHT AT TUCUMAN N. Ortiz de Adler and A. M. Sauvage de Avila Loboratorio de Ionosfera, Institute de Fisica, Facultad de Ciencias, Exactas y Tecnologi’a, Universidad National de Tucwnh, Argentina
ABSTRACT hmF2 obtainedby differentmodelsis comparedwith the parabolicpeak hattht hp and with hmF2 from Paul’s invemion mathod. hp compareswall wlth hmF2 darlvad by any mathod baaed on M(3OOO)F2 while Paul’s inversiongivasconsidambtylarger haigftts,in somacasesaxtmmavalues. TherssultsofttreBESmsthod~inthelRIarewellconsletsdwiththoseofthsmethods~on lW(3OOQF2, muchlasswallwiththosaderivedby Paul’sinversiontedwique. Mn?cmucTloN Tucuman (28.4 S, 65.4” W) is located near tha suuthem crast of the aquatodalanomaly. Our analysisis basadon parametersdetenninedon 88 ionogramsof August1081, a wintermonthwith high sofaractivii (madtanRz 158.2). Two dassicalparametan? were read hp (at 0.834 foF2) and M@OOO)F2. Paul’sinversionmethodthat usesthe full lonogramswas appliedfor cumpartson. Many mathodsfor derivinghmF2 fromM(3OOQF2have baen pmposad(Appandbc. Tabfa 1) hp [l] , Shim[21, W&D (31, Bent (41,ED [5], Eyfrig161, Dud m, BES (61. In tha mom recantmathuds [5-8]. the effact of lowarlayersis taken into account(vfa ratio hmE / hmF2). Tha canstaM 4 the ralatfonbatwaanhmF2 and M(3OOO)F2 wara determinadby axnparfngwfth pfnflbs obtainadfrom bottomsidaianagrams(axbapolatadtuwardfoF2). MethodBES [8] howavarwas mainlyda&ad fmm incoharantscatterdata wtch allow a diractdatarm4ationof the peak. Thii is tha mathodactual@ usadin tha IRI. lt alsoincludaseffactsof the sunspotnumberand of tha magnetic(dii) latltude. Baaad on ionosondedata, empiricalformulasdescrtbingthe wortdwilevariation of hmF2 are pmposed[Q- 121.Thesawill not be discussedhere. Paul’s invamtanmethod(Table 1 [13] ) that usas continuousgradientsand includesthe effact of undartylngtonlzatlonis to be testedin tha following.
AUdata appearin the massplotof Figure1. Paul’s resultsare nottoo wallootrelatadwiththe others; the tzomWon aMickmt is only 0.47. (A largarvalue resultedwken the three extramapolntawera dfsragardad).Flgura 2. for an indivfdualday compamsthesamemsultswiththosaoftheaarliast M@OOO)F2-formula ( [2] in Tabk 1). and of [4] . Fiim 3 shawsmonthlymedtanas obwnai with hp [I] , Shim [21,BES (81and Paul’s kwamion(131gbing heights largerby about40 km. Fiiures 4 and 5 comparettte BES method[8] with[!ij , m and [3} , [4], [5] raspactivaly. Table 2 (in tha Appendix)is the Pearsonconalationmat& (14) astabkshadwith the resultsof all hm-mathodacar&tad in Table 1. JASR 152-K
(2)154
N. 0th
de Adler and A. M. Sawage de Avila
CONCLUSIONS At Tucuman, in August 1981 all methods based on M@OOO)F2gave compamble values of hmF2 , not too far from those by the parabolic method. Pauls’s inversion method, however, gave considerabte larger heights and variations that are not well correlated with those of the other methods. Therefore we do not intend to use Paul’s technique [13] in our current implementation. Resutts of method 181, used in IRI are well correlated whiih those obtained by methods [l] to [7] . The absolute values found with the IRI method agree with those of the other methods by day ; they are up to t0 Km larger by night. REFERENCES
5. 8.
7. 8.
9.
IO. 11 12 13
14
H.G.Booker and S.L.Seaton, Retation between actual and virtual ionospheric height, Phvsical Review, 57, 87-94 (1940). T.Shimazaki, World-wide daily variation in the height of the maximum electron density, J.Geoohvs. Res. I abs., 2,85-97 (1955). J.W. Wright and R.E. McDuffie, The relation of hmaxF2 to M(3000)FZ and hpF2, ,l.Rad. Res. w. 7(32), 409-417 (1960). R.B. Bent and S.K.Llewellyn, Description of the 1985 - 1971 ionospheric model used in the definitive orbit determination System (DODS) DBA Svstems , Melbourne (United States) (1970). P.A.Bradley and J.R. Dudeney, A simple model of the vertical distribution of electron concentration in the ionosphere, Journal Atmosp. Terr. Phvs. 35 (la), 213% 2148 (1972). R.W.Eyfrtg,Prediction of ionospheric layer height parameters and oblique path modes of propagation vie ionosphere in band 7 (HF).Contribution to tnterim Working Party 6/l from the Federal Republic of Germany ( 1974 ). J.R. Dudeney , A simple empirical method for estimating height and semithickness of the F2 layer at the Argentine Islands, Graham, Land Brit. Antar. Surv., Sci. Reo., 88 ,46 ( 1975). D. Bilitza,R. Eyfrig and N.M.Sheik , A global model for the heigth of the F2-peak using M(3000) values from the CCIR numerical map _ Telecommunication Journal ,46 1X-1979, 549553 (1979). W.Becker, ‘The standard-profile of the mid-latitude F-region of the ionosphere as deduced from bottomside and topside ionograms”,Soace Research # 12,1241-1252 (1972). J.S.Nisbet, “On a construction and use of a simple ionospheric model”, Radio Science # 8, 437484 (1971). B.K.Ching and Y.T. Chiu, A phenomenoiogicai model of global ionospheric electron density in the E, Fl and F2 regions, J. Atmoso. Ten: Phvs., 35 # 9,1615-1630 (1973). Y.f.Chiu,” An improved phenomenological model of the ionospheric density, J. AtmOsD. Terra Phvs. 37, # 12,1583-1570 (1975). A.K.Paul, ionospheric electron-density profiles wtth continuous gradients and underlying ionization corrections. I. The mathematical-physical problem of real-height determination from ionograms, Radio Science , 2 (lo), 1127-I 133 (1987). F.A. Graybill, Theory and aoolication of the lineal model, Duxbury Press (1978).
Adv. Space Res. Vol. 15,No. 2,pp.(2)153-(2)154,199~ copyright 8 1994COSPAR Printed in GreatBritain. All d tsrwervcd. P $7.00+ 0.00 0273-1177/9
TESTING DIFFERENT MODELS TO CALCULATE THE PEAK HEIGHT AT TUCUMAN N. Ortiz de Adler and A. M. Sauvage de Avila Loboratorio de Ionosfera, Institute de Fisica, Facultad de Ciencias, Exactas y Tecnologi’a, Universidad National de Tucwnh, Argentina
ABSTRACT hmF2 obtainedby differentmodelsis comparedwith the parabolicpeak hattht hp and with hmF2 from Paul’s invemion mathod. hp compareswall wlth hmF2 darlvad by any mathod baaed on M(3OOO)F2 while Paul’s inversiongivasconsidambtylarger haigftts,in somacasesaxtmmavalues. TherssultsofttreBESmsthod~inthelRIarewellconsletsdwiththoseofthsmethods~on lW(3OOQF2, muchlasswallwiththosaderivedby Paul’sinversiontedwique. Mn?cmucTloN Tucuman (28.4 S, 65.4” W) is located near tha suuthem crast of the aquatodalanomaly. Our analysisis basadon parametersdetenninedon 88 ionogramsof August1081, a wintermonthwith high sofaractivii (madtanRz 158.2). Two dassicalparametan? were read hp (at 0.834 foF2) and M@OOO)F2. Paul’sinversionmethodthat usesthe full lonogramswas appliedfor cumpartson. Many mathodsfor derivinghmF2 fromM(3OOQF2have baen pmposad(Appandbc. Tabfa 1) hp [l] , Shim[21, W&D (31, Bent (41,ED [5], Eyfrig161, Dud m, BES (61. In tha mom recantmathuds [5-8]. the effact of lowarlayersis taken into account(vfa ratio hmE / hmF2). Tha canstaM 4 the ralatfonbatwaanhmF2 and M(3OOO)F2 wara determinadby axnparfngwfth pfnflbs obtainadfrom bottomsidaianagrams(axbapolatadtuwardfoF2). MethodBES [8] howavarwas mainlyda&ad fmm incoharantscatterdata wtch allow a diractdatarm4ationof the peak. Thii is tha mathodactual@ usadin tha IRI. lt alsoincludaseffactsof the sunspotnumberand of tha magnetic(dii) latltude. Baaad on ionosondedata, empiricalformulasdescrtbingthe wortdwilevariation of hmF2 are pmposed[Q- 121.Thesawill not be discussedhere. Paul’s invamtanmethod(Table 1 [13] ) that usas continuousgradientsand includesthe effact of undartylngtonlzatlonis to be testedin tha following.
AUdata appearin the massplotof Figure1. Paul’s resultsare nottoo wallootrelatadwiththe others; the tzomWon aMickmt is only 0.47. (A largarvalue resultedwken the three extramapolntawera dfsragardad).Flgura 2. for an indivfdualday compamsthesamemsultswiththosaoftheaarliast M@OOO)F2-formula ( [2] in Tabk 1). and of [4] . Fiim 3 shawsmonthlymedtanas obwnai with hp [I] , Shim [21,BES (81and Paul’s kwamion(131gbing heights largerby about40 km. Fiiures 4 and 5 comparettte BES method[8] with[!ij , m and [3} , [4], [5] raspactivaly. Table 2 (in tha Appendix)is the Pearsonconalationmat& (14) astabkshadwith the resultsof all hm-mathodacar&tad in Table 1. JASR 152-K
(2)154
N. 0th
de Adler and A. M. Sawage de Avila
CONCLUSIONS At Tucuman, in August 1981 all methods based on M@OOO)F2gave compamble values of hmF2 , not too far from those by the parabolic method. Pauls’s inversion method, however, gave considerabte larger heights and variations that are not well correlated with those of the other methods. Therefore we do not intend to use Paul’s technique [13] in our current implementation. Resutts of method 181, used in IRI are well correlated whiih those obtained by methods [l] to [7] . The absolute values found with the IRI method agree with those of the other methods by day ; they are up to t0 Km larger by night. REFERENCES
5. 8.
7. 8.
9.
IO. 11 12 13
14
H.G.Booker and S.L.Seaton, Retation between actual and virtual ionospheric height, Phvsical Review, 57, 87-94 (1940). T.Shimazaki, World-wide daily variation in the height of the maximum electron density, J.Geoohvs. Res. I abs., 2,85-97 (1955). J.W. Wright and R.E. McDuffie, The relation of hmaxF2 to M(3000)FZ and hpF2, ,l.Rad. Res. w. 7(32), 409-417 (1960). R.B. Bent and S.K.Llewellyn, Description of the 1985 - 1971 ionospheric model used in the definitive orbit determination System (DODS) DBA Svstems , Melbourne (United States) (1970). P.A.Bradley and J.R. Dudeney, A simple model of the vertical distribution of electron concentration in the ionosphere, Journal Atmosp. Terr. Phvs. 35 (la), 213% 2148 (1972). R.W.Eyfrtg,Prediction of ionospheric layer height parameters and oblique path modes of propagation vie ionosphere in band 7 (HF).Contribution to tnterim Working Party 6/l from the Federal Republic of Germany ( 1974 ). J.R. Dudeney , A simple empirical method for estimating height and semithickness of the F2 layer at the Argentine Islands, Graham, Land Brit. Antar. Surv., Sci. Reo., 88 ,46 ( 1975). D. Bilitza,R. Eyfrig and N.M.Sheik , A global model for the heigth of the F2-peak using M(3000) values from the CCIR numerical map _ Telecommunication Journal ,46 1X-1979, 549553 (1979). W.Becker, ‘The standard-profile of the mid-latitude F-region of the ionosphere as deduced from bottomside and topside ionograms”,Soace Research # 12,1241-1252 (1972). J.S.Nisbet, “On a construction and use of a simple ionospheric model”, Radio Science # 8, 437484 (1971). B.K.Ching and Y.T. Chiu, A phenomenoiogicai model of global ionospheric electron density in the E, Fl and F2 regions, J. Atmoso. Ten: Phvs., 35 # 9,1615-1630 (1973). Y.f.Chiu,” An improved phenomenological model of the ionospheric density, J. AtmOsD. Terra Phvs. 37, # 12,1583-1570 (1975). A.K.Paul, ionospheric electron-density profiles wtth continuous gradients and underlying ionization corrections. I. The mathematical-physical problem of real-height determination from ionograms, Radio Science , 2 (lo), 1127-I 133 (1987). F.A. Graybill, Theory and aoolication of the lineal model, Duxbury Press (1978).