# Presentation: 488470

## International Reference Ionosphere

**Update 2005**
- Dieter Bilitza
*Raytheon ITSS, Goddard Space Flight Center*
*Space Physics Data Facility*
*Greenbelt, Maryland, USA*

**I**
**I R I**
**I**

**I**
**R**
**I**

## Advances in Radio Science 

** **
**G.2.** **Three Decades of the International Reference Ionosphere - a special session in honour of Prof. K. Rawer's 90th Birthday**
***Altes Rathaus, Miltenberg, Germany******29 September - 02 Oktober 2003***

**Advances in Radio Science **
***Volume 2, 2004***
**Editor: B.W. Reinisch**

## Advances in Space Research 

**INTERNATIONAL REFERENCE IONOSPHERE**
**WORKSHOP 2003: **
**Quantifying Ionospheric Variability**
**Grahamstown, South Africa**
**October 6-10, 2003**

**Advances in Space Research **
***Volume 34, Number 9, 2004***
**Editors: B.W. Reinisch, D. Bilitza, L.A. McKinnell**
***IRI: Quantifying Ionospheric Variability ***
*** ***
***37 papers, 259 pages***
***Dedicated to Prof. Rawer in celebration of his 90******th****** birthday***

## Advances in Space Research 

***35th COSPAR SCIENTIFIC ASSEMBLY***** **
**C4.2 Advances in Specifying Plasma Temperatures and Ion Composition in the Ionosphere **
***PARIS, FRANCE, 18 - 25 JULY 2004***

**Advances in Space Research **
**Editors: D. Bilitza, B.W. Reinisch**
***Most papers are reviewed and reviewer’s comments have been sent back to authors.***
***Publication later this year***

## IRI Working Group Members

**B. Reinisch **
**D. Bilitza **
**T. Fuller-Rowell**
**K. Bibl  **
**X. Huang **
**J. Sojka **
**D. Anderson **
**V. Wickwar**
**L. Scherliess**
**M. Codrescu **

**M. Abdu**

**R. Ezquer **
**M. Mosert de Gonzalez**

**A. Poole, L.-A. McKinnell**

**J. Adeniyi**

**P. Bradley, M. Rycroft, Lj. Cander (U.K.), **
**K. Rawer, W. Singer (Germany), **
**A. Alcayde, R. Hanbaba (France), **
**B. Zolesi, S. Radicella (Italy), **
**M. Friedrich(Austria), **
**E. Kopp (Switzerland), **

**A. Danilov **
**V. K. Depuev **
**T. Gulyaeva **
**G. Ivanov-Kholodny**
**E. Kazimirovsky **
**A. Mikhailov **
**S. Pulinets**

**K. Oyama**
**K. Igarashi **
**S. Watanabe **

**K. Mahajan **
**A.P. Mitra **
**S.P. Gupta**
**P.K. Bhuyan**** **

**P. Wilkinson **
**P. Dyson **
**B. Ward **

**L. Triskova, V. Truhlik (Czech Rep) **
**I. Kutiev (Bulgaria) **
**I. Stanislawska (Poland), **
**S. Kouris (Greece)**

**O. Obrou**

**M.-L. Zhang**

## IRI

- C.K. Chao; S.-Y. Su; H.C. Yeh,
- Ion Temperature Variation Observed by ROCSAT-1 Satellite in the Afternoon Sector and Its Comparison with IRI-2001 Model  (600 km)

- ROCSAT 1

## THERMAL ELECTRON MEASUREMENT OF THE NIGHTTIME UPPER IONOSPHERE BY KOMPSAT-1

- K. W. Min, H. J. Kim, J. Park, J. J. Lee, V. P. Kim
- KOMPSAT-1, 685 km, HSA

## The comparison of incoherent scatter data with the International Reference Ionosphere model IRI-2001 In East-Siberian region

- B.G.Spynev, A.P.Potekhin, A.V.Tashchilin, V.I.Kurkin, A.V.Zavorin, G.A.Zherebtsov

- Spring 1998

## New Models for IRI

- Te            1000-10,000 km	h, , LT	Akebono	  Kutiev et al. (2002, 2004)
- Te             600 km, ||<42, HSA 	, LT,m	Hinotori	  Oyama et al. (2005)         PARIS
- Te	500 km, LSA               , LT        SROSS C2   Bhuyan, Chamua (2005) PARIS
- Ti                     550, 900, 1500 km      invdip, LT IC-24	  Triskova et al. (2004)
- O+, H+, 	500-2500 km 	invdip,	AE-C, E, 	  Triskova et al. (2003),
- He+,N+ 			LT,doy, 	IK-24	  Truhlik et al. (2004) 				                  F107d
- O+-H+ 	transition height 	, LT,m	Alouette 	  Marinov et al. (2005)      PARIS
- 			F10.7	ISIS TS
- Ne	D-region, auroral, 	season,,   Rockets	  Friedrich et al. (2004)
- 	quiet and disturbed     Abs, Kp	EISCAT      McKinnell, Friedrich (2005)
- Ne, Te, 	1970-2001 	h,LT, ap	Millstone     Holt et al. (2002)
- Ti, vi 			F10.7 	Hill Radar    Zhang and Holt (2004)
-                                                                         St. Santin     Zhang et al. (2005)         PARIS
- Htop	Topside O+ 	m,LT,,	Alouette	   Kutiev et al. (2005)     PARIS
- 	scale height	F107,Kp	ISIS TS
- 	   geomagnetic latitude     invdip    invariant latitude/dip variable
- 	m    month                           Abs       absorption

## IRI Topside Improvement Efforts 

**Papers in Paris: **
**COMPARISON OF THE TOPSIDE IONOSPHERE SCALE HEIGHT DETERMINED**
**BY TOPSIDE SOUNDERS MODEL AND BOTTOMSIDE DIGISONDE PROFILES**
- A. Belehaki, Pencho Marinov, Ivan Kutiev, Norbert Jakowski and Stanimir Stankov
**Altitude variations of middle-latitude topside ionospheric electron-density profiles**
- P. A. Webb, R. F. Benson, J. Grebowsky
**Topside Plasma Scale Height Retrieved from Radio Occultation Measurements**
- S. M. Stankov and N. Jakowski
**Topside electron density in IRI and NeQuick**
- P. Co ̈ısson*,. *S. M. Radicella, R. Leitinger, B. Nava
**Diurnal and Seasonal Variation of the Ionogram-derived Scale Height at the F2 Peak**
- Man-Lian Zhang, Bodo W. Reinisch, Jian-Kui Shi, Shun-Zhi Wu, Xiao Wang
-  **Deducing an IRI topside profile from the IRI bottomside profile **
- Reinisch, B.W.; Huang, X.

## IRI Topside Improvement Efforts 

** ****	**_**Correction Term for IRI Model – Bilitza, ASR, 33, 838, 2004**_
** ****	**_**IRI Parameters Constraint – Coisson and Radicella, ASR, 33, 838, 2004**_
**	**
**	**_**NeQuick model – **__**Radicella and Leitinger, ASR, 27(1), 35, 2001**_** **
**	**
**	**_**I**__**ntercosmos 19 Model – Depuev & Pulinets, ASR, 34, 2016, 2004**_
**	**
**	**_**Combined IMAGE/RPI Ionosonde Model – Reinisch et al., 2004**_
** ****	**_**Fixed-height Model – Triskova, Truhlik, Smilauer, ASR, 2005**_
** ****	**_**Topside Half-Width Model  – Gulyaeva, Int. J. Geom. Aeron., 4(3), 2003**_
**	**_**Merge with Plasmaspheric Model: Gallagher et al. (1988, 2000)**_

- Corr

- Corr

- New

- New

- New

- New

- New

- IRI-2005

- IRI-2005

- IRI+

## Correction Term for IRI Model – Bilitza, ASR, 33, 838, 2004

**Correction Term for IRI Model – Bilitza, ASR, 33, 838, 2004**

**           ****Ne_TOPS / Ne_IRI**

**           ****Ne_TOPS / Ne_IRI**

**           ****h-hmF2  [km]**

**           ****h-hmF2  [km]**

- Modip:-40 to 40

-   Modip:
-  -40 to –80
-   40 to 80

**Ne_IRI****corr**** = Ne_IRI * T (h, LT, modip)**

- 2.0

- 1.0

- 1.5

- 0.5

- 0.0

-                               Correction Factor T

-                                            modified dip latitude

##   0.02 

-   0.015
-   constraint

- Constraints for current topside model (Coisson and Radicella (2004)

**The Epstein formalism implemented in the current model can lead to unrealistic profiles for very high solar activity at high latitudes. Setting artificial limits for some of the model parameters helps to stabilize the mathematical formalism but does not fully**

**IRI Parameter Constraints - Coisson and Radicella, ASR, 2004**

## NeQuick model – Radicella and Leitinger, ASR, 27(1), 35, 2001

**Model is based on a selection of ionosonde and topside sounder (ISIS, Intercosmos 19) data. It uses an Epstein-layer function with a height-varying scale height H(h)**
**H(h) = H****0**** [ 1 + 12.5  ( h - hmF2 ) / { 100  H****0**** + 0.125  ( h -  hmF) } ], **
**where H****0**** is given as a function of bottomside thickness, F peak density, F peak height, and sunspot number.**** **

## Intercosmos 19 Model – Depuev & Pulinets, ASR, 34, 2016, 2004

**	****H = H****0**** + k (h-hmF2)**
** **
**for high solar activity, different latitudes, seasons, and LT.**

**Intercosmos 19 Model – Depuev & Pulinets, ASR, 34, 2016, 2004**

| Rz12 = 30 | I= 55 | I= 27 | I= 0 | I=-30 | I=-50 |
| --- | --- | --- | --- | --- | --- |
| Chapman | 0.023 | 0.072 | 0.046 | 0.059 | 0.056 |
| Epstein | 0.037 | 0.071 | 0.119 | 0.059 | 0.070 |
| Exponential | 0.146 | 0.099 | 0.241 | 0.199 | 0.319 |

| Rz12 = 140 | I= 52 | I= 32 | I=-2 | I=-30 | I=-50 |
| --- | --- | --- | --- | --- | --- |
| Chapman | 0.144 | 0.025 | 0.059 | 0.099 | 0.045 |
| Epstein | 0.139 | 0.032 | 0.056 | 0.087 | 0.028 |
| Exponential | 0.221 | 0.237 | 0.152 | 0.164 | 0.261 |
| IRI | 0.295 | 0.190 | 0.332 | 0.259 | 0.052 |

**Alouette**

**Intercosmos 19**

## Combined IMAGE/RPI Ionosonde Model – Reinisch et al., 2004

**Combined IMAGE/RPI Ionosonde Model – Reinisch et al., 2004**

**N****e****(L, invLat) model from IMAGE/ RPI measurements (Huang et al.,2004)**

**Representing the topside profile by assuming a Chapman layer with a constant scale height from the peak upward.**

**Using the Chapman approach with a height-varying scale height to merge the bottomside model with the IMAGE/RPI plasmasphere model. **

- Chapman with
- constant H

- IRI

- Chapman
- with height-
- varying  H

- Scale height / km

-  Height / km

-                        Height / km

-                                   Ne / cm-3

## Fixed-height Model – Triskova, Truhlik, Smilauer, ASR, 2005

- Comparison of ISIS 2 insitu electron density measurements at 1400 km (dots) with the IRI model (broken line) and with the Triskova et al. (2005) model (solid line). Also shown are averages and standard deviations.

**Mission-specific, global models for heights that are well covered by the satellite orbit: **
_**IC-24, -25 (high solar activity):**_
** **
**550 ± 80km, 900 ± 100km, **
**1500 ± 150km, 2250 ± 250 km**
_**AE-C,-D,-E (low solar activity):**_** **
**400 ± 50km, 650 ± 80km, **
**1000 ± 150km**
**Spherical harmonics representation in InvDip and MLT. InvDip (Truhlik et al., 2001) is close to dip latitude near the equator and close to invariant latitude at high latitudes.**

**Fixed-height Model – Triskova, Truhlik, Smilauer, ASR, 2005**

## Topside Half-Width Model  – Gulyaeva, IJGA 2003

**Uses the**** topside half-density point, ****h****0.5t**
**	****	****N****e****(h****0.5t****) = NmF2 / 2**
**that is easy scalable from topside profiles.  For a ********-Chapman function **** the scale height H is **
**	****	****H****top**** = 1.3236 ******** (****h****0.5t**** – hmF2)**
**A first ****h****0.5t**** ****model ****in terms of sunspot number, LT, and geomagnetic latitude**** based on ****ISIS1,2 and IK19 data was presented by Gulyaeva (****Int. J. Geom. Aeron., 4(3), ****2003). **

## Current IRI Topside Electron Density Model - Examples

**Current IRI Topside Electron Density Model - Examples**

** **
**Welches sind die besten Parameter zur Darstellung der Variabilit****ä****t?**

## Quantifying ionospheric variability 

***IRI Task Force Activity at the ICTP***
***2003 IRI Workshop in Grahamstown, South Africa ***

*Parameters:* foF2, foF1, foE, hmF2, M(3000)F2, B0, B1
- Also studying the change in variability with altitude

## Many earlier studies have assumed a Normal (Gaussian) probability distribution: 

**Many earlier studies have assumed a Normal (Gaussian) probability distribution:**

**68,27 %**

**95,45 %**

- Distribution is defined by the mean  and standard deviation .
- The range  ±  covers 68% of all data.

- -2

- -2

- bell curve

## Median, Quartiles and Deciles

- Qlow

- Qup

- 50%

- 80%

- Dlow

- Dup

- Median

- Median, quartiles, and deciles provide probability information
- for any type of distribution and are less affected by far outlying values.

## foF2 distribution at two equatorial stations

*foF2 *distribution* *at two equatorial stations

## u

- u

- u

- d

- d

- (Bradley et al., 2004)

- Describing the Distribution with Median, Quartiles, and Deciles

- Probability P that the value is greater than L (X0 in graph)

- Using Normal distributions but with different  on each side of median.

## African Equatorial Ionosonde Data

**African Equatorial Ionosonde Data**

- Ouagadougou       Korhogo

- Upper quartile/Median

- Upper decile/Median

- Ouagadougou       Korhogo

## Main variability patterns (%) : 

- Lowest value during daytime, higher at night, highest values at sunrise.
- No significant seasonal differences
- Lowest values at magnetic equator and mid-latitudes increasing towards higher latitudes; highest values at equator anomaly crests
- Decrease with increasing solar activity

## New in next version of IRI model:

**Topside correction and Ne-Quick model**
**Spread-F occurrence probability model (Abdu et al, 2002)**
**Model for the auroral D-region electron density (Friedrich et al., 2003)**
**Improved specification of topside ion composition (Truhlik et al., 2003)**
**Akebono model for plasmaspheric temperatures (Kutiev et al. 2002, 2004)**
**Equatorial disturbance ion drift **** ****model (Fejer and Scherliess, 1997, Scherliess and Fejer, 1999)**

**N****e**

**N****i**

**T****e**

**v****i**

## M. Abdu,

- J. deSouza,
- I. Batista,
- J. Sobral
- Spread-F
- occurrence
- probability model
- for Brazilian
- longitudes
- Ionosondes
- range spread
- (plasma bubble
- event)

## ION COMPOSITION:

- New model for O+, H+, He+, and N+ from 500km to 2500 km based on AE-C, E and IK-24 data

*V. Truhlik,*
*L. Triskova,*
*J. Smilauer (2003)*

**ION COMPOSITION:**

- IRI

- new

## IRI

- new

## Akebono/TED

**Kutiev et al. (2004)**
**Akebono/TED**
** **
**1000-10,000 km**
** **
**f(h, ********, LT) **

## Prompt Penetration

- Disturbance Dynamo