1. Nowcasting of neutral and ion composition of the mesosphere:
Ionosphere chemistry module.
Egorova, T., E. Rozanov, J.-F. Hochedez, and W. Schmutz
PMOD/WRC, Davos, Switzerland
ROB, Brussels, Belgium
SCSL meeting, 29 Nov.-1 Dec., 2006

2. LYRA Instrument on PROBA2
The project idea:
To evaluate the response of the middle atmosphere
to the solar UV irradiance variability
LYRA
Instrument
on PROBA2
tools
for nowcast and
short-term forecast
of the solar irradiance
(solar spectral restoration)
On-line LYRA data
and nowcast/forecast
results
for space-weather
community
Other observations
of solar irradiance
Chemistry ionosphere
climate model
(CICM)
extension of SOCOL
(Egorova et al.,2005)
Nowcast and short-term forecast
of the neutral and ionic composition
of the middle atmosphere

3. GCM CTM Modeling tool description
SOCOL : modeling tool to study SOlar-Climate-Ozone Links
General Circulation component (GCM): MA-ECHAM4 (Manzini & McFarlane,1998)
Chemistry/transport component (CTM) : MEZON (Egorova et al., 2003)
Main features: ~4ºx4º (T30); L39; ~80km
Winds and temperature
H2O (troposphere)
Ported on PC (3.8 GHz):
3 hours => ~ 18 s CPU
Documentation:
Egorova et al., 2005, ACP
GCM
CTM
Ozone
H2O(stratosphere)

4. Solar irradiance at 205 nm

5. Maximum correlation with I205nm
from CCM
Hydroxyl
Temperature
Ozone

6. Ozone at 40 km from CCM

7. Comparison 3D simulation and observations:
signal of 27-day solar cycle in ozone
Red: Ly-alpha
Blue: Herzberg (scaled)
SUSIM
Microwave
radiometer:
Data provided by
Bern University
(N.Kämpfer group)
SOMORA
SOCOL
calculations:
without ionosphere
SOCOL

8. Maximum correlation with I205nm
from CCM
Hydroxyl
Temperature
Ozone

9. Hydroxyl at 50 km from CCM

10. Ion chemistry in the D-region: 1-D model
Space: 0-90 km, Z = ~ 2 km
Time : t = 2 hours
Chemistry:
Electron density: e
30 positive ions:
O+, O2+, O4+, N+, NO+, N2+, H2O2+, H3O+,O2+∙N2, O2+∙H2O, H3O+∙OH, NO+∙H2O, NO+∙(H2O)2, NO+∙(H2O)3, NO+∙CO2, NO+∙N2, NO+∙H2O∙CO2, NO+∙H2O∙N2, NO+∙(H2O)2∙CO2, NO+∙(H2O)2∙N2, H+∙(H2O)2, H+∙(H2O)3, H+∙(H2O)4, H+∙(H2O)5, H+∙(H2O)6, H+∙(H2O)7, H3O+∙CO2, H3O+∙N2, H+∙(H2O)2∙CO2, H+∙(H2O)2∙N2
17 negative ions:
O¯, O2¯, O3¯, O4¯, OH¯, CO3¯, CO4¯, NO2¯, NO3¯, HCO3¯, ClO¯, Cl¯, CH3¯,O2¯∙H2O, NO3¯∙H2O, CO3¯∙H2O
43 neutral species:
O3 , O* , O , O2*, NO, HO2, ClO, NO2 , OH, NO3, N2O5, HNO3,HONO3, ClONO2, Cl, N, N*, H2O2, H, HOCl, Cl2, Cl2O2, HCl ,Br, CH2O, BrO, HBr, HOBr, BrNO3, BrCl, CH3, CH3O2, CH3O, HCO, CH3O2H, H2O, CFC-11, CFC-12, N2O, CH4, CO, H2, CBrF3
~ 200 reactions for ions and ~ 200 neutral gaseous reactions

11. Ion chemistry in the D-region: 1-D model
Ionization: - Ly-alpha above 65 km: NO
- Galactic Cosmic Rays below 65 km (Heaps, 1978): N2 and O2
- Energetic Particles Precipitation (EPP)
- Solar Proton Events (SPE)
Radiation:
- spectral region nm with 73 spectral intervals (Rozanov et al., 2002)
- radiation data source: daily SUSIM UARS observations
Simulations performed for 500N, for max and min solar activity

12. Vertical distribution of electron
and total negative ( N- ) and positive (N+) ions density

13. Daily cycle

14. Sensitivity study: Solar max- solar min
Positive ions
Negative ions
and electrons
Experiments: 1) – 2)
Solar maximum with GCR at min + NO ionization
Solar minimum control with GCR at max + NO ionization
Neutrals

15. Nowcasting in the D-region: request for hourly data
Data in use:
LYRA measurements of
Ly-alpha and Herzberg fluxes
INPUT: sol. sp. reconstruction
(how ???)
Solar spectrum forecast
(up to 3-4 hours)
(how ???)
Comparison
with obs.
Availability
from web
Tool for nowcast:
free running global CCM:
CICM (SOCOL with ion chemistry)
3-hour long ensemble run (~10)
1 hour – time step
Output parameters
3D anomalies:
e, NO+, O2+, O2-, O-
O3, OH, NO, H2O
- T, U

16. More frequent data input allows the forecast with
Solar rad. flux
GCR flux
SPE flux
EEP flux
Sun_cur.dat
Neutron_cur.dat
SPE_cur.dat
EEP_cur.dat
not important
for D-region ?
important only
for high geom.lat ?
Sun_nowcast.dat
(t = 1, 2 h)
More frequent data input
allows the forecast with
higher precision
0 hour
1 hour
2 hour
3 hour
Takes into account radiation changes every hour