Empirical Ionospheric Models from Worldwide Incoherent Scatter Radars. Shun-Rong Zhang and John Holt MIT Haystack Observatory, USA Tony van Eyken EISCAT Association, Norway Mary McCready SRI International, USA Christine Amory-Mazaudier - PowerPoint PPT Presentation
Empirical Ionospheric Models from Worldwide Incoherent Scatter Radars Shun-Rong Zhang and John Holt MIT Haystack Observatory, USA Tony van Eyken EISCAT Association, Norway Mary McCready SRI International, USA Christine Amory-Mazaudier Centre for the Study of Earth and Planets Environments, CNRS, France Shoichiro Fukao Research Institute for Sustainable Humanosphere, Kyoto University, Japan Michael Sulzer Arecibo Observatory, National Astronomy & Ionosphere Center, Puerto Rico
Transcript
Empirical Ionospheric Models from Worldwide Incoherent Scatter Radars
Shun-Rong Zhang and John Holt MIT Haystack Observatory, USA
Tony van Eyken EISCAT Association, Norway
Mary McCready SRI International, USA
Christine Amory-Mazaudier Centre for the Study of Earth and Planets Environments, CNRS, France
Shoichiro Fukao Research Institute for Sustainable Humanosphere, Kyoto University, Japan
Michael Sulzer Arecibo Observatory, National Astronomy & Ionosphere Center, Puerto Rico
Outline
ISR long-term database Modeling technique Results: local models
A case study: Annual variations Comparisons with IRI Applications
Regional Models ISR Convection Model Model Availability Future Projects
World Incoherent Scatter Radars
MADRIGAL: Long-term ISR Database
www.openmadrigal.org
Madrigal
•The European Chain:EISCAT Svalbard Radar (1997-), in polar cap, the highest latitude EISCAT Tromsø UHF radar (1984-) and VHF radar (1990-), St. Santin Radar (1973-1986)
• East America ChainSondrestrom Radar (1990-)Millstone Hill Radar (1970-)Arecibo Radar (1966-)
• East AsiaMU Radar (1986-2003)
Existing Long-term Data
Binning and Fitting technique
Data are binned according to local time and month
Piece-wise linear height profile is used for initial data binning with 17-19 height nodes.
Solar activity dependency is determined by a leaset-squares fit to a linear function to F107.
Median filter (3 months x 3 hours) is applied to the fitting coefficients.
Analytic representations of bin-fit results
Seasonal variations: harmonics with 12, 6 and 3 month components
Local time variations: harmonics with 24, 12, 6 and 3 hour components
Height variations: cubic B-spline with 17 breaks and gradient controls at upper and lower boundaries.
Height Profile
Height Profile Basis Function
Data Distribution
Results:Midday Ne
Svalbard
Millstone
AreciboShigariki
Curve Color Code
Winter
Spring
Summer
Autumn
St. Santin
Tromso
Sondrestrom
Results:Latitudinal and Longitudinal features
subauroral
midlatitude
highlatitude
Semiannual components, longitudinal differences
Strong semiannual components, asymmetry
Semiannual components starts to occur
Lower
midlatitude
O/N2 and SZA change
O/N2 (from MSIS) O/N2 x cos (SZA)
SZA = solar zenith angle
Ti
At Millstone, highest Ti occurs in May.
Yearly variations: Millstone
Yearly variations in midday Ti at 350 km: Millstone
Circles: DataDashed: Model
Percentage difference
Data - Model difference
F107
Comparisons with IRI: diurnal
Are MU StS MH Tro Son Sva
Ne
Ti
Te
Ne NeNe Ne Ne Ne
Ti TiTi Ti Ti Ti
Te TeTe Te Te Te
Median solar activity conditions with F107=135 or Rz=88
Comparisons with IRI: profile
Are MU StS MH Tro Son Sva
Ne
Ti
Te
Ne NeNe Ne Ne Ne
Ti TiTi Ti Ti Ti
Te TeTe Te Te Te
Median solar activity conditions with F107=135 or Rz=88
Model Applications: Tn and [O]
Using a simplified energy equations for ions
(widely used in the ISR community for the neutral parameter deduction)
ISR Convection Model
Regional Ionospheric Models: Millstone Areas
Millstone Regional Ionospheric Model covers geodetic latitudes 35-55 degrees.
ISR Convection Model: data
A Combined Dataset from Millstone and Sondrestrom ISRs Observations
ISR Convection Model: IMF Bz controls
ISR Model Availability
Virtual Incoherent Scatter Radars Web interface FTP
http://madrigal.haystack.mit.edu/models
ORhttp://www.openmadrigal.org
Virtual ISRs – current day
Virtual ISRs – current time
Future Projects
Regional ionospheric models for Eastern America longitudes European longitudes
A New Space Weather Project
Multiple incoherent scatter radar long-term database study of upper atmosphere climatology and variability
1. to generate databases of thermospheric Tn, [O], winds for multiple ISRs;
2. to develop local and regional models of the thermospheric parameters;
3. to create variability models of the ionospheric as well as thermospheric parameters;
4. to study latitudinal/longitudinal features of the ionosphere and thermosphere.
