scholarly journals Polar F-layer model-observation comparisons: a neutral wind surprise

2005 ◽  
Vol 23 (1) ◽  
pp. 191-199 ◽  
Author(s):  
J. J. Sojka ◽  
M. David ◽  
R. W. Schunk ◽  
A. P. van Eyken
Keyword(s):  
Input Parameter ◽  
Auroral Oval ◽  
Neutral Wind ◽  
Neutral Atmosphere ◽  
State University ◽  
Utah State University ◽  
Daily Weather ◽  
Magnetospheric Convection ◽  
Ionospheric Models ◽  
Model Input Parameter

Abstract. The existence of a month-long continuous database of incoherent scatter radar observations of the ionosphere from the EISCAT Savlbard Radar (ESR) at Longyearbyen, Norway, provides an unprecedented opportunity for model/data comparisons. Physics-based ionospheric models, such as the Utah State University Time Dependent Ionospheric Model (TDIM), are usually only compared with observations over restricted one or two day events or against climatological averages. In this study, using the ESR observations, the daily weather, day-to-day variability, and month-long climatology can be simultaneously addressed to identify modeling shortcomings and successes. Since for this study the TDIM is driven by climatological representations of the magnetospheric convection, auroral oval, neutral atmosphere, and neutral winds, whose inputs are solar and geomagnetic indices, it is not surprising that the daily weather cannot be reproduced. What is unexpected is that the horizontal neutral wind has come to the forefront as a decisive model input parameter in matching the diurnal morphology of density structuring seen in the observations.

Structured-Objective Rorschach Test: A Question of Choice Location

1965 ◽  
Vol 21 (3) ◽  
pp. 703-706
Author(s):  
Philip Langer ◽  
Ron Norton
Keyword(s):  
State University ◽  
Rorschach Test ◽  
Utah State University ◽  
Choice Location ◽  
Response Choices

50 Ss at Utah State University were given the Structured-Objective Rorschach test. An inquiry phase followed each of the responses given by S. Results seem to indicate that: (1) location scores are valid less than 50% of the time, (2) there is an increase in rejection of answers and lessened validity of location scores for the last five blots when compared with the first five, and (3) it is assumed that Ss are making response-choices on bases other than the assigned blot characteristics.

scholarly journals Numerical Modeling of the Influence of Solar Activity on the Global Circulation in the Earth’s Mesosphere and Lower Thermosphere

2012 ◽  
Vol 2012 ◽  
pp. 1-15 ◽  
Author(s):  
Igor Mingalev ◽  
Victor Mingalev
Keyword(s):  
Solar Activity ◽  
Large Scale ◽  
Input Parameter ◽  
Lower Thermosphere ◽  
Vertical Component ◽  
Neutral Wind ◽  
Wind System ◽  
Model Calculations ◽  
Global Circulation ◽  
Mesosphere And Lower Thermosphere

The nonhydrostatic model of the global neutral wind system of the earth’s atmosphere, developed earlier in the Polar Geophysical Institute, is utilized to investigate how solar activity affects the formation of the large-scale global circulation of the mesosphere and lower thermosphere. The peculiarity of the utilized model consists in that the internal energy equation for the neutral gas is not solved in the model calculations. Instead, the global temperature field is assumed to be a given distribution, that is, the input parameter of the model. Moreover, in the model calculations, not only the horizontal components but also the vertical component of the neutral wind velocity is obtained by means of a numerical solution of a generalized Navier-Stokes equation for compressible gas, so the hydrostatic equation is not applied. The simulation results indicate that solar activity ought to influence considerably on the formation of global neutral wind system in the mesosphere and lower thermosphere. The influence is conditioned by the vertical transport of air from the lower thermosphere to the mesosphere and stratosphere. This transport may be rather different under distinct solar activity conditions.

scholarly journals Aurora and open magnetic flux during isolated substorms, sawteeth, and SMC events

2007 ◽  
Vol 25 (8) ◽  
pp. 1865-1876 ◽  
Author(s):  
A. D. DeJong ◽  
X. Cai ◽  
R. C. Clauer ◽  
J. F. Spann
Keyword(s):  
Magnetic Flux ◽  
Temporal Variations ◽  
Auroral Oval ◽  
Polar Cap ◽  
Expansion Phase ◽  
Magnetospheric Convection ◽  
Open Magnetic Flux ◽  
Open Flux ◽  
The Individual

Abstract. Using Polar UVI LBHl and IMAGE FUV WIC data, we have compared the auroral signatures and polar cap open flux for isolated substorms, sawteeth oscillations, and steady magnetospheric convection (SMC) events. First, a case study of each event type is performed, comparing auroral signatures and open magnetic fluxes to one another. The latitude location of the auroral oval is similar during isolated substorms and SMC events. The auroral intensity during SMC events is similar to that observed during the expansion phase of an isolated substorm. Examination of an individual sawtooth shows that the auroral intensity is much greater than the SMC or isolated substorm events and the auroral oval is displaced equatorward making a larger polar cap. The temporal variations observed during the individual sawtooth are similar to that observed during the isolated substorm, and while the change in polar cap flux measured during the sawtooth is larger, the percent change in flux is similar to that measured during the isolated substorm. These results are confirmed by a statistical analysis of events within these three classes. The results show that the auroral oval measured during individual sawteeth contains a polar cap with, on average, 150% more magnetic flux than the oval measured during isolated substorms or during SMC events. However, both isolated substorms and sawteeth show a 30% decrease in polar cap magnetic flux during the dipolarization (expansion) phase.

Sign in / Sign up

Export Citation Format

Share Document