Sentences with phrase «as ionospheric»

Then, as the ionospheric response evolves and recovers on its own time scales, STIM estimates the time delay in the ionospheric storm onset and formulates the ionospheric storm - time response by taking into account the latitude and the LT of the observation point at the storm onset.

Based on this, SWIF is able to provide alerts and warnings for upcoming ionospheric storm - time disturbances as well as ionospheric forecasts up to 24 h ahead under all possible conditions.

The phenomenon, known as ionospheric lightning, occurs in the upper atmosphere, according to meteorologist Joe Pollina of the National Weather Service.

Trained as an ionospheric physicist, Strømme began working at NSF in March 2012 as a program officer in its geospace section.

Not exact matches

VLA measures correlations between signals from pairs of antennas to reconstruct images of the sky, as though they were one single, giant telescope — and so VLA, too, is sensitive to ionospheric fluctuations.

Since the KAIRA telescope is built on the same technology as the larger distributed European radio telescope LOFAR, the IONONEST code can be used directly to perform ionospheric measurements from any LOFAR station.

Ionospheric photoelectrons can be used as an important diagnostic tool for the topology of the solar wind interaction with both magnetized and unmagnetized objects (Coates et al. 2011), possibly playing a role also in enhancing the ion escape.

Bremer et al. (2009) summarized various results on geomagnetic activity control of trends in the ionosphere and found that the change of dependence of trends on long - term change of geomagnetic activity, i.e., the loss of dominant geomagnetic activity control of ionospheric trends, occurred around 1970 in the E region, in the early 1990s in the F1 region, and around 2000 in the F2 region as illustrated in Figure 5 for two European stations Roma and Slough / Chilton.

The modeling approach is based on presenting the ionospheric parameter (most frequently the F - layer critical frequency foF2) by analytical expressions as a function of one or more geomagnetic or solar indices, called drivers.

Limitations are imposed for small - scale effects, such as positive effects of short duration observed locally indicating ΔR12eff responses to the averaged ionospheric activity over Europe.

The arrival of a single MC, in general, is connected to a decreasing of SPE and consequently of the ionospheric absorption as it is observed in this case when Bz flows Southward, while the large decay, observed in this case, in the recovery phase of Dst index is connected, in general, to the presence of multiple Interplanetary medium structures, as two MCs, near Earth (Xie et al. 2006).

This is achieved through the cooperation of an autoregression forecasting algorithm, called Time Series AutoRegressive — TSAR (Koutroumbas et al. 2008), with the empirical Storm Time Ionospheric Model — STIM (Tsagouri & Belehaki 2006, 2008) that formulates the ionospheric storm - time response based on solar wind input, exploiting recent advances in ionospheric storm dynamics that correlate the ionospheric storm effects with solar wind parameters (e.g., the magnitude of the IMF and its rate of change as well as the IMF's orientation in the north - south Ionospheric Model — STIM (Tsagouri & Belehaki 2006, 2008) that formulates the ionospheric storm - time response based on solar wind input, exploiting recent advances in ionospheric storm dynamics that correlate the ionospheric storm effects with solar wind parameters (e.g., the magnitude of the IMF and its rate of change as well as the IMF's orientation in the north - south ionospheric storm - time response based on solar wind input, exploiting recent advances in ionospheric storm dynamics that correlate the ionospheric storm effects with solar wind parameters (e.g., the magnitude of the IMF and its rate of change as well as the IMF's orientation in the north - south ionospheric storm dynamics that correlate the ionospheric storm effects with solar wind parameters (e.g., the magnitude of the IMF and its rate of change as well as the IMF's orientation in the north - south ionospheric storm effects with solar wind parameters (e.g., the magnitude of the IMF and its rate of change as well as the IMF's orientation in the north - south direction).

Empirical models using solar wind parameters and / or IMF as drivers, usually, are used for now - casting (specification of ionospheric state) or forecasting 1 — 3 h ahead.

The quiet - time behavior of the ionospheric electron density peak height of the F2 region, hmF2, has been evaluated from average electron density profiles and analytically modeled by the Spherical Harmonic Analysis (SHA) technique following the same methodology as described by Altadill et al. (2009).

The effective sunspot number — R12eff is used in DIAS (European Digital Upper Atmosphere Server) as a proxy of the ionospheric conditions over Europe for regional ionospheric mapping purposes (Zolesi et al. 2004; Tsagouri et al. 2005).

In addition, as a clear advance for radio science purposes, it should be noted that SWIF provides an alternative approach to ionospheric forecasting issue, using solar wind parameters as a proxy of the ionospheric activity level.

DIAS (European Digital Upper Atmosphere Server) effective sunspot number — R12eff was introduced as a proxy of the ionospheric conditions over Europe for regional ionospheric mapping purposes (Zolesi et al. 2004; Tsagouri et al. 2005).

SWIF is currently implemented online in DIAS system to provide ionospheric forecasts up to 24 h ahead as well as alerts and warnings for the European region (http://dias.space.noa.gr).

As the energy transfer is a combination of Joule heating and particle precipitations then the main drivers of the ionospheric response to recurrent geomagnetic activity are related to changes in the temperature, thermospheric neutral composition, and neutral winds.

In particular, ionospheric disturbances caused by large - scale phenomena such as the prolonged negative and positive effects observed all over Europe are sufficiently captured in ΔR12eff variation from the onset of the disturbance until the full recovery (Fig. 16).

The lower thermospheric temperatures, as a consequence of an unusually long minimum in solar extreme - ultraviolet flux, not only decreased density, but the contraction of the upper atmosphere also lowered the height of the peak of the ionospheric F - layer.

The authors show that the deviation of the real - time R12eff estimates from the reference values (ΔR12eff) follows successfully the ionospheric response to geomagnetic storm enhancements and can be used as a better proxy in specifying the ionospheric state.