Abstract. Atmospheric water vapour has been acknowledged as an essential climate variable. Weather prediction and hazard assessment systems benefit from real-time observations, whereas long-term records contribute to studies. Nowadays, ground-based global navigation satellite system (GNSS) products have become widely employed, complementing observations over the oceans. Although past decade seen a significant development of GNSS infrastructure in Central South America, its potential for...

Abstract. Annual, semiannual and seasonal variations of the Vertical Total Electron Content (VTEC) have been investigated during high solar activity in 2000. In this work we use Global IGS VTEC maps Principal Component Analysis to study spatial temporal ionospheric variability. The behavior at two-hour periods, noon night is analyzed. Particular characteristics associated with each period geomagnetic regions are highlighted. smaller than those obtained noon. At it possible see patterns...

Abstract Taking advantage of the public Global Navigational Satellite Systems (GNSS) infrastructure in South America, an operational monitoring system for total electron content (TEC) ionosphere has been developed. It incorporates data near real time, from more than 90 GNSS satellites tracked by 200 ground stations. In turn, produces every 15 min a snapshot, that is map, current state regional ionosphere, which immediately available online. These maps could be employed, example, to augment...

Our work is focused on the analysis of seasonal and semiannual ionospheric anomalies using vertical total electron content (VTEC) measurements obtained by International GNSS Service (IGS). For this study we use principal component (PCA) wavelet transform (WT) because both numerical tools allow us to isolate components VTEC variability as much spatially temporally. The IGS maps are reorganized, from each daily global data set, two were constructed: one at 12:00 LT other 22:00 LT. From these...

Signals from Global Positioning System (GPS) satellites received at the surface of Earth have passed through terrestrial atmosphere and are therefore affected by refraction in ionosphere. A large number permanent dual frequencies GPS tracking stations been built up last years their data proved to be suitable study The main goal this paper is assess capability these observations continuously routinely monitor ionosphere a global scale. interest was focused on retrieving coefficients spherical...

Abstract Simulations based on physical models of the thermosphere‐ionosphere system suggest that ionosphere will sink as thermosphere cools and contracts in response to increasing greenhouse gas concentrations. As a consequence, long‐term trends can be expected ionospheric parameters such as: total electron content (TEC), critical frequency F2 layer, foF2, its peak height, hmF2. Since early 1990s, foF2 hmF2, though lesser extent, have been widely analyzed find these trends. This study shows...

The effect of the thermospheric vertical neutral wind on total electron content (vTEC) variations including longitudinal anomaly, remaining winter mid-latitude summer night and semiannual anomaly is studied at regions around zero magnetic declination midnight during high solar activity. By using principal component analysis (PCA) numerical technique, this work studies spatial temporal ionosphere over 2000–2002. PCA applied to a time series global vTEC maps produced by International Global...

Abstract The Weddell Sea Anomaly (WSA) is defined when the nighttime plasma density greater than daytime in area near Sea, more specifically region limited by 50° S–70° S latitude and 225° E–315° E longitude. A similar ionospheric anomaly also observed Okhotsk northern hemisphere, such a feature was named as (OSA). objective of this work to infer possible physical causes WSA OSA phenomena. To that end, we applied principal component analysis (PCA) technique vertical total electron content...

Annual and seasonal diurnal precipitable water vapor (PWV) variations over Central South America are analyzed for the period 2007–2013. PWV values were obtained from Global Navigation Satellite Systems (GNSS) observations of sixty-nine GNSS tracking stations. Histograms by climate categories show that temperate, polar cold dry have a positive skewed distribution tropical climates (except monsoon subtype) negative distribution. The surface temperatures (T) anomaly datasets using principal...

The aim of this work is the analysis annual and semiannual effects in total electron content (TEC) terrestrial atmosphere during low solar activity. region study Atlantic Ocean at mid geomagnetic latitudes. Spatial temporal ionospheric variability are investigated from TOPEX/POSEIDON (T/P) altimetry data. To correct Earth delay on radar pulse, satellite's altimeter makes measurements two channels. difference between both yields estimated values TEC lower part ionosphere up to height...

This study applied logistic regression modelling for the development of a quantitative index most admired knowledge cities. Drawing on MAKCi framework and theoretical model generic capitals system, was defined as probability city has being selected city. The resulting satisfactorily tested validity, it utilised evaluating ranking

The aim of this work is the analysis annual, semiannual, and seasonal effects in total electron content (TEC) terrestrial atmosphere during low solar activity. Spatial temporal ionospheric variability are investigated from global International Global Navigation Satellite System Service (IGS) VTEC maps activity 2006. Two different techniques, principal component (PCA) Fourier analysis, applied to data set. Applying PCA technique on a time series IGS gives us method analyze main anomalies...