P. Corona-Romero

Mexican Space Weather Service (SCIESMEX)

Legislative modifications of the General Civil Protection Law in Mexico in 2014 included specific references to space hazards and space weather phenomena. The legislation is consistent with United Nations promotion of international engagement and cooperation on space weather awareness, studies and monitoring. These internal and external conditions motivated the creation of a space weather service in Mexico. The Mexican Space Weather Service (SCiESMEX in Spanish) (www.sciesmex.unam.mx) was initiated in October 2014 and is operated by the Institute of Geophysics at the Universidad Nacional Autonoma de Mexico (UNAM). SCiESMEX became a Regional Warning Center of the International Space Environment Services (ISES) in June 2015. We present the characteristics of the service, some products and the initial actions for developing a space weather strategy in Mexico. The service operates a computing infrastructure including a web application, data repository and a high-performance computing server to run numerical models. SCiESMEX uses data of the ground-based instrumental network of the National Space Weather Laboratory (LANCE), covering solar radio burst emissions, solar wind and interplanetary disturbances (by interplanetary scintillation observations), geomagnetic measurements, and analysis of the total electron content (TEC) of the ionosphere (by employing data from local networks of GPS receiver stations).

Dynamic evolution of interplanetary shock waves driven by CMEs

We present a study about the propagation of interplanetary shock waves driven by super magnetosonic coronal mass ejections (CMEs). The discussion focuses on a model which describes the dynamic relationship between the CME and its driven shock and the way to approximate the trajectory of shocks based on those relationships, from near the Sun to 1 AU. We apply the model to the analysis of a case study in which our calculations show quantitative and qualitative agreements with different kinds of data. We discuss the importance of solar wind and CME initial conditions on the shock wave evolution.

Calculating travel times and arrival speeds of CMEs to Earth: An analytic tool for space weather forecasting

Coronal mass ejections (CME) are one of the most important phenomena derived from solar activity that potentially perturbs space weather of Earth. In this work we present a semi-empirical arrival-forecasting tool for Earth-directed halo CMEs. This tool combines the piston-shock model and an empirical relationship to estimate in-situ arrivals of halo CMEs. The empirical relationship uses the initial conditions of CMEs to calculate the value of free parameter of piston-shock model, parameter which is closely related with the initial inertia of CMEs. Such a value will let the model to simultaneously approximate the travel time and arrival speed of CMEs (i.e. CME arrivals). We test the forecasting capabilities of our model and its empirical relationship by calculating the arrivals of 40 halo CMEs detected during the period of 1995-2015. Our results indicate that, together, the piston-shock model and its empirical relationship approximate CME arrivals with average errors of 7h for travel times, and 100 km s−1 for arrival speeds. Our results show that our model is suitable for arrival forecasting of isolated events propagating through quiet interplanetary medium.

Estimates of ionosphere state over Mexico with TEC data

The ionosphere behaviour over Mexico was studied. We analysed variations of Total Electron Content (TEC) and critical frequency of F2-layer of the ionosphere (foF2). TEC values were extracted from data of local GNSS receivers and if missed then from global ionospheric maps. foF2 values were reconstructed using TEC measured over Mexico and equivalent slab thickness of the ionosphere measured in the adjacent to Mexico regions having ionosondes. Diurnal and seasonal patterns of TEC and foF2 behaviour over Mexico were revealed. The peculiarity of TEC behaviour during disturbances were studied. The presence of strong positive enhancements is a characteristic feature for Mexico that is confirmed by measurements of electron concentration at satellites CHAMP and DSMP.