Atmospheric temperature profiles at the Antarctic node of LAGO: Quiet and perturbed conditions

O. ARESO; A.M GULISANO; M. RAMELLI; S. DASSO

Ostend

Congreso; European Space Weather Week; 2017

The LatinAmerican Giant Observatory (LAGO) is a collaborative network formed by ten countries (Argentina, Bolivia, Colombia,Chile, Ecuador, Guatemala, Mexico, Perú, Venezuela, and Brazil). LAGO has aSpace Weatherprogram and one of its main aims is to study the modulation of variabilityof Cosmic Rays (CRs) using its net of Water Cherenkov Detector(WCDs) and making numerical simulations of the transport of CRs in differentphysical scenarios. LAGO plans to deploy WCDs at the Antarcticpeninsula, in the Argentinean Marambio base. Observations at this nodewill help to make scientific studies and also to make a monitoringof space weather conditions. Due to the low rigidity cut-off of this highlatitude site, observations of Ground Level Enhancements (GLEs) willbe possible. In order to carry out numerical simulations to betterunderstand the ground observations of the CRs fluxes, is necessary tocharacterize the atmosphere, where the secondary particles are createdduring the extended CRs shower. In this work, we present a characterizationof the atmospheric conditions at the Argentinean Marambiobase, where the Antarctic LAGO node will be deployed. In particular,we analyze the temperature altitude profile in a range covering theupper troposphere, and the low-mid stratosphere, for quiet conditionsand during two major geomagnetic storms, the seasonal climatologyof temperatures and investigated possible variations during five intensegeomagnetic storms and the possibility of physical and chemicaleffects during these events. We analyze data obtained from balloonsurveys measured at Marambio by the National Meteorological Service ofArgentina from 1998 to 2016. We present the seasonal behavior, ofthe temperature variable environment from 8 to 40 km throughoutthe period, and analyze the median and quartile statistics during twogeomagnetic storms: one in summer and one in winter, extendingthe analysis period to seven days prior to the occurrence of the stormsand to the fourteen subsequent days. In addition, given the differentvalues of the Dst index, we calculated the temperature anomalies,for each geomagnetic storm and the subsequent days, and we alsoobtained the degrees of cooling and heating, relative to the days prior to thefive events.The results of this study will be useful to betterunderstand the possible events of Space Weather and, on the other hand, willalso be very useful to make corrections to the flow of cosmic rays, whichwill be observed in the near future with the particle detector ofLAGO to study the solar modulation of the cosmic ray flux and GLEevents, in the site with the lower rigidity cut off of this observatory.