Abstract. Geomagnetic storms are the most pronounced phenomenon of space weather. When studying ionospheric response to a storm of 15 August 2015, an unexpected phenomenon was observed at higher middle latitudes of the Southern Hemisphere. This phenomenon was a localized total electron content (TEC) enhancement (LTE) in the form of two separated plumes, which peaked southward of South Africa. The plumes were first observed at 05:00 UT near the southwestern coast of Australia. The southern plume was associated with local time slightly after noontime (1–2 h after local noon). The plumes moved with the Sun. They peaked near 13:00 UT southward of South Africa. The southern plume kept constant geomagnetic latitude (63–64° S); it persisted for about 10 h, whereas the northern plume persisted for about 2 h more. Both plumes disappeared over the South Atlantic Ocean. No similar LTE event was observed during the prolonged solar activity minimum period of 2006–2009. In 2012–2016 we detected altogether 26 LTEs and all of them were associated with the southward excursion of Bz. The negative Bz excursion is a necessary but not sufficient condition for the LTE occurrence as during some geomagnetic storms associated with negative Bz excursions the LTE events did not appear.

Currently, the trend of globalization of the world economy is intensifying, therefore corporate entities seek to expand their economic power and influence, which encourages them to constantly search for ways to increase the efficiency of their activities both in the domestic and foreign markets. These circumstances force corporate structures to accelerate the pace of development through the introduction of innovations, lower costs and risks. Solving the above problems allows the use of controlling. To carry out controlling in order to reduce risks, it is necessary to have relevant financial information not only external but also internal, in this connection, the role of corporate structures using the internal audit (control) mechanism is growing. The aim of the study is to develop a system of indicators for assessing the effectiveness of controlling in the corporate environment. The main results and conclusions obtained personally by the authors and possessing scientific novelty are as follows: 1. The development of a mechanism for assessing the effectiveness of controlling through the use of an internal audit (control) system and corporate risk management, the use of which allows us to create models that can increase the effectiveness and external attractiveness of the corporate structure. 2. A methodology for assessing the effectiveness of controlling is proposed, algorithms for its development in the corporate structure are modeled, based on strategic planning methods.