The Evolving Role of External Forcing in North Atlantic SST Variability Over the Last Millennium

Atlantic Multidecadal Variability (AMV) impacts temperature, precipitation, and extreme events on both sides of the Atlantic basin. Previous studies with climate models have suggested that when external radiative forcing is held constant, the large-scale ocean and atmosphere circulation are associated with sea-surface temperature anomalies that have similar characteristics to the observed AMV. However, there is an active debate as to whether these internal fluctuations driven by coupled atmosphere-ocean variability remain influential to the AMV on multidecadal timescales in our modern, anthropogenically-forced climate. Here we provide evidence from multiple large ensembles of climate models, paleo reconstructions, and instrumental observations of a growing role for external forcing in the AMV. Prior to 1850, external forcing, primarily from volcanoes, explains about one third of AMV variance. Between 1850 and 1950, there is a transitional period, where external forcing explains half of AMV variance, but volcanic forcing only accounts for about 10% of that. After 1950, external forcing explains three quarters of AMV variance. That is, the role for external forcing in the AMV grows as the variations in external forcing grow, even if the forcing is from different sources. When forcing is relatively stable, as in earlier modeling studies, a higher percentage of AMV variations are internally generated.

Climate changes and trends over India

Based on the instrumental observations of over a century available in India, attempt is made to study if there is a clear-cut evidence of any climate change or trend over .India with particular reference to rainfall, surface temperature, atmospheric pressure and total ozone. The study concludes that while there are year to year random. fluctuations in these atmospheric variables and there are certain epochal increases and decreases in respect of rainfall and .surface temperature, .there appears to be no systematic climate charge or trend over India. There IS also no evidence of ozone depletion over India.

Results and prospects of seismological observations in the central part of the Baikal rift

This article reports the results of detailed seismological observations in the Central Baikal region conducted by the local network of seismological stations of the Buryat Division of the Geophysical Survey of the Russian Academy of Sciences. The local network was created in the 1990s. A crucial feature of the network is the combination of seismic monitoring both in the passive mode (the study of natural seismicity) and in the active mode, with a controlled vibration source of seismic waves. The study area covers the Lake Baikal region and adjacent territories characterized by high seismic activity. Here occurred several catastrophic earthquakes including the strongest one during the period of instrumental observations – the Middle Baikal’1959 earthquake. Recently here occurred the Kudarinsky earthquake on December 9, 2020 with mb=5.4. For more than twenty years the network of observations has been expanding, the equipment has been upgrading. A significant amount of seismo-logical material has been accumulated. Broadband data was processed by the receiver function method. The Moho and the lithosphere-asthenosphere boundaries for stations of the network are determined. Shear seismic wave attenuation characteristics are obtained and the possibility of energy classification of Baikal earthquakes by coda-waves total oscillations is shown.

THE COMPLEX OF ANCIENT OBSERVATORIES ON THE TABLE MOUNTAIN IN INGUSHETIA

The proximity of the three ancient sanctuaries to each other on the flat top of the Table Mountain against the background of the sacred peaks of Kazbek and Tsey-Loam, the opportunity to observe the sunrises and sunsets in the highlands of the Caucasus, cosmogonic myths, all this gave an assumption about the astronomical functions of these sanctuaries. The purpose of the study was to prove that these ancient sanctuaries were used by the priests to determine the key moments in the annual cycle of the Sun and were a calendar. This is proved by using special computer programs and calculators that determine the azimuth and altitude of the Sun; instrumental observations and measurements on the ground. It is established that the shrines of Myat-Seli and Myater-Dyal on Table Mountain in Ingushetia are a complex of medieval solar near-horizon observatories. And it is hypothesized that these sanctuaries were built on the site from which solar cycles were observed from about the beginning of the 1st millennium BC. This work also provides prerequisites for determining various astronomical observations from sanctuaries and the presence of other ancient observatories in the Caucasus. A method has been developed for searching for prehistoric solar, lunar and stellar near-horizon observatories.

SEISMICITY of TAJIKISTAN and ADJACENT TERRITORIES in 2015

The seismic monitoring system consisting of seven digital stations continued to operate in Tajikistan in 2015. This network has registered 9071 earthquakes with KR=8.6–17.0, 6427 of which were Pamir-Hindu Kush earthquakes with intermediate depths (h=70–300 km), and 2644 were shallow events. The total seismic energy released was E=1.8151017 J. The strongest for 2015 was the Hindu Kush earthquake on Octo-ber 26 with Mw=7.5, h=230 km (hpP=217 km) that occurred near the southern borders of the Republic. This earthquake caused significant damage and the death of at least 115 people. It was felt on the territory of 14 states, with a total shaking area of more than 14106 km2. A detailed isoseismal map of this earthquake is given for the Tajikistan territory only. The earthquake was accompanied by a series of over 1400 aftershocks with KR=8.6–12.8, unexpectedly numerous for a deep earthquake. Within the borders of the Republic, the Sarez-II earthquake occurred near the Lake of Sarez on December 7 with Mw=7.2, h=20 km, I0=8, was the strongest one. Undoubtedly, it was triggered by the Hindu Kush earthquake on October 26. In total, more than 500 houses were damaged, dozens of people were injured, and there were human casualties. A detailed isoseismal map of this earthquake was made for four levels of intensity – I=7, 6, 5 and 4. The number of its aftershocks for 24 days only was 1342, with KR=8.6–13.9. As a result the level of seismicity in Tajikistan in 2015, both in terms of the number of earthquakes and the level of released seismic energy, was the highest during the period of instrumental observations.

Creation of the Simulator to Train Cosmonauts for Visual Instrumental Observations from the International Space Station Using Up-to-Date Information Technologies.

Visual Instrumental Observations (VIOs) of the Earth’s surface is a very special activity for cosmonauts that include searching, finding, and monitoring the objects with the unaided eye and their registration using optical facilities expanding capabilities of an operator’s visual analyzer. In order to impart the correct practical skills in performing VIOs from the ISS to cosmonauts in the course their ground training it is necessary to visualize the image observed by the naked eye and/or in the camera view finder taking into account an optical zoom, mutual location of a cosmonaut, a camera, a window, and the station at a certain point in orbit. For these purposes, the special simulator which simulates an external visual environment as close as possible to the flight conditions has been developed, that is the VIOs simulator designated to train cosmonauts for performing tasks in the field of geophysical studies and monitoring of the Earth.

MONITORING OF SEASONAL OPENING OF CRACKS ON THE EXAMPLE OF SOFIA KYIVSKA NATIONAL RESERVE

An instrumental method for monitoring changes in the width of crack opening in the constructions of the National Reserve "Sofia Kievska" is presented. Due to the uneven sediment of the foundations, causing the appearance of stress and effort in the load-bearing building structures, there is a process of cracking. The process of cracking is one of the manifestations of deformation processes that need to be monitored, and therefore to conduct regular instrumental observations. The urgency of instrumental monitoring is assumed to be a careful attitude to the historical and cultural heritage of Ukraine, in particular the National Reserve "Sofia Kievska". The main task of the publication was to consider the method of instrumental observation of the change in the width of the crack opening using the comparator "SDM 50/500". Investigate the dependence and analysis of seasonal fluctuations in ambient temperature and humidity changes in the width of crack opening based on the results of five years of monitoring of cracks in the structures of St. Sofia Cathedral of the National Reserve "Sofia Kievska". The article presents the results of long-term monitoring by a unique method using the comparator "SDM 50/500" width of cracks in the walls of the historical and cultural monument of architecture and history of Ukraine of St. Sofia Cathedral of National Reserve "Sofia Kievska". The presented monitoring results were collected during five years of work. According to the results of observations, a graph of the development of changes in the width of crack opening over time over 5 years is constructed. The direct dependence on air humidity and the inverse dependence on the ambient air temperature are analyzed with the help of the constructed dependence graphs. The results of the study provided an opportunity to develop clear recommendations for further studies to monitor the development of cracks. The main direction of further research will be to improve the method of surveying the change in the width of the crack opening using a portable comparator "SDM 50/500".

History of the Hydrometeorological Service of Belarus

The first weather observations within the modern territory of Belarus go back to ancient times and are found as mentions of weather conditions in chronicles. Hydrometeorology in those times was not a defined science but connected to the everyday needs of people in different regions. In the period from 1000 to 1800, there were first efforts to document outstanding weather conditions and phenomena. They are stored in chronicles, books, and reports. The first instrumental observations started in the early 1800s. They have varying observing practices and periods of observations. The hydrometeorological network saw the active expansion of observations in the following century, but the network was destroyed at the beginning of the civil war (1917–1922). Five years later, hydrometeorological activity resumed, and the foundation of meteorological services of the Russian Soviet Federal Socialist Republic (RSFSR) was initiated. The next years saw a complicated Belarusian hydrometeorological service formation and reorganization. The meteorological bureau was formed in 1924, and this year is considered the official date of the Hydrometeorological Service of Belarus foundation, despite multiple changes in title and functions during its course. During the Great Patriotic War (1941–1945) people’s courage and efforts were directed to saving the existing network of hydrometeorological observations and providing weather services for military purposes. The postwar period was characterized by the implementation of new methods of weather forecasting and new forms of hydrometeorological information. Later decades were marked by the invention and implementation of new observational equipment. The Hydrometeorological Service of Belarus in this period was a testing ground within the Soviet Union for the development of meteorological tools and devices. The current Hydrometeorological Service of Belarus is described as an efficient, modern-equipped, and constantly developing weather service.

Strong earthquakes in Azerbaijan for historical and contemporary periods (conceptual review)

Based on the results of the study of literary and archival primary sources, the paper clarifies the available information about catastrophic and destructive earthquakes in Azerbaijan for the historical period with a magnitude of M≥6. Among the strong historical earthquakes in Azerbaijan there are the following: earthquakes in 427, the Ganja (Goygol in 1139), the Ganja in 1235, the East Caucasian in 1667 (± 1 year), the Mashtaga (1842), numerous Shamakhi earthquakes (1192, 1667, 1668, 1669, 1828, 1859, 1868, 1872, 1902), Ardebil (1924), Lankaran (1913), Caspian earthquakes (957, 1812, 1842, 1852, 1911, 1935, 1961, 1963, 1986, 1989, 2000), which caused both changes in the relief of the Earth’s surface, and the destruction of buildings and numerous human casualties. The background seismicity was investigated based on the results of continuous instrumental observations for the period 1902—2019. Seismic processes are unevenly distributed on the territory of Azerbaijan. Existing catalogs of seismic events have been investigated. The behavioral changes in seismicity parameters have been studied. An overview conceptual analysis of two main methods for assessing seismic hazard is given: probabilistic and deterministic, which have found their wide application in recent decades. In conclusion, the most important and general tasks of future seismological studies are emphasized, which are to be performed in the next decades.