Malaco temperature reconstructions and numerical simulation of environmental conditions in the southeastern Carpathian Basin during the Last Glacial Maximum

We investigate the glacial climate conditions in the southeastern Carpathian Basin (Vojvodina, Serbia) based on the reconstruction of malacological palaeotemperatures and results from a high‐resolution regional climate simulation. Land snail assemblages from eight loess profiles are used to reconstruct July temperatures during the Last Glacial Maximum (LGM). The malacological reconstructed temperatures are in good agreement with the simulated LGM July temperatures by the Weather Research and Forecast model. Both methods indicate increasing temperatures from the northwestern towards the southeastern parts of the study area. LGM aridity indices calculated based on the regional climate model data suggest more arid conditions in the southeastern parts compared with more humid conditions in the northwestern parts. However, for present‐day conditions, the moisture gradient is reversed, exhibiting more humid (arid) conditions in the southeast (northwest). An explanation for the reversed LGM aridity pattern is provided by an analysis of the prevailing wind directions over the South Banat district (Serbia). The prevailing moist northwesterly winds during summer are not able to compensate for the annual lack of moisture induced by the dry winds from the southeast that are more frequent during the LGM for the other seasons

Spatiotemporal variability of air temperatures in Central Serbia from 1949 to 2018

The paper presents trends for three categories of variables: average annual, average maximum and average minimum air temperatures. Data was provided by the meteorological yearbooks of the Republic Hydrometeorological Service of Serbia. The main goal of this paper is to detect possible temperature trends in Central Serbia. The trend equation, trend magnitude, and Mann-Kendall non-parametric test were used in the analysis of climate parameters. The used statistical methods were supplemented by GIS numerical analysis, which aimed to analyze the spatial distribution of isotherms from 1949 to 2018. The obtained results indicate that out of the 72 analyzed time series, an increase in air temperature is dominant in 61 time series, while 11 time series show no changes. The highest increase was recorded in the average maximum time series (4.2 °C), followed by an increase of 3.5°C in average maximum air temperatures. The highest increase in the average annual time-series was 3.0 °C. The lowest increases in air temperature were recorded in the average minimum time series (0.1 and 0.2 °C). In two average minimum time series a decrease in average air temperatures was identified (-0.6 and -0.4 °C. The application of GIS tools indicates the existence of interregional differences in the arrangement of isotherms, leaded by the orography of the terrain. In the spatial distribution of the analyzed variables, "poles of heat" and "poles of cold" stand out, and the influence of the urban heat island is evident (especially in the case of the urban agglomeration of Belgrade). The manifested spatial patterns of air temperature need to be further examined and the correlation with possible causes need to be determined. For these reasons, the paper provides a solid basis for studying the climate of this area in the future, as it provides insight into climate dynamics over the past decades

Reconstructed Malacothermometer July Paleotemperatures from the Last Nine Glacials over the South-Eastern Carpathian Basin (Serbia)

In this study, the compiled malacological record of the two most important loess–palaeosol sequences (LPS) in Serbia was used to reconstruct the Malacothermometer July Paleotemperature (MTJP) of the last nine glacials. The sieved loess samples yielded shells of 11 terrestrial gastropod species that were used to estimate the MTJP. Veliki Surduk (covering the last three glacial cycles) and Stari Slankamen (covering the last fourth to ninth glacial cycle) LPSs previously lacked the malacological investigations. After the sieving, a total of 66,871 shells were found, from which 48,459 shells were used for the estimation of the MTJP. Through the studied period, the reconstructed MTJP was ranging from 14.4 °C to 21.5 °C. The lowest temperature was recorded during the formation of the loess unit L5, equivalent to the Marine Isotope Stage (MIS) 12. The second-coldest summers were occurring during the MIS 16 glacial. Although the warmest glacial was L8 (MIS 20) according to MTJP, these July temperatures might be overestimated due to only two samples from the poorly preserved L8 unit. The malacological material derived from the loess units at Veliki Surduk and Stari Slankamen LPSs showed great potential for July temperature reconstruction, as the comparison with other regional records showed similar climate changes. Further work is necessary to validate the age scale of the oldest samples, and a higher resolution sampling could lead to more detailed July temperature fluctuations, as was shown for the youngest glacial in this study. Likewise, estimating the July temperature using different proxies (e.g., pollen) from the same LPSs could be used to confirm the observed climate trends

Aridity in the central and southern Pannonian basin

For the investigation of geographical, monthly, seasonal, and annual distributions of aridity and its annual trend in the region of the Central and Southern Pannonian Basin (CSPB), which includes the territories of Hungary and Vojvodina (Northern Serbia), the De Martonne Aridity Index (DMAI) was used. The DMAI was originally calculated from a total of 78 meteorological stations with the maximum available time series of climatological data in three cases: 1931–2017 for Hungary; 1949–2017 for Vojvodina; and 1949–2017 for Hungary and Vojvodina jointly. The Palmer Drought Severity Index (PDSI) was used to control the DMAI results. Temperature and precipitation trends were also investigated to understand their effects on the aridity trend. Three aridity types are distinguished on the annual level, five on the seasonal level, and four on the monthly level. The annual aridity had no trends in all three periods. It seems that aridity can be considered a more stable climate indicator of climate change than the temperature, at least in the CSPB. © 2020 by the authors. Licensee MDPI, Basel, Switzerland

Climate variability impact on the spatiotemporal characteristics of drought and aridity in arid and semi-arid regions

Investigating the spatiotemporal distribution of climate data and their impact on the allocation of the regional aridity and meteorological drought, particularly in semi-arid and arid climate, it is critical to evaluate the climate variability effect and propose sufficient adaptation strategies. The coefficient of variation, precipitation concentration index and anomaly index were used to evaluate the climate variability, while the Mann-Kendall and Sen’s slope were applied for trend analysis, together with homogeneity tests. The aridity was evaluated using the alpha form of the reconnaissance drought index (Mohammed & Scholz, Water Resour Manag 31(1):531–538, 2017c), whereas drought episodes were predicted by applying three of the commonly used meteorological drought indices, which are the standardised reconnaissance drought index, standardized precipitation index and standardized precipitation evapotranspiration index. The Upper Zab River Basin (UZRB), which is located in the northern part of Iraq and covers a high range of climate variability, has been considered as an illustrative basin for arid and semi-arid climatic conditions. There were general increasing trends in average temperature and potential evapotranspiration and decreasing trends in precipitation from the upstream to the downstream of the UZRB. The long-term analysis of climate data indicates that the number of dry years has temporally risen and the basin has experienced succeeding years of drought, particularly after 1994/1995. There was a potential link between drought, aridity and climate variability. Pettitt’s, SNHT, Buishand’s and von Neumann’s homogeneity test results demonstrated that there is an evident alteration in the mean of the drought and aridity between the pre- and post-alteration point (1994)

The analysis of aridity in Central Serbia from 1949 to 2015

In this study, we apply De Martonne and Pinna combinative indices to analyze the aridity in Central Serbia. Our dataset consists of mean monthly surface air temperature (MMT) and mean monthly precipitation (MMP) for 26 meteorological stations during the period 1949-2015. MMT and MMP are used for calculating monthly, seasonal, and annual aridity indices for period of 66 years. According to the De Martonne climate classification, we determine five, three, and four types of climate on the monthly, seasonal, and annual basis, respectively. During the observed period, winter was extremely humid, spring and autumn were humid, and summer was semi-humid. Humid and semi-humid climate with Mediterranean vegetation are identified by the annual Pinna combinative index. We find that there is no change in aridity trend in Central Serbia for the period 1949-2015. Aridity indices are additionally compared with the North Atlantic Oscillation and El-Nino South Oscillation in order to establish a possible connection with the large-scale processes. Results are further compared with several earlier studies of aridity in Serbia. With this study, the analysis of aridity in whole Serbia has become complete

Quantitative relationships between climate and magnetic susceptibility of soils on the Backa Loess Plateau (Vojvodina, Serbia)

Magnetic properties of soils formed in and on loess substrate and their relation to climate are of general interest in paleoclimate and pedological research. The loess-paleosol sequences (LPS) in the Vojvodina region (Serbia) have been the subject of intensive study. On the Backa loess plateau (BLP), covering approximately 2500 km(2), six different soil types are observed. While the stratigraphy of the LPS has been investigated the relation between climatic factors and magnetic properties of surface soil have not yet been examined. In this study we analyze 50 samples of chernozem soils, which have been dominated by climatic factors during their formation. Previous studies have confirmed that the formation of magnetic properties in soils is related to climate, and especially rainfall, because of the response of hematite and goethite to different, climatically-driven regimes. The sensitivity of certain iron-bearing minerals to climate has also been documented in the literature. Climatic variables for the BLP were derived from six-decade national meteorological datasets. Low frequency magnetic susceptibility (chi) and frequency dependent magnetic susceptibility (chi(fd)) were determined for each site and compared to the mean annual precipitation (MAP), mean annual temperature (MAT) and the De Martonne aridity index (I-DM). The meteorological variables were interpolated to sampling points by Kriging method in ArcMap 10.1. Our results suggest that values of chi and chi(fd) both decrease from south to north and so does the precipitation. Thus, our work provides new evidence for the relationship between precipitation, temperature, aridity and magnetic properties of modern top soils. The obtained and analyzed data may help in the future to improve transfer functions of the relationship between magnetic susceptibility and climatic data

The analysis of annual and seasonal surface air temperature trends of southern and southeastern Bosnia and Herzegovina from 1961 to 2017

In some areas of the world, regional climate change is in good agreement with global climate change. This study brings new information about what defines climate change in the contact area of Adriatic Sea and Southeastern Europe, and conclusions are based on trend analysis of annual and seasonal temperatures in the southern and southeastern parts of Bosnia and Herzegovina. Trend analysis was applied on mean annual surface air temperatures, mean maximum temperatures, and mean minimum temperatures of all four seasons. This study used 4 meteorological stations: Livno, Bileća, Mostar, and Ivan Sedlo for 56 years. The main statistical method is the Mann-Kendall test. The total number of analysis is 48. A statistically significant positive trend was determined in 36 analysis, while in the rest of the tests this was not the case. The highest amount of temperature increase is present in the mean maximum summer air temperatures in Livno and Ivan Sedlo. Mean minimum autumn air temperatures had the smallest increase. Negative trend is present in the mean autumn surface air temperatures and mean maximum autumn temperatures. Using a geographical information system resulted in visualizing regional differences in the spatial distribution of isotherms. The study area has combined the influence of orography and maritime effects of the Adriatic Sea. Having in mind these results, the growing temperature has been recognized as a problem which needs more attention in Bosnia and Herzegovina. Unfortunately, official documents which propose economic adaptation on climate change in this country are not at a satisfactory level

Local Differentiation in the Loess Deposition as a Function of Dust Source: Key Study Novo Orahovo Loess Paleosol Sequence (Vojvodina, Serbia)

Typical patterns of the Late Pleistocene loess–paleosol units are preserved in the Novo Orahovo brickyard, Northern Serbia. Presented preliminary luminescence chronology supports the chronostratigraphic interpretations of global isotopic marine climate reconstructions. Magnetic susceptibility and sedimentological evidence exhibit general similarities with the marine oxygen-isotope stratigraphy. These records provide new insights into the dust accumulation regimes over the eastern side of the Bačka loess plateau and offer new paleoenvironmental information for the region. They represent an important step forward towards the establishment of a catena from the thin loess-like sediments of the Banat foothills in the east towards the thicker and seemingly more complete loess sections of the southeastern and central Carpathian Basin. Grain-size data from the loess record of Nova Orahovo explain the regional differentiation in dust deposition

The relationship between the loess stratigraphy in the Vojvodina region of northern Serbia and the Saalian and Rissian Stage glaciations – a review

Publication status: PublishedThe regional loess stratigraphy in the Vojvodina region, in the southeastern Carpathian Basin, has often been successfully correlated to the global palaeoclimate. This is a quasi‐continuous sedimentary record that provides detailed environmental reconstruction during the last four glacial/interglacial cycles. In this study, we present a standardized loess stratigraphy and illustrate how it correlates with the marine oxygen isotope and Chinese loess stratigraphical records. We argue that the loess stratigraphy in Vojvodina region is an important link in the integration of European terrestrial stratigraphical schemes and the deep‐sea stratigraphical model. We highlight how the loess record can better illustrate terrestrial environmental change through multiple glacial cycles than other records, such as glacial records. The investigated loess record enables direct links to be made between the loess sediments and their glacial sources. This reveals evidence of glaciations during every glacial cycle of the Saalian Stage complex, equivalent to Marine Isotope Stage (MIS) 10, 8 and 6. Therefore, Serbian loess has the potential to provide a direct link between terrestrial glaciations and wider records of global climate change, which is an enigma for many other continental records. These loess records display a strong relationship with the intensity of European glaciations during different glacial cycles. Loess sedimentation rates are highest in the most intensive European glaciation of the Saalian complex (MIS 6) and much lower during the weaker ‘missing’ glaciations equivalent to MIS 8 and 10. A key observation from the Vojvodina loess is the gradual increase in interglacial aridity through the late Middle Pleistocene. The explanation for the progressively increasing aridity in the investigated region at this time is still unclear. However, this trend is consistent with the idea of the Saalian complex as representing a 400 ka mega glacial cycle modulated by shorter classic 100 ka glacial cycles.</jats:p