Assessment of the Impact of Climate Extremes on the Groundwater of Eastern Croatia

This paper analyzes the groundwater in the deep Quaternary aquifer of Eastern Croatia. These waters are collected at the Vinogradi Pumping Station (Osijek, Croatia) for the needs of public water supply. This research aimed to assess the impact of climate extremes, namely, high air temperatures and low rainfall, on the quantity and quality of groundwater. On the basis of data from the Vinogradi Pumping Station in the period 1987–2015, three extremely warm and low-water years were singled out. For these three years, the following were analyzed: climate diagrams, groundwater levels (in the piezometers closest to and farthest from the pumping station), and the quality of the affected groundwater. The results of this research indicate that the reaction of aquifers to the analyzed extreme climatic conditions for the observed period was manifested in the variation of the amplitude of groundwater levels by a maximum of 4–5 m. Considering the total thickness of the affected layers (60–80 m), this variation is not a concern from the point of view of water supply. As for the quality of groundwater, it was found to be of constant quality in its composition and was not affected by climatic extremes.

Molecular Responses to Thermal and Osmotic Stress in Arctic Intertidal Mussels (Mytilus edulis): The Limits of Resilience

Increases in Arctic temperatures have accelerated melting of the Greenland icesheet, exposing intertidal organisms, such as the blue mussel Mytilus edulis, to high air temperatures and low salinities in summer. However, the interaction of these combined stressors is poorly described at the transcriptional level. Comparing expression profiles of M. edulis from experimentally warmed (30 °C and 33 °C) animals kept at control (23‰) and low salinities (15‰) revealed a significant lack of enrichment for Gene Ontology terms (GO), indicating that similar processes were active under all conditions. However, there was a progressive increase in the abundance of upregulated genes as each stressor was applied, with synergistic increases at 33 °C and 15‰, suggesting combined stressors push the animal towards their tolerance thresholds. Further analyses comparing the effects of salinity alone (23‰, 15‰ and 5‰) showed high expression of stress and osmoregulatory marker genes at the lowest salinity, implying that the cell is carrying out intracellular osmoregulation to maintain the cytosol as hyperosmotic. Identification of aquaporins and vacuolar-type ATPase transcripts suggested the cell may use fluid-filled cavities to excrete excess intracellular water, as previously identified in embryonic freshwater mussels. These results indicate that M. edulis has considerable resilience to heat stress and highly efficient mechanisms to acclimatise to lowered salinity in a changing world.

Fifty Years of Tidewater Glacier Surface Elevation and Retreat Dynamics along the South-East Coast of Spitsbergen (Svalbard Archipelago)

Tidewater glaciers on the east coast of Svalbard were examined for surface elevation changes and retreat rate. An archival digital elevation model (DEM) from 1970 (generated from aerial images by the Norwegian Polar Institute) in combination with recent ArcticDEM were used to compare the surface elevation changes of eleven glaciers. This approach was complemented by a retreat rate estimation based on the analysis of Landsat and Sentinel-2 images. In total, four of the 11 tidewater glaciers became land-based due to the retreat of their termini. The remaining tidewater glaciers retreated at an average annual retreat rate of 48 m year−1, and with range between 10–150 m year−1. All the glaciers studied experienced thinning in their frontal zones with maximum surface elevation loss exceeding 100 m in the ablation areas of three glaciers. In contrast to the massive retreat and thinning of the frontal zones, a minor increase in ice thickness was recorded in some accumulation areas of the glaciers, exceeding 10 m on three glaciers. The change in glacier geometry suggests an important shift in glacier dynamics over the last 50 years, which very likely reflects the overall trend of increasing air temperatures. Such changes in glacier geometry are common at surging glaciers in their quiescent phase. Surging was detected on two glaciers studied, and was documented by the glacier front readvance and massive surface thinning in high elevated areas.

A comparative study of temperatures of direct sunlight and air temperatures in a standard screen measured at Doha International Airport - a pilot study

An observational campaign was conducted at Doha International Airport, Arabian Gulf to find out difference between air temperature in a standard screen and direct sunlight. Hourly observations recorded during July-August 1998 and June-August 1999 formed the basis of the study. Difference between screen temperature (ST) and outside temperature (OT) in respect of all hourly data in the above period from 0600 to 1800 hrs of local time have been computed and analysed. In order to examine the difference before sunrise and after sunset, observations were also made during 1900-0500 hrs of local time from 1st to 18th of July 1998. Results of the study revealed that the magnitude of the differences between OT and ST is not as high as expected. The highest difference observed was 5.1° C on 16th July 1999 at 0900 hr. As anticipated, the temperature of direct sunlight between 0600 hr and 1700 hr were always higher than the screen temperature. However, after 0500 pm of local time, the screen temperatures are found to be higher than outside temperature though the sunset time in these months are after 0600 pm. The mean difference between ST and DT in June, July and August respectively found to be 1.43° C, 1.53° C and 1.67° C. The highest difference observed in these months was 3.8° C, 5.1° C and 4.1° C respectively. The study has also indicated that the difference between OT and ST is generally higher during 0900-1000 hrs of local time and lower during two hours before sunrise and sunset.

Objective and probabilistic long-range forecasts of summertime air temperatures in South Korea based on Gaussian processes

We propose the objective long-range forecasting model based on Gaussian processes (OLRAF-GP), focusing on summertime near-surface air temperatures in June (1-month lead), July (2-month lead), and August (3-month lead). The predictors were objectively selected based on their relationships with the target variables, either from observations (GP-OBS) or from observations and dynamical climate model results from APEC Climate Center multi-model ensemble (APCC MME) for the period with no observed data (GP-MME). The performances of the OLRAF-GP models were compared with the model with pre-determined predictors from observations (GP-PD). Both GP-MME and GP-OBS outperformed GP-PD in June (Heidke skill score; HSS = 0.46, 0.72, and 0.16 for mean temperature) and July (HSS = 0.53, 0.3, and 0.07 for mean temperature). Furthermore, GP-MME mostly outperformed GP-OBS and GP-PD in August (HSS = 0.52, 0.28, and 0.5, respectively, for mean temperature), implying larger contributions of the additional predictors from MME. OLRAF-GP models, especially GP-MME, are expected to better forecast summertime temperatures in regions where existing models have been struggling. We find that the physical processes associated with the notable predictors are aligned with those in previous studies, such as the attribution of the La Niña conditions in the previous winter, the related Indian Ocean capacitor effect, and the impacts of wintertime Polar/Eurasia pattern. These results imply that the mechanisms of the objectively selected predictors can be physically meaningful, and their inclusion can improve model performance and efficiency.

Growth and development of representatives of the genus Rosa L. in the Stavropol Botanical Garden

Relevance. To identify the features of the growth and development of species of roses of different geographical origin, to establish the biological minimum temperatures necessary for the beginning of flowering of representatives of the genus Rosa L., to study the morphological indicators of fruits.Methodology. The research material was 12 wild roses belonging to 4 sections: Canina Crep, Cinnamomeae DC, Luteae Crep, Pimpinellifoliae DC. The research was carried out using the methods of the Main Botanical Garden, floral and geographical analyses — according to Hrzhanovsky. A caliper was used to measure the length and diameter of 10 fruits. For the analysis of statistical data, the MS Excel table processor and the integrated MATLAB mathematical package were used.Results. The article presents the results of a study of species of roses in the Stavropol Botanical Garden of various geographical origin. The study involved 12 species belonging to 4 sections. The features of growth and development of plants in new soil and climatic conditions are revealed. The dates of the beginning of the main phenological phases andtheir duration have been established: spring regrowth of shoots, budding, beginning and end of flowering, fruiting. In the studied species of roses, the growing season begins in the first — second decade of March, flowering occurs in late May — early June, the fruits ripen in August — September. The dependence of the timing of the beginning of flowering in the studied roses on the dynamics of the accumulated average daily air temperatures and the sum of effective temperatures above 5 °C was revealed. Mathematically, it was proved that the lower limit of the air temperature required for the beginning of flowering of species of roses is +16 °C, when the sum of the average daily temperature air St° = 1007.75–1069.48 °С and St эф > 5 °С = 530.75–594.75 °С are accumulated. Early flowering species of roses include Rosa foetida Herrm., R. pendulina L., R. pimpinellifolia L., late flowering — R. caudata Baker and R. corymbifera Borkh. The shortest flowering period is in R. caudata Baker, R. jacutica Juz. and R. kamtschatica Vent. Representatives of those types mostly bloom once. Their flowers are formed on biennial and more mature shoots. The flowering period is 13–23 days. Rosa rugosa Thunb. blooms again, its flowering period is extended and long — from 40 to 48 days. All species of roses form fruits. The longest fruits are in R. pendulina L., R. caudata Baker, R. rugosa Thunb., R. corymbifera Borkh. and R. canina L., and large ones — in R. rugosa Thunb., R. marretii Lev. and R. roxburghi Tratt.

Evaluating the Effect of Cover Materials on Greenhouse Microclimates and Thermal Performance

This study compared and analyzed changes in the microclimate and thermal environment inside single-span greenhouses covered with a single layer of plastic film, polycarbonate (PC), and glass. The results of the experiment show that the PC-covered greenhouse was the most favorable for managing the nighttime heating effect during the cold season. However, the glass-covered greenhouse was found to be the most favorable for managing the cooling effect during the hot season. Although the plastic-covered greenhouse was inexpensive and easy to install, the air temperature inside varied significantly, and it was difficult to control its indoor environment. The thermal load leveling values showed that the PC-covered greenhouse had the lowest variation, confirming its superiority in terms of environmental control and energy savings. In terms of the overall heat transfer, heat was generally transferred from the interior to the exterior of the greenhouses. In the plastic-covered greenhouse, however, heat was transferred in the opposite direction at night due to the influence of radiant cooling. The occurrence of the minimum and maximum heat transfer values had a tendency similar to that of the occurrence of the minimum and maximum air temperatures inside the greenhouses.

Effects of NIR Reflective Film as a High Tunnel-Covering Material on Fruit Cracking and Biomass Production of Tomatoes

Tomatoes require higher irradiance, although the incidence of physiological disorders in fruit increases at high temperatures. Near-infrared (800–2500 nm) (NIR) reflective materials are effective tools to suppress rising air temperatures in greenhouses. We examined the physiological and morphological changes in tomato growth and fruit quality when grown in a high tunnel covered with NIR reflective film (NR) and in another covered with polyolefin film (PO; control). There was no relationship between the fruit cracking rate and mean daytime temperature under NR. The fruit temperature at the same truss was lower and the increase in air temperature was slow under NR. Fruit dry matter (DM) content under NR was also significantly decreased. These findings suggest that the reduction in fruit cracking under NR results from a decrease in fruit DM content as a consequence of lower fruit temperature and a decrease in total DM (TDM). Total fruit yield did not differ, whereas TDM was significantly decreased under NR. This was considered to result from a lower transmitted photosynthetic photon flux density (400–700 nm) (PPFD) and LAI, and lower photosynthetic capacity in single leaves because of a decrease in both total nitrogen and chlorophyll content. We conclude that NR film reduces fruit cracking in exchange for a slight reduction in TDM.

Too Hot to Nest? In a Hot Summer the Tortoise Chersina angulata Can Switch From Nesting to Facultative Viviparity

In a captive colony of Chersina angulata in Cape Town, South Africa, we observed in 2015/16 retention of the last egg clutch inside the female until the hatching stage was reached, conforming to the generally accepted definition of viviparity. Retrospective climatic analysis indicates egg retention until the hatching stage co-occurred with unusually hot summer weather: the average air temperatures in December 2015 and January and February 2016 were higher than during the preceding five and the following 5 years when facultative viviparity could not be observed. Late December and January appears to be the critical period for females to either deposit their last clutch of the nesting season into a nest, or to retain the last clutch for embryonic development inside the female. Over the 28 December to 24 January period the minimum, average and maximum air temperatures in 2015–16 were about 3°C higher than in the five following years. This association of facultative viviparity with unusual summer heat suggests that hot ambient temperatures at the end of the nesting season may cue females to switch from oviposition to facultative viviparity. Compared to incubation in a nest this phenotypic plasticity of the reproductive mode—to retain during hot summers the season’s last clutch inside the female—may buffer the developing embryos from excessive heat exposure: females can thermo-regulate by moving among microhabitats whereas sun exposed shallow nests cannot escape high ground temperatures. This novel reproductive strategy has the potential to enhance the resilience of species to global warming.

Numerical Simulation of Operating Parameters of the Ground Source Heat Pump

Due to the growing demand for new ecological, low-emission heat sources, there is a need to develop new tools for simulating the operating parameters and costs of the implemented solutions. The article analyses the existing solutions for the simulation of heat pump operation parameters, describes the requirements for a modern building—nZEB and proposes a simulation tool based on thermodynamic parameters of the refrigerant. The script allows for deriving simple linear equations that can be used for the overall simulation of a system in which the heat pump is a key part and the efficiency of the entire system depends on its performance. The developed numerical script allows for reproducing the Linde refrigeration cycle and the parameters of its characteristic points. To calibrate the simulation, historical data obtained from the SOPSAR system were used. These data were pre-cleaned (peaks and other obvious measurement errors were removed). The obtained numerical model in combination with ground and air temperatures, anticipated hot water consumption and energy losses of the building can be used to simulate the annual performance and energy consumption of the heat pump. The obtained linear models have an RSMD error of 8% compared to historical data from SOPSAR system for all sets of simulated temperatures.