Annual Amplitude Research Articles

Combined impacts of environmental and socioeconomic covariates on HFMD risk in China: A spatiotemporal heterogeneous perspective.

Understanding geospatial impacts of multi-sourced influencing factors on the epidemic of hand-foot-and-mouth disease (HFMD) is of great significance for formulating disease control policies tailored to regional-specific needs, yet the knowledge is very limited. We aim to identify and further quantify the spatiotemporal heterogeneous effects of environmental and socioeconomic factors on HFMD dynamics. We collected monthly province-level HFMD incidence and related environmental and socioeconomic data in China during 2009-2018. Hierarchical Bayesian models were constructed to investigate the spatiotemporal relationships between regional HFMD and various covariates: linear and nonlinear effects for environmental covariates, and linear effects for socioeconomic covariates. The spatiotemporal distribution of HFMD cases was highly heterogeneous, indicated by the Lorenz curves and the corresponding Gini indices. The peak time (R2 = 0.65, P = 0.009), annual amplitude (R2 = 0.94, P<0.001), and semi-annual periodicity contribution (R2 = 0.88, P<0.001) displayed marked latitudinal gradients in Central China region. The most likely cluster areas for HFMD were located in south China (Guangdong, Guangxi, Hunan, Hainan) from April 2013 to October 2017. The Bayesian models achieved the best predictive performance (R2 = 0.87, P<0.001). We found significant nonlinear associations between monthly average temperature, relative humidity, normalized difference vegetation index and HFMD transmission. Besides, population density (RR = 1.261; 95%CI, 1.169-1.353), birth rate (RR = 1.058; 95%CI, 1.025-1.090), real GDP per capita (RR = 1.163; 95%CI, 1.033-1.310) and school vacation (RR = 0.507; 95%CI, 0.459-0.559) were identified to have positive or negative effects on HFMD respectively. Our model could successfully predict months with HFMD outbreaks versus non-outbreaks in provinces of China from Jan 2009 to Dec 2018. Our study highlights the importance of refined spatial and temporal data, as well as environmental and socioeconomic information, on HFMD transmission dynamics. The spatiotemporal analysis framework may provide insights into adjusting regional interventions to local conditions and temporal variations in broader natural and social sciences.

PREVALENCE OF CAUSATIVE AGENTS OF RING ROT CLAVIBACTER SEPEDONICUS, BLACKLEG AND WET ROT PECTOBACTERIUM ATROCEPTICUM IN THE 2021 YEAR POTATO HARVEST IN THE TERRITORY OF UKRAINE

Aim. To investigate the prevalence of causative agents of ring rot and soft rot in the potato harvest by the DAS ELISA method. Materials and methods. Samples of the potato harvest from Ternopil, Zhytomyr, Kyiv, Cherkasy, Dnipropetrovsk, Donetsk, Mykolaiv, Odesa, and Kherson regions were used in the study. The detection of bacterial agents was conducted by enzyme-linked immunosorbent assay using commercial test systems LOEWE® Standard Complete Kit (Germany). Results. The highest percentage of affected potatoes was registered in the Donetsk region: 11.1% – by the Clavibacter seedonicus, 31.0% – by the Pectobacterium atrosepticum, and 8.9% – by both bacteria. The causative agent of soft rot was detected twice as often as a causative agent of ring rot in tuber samples from all regions, except the Ternopil region, where the predominance of Clavibacter sepedonicus was revealed. In addition to the Donetsk region, a high prevalence of the causative agent of soft rot was found in the potato harvest from Kyiv (10.2%) and Odesa (10.0%) regions, the highest abundance of the causative agent of ring rot was detected in the Ternopil region. The mixed bacterial infection of potato tubers was diagnosed in 6 areas, and the highest rate was detected in the Donetsk region. Conclusion. The analysis of the distribution of ring rot pathogen Clavibacter sepedonicus and soft rot pathogen Pectobacterium atrocepticum in the potato crop shows the presence of research pathogens in all studied regions. It was discovered the dominance of the representative of pectolytic bacteria in all regions except Ternopil, where the distribution of Clavibacter sepedonicus, the causative agent of ring rot, was dominated. High rates of spread of the studied pathogens were associated with increased local average annual precipitation, as well as with increased annual amplitude of this indicator.

Trend of annual and semiannual harmonics of sea surface temperature in the tropical Indian Ocean, 1979–2018

In the Indian Ocean (IO), the annual and semiannual oscillations of the sea surface temperature (SST) contribute more than 80% of the total variance. It is known that the SST in the tropical IO has warmed at a rate of 0.15 °C/decade since 1979. However, such an estimate of the decadal trend of the annual and semiannual harmonics of SST remains unknown, despite being a strong component of the SST signal. Here we use a widely accepted data product (TropFlux) to quantify the annual and semiannual harmonics in the tropical IO for the first time. The northern IO has a distinctly strong semiannual cycle (1–1.8 °C), which is showing an amplifying trend (∼ 0.04 °C/decade) since 1979. Furthermore, a damping trend in annual amplitude exists over much of the IO, except along the northwestern Bay of Bengal, the Seychelles-Chagos thermocline ridge, the Persian Gulf, and the Indonesian throughflow region. The estimated damping of the annual amplitude is highest over the Arabian Sea. In contrast, the southern tropical IO has a predominant annual cycle, the amplitude of which has weakened during 1979–2018. In the north IO, net air-sea heat flux and vertical processes show a dominant semiannual harmonic oscillation similar to SST. Additionally, the annual amplitude is influential over southern IO. Horizontal advection contributes significantly along the boundary-current regions and the western equatorial IO. Our analysis of combined annual and semiannual cycles shows significant warming in the tropical IO during October–November and cooling during July–August owing to the amplification of semiannual oscillation. These changes in the SST can influence air-sea interaction processes such as cyclogenesis and monsoon.

Climate as a determinant of dung beetle response to native forest replacement by cattle pastures in South America

AbstractAnthropogenic disturbance in natural ecosystems reduces the number of species in biological communities and homogenizes their composition across different regions. Climate is one of the main abiotic determinants of species distributions and different factors were proposed as the main climatic drivers. Here we explored the role of regional climate on the local response of dung beetle assemblages to the replacement of native forest by cattle pastures in South America by simultaneously contrasting three climatic hypotheses: energy, seasonality and heterogeneity. We compiled a database by searching published studies comparing dung beetle richness and composition between both native forests and cattle pastures. We calculated the proportional difference in species richness and composition between habitat types. As explanatory variables, we used seven abiotic variables grouped into the three climatic hypotheses. Energy/Productivity: mean annual temperature (°C/year) and total annual precipitation (mm/year). Seasonality: annual thermal amplitude (°C/year), the average coefficient of variation of monthly precipitation and the coefficient of average monthly variation in temperature. Heterogeneity: coefficient of variation of mean annual temperature, coefficient of variation of mean annual precipitation. Using regression analyses and a model selection procedure, we found differences in species richness between native forests and cattle pastures were explained by the coefficient of variation of mean annual precipitation, whereas changes in species composition were explained by total annual precipitation and the coefficient of variation of mean annual precipitation. The response of dung beetle assemblages to livestock grazing in South American forests was associated with precipitation variation. The heterogeneity hypothesis better explained changes in species richness following forest replacement by cattle pastures, while both energy/productivity and heterogeneity hypotheses explained the changes in species composition.

Evaluation of temporal changes in methane content in the atmosphere for areas with a very high rice concentration based on Sentinel-5P data

Rice cultivation is one of the main sources of methane (CH4) emission into the atmosphere. The research aimed to assess long–term and seasonal changes in CH4 content in the atmosphere in areas where rice production exceeds 30% of the area. These areas include India, Bangladesh, Myanmar and Indonesia. CH4 content was evaluated using the Sentinel–5P TROPOMI sensor on a monthly basis from February 2019 to January 2022. Long–term and seasonal changes were assessed using statistical methods such as regression analysis and time–series analysis. The results showed that the long-term trend indicates an increase in CH4 concentration. In the analyzed period, the average annual increase in the CH4 content in the atmosphere was highest in eastern India (Bihar and West Bengal areas) and Bangladesh, from 15.9 to 19.6 ppb per year, while in Myanmar (Ayeyarwady) and Indonesia (Java) it was much lower, 3.7 and 9.9 ppb, respectively. Seasonal variability in CH4 content in the atmosphere was characterized by a large annual amplitude in the rice regions of India (from 47 to 58 ppb) and was consistent with CH4 emissions during a typical rice growth cycle. The highest CH4 content was observed in late summer i.e., before rice harvest. The results of the Sentinel–5P measurements confirm the spatial–temporal variability of atmospheric CH4 content in regions with a high share of rice production.

Влияние верхнего граничного условия на гидротермическое поле земляного полотна железных дорог в районах вечной мерзлоты

Purpose: Based on numerical model that takes into account the hydrothermal interrelation of soil humidity and temperature, to carry out numerical modeling of hydrothermal field of railway subgrade in the area of permafrost spread. To study the influence degree of global warming and temperature annual amplitude on hydrothermal field of subgrade. To determine the need for reasonable and economical engineering measures to ensure the stability of subgrade. Method: Calculation of hydrothermal bonding of railroad subgrade has been performed in COMSOL Multiphysics software with the use of partial differential equation (PDE) module with the methods of finite elements. Different values of the parameters of subgrade upper boundary temperature function are specified and the effect of these parameters on subgrade hydrothermal field is studied. Results: Based on measured data temperature function, the influence of global warming effect and temperature annual amplitude on subgrade hydrothermal field was determined. Change law and characteristics of temperature distribution, ice content and unfrozen water in railway subgrade in permafrost areas after hydrothermal field stabilization has been obtained. The periods of maxima and minima onset for temperature as well as for ice content and unfrozen water are given. Practical significance: The use of given numerical model allows to predict effectively the tendency of subgrade hydrothermal field change in permafrost areas under global warming influence. Based on the numerical calculation results, relevant technical recommendations are shown for elimination or reduction of engineering accidents caused by temperature changes in permafrost regions.

Water Masses at the Surface of the Indian Ocean

Water masses in the surface layer of the ocean are harder to define in terms of hydrographic properties because they undergo large seasonal and interannual variations. Therefore, single TS-combinations cannot be used to define surface water masses. The solution to the definition of surface water masses is the temperature/salinity time diagram (TS-time diagram) and/or the temperature/chlorophyll time diagram (TC-time diagram). This work establishes a systematic definition of regional water masses in the surface layer of the tropical Indian Ocean based on TC-time and TS-time diagrams of mean and standard deviation for 5° squares. This classification is based on an analysis of the ratios between semi-annual and annual amplitudes of temperature and a multiple regression analysis between temperature, salinity, and chlorophyll, with Ekman pumping, components of pseudo-stress wind, wind magnitude and net-down-freshwater-flux. Four water masses are identified for the surface of the Indian Ocean: The Arabian Sea Surface Water (ASSW), the Bay of Bengal Surface Water (BBSW), the Equatorial Indian Surface Water (EISW) and the Southern Indian Surface Water (SISW). The geographical representation of the water masses agrees well with the theoretical frame of reference.

Response of soil hydrothermal processes within the active layer to variable alpine vegetation conditions on the Qinghai‒Tibet Plateau

Alpine vegetation plays an important role in the thermal stability of the permafrost under a warming climate, as it affects ground hydrothermal dynamics. The response of soil hydrothermal dynamics in the active layer to permafrost degradation under different alpine grassland types is unclear on the Qinghai‒Tibet Plateau. In this study, long-term soil temperature and soil water content in the active layer were monitored in situ from October 2010 to December 2018 at five sites in the Kaixinling permafrost region on the interior Qinghai‒Tibet Plateau along the Qinghai–Tibet Railway. The sites included an alpine steppe (AS), three alpine meadows (AM) with different degrees of degraded vegetation, and an alpine swamp meadow (ASM). Based on field-monitored data, the variations in soil temperature, soil water content, and freeze–thaw processes were examined in the active layer. The response characteristics of the soil hydrothermal processes to climate change were analysed under the different alpine grasslands. The results showed that the duration of the thawing and freezing stages of the active layer of the AMs was shorter than that of the ASM and the AS. The average mean annual soil temperature (MAST) in the active layer of the AM ((−1.25 ± 0.50) °C) was lower than those in the AS ((−0.71 ± 0.39) °C) and ASM ((−0.45 ± 0.57) °C), while the AM had the highest rate of soil temperature increase ((0.2 ± 0.06) °C per year). The annual amplitude of ground temperature in the active layer increased with the transition direction of the alpine vegetation type from ASM to AM to AS. The small surface offset (SO) and thermal offset (TO) (absolute values) indicated that the ground thermal state of the AM was more unstable, as it was more sensitive to the increase in air temperature than the ASM or the AS. Soil properties controlled the distribution of soil water content within the active layer, but vegetation improved the shallow soil structure by producing more belowground phytomass, thus, enhancing soil water content in the 0–30 cm layer. The average soil water content at depths of 0–30 cm was directly proportional (p < 0.05) to the phytomass. Soil water contents at depths of 0–30 cm in the ASM ((37.7 ± 5.3)%) and the AM ((40.8 ± 5.9)%) were significantly higher than those in the AS ((22.7 ± 3.2)%). These results provide valuable insight into the hydrothermal interactions between the degradation of permafrost and alpine vegetation under a warming climate.

Impacts of National Highway G214 on Vegetation in the Source Area of Yellow and Yangtze Rivers on the Southern Qinghai Plateau, West China

Engineering corridors on the Qinghai–Tibet Plateau have substantially modified the regional ecosystem functions and environment, resulting in changes in the alpine ecosystem. In addition, the building and operation of these engineering corridors have led to rapid permafrost degradation, which in turn has impacted local vegetation along these corridors. This study investigated vegetation changes and their driving factors by the methods of coefficient of variation, correlation analysis, and GeoDetector in a 30 km wide buffer zone at each side along the National Highway G214 (G214) at the northern and southern flanks of the Bayan Har Mountains in part of the source area of the Yellow and Yangtze rivers on the southern Qinghai Plateau, West China. The following results were obtained: (1) The Normalized Difference Vegetation Index in Growing Season (NDVIgs) rose slightly in 2010–2019, with an average annual change rate of 0.006/a. Patterns of NDVIgs along the G214 exhibited “low at the northern flank and high at the southern flank of the Bayan Har Mountains”. (2) Spatially, average NDVIgs increased from the first buffer zone at the distance of 0–10 km from the highway centerline to the second buffer zone at 20–30 km perpendicularly away from the G214. Furthermore, the first buffer zone had the lowest coefficient of variation, possibly due to a low vegetation recovery as a result of the greatest influence of the G214 on NDVIgs at 0–10 km. (3) Furthermore, annual precipitation (AP) was the dominant factor for significantly (p &lt; 0.01) and positively influencing the variations in NDVIgs (R = 0.75, p &lt; 0.01). Additionally, NDVIgs was more strongly influenced by the two combined factors than any single one, with the highest q-value (0.74) for the interactive influences of AP and annual average air temperature (AAAT) and followed by that of the AP and mean annual ground temperature (MAGT) at the depth of zero annual amplitude (15 m). Evidently, the construction and operation of the G214 have directly and indirectly affected vegetation through changing environmental variables, with significant impacts on NDVIgs extended at least 20 km outwards from the highway. This study helps better understand the environmental impacts along the engineering corridors in elevational permafrost regions at mid and low latitudes and their management.

Geocenter Motions Derived from BDS Observations: Effects of the Solar Radiation Pressure Model and Constellation Configuration

As the first hybrid-constellation global navigation system, China’s BeiDou navigation satellite system (BDS) has been fully constructed since July 2020 and provides open services for worldwide users. Due to the natural sensitivity of satellite tracking techniques to geocenter motion, BDS has the capability to determine the geocenter coordinates (GCC). This study aims to improve the precision of geocenter coordinates derived from BDS. To that end, 3-year sets of daily geocenter coordinates have been determined with BDS observations. Different solar radiation pressure (SRP) models, including the empirical CODE orbit model (ECOM), the extended ECOM model (ECOM2), and the a priori box-wing along with the ECOM model (BW + ECOM), have been applied for the BDS geocenter estimation. We show that the BW + ECOM model is beneficial in recovering the geocenter motion. Compared to the ECOM, the BW + ECOM model appears to mitigate the draconitic signal of BDS, which reduces the annual amplitude of the GCC-Z by a factor of 2.9. On the other hand, the amplitude of the 3 cpy signal is also reduced by a factor of 2.9. Furthermore, we studied the impact of BDS constellation configuration on the geocenter estimation. The results indicate that the inclusion of IGSO satellites significantly mitigates the spurious signals in the spectra of the GCC-Z. The amplitudes of the annual signal and 3 cpy signal are reduced by (28%, 14%), (33%, 61%), and (31%, 9%) for ECOM, ECOM2, and BW + ECOM cases, respectively. Meanwhile, the amplitude of the 7-day signal related to the orbital period of MEO satellites is also reduced by 32–45%. Thus, the BW + ECOM model and the MEO+IGSO hybrid configuration are recommended for BDS to determine the geocenter coordinates. However, despite these improvements, a significant annual signal with an amplitude of 20.2 mm and a visible 3 cpy signal with an amplitude of 6.1 mm still exist when compared to the Satellite Laser Ranging (SLR) solution.

Seasonal variations in acute diverticular disease hospitalisations in New Zealand

PurposeSeasonal variation of acute diverticular disease is variably reported in observational studies. This study aimed to describe seasonal variation of acute diverticular disease hospital admissions in New Zealand.MethodsA time series analysis of national diverticular disease hospitalisations from 2000 to 2015 was conducted among adults aged 30 years or over. Monthly counts of acute hospitalisations’ primary diagnosis of diverticular disease were decomposed using Census X-11 times series methods. A combined test for the presence of identifiable seasonality was used to determine if overall seasonality was present; thereafter, annual seasonal amplitude was calculated. The mean seasonal amplitude of demographic groups was compared by analysis of variance.ResultsOver the 16-year period, 35,582 hospital admissions with acute diverticular disease were included. Seasonality in monthly acute diverticular disease admissions was identified. The mean monthly seasonal component of acute diverticular disease admissions peaked in early-autumn (March) and troughed in early-spring (September). The mean annual seasonal amplitude was 23%, suggesting on average 23% higher acute diverticular disease hospitalisations during early-autumn (March) than in early-spring (September). The results were similar in sensitivity analyses that employed different definitions of diverticular disease. Seasonal variation was less pronounced in patients aged over 80 (p = 0.002). Seasonal variation was significantly greater among Māori than Europeans (p < 0.001) and in more southern regions (p < 0.001). However, seasonal variations were not significantly different by gender.ConclusionsAcute diverticular disease admissions in New Zealand exhibit seasonal variation with a peak in Autumn (March) and a trough in Spring (September). Significant seasonal variations are associated with ethnicity, age, and region, but not with gender.

Caspian Sea Level Change Observed by Satellite Altimetry

We analyze satellite altimeter observed Caspian Sea level (CSL) changes over the period January 1993 to December 2021 using the lake level series from the Hydroweb project and global sea level anomalies (SLA) grids provided by the Copernicus Marine Environment Monitoring Service (CMEMS). The two altimeter-based CSL series agree well at interannual and longer time scales, but show significantly large discrepancies at seasonal and shorter time scales. The large discrepancies are found to be introduced by the approximately inverted barometer (IB) correction applied to the CMEMS SLA over the Caspian Sea. The IB correction over the Caspian Sea or any enclosed lakes needs to be treated separately from the ocean by using the correct reference mean pressure. The actual IB effects over the Caspian Sea are significantly smaller than those applied in the CMEMS SLA grids. After applying an improved IB correction using the global mean sea level pressure fields from the European Centre for Medium-Range Weather Forecasts (ECMWF) ERA5 reanalysis atmospheric model, the two CSL series agree remarkably well. Altimeter observed CSL series show a significant decreasing trend on top of strong seasonal variations. The estimated linear trends for the Hydroweb and CMEMS CSL series are −5.37 ± 0.11 and −5.40 ± 0.11 cm/yr, respectively. Annual amplitudes are 17.03 ± 1.33 vs. 15.79 ± 1.30 cm, with nearly the same phases. The CSL change shows notable acceleration in the decreasing trend since around 2005, and the estimated trends have increased to −8.86 ± 0.10 and −8.81 ± 0.10 cm/yr, respectively for the two-altimeter CSL series.

Solar Gravitational Radiation Reflected on the Hydrogen Wall might explain the Pioneer Anomaly: Do Mirrors for Gravitational Radiation Exist?

The Hydrogen wall found in the Voyager 1 data was modeled as the spherical mirror reflecting the Solar gravitational radiation back to the Solar System. A similar proposal appeared in the forgotten publication of Jaumann in 1912. The formula describing the anomalous acceleration of Pioneer 10 and 11 towards the Sun was derived. The decreasing temperature in the Solar System decreases slightly the mass of both Pioneers 10 and 11 as it was predicted by Einstein in 1907. The experimental value for both Pioneers was published as ap = (8.74 ± 1.33) * 10-10 ms-2. This new model predicts the value of the anomalous acceleration towards the Sun as ap = (8.50 – 0.0106 * x) * 10-10 ms-2 AU-1 where x is the distance of Pioneers from the Sun in astronomical unit AU. The annual amplitude visible in the Pioneer data (~ 1.6 *10-10 ms-2) was interpreted as the reflection of the Earth´s gravitational radiation from the surface of the Sun – the Earth´s self-gravitational effect with the predicted value 1.49 * 10-10 ms-2. The diurnal amplitude visible in the Pioneer anomaly (~ 3 * 10-12 ms-2) was interpreted as the result of Newton´s third law – for every action, there is an equal and opposite reaction between the Sun and the Earth: the diurnal amplitude was derived as 3.05 * 10-12 ms-2. It will be very helpful to get more experimental data from the next missions towards the Termination shock, the Hydrogen wall using the spacecraft of the type Voyager and Pioneer.

Effects of thermal stability on microcrustacean assemblages in spring fens

ABSTRACT Springs are considered relatively stable aquatic environments and possible thermal refugia for cold-adapted taxa under climate change. However, permanent and pristine spring fens in the Western Carpathians show between-site variation in thermal stability with significant effects on macroinvertebrate assemblages. In this study, we investigated the impact of the thermal stability on microcrustaceans (Harpacticoida, Ostracoda). We disentangled various parameters of thermal stability, such as mean summer and winter temperatures, annual amplitude, and daily fluctuations, and related these parameters to mesoclimate, vegetation cover, and water table. We found that the relative abundance of cold-stenothermal species decreased significantly with increasing mean water temperature in summer, which had a significant effect on species composition. Surprisingly, ostracods were completely indifferent to thermal stability despite including cold stenotherms and crenobionts, suggesting that these species might have broader thermal tolerance. By contrast, harpacticoids significantly responded to both summer and winter mean temperatures, showing upper and lower limits of thermal tolerance. While vegetation cover significantly suppressed daily fluctuations in summer, no effect of daily fluctuations on microcrustaceans was found. The effect of water table was also significant but independent of thermal stability. We assume that the less thermally stable sites will not support the occurrence of cold-stenothermic harpacticoids as air temperature rises. However, an increase in winter temperatures may result in higher overall abundance of harpacticoids. We discuss how spring fens are probably most threatened by the combination of drought and increasing temperature.

Comparison of GRACE/GRACE-FO Spherical Harmonic and Mascon Products in Interpreting GNSS Vertical Loading Deformations over the Amazon Basin

We compute the vertical displacements in the Amazon Basin using the Gravity Recovery and Climate Experiment (GRACE) and GRACE Follow-On (GRACE-FO) observations, including both the gravity spherical harmonic (SH) solutions from the Center for Space Research (CSR), GeoForschungsZentrum (GFZ) and Jet Propulsion Laboratory (JPL) and mascons from CSR, JPL and Goddard Space Flight Center (GSFC). The correlation coefficients, annual amplitude and root mean squares (RMS) reductions are calculated to assess the agreements between the GRACE/GRACE-FO and Global Navigation Satellite System (GNSS) vertical displacements at 22 selected GNSS stations. For the six GRACE/GRACE-FO products (i.e., CSR SH, GFZ SH, JPL SH, CSR mascon, GSFC mascon and JPL mascon), the mean annual amplitude reductions are 77.6%, 76.4%, 76.3%, 78.6%, 78.5% and 76.6%, respectively, the corresponding mean RMS reductions are 63.2%, 61.7%, 62.3%, 64.9%, 65.3% and 63.8%, respectively, and the mean correlation coefficients are all over 0.93. On the whole, mascon solutions agree slightly better with GNSS solutions than SH solutions do. The CSR SH and the GSFC mascon solutions show the best agreements with the GNSS solution among the 3 SH and 3 mascon products, respectively. We estimate GRACE/GRACE-FO noises using the three-cornered hat (TCH) method and find that the CSR SH and GSFC mascons also have the smallest noise variances among the SH and mascon products, respectively. By analyzing the GNSS stations from the central and southern Amazon Basin, we find that: (1) the RMS reductions when the mascon solutions are removed from GNSS height series are slightly larger than those using the SH solutions in the center, while in south all the RMS reductions are fairly close; (2) for both SH solutions and mascon solutions, the correlation coefficients in the center are slightly larger than those in the south, but conversely, the mean annual amplitude reductions in the center are much smaller than those in the south.

Внутригодовая изменчивость температуры приземного воздуха и её моделирование для города Ставрополя

Introduction. It is known that the time course of temperature during the year is seasonal. However, the rates of temperature growth in transition periods are different. This complicates the prediction of such an important parameter, in particular for agriculture, as the air temperature of the surface layer of the atmosphere. Accordingly, the article analyzes the intra-annual variability of air temperature and compares it with a sinusoidal model of the annual temperature course. Materials and research methods. The time series of the air temperature of the surface layer of the atmosphere for the city of Stavropol are considered and the task is to compare the actual and theoretical values of annual amplitudes. In the elementary (sinusoidal) model, this theoretical value turns out to be directly proportional to the annual variance. The time series of temperature differences (inter-monthly changes), the so-called discrete derivatives, is also considered, and the comparison of the usual and discrete derivative of the sine function as an elementary model of the annual temperature course is carried out. A new value is introduced – the standard deviation of variability, which also characterizes the variance, yet not for a number of temperatures, but their differences. Research results and their discussion. It is noted that the theoretical (i.e., valid for the sinusoidal model) and the actual value of the amplitude of the annual temperature course are quite well matched. However, due to non-periodic deviations, the difference between these values can reach 2 °C, which is characterized by asymmetry on the intra-annual variability chart. In addition, the average annual temperature course is considered and its analysis is carried out using discrete derivatives. It is shown that the ratio of the annual temperature amplitude to the amplitude of the discrete derivative of this value is equal to the cyclic frequency of fluctuations of the annual temperature course. Conclusions. The results obtained confirm the possibility of using a sinusoidal model of the annual temperature course (although with some limitations related to the asymmetry and shift of intra-annual peak points). The analysis of the annual temperature course using discrete derivatives and its comparison with the sinusoidal model revealed the features of the average annual intra-annual variability of surface air temperature for the city of Stavropol for the period 1944 – 2022. Sometimes there is a change in the rate of heating or cooling; in rare cases, there is an inversion when considering the time series of average monthly temperatures).

WATER LEVEL VARIATIONS ON THE BALKASH LAKE IN THE MODERN PERIOD

The article considers the nature of long-term and storm surge fluctuations in the level on the Balkash Lake. Statistics are presented and their seasonal distribution in different parts of the lake is described. It is noted that a change in the level entails a change in the morphometric characteristics of the lake; there is a tendency to reduce the area and, accordingly, the water volume of lake. The most vulnerable is the southern coast, which is a low-lying accumulative sandy plain. With wind surges, the coast is flooded in a strip from several hundred meters to several kilometers. Even fluctuations in the lake level (20...30 cm) lead here to significant displacements of the coastline. Surge phenomena in this area are the main factor in the for-mation of the relief. The amplitude of surge fluctuations of the Balkash Lake level signifi-cantly exceeds the annual amplitude of changes in the filling of the lake. The highest ampli-tude of surge oscillations is observed in Western Balkhash and at the end sections of the lake.

The responses of SST annual cycle in the eastern equatorial Pacific to global warming

The eastern equatorial Pacific exhibits a pronounced westward propagating sea surface temperature annual cycle (SSTAC). The responses of the equatorial Pacific SSTAC to CO2-induced global warming are examined using 15 Coupled Model Intercomparison Project Phase 5 (CMIP5) experiments. The annual cycle patterns of global-warming simulations over 2006-2100 are compared with that of present-day simulations over 1850-2005. We see no statistically significant changes in SSTAC amplitude in the future. A coupled dynamical diagnostic framework is adopted to assess four factors, including the damping rate, phase speed and strength of the annual and semi-annual harmonic forcing of SSTAC. Under global warming, changes relative to the present-day simulations in these four diagnostic factors have a clear multi-model trend. Most coupled models exhibit relatively weaker (an average of 18%) propagation speed, and stronger annual (18%) and semi-annual (39%) external forcing. Half of the models show a relatively stronger (about one time) damping rate, while the rest show a weaker (30%) damping rate. When these four diagnostic factors are further condensed into a dynamical response factor and a forcing factor, it is revealed that the same annual cycle amplitudes with respect to the present-day simulations may result from the compensations in terms of bias in the dynamical response factor and forcing factor under increased CO2-induced warm climate.

Relationship between Phytocenotic Diversity of the Northeastern Transbaikal Orobiome and Bioclimatic Parameters

The most important spatial patterns of plant cover of the Northern Transbaikalia, its regional features being represented by the structure of altitudinal zonality of the Northeastern Transbaikal orobiome, have been determined in relationship with the climatic factor. The regional climate assessment of the altitudinal belt structure of the plant cover of the orobiome has been performed for typological subdivisions of the highest hierarchic level (phratries of the classes of plant formations) using the BioClim global climate model. Principal component analysis, discriminant and cluster analysis were used to demonstrate that the summer ombrothermic index, continentality and climate moisture indices and the mean annual rainfall of many years are the most significant bioclimatic parameters determining the spatial structure of plant cover in the mountain taiga, subgoletz, mountain tundra and goletz belts. The background communities of orobiome belts develop under the conditions of continental climate (continentality index from 36 to 50). Heat supply parameters, first of all, in the vegetation period, are crucial for the spatial differentiation of altitudinal subelts, characterizing the change of light forest and dwarf pine communities in the subgoletz belt, larch, larch-pine and dark-coniferous forests in the mountain taiga belt. Moisture supply is related to the regional differences in the typological diversity of the belts, which are manifested in the development of more moisture-demanding fir-spruce forests in the low parts of the Patom Highland (rainfall amount more than 450 mm per year) and pine forests in the intermountain basins of the Stanovoy Highlands, existing under the conditions with the maximum annual temperature amplitude and low rainfall levels (up to 400 mm per year).

Inverted Algorithm of Groundwater Storage Anomalies by Combining the GNSS, GRACE/GRACE-FO, and GLDAS: A Case Study in the North China Plain

As the largest groundwater drainage region in China, the per capita water resources in the North China Plain (NCP) account for only one-seventh of the country’s available water resources. Currently, the NCP is experiencing a serious water shortage due to the overexploitation of groundwater resources and a subsequent series of natural disasters. Thus, accurate regional assessments and effective water resource management policies are of critical importance. To accomplish this phenomenon, the daily terrestrial water storage anomaly (TWSA) over the NCP is calculated from the combination of the GNSS vertical deformation sequences (seasonal items) and GRACE (trend items). The groundwater storage anomaly (GWSA) in the NCP is obtained by subtracting the canopy water, soil water, and snow water equivalent components from the TWSA. The inversion results of this study are verified by comparisons with the Global Land Data Assimilation System (GLDAS) data products. The elevated annual amplitude areas are located in Beijing and Tianjin, and the Pearson correlation coefficient (PCC), root mean square error (RMSE), and Nash–Sutcliffe efficiency (NSE) between the two GWSA results are 0.67, 4.01 cm, and 0.61, respectively. This indicates that the methods proposed in this study are reliable. Finally, the groundwater drought index was calculated for the period from 2011 to 2021, and the results showed that 2019 was the driest year, with a drought severity index value of −0.12, indicative of slightly moderate drought conditions. By calculating and analyzing the annual GWSA, this work shows that the South–North Water Transfer Project does provide some regional drought mitigation.