Latitudinal Zones Research Articles

Twentieth century extreme precipitation detected in a high-resolution, coastal lake-sediment record from California

AbstractCalifornia faces increasing economic and societal risks from extreme precipitation and flooding associated with atmospheric rivers (ARs) under projected twenty-first century climate warming. Lake sediments can retain signals of past extreme precipitation events, allowing reconstructions beyond the period of instrumental records. Here, we calibrate AR-related extreme precipitation from the last century to proxy data from lake sediments collected in the latitudinal zone of the highest frequency landfall for modern ARs in California. Excursions in erosional proxy data (Ti/Al) are positively and significantly correlated (rmedian = 0.45, pmedian = 0.04) with modern records of integrated vapor transport (IVT, kg m−1 s−1), a key metric of AR intensity, using correlations that incorporate age-model uncertainty. Despite the land-use change near the study site, the data suggest intense and long-lasting AR storms are identifiable in this sedimentary record. These results allow conservative inferences concerning past extreme hydrology at this site.

Emergent constraints on historical and future global gross primary productivity.

Terrestrial gross primary productivity (GPP) is the largest carbon flux in the global carbon cycle and plays a crucial role in terrestrial carbon sequestration. However, historical and future global GPP estimates still vary markedly. In this study, we reduced uncertainties in global GPP estimates by employing an innovative emergent constraint method on remote sensing-based GPP datasets (RS-GPP), using ground-based estimates of GPP from flux towers as the observational constraint. Using this approach, the global GPP in 2001-2014 was estimated to be 126.8 ± 6.4 PgC year-1, compared to the original RS-GPP ensemble mean of 120.9 ± 10.6 PgC year-1, which reduced the uncertainty range by 39.6%. Independent space- and time-based (different latitudinal zones, different vegetation types, and individual year) constraints further confirmed the robustness of the global GPP estimate. Building on these insights, we extended our constraints to project global GPP estimates in 2081-2100 under various Shared Socioeconomic Pathway (SSP) scenarios: SSP126 (140.6 ± 9.3 PgC year-1), SSP245 (153.5 ± 13.4 PgC year-1), SSP370 (170.7 ± 16.9 PgC year-1), and SSP585 (194.1 ± 23.2 PgC year-1). These findings have important implications for understanding and projecting climate change, helping to develop more effective climate policies and carbon reduction strategies.

Arctic Sea Ice Variations in the First Half of the 20th Century: A New Reconstruction Based on Hydrometeorological Data

The shrinking Arctic sea-ice area (SIA) in recent decades is a striking manifestation of the ongoing climate change. Variations of the Arctic sea ice have been continuously observed by satellites since 1979, relatively well monitored since the 1950s, but are highly uncertain in the earlier period due to a lack of observations. Several reconstructions of the historical gridded sea-ice concentration (SIC) data were recently presented based on synthesized regional sea-ice observations or by applying a hybrid model–empirical approach. Here, we present an SIC reconstruction for the period 1901–2019 based on established co-variability between SIC and surface air temperature, sea surface temperature, and sea level pressure patterns. The reconstructed sea-ice data for March and September are compared to the frequently used HadISST1.1 and SIBT1850 datasets. Our reconstruction shows a large decrease in SIA from the 1920 to 1940 concurrent with the Early 20th Century Warming event in the Arctic. Such a negative SIA anomaly is absent in HadISST1.1 data. The amplitude of the SIA anomaly reaches about 0.8 mln km2 in March and 1.5 mln km2 in September. The anomaly is about three times stronger than that in the SIBT1850 dataset. The larger decrease in SIA in September is largely due to the stronger SIC reduction in the western sector of the Arctic Ocean in the 70°–80°N latitudinal zone. Our reconstruction provides gridded monthly data that can be used as boundary conditions for atmospheric reanalyses and model experiments to study the Arctic climate for the first half of the 20th century.

Global cloud optical depth daily variability based on DSCOVR/ EPIC observations

When investigating the potential effects of cloud changes on climate, the interday and intraday variabilities should be distinguished. Historically, studies have focused on the long-term cloud changes, and the intraday cycles of cloud properties have been mostly ignored partly owing to the limited availability of global datasets to study higher frequency variabilities. In this regard, DSCOVR’s vantage point at the Lagrange L1 point overcomes the temporal limitations of polar orbiters as well as the limited spatial views of geostationary satellites, allowing characterization of the daytime variability of cloud properties using a single sensor. In previous analyses, we used DSCOVR’s EPIC instrument to characterize the diurnal cycles of cloud height and cloud fraction; here, we expand on previous studies to additionally investigate the variability of cloud optical thickness. We observe a recurring diurnal pattern of cloud optical thicknesses for different latitudinal zones that reaches a maximum around noon regardless of the underlying surface. Once we separate the clouds based on their optical thickness into optically thin (0–3), intermediate (3–10), and thick (10–25), we find that these cloud classes follow different optical thickness diurnal cycles on the global scale. We further explore these differences by combining the evolution of cloud fraction and optical thickness of each group to obtain the diurnal evolution of cloud-fraction-weighted optical depths.

Disentangling the impact of climate change, human activities, vegetation dynamics and atmospheric CO2 concentration on soil water use efficiency in global karst landscapes

Soil Water Use Efficiency (SWUE), which quantifies the carbon gain against each unit of soil moisture depletion, represents an essential ecological parameter that delineates the carbon-water coupling within terrestrial ecosystems. However, the spatiotemporal dynamics of SWUE, its sensitivity to environmental variables, and the underlying driving mechanisms across various temporal scales in the global karst region are largely uncharted. This study utilized the sensitivity algorithm of partial least squares regression, partial differential equations, and elasticity coefficients to investigate the characteristics of SWUE variations across different climatic zones in the global karst region and their responsiveness to environmental variables. Moreover, the study quantified the individual contributions of climate variability, atmospheric carbon dioxide concentration, human activities, and vegetation changes to SWUE variations. The results indicated that SWUE across different climatic zones in the global karst region demonstrated an increasing trend from 2000 to 2018, with the most notable improvement observed in the humid zone. SWUE presented regular distribution and variation characteristics across different latitudinal zones at a monthly scale. The sensitivity of SWUE to precipitation was significantly higher compared to its responsiveness to other environmental factors. Additionally, the trend in SWUE's sensitivity to precipitation demonstrated the most significant change. The sensitivity of SWUE to various environmental factors and the trend of this sensitivity in the arid zone revealed significant variation compared to other climatic zones. Gross primary productivity and soil moisture were identified as the intrinsic factors influencing SWUE changes, contributing 16 % and − 84 %, respectively. Climate variability and human activities were identified as the primary exogenous factors contributing to the increase in SWUE, accounting for 76 % and 16 %, respectively. This study advances the understanding of carbon-water coupling in karst regions, providing significant insights into the ecological management of global karst environments amidst climate variations.

Unusually weak signal of summer surface air temperature change over North China

AbstractUnder global warming, the summer surface air temperature (SAT) change signal in the northern mid‐latitudes is generally the most significant, while the SAT change in North China (NC) shows distinct local characteristics. Using simulations from the Coupled Model Intercomparison Project Phase 6 and observation from Berkeley Earth Surface Temperature, this study reveals an unusually weak signal of summer SAT change in NC since the 1960s. This uniquely weak signal can be attributed to the small net contribution of external forcings, mainly from anthropogenic greenhouse gases (GHG) and aerosols (AA). Compared to other land regions in the same latitudinal band, the GHG‐induced warming was weaker and AA‐induced cooling was stronger in NC, resulting in the weakest SAT change signal and thus the lowest signal‐to‐noise ratio. This weaker GHG‐induced warming plays a more important role in the SAT change difference between NC and other land regions in the same latitudinal zone. Under different emission scenarios in the future, the signal‐to‐noise ratio in NC will become as large as those in the other land regions in the same latitudinal band and the northern hemisphere, which is partly due to the smaller relative differences in the SAT change signal between NC and the other two regions. The projections of SAT change indicate that climate change in NC will probably become more violent and vulnerable.

Editing the nuclear localization signals of E1 and E1Lb enables the production of tropical soybean in temperate growing regions.

Soybean is a typical short-day crop, and most commercial soybean cultivars are restricted to a relatively narrow range of latitudes due to photoperiod sensitivity. Photoperiod sensitivity hinders the utilization of soybean germplasms across geographical regions. When grown in temperate regions, tropical soybean responds to prolonged day length by increasing the vegetative growth phase and delaying flowering and maturity, which often pushes the harvest window past the first frost date. In this study, we used CRISPR/LbCas12a to edit a North American subtropical soybean cultivar named 06KG218440 that belongs to maturity group 5.5. By designing one gRNA to edit the nuclear localization signal (NLS) regions of both E1 and E1Lb, we created a series of new germplasms with shortened flowering time and time to maturity and determined their favourable latitudinal zone for cultivation. The novel partial function alleles successfully achieve yield and early maturity trade-offs and exhibit good agronomic traits and high yields in temperate regions. This work offers a straightforward editing strategy to modify subtropical and tropical soybean cultivars for temperate growing regions, a strategy that could be used to enrich genetic diversity in temperate breeding programmes and facilitate the introduction of important crop traits such as disease tolerance or high yield.

Seasonal constraint of dynamic water temperature on riverine dissolved inorganic nitrogen transport in land surface modeling

Riverine dissolved inorganic nitrogen (DIN) transport plays an important role in the link between terrestrial and marine ecosystems, while the seasonal changes of water temperature exert a strong control on DIN dynamics. However, the response of the flow of DIN to dynamic water temperature in large rivers is not well known at the global scale. In this study, based on a recently developed land surface model coupled with riverine water temperature and DIN transport schemes, two numerical simulations, with and without dynamic water temperature, were implemented to investigate the seasonal constraint of dynamic water temperature on the change in riverine DIN flow. Results show that the water temperature could be a key controlling factor for the spatial distribution of global DIN flows. After integrating dynamic water temperature estimation into land surface modeling, the annual amplitudes of DIN flow were 5%–25% smaller than before between 30°N and 30°S, while approximately 10% larger in other latitudinal zones. Less denitrification was out of the scope of 40°N–20°S in summer. In eastern China, the dynamic water temperature made the DIN flow reduce by 1%–3% in summer, while it made it increase by 1%–5% in winter. A seasonal constraint of dynamic water temperature, making the amplitude of monthly fluctuation reduce by about 60%, was found in global large rivers. This study shows the importance of dynamic water temperature in the seasonal modeling of riverine DIN flow, and provides a scientific reference for land surface model development and water environment management.摘要水体温度变化对河流可溶性无机氮(DIN)输送有着强烈控制作用. 然而, 在全球尺度上河流DIN输送量对水温度变化的响应尚不清楚. 因此, 本文基于陆面过程模式, 耦合河流水温估算和DIN传输方案, 设定有, 无动态水温情景, 对比研究陆面模拟中水温变化对河流DIN通量变化的影响. 结果表明: 在考虑水温动态变化后, 在30°N和30°S之间, DIN通量年振幅减小5%–25%. 在中国东部地区, 水温动态变化使河流DIN通量在夏季减少1%–3%, 在冬季增加1%–5%, 对DIN通量具有明显的季节性约束作用, 表明动态水温的表达在河流DIN输送模拟中的重要性.

A single Prochlorococcus ecotype dominates the tropical Bay of Bengal with ultradian growth.

The Bay of Bengal (BoB) spans >2.2 million km2 in the northeastern Indian Ocean and is bordered by dense populations that depend upon its resources. Over recent decades, a shift from larger phytoplankton to picoplankton has been reported, yet the abundance, activity, and composition of primary producer communities are not well-characterized. We analysed the BoB regions during the summer monsoon. Prochlorococcus ranged up to 3.14 × 105 cells mL-1 in the surface mixed layer, averaging 1.74 ± 0.46 × 105 in the upper 10 m and consistently higher than Synechococcus and eukaryotic phytoplankton. V1-V2 rRNA gene amplicon analyses showed the High Light II (HLII) ecotype formed 98 ± 1% of Prochlorococcus amplicons in surface waters, comprising six oligotypes, with the dominant oligotype accounting for 65 ± 4% of HLII. Diel sampling of a coherent water mass demonstrated evening onset of cell division and rapid Prochlorococcus growth between 1.5 and 3.1 div day-1, based on cell cycle analysis, as confirmed by abundance-based estimates of 2.1 div day-1. Accumulation of Prochlorococcus produced by ultradian growth was restricted by high loss rates. Alongside prior Arabian Sea and tropical Atlantic rates, our results indicate Prochlorococcus growth rates should be reevaluated with greater attention to latitudinal zones and influences on contributions to global primary production.

Global potential distribution of mangroves: Taking into account salt marsh interactions along latitudinal gradients

Mangrove is one of the most productive and sensitive ecosystems in the world. Due to the complexity and specificity of mangrove habitat, the development of mangrove is regulated by several factors. Species distribution models (SDMs) are effective tools to identify the potential habitats for establishing and regenerating the ecosystem. Such models usually include exclusively environmental factors. Nevertheless, recent studies have challenged this notion and highlight the importance of including biotic interactions. Both factors are necessary for a mechanistic understanding of the mangrove distribution in order to promote the protection and restoration of mangroves. Thus, we present a novel approach of combining environmental factors and interactions with salt marsh for projecting mangrove distributions at the global level and within latitudinal zones. To test the salt marsh interaction, we fit the MaxEnt model with two predicting sets: (1) environments only and (2) environments + salt marsh interaction index (SII). We found that both sets of models had good predictive ability, although the SII improved model performance slightly. Potential distribution areas of mangrove decrease with latitudes, and are controlled by biotic and abiotic factors. Temperature, precipitation and wind speed are generally critical at both global scale and ecotones along latitudes. SII is important on global scale, with a contribution of 5.9%, ranking 6th, and is particularly critical in the 10–30°S and 20–30°N zone. Interactions with salt marsh, including facilitation and competition, are shown to affect the distribution of mangroves at the zone of coastal ecotone, especially in the latitudinal range from 10° - 30°. The contribution of SII to mangrove distribution increases with latitudes due to the difference in the adaptive capacity of salt marsh plants and mangroves to environments. Totally, this study identified and quantified the effects of salt marsh on mangrove distribution by establishing the SII. The results not only facilitate to establish a more accurate mangrove distribution map, but also improve the efficiency of mangrove restoration by considering the salt marsh interaction in the mangrove management projects. In addition, the method of incorporating biotic interaction into SDMs through establish the biotic interaction index has contributed to the development of SDMs.

О геохимической зональности Верхне-Алиинского месторождения золота в Забайкалье (Россия)

The relevance of the study lies in the need to have objective geochemical data to assess the erosion section level of newly discovered manifestations of ore deposits. One of the examples, used to solve this problem, is the results of the mineralogy and geochemistry study of the Verkhnealiinsky gold deposit in Transbaikalia. The purpose of the study is to determine the zonality in the distribution of minerals, gold and associated chemical elements in the deposit space and to evaluate them as criteria for ore zoning. The object of the study is the Verkhnealinsky gold deposit. The subject of the research is the spatial distribution of minerals and chemical elements in the gold ore zones of the deposit. The methodology consists in diagnostics, determination of the chemical elements content and the establishment of regularities in their spatial distribution using modern methods of analysis, namely, electron microscopy, assay analysis and ICP MS, determination of the degree of the crystal structure perfection. The results of the study are as follows: the content of gold and associated chemical elements in the three most industrially important ore-bearing zones of the Western, Latitudinal and Eastern zones, which differ in the depth of formation, have been determined. The least deep Eastern zone is characterized by the intensive development of zinc, lead, antimony, and arsenic minerals and, accordingly, their maximum content in its upper part. For the deepest Western zone, the maximum development of pyrrhotite, chalcopyrite, and cobalt has been revealed, and it is shown that the cobalt-nickel ratio is an important criterion for assessing the level of erosion cut. An important criterion of depth is also the degree of the crystalline structure perfection of vein quartz, which depends both on the crystallization rate, which is determined by the depth from the day surface during the formation of the deposit, and on the amount of isomorphic impurities in it. It is also shown that one of the important criteria for the level of erosion section is the content of rubidium in veined quartz and arsenic in pyrite.

Temporal and spatial distribution and development of permanent gully in cropland in the rolling hill region (phaeozems area) of northeast China

The cropland in the Songnen phaeozems area (SPA) experiences an extensive gully erosion in the black soil region of northeast China. This study investigates the historical trends, current status, and future trajectories of permanent gully (PG) development, aiming to reveal the mechanisms behind PG development and protect the black soil. We selected nine study areas, totalling 378 km2, across three latitudinal zones in the SPA with slopes of 0–1 %, 1–3 %, and 3–5 %. The results revealed a consistent rise in gully density over time in the SPA, with values increasing from 0.87 km/km2 in 1970 to 0.94 km/km2 in 2010, and 1.32 km/km2 in 2021. Conversely, the ground lacerative degree significantly decreased from 0.025 km2/ km2 in 1970 to 0.010 km2/ km2 in 2010, and rebounding slightly to 0.019 km2/ km2 in 2021. The development rate of PG in the northern area was higher than that in the middle and southern areas, with steeper slopes (3–5 %) having more PGs compared to gentler slopes. The average rate of gully area extension increased with increasing gully level. From 1970 to 2010, the area of PG experienced a decline attributed to extensive gully management. However, subsequent decade (2010–2021) experienced a more rapid PG development, resulting in an annual cropland loss of 0.097 %. The northern area has consistently exhibited the fastest PG development rate in 1970–2021. It is noteworthy that managing gullies through reclamation after filling PG has resulted in the re-generation of secondary gullies in the same locations, which developed more rapidly than natural gullies. The reclamation after filling PG, without improvement of field drainage systems, contributes to an accelerated development rate of PG in cropland. Despite significant reductions in the total area and length of PGs through large-scale gully management, the notable increase in the development rate of gullies warrantsattention in the SPA of northeast China. Furthermore, the global community should take caution with inappropriate gully management measures because they not only prove ineffective but aggravate gully erosion.

Preliminary Seismo-Tectonic Analysis of the Catastrophic Earthquake in South-Eastern Turkey on Feb 6, 2023

Abstract—In this paper, we carried out a kinematic analysis of the movements of plates and blocks of the region based on a homogeneous database of displacement velocities of GNSS permanent monitoring stations for the region of southeastern Turkey, where strong earthquakes occurred on February 6, 2023. Along the East Anatolian fault zone from 2008 to 2018, the Arabian Plate was established to shift relative to the Anatolian Plate, corresponding to a left shift (without a normal component) at a rate of 1 cm/yr in the eastern part to 0.8 cm/yr in the western part. Displacements occurred along the Chardak fault, corresponding to a left-hand strike-slip fault, at a rate of less than 0.7 cm/year. The revealed kinematics is confirmed by focal mechanisms and cosesismic displacements of the studied earthquakes. The M7.5 earthquake that occurred directly on the Chardak fault is not an aftershock of the M7.8 earthquake, but is a relatively independent event. An analysis of the seismic regime shows that the stresses on the East Anatolian fault after the main event M7.8 are relieved by the first large latitudinal fault zone (the Chardak fault). The results of our study suggest that the counterclockwise rotation of the Anatolian and Arabian plates associated with the opening of the Red Sea Rift is most likely decisive for the general kinematics of the plates in the region.

Using the Commercial GNSS RO Spire Data in the Neutral Atmosphere for Climate and Weather Prediction Studies

Recently, the NOAA has included GNSS (Global Navigation Satellite System) Radio Occultation (RO) data as one of the crucial long-term observables for weather and climate applications. To include more GNSS RO data in its numerical weather prediction systems, the NOAA Commercial Weather Data Pilot program (CWDP) started to explore the commercial RO data available on the market. After two rounds of pilot studies, the CWDP decided to award the first Indefinite Delivery Indefinite Quantity (IDIQ) contract to GeoOptics and Spire Incs. in 2020. This study examines the quality of Spire RO data products for weather and climate applications. Spire RO data collected from commercial CubeSats are carefully compared with data from Formosa Satellite Mission 7–Constellation Observing System for Meteorology, Ionosphere, and Climate-2 (COSMIC-2), the fifth-generation European Centre for Medium-Range Weather Forecasts (ECMWF) atmospheric reanalysis (ERA5), and high-quality radiosonde data. The results demonstrate that, despite their generally lower Signal-Noise-Ratio (SNR), Spire RO data show a pattern of lowest penetration height similar to that of COSMIC-2. The Spire and COSMIC-2 penetration heights are between 0.6 and 0.8 km altitude over tropical oceans. Although using different GNSS RO receivers, the precision of Spire STRATOS receivers is of the same quality as those of the COSMIC-2 TriG (Global Positioning System—GPS, GALILEO, and GLObal NAvigation Satellite System—GLONASS) RO Receiver System (TGRS) receivers. Furthermore, the Spire and COSMIC-2 retrieval accuracies are quite comparable. We validate the Spire temperature and water vapor profiles by comparing them with collocated radiosonde observation (RAOB) data. Generally, over the height region between 8 km and 16.5 km, the Spire temperature profiles match those from RS41 RAOB very well, with temperature biases of <0.02 K. Over the height range from 17.8 to 26.4 km, the temperature differences are ~−0.034 K, with RS41 RAOB being warmer. We also estimate the error covariance matrix for Spire, COSMIC-2, and KOMPSAT-5. The results show that the COSMIC-2 estimated error covariance values are slightly more significant than those from Spire over the oceans at the mid-latitudes (45°N–30°N and 30°S–45°S), which may be owing to COSMIC-2 SNR being relatively lower at those latitudinal zones.

New global topography of Enceladus: Hypsometry, basins, spherical harmonics, shell thickness, and true polar wander revisited

A new global high-resolution stereogrammetric and photogrammetric topographic map and updated 3-color global mosaic of Enceladus reveal that the shape of this active icy ocean world is distorted from a simple triaxial ellipsoid. Although the topographic range (high-to-low) of Enceladus, when referenced to its global triaxial figure, is the narrowest among icy bodies mapped globally thus far, the global DEM indicates a pronounced zonal latitudinal zoning of topography, with the north polar region and mid-southern latitudes being ∼300–400 m higher and south polar and mid-northern latitudes being ∼400 m lower on average than the triaxial figure. Dynamically, both north and south poles are low, but the south remarkably so, by >1 km. Spherical harmonic analysis also indicates the tidal axis of the body is located ∼4°W of the current IAU-defined prime meridian. Superposed on this global pattern are topographic features associated with geologic units within each terrain, as well as several prominent regional 100-km-scale basins, 1-to-1.8 km deep, previously reported. The shapes of these large basins depend on the terrains they formed in; those in older cratered terrains are relatively simple (i.e., ovate) in shape, but those in resurfaced terrains are more complex in shape, often correlating with geologic features and units within those terrains. Thus, while these basins exhibit no explicit local-scale geologic deformation or disruption of the icy shell in association with their elevations/formation, they are partially controlled by the physical characteristics of the terrains they formed in, suggesting that the icy shell can be heterogenous in character. Most of these basins occur on the trailing hemisphere and although a few of these are aligned, we find that they do not form a global great circle pattern, weakening previous arguments for true polar wander. Our preferred hypothesis is that these basins are due to isostatic adjustment of the ice shell in response to thermal anomalies from below and suggest that they may be surface manifestations of diffused hydrothermal plumes originating at the surface of Enceladus' rocky core. If so, similar patterns in core activity might be revealed once global topographic mapping is complete on Europa.

Ecological distribution patterns in Chinese seas and adjacent waters: Marine ecological zones

To provide a natural foundation and regionalization framework for ecological monitoring, assessment, and mapping to support ecosystem-based management practices of natural resources, three levels of ecological zones were classified in Chinese seas and adjacent waters using top-down and step wise nesting. At the largest spatial scale, the Chinese seas and adjacent waters were classified into three first-level ecological zones according to latitudinal zones and geographic profiles. To incorporate the dimensionalities and mobility of the seas, 22 second-level ecological zones were classified according to changes in water depth and the distribution of large water masses, and 53 third-level ecological zones were further delineated according to the type of geomorphology and the distribution of water masses and currents. This study identifies dominant factors at different spatiotemporal scales and defines the physical geographical patterns and ecological characteristics in Chinese seas and adjacent waters in a readily understood manner and fills the gap in research on ecological zoning in China.

The response of rhythmically forming processes to the latitudinal position of the zones of their implementation

The problem of variability of the Milankovich scale and cyclic oscillations in the troposphere circulation mode depending on the geographical latitude of the area is investigated. Parallels in the dynamics of multi-thousand-year and intra-century climate cycles in different latitudinal zones and possible causes of this phenomenon are considered. New data on the influence of axial rotation and the shape of the Earth on the structure of rhythm-forming processes are presented. It is established that the zone with a high frequency of pulsations of climatic phases is confined to low latitudes with the highest energy potential. The dependence of the velocity of air currents on the length of geographical parallels is shown. Thus, during the formation of air currents near the equator – the longest parallel of the planet (Hadley circulation cell), their velocity, which is set by the axial rotation of the Earth, is higher than the speed of sound and twice as high as similar flows originating in the temperate latitudes (Ferell cell). Paleogeographic evidence confirming Milankovich’s calculations about the different duration of the solar cycle period in the low, temperate and polar latitudes is presented. Thus, the dating of the terraces of the island of Barbados in the Caribbean Sea (low latitudes) showed that the period of the Milankovich cycle here is close to 20 thousand years. While in the zone of temperate latitudes, the period of the same cycle, judging by the dating of the stadial moraines of the former glacial covers, is 41 thousand years, i. e. twice as long. Maximum – up to 100 thousand years – set for polar latitudes in the study of the ice sheets of Antarctica and Greenland. Different degrees of meteorological impacts on ecosystems and the level of natural hazards within different latitudinal corridors have been revealed. The most dynamic and dangerous are the low latitudes with their hurricanes, typhoons, floods and storms with high frequency. This should be taken into account when developing a strategy for the economic development of high-risk territories and preventive measures for the protection of engineering orientation.

210Pb Deposition Distribution in the Northern Hemisphere Based on a Long-Range Atmospheric Transport and Deposition Model Calculation

This study delves into the long-term atmospheric transport and deposition of 210Pb in the Northern Hemisphere by using the atmospheric transport model HIRAT. The calculation for the four-year (2012–2015) period showed an average deposition flux of 13.0 Bq m−2 month−1 with significant seasonal variations characterized by higher deposition rates during summer and lower during winter. High deposition was found in the Northern Bay of Bengal and Bangladesh regions, Southern China, the Western Philippine Sea, the Eastern Japan Sea, the Northwestern Pacific region, the Eastern and Western coasts of North America, the Caribbean Sea, the Eastern Pacific region off of Central America, the Central Atlantic region between Central America and Africa, and the Northwestern Atlantic Ocean. Deposition patterns varied across latitudinal zones, with tropical areas experiencing the highest deposition and polar/subpolar zones the lowest. This study emphasized the impact of monsoons on the significantly large 210Pb deposition in the Japan Sea region. Furthermore, this study showed that the lower troposphere (0 to 3 km) dominates with about 53%, and the middle troposphere (3 to 6 km) and upper troposphere (above 6 km) also contribute significantly to the total 210Pb inventory with 37% and 10%, respectively. These findings provide essential insights into the characteristics of atmospheric transport and deposition of 210Pb, and their mechanisms.

Специализированная топографическая карта природоохранного назначения: концепция и система содержания (на примере болотных массивов)

The type of specialized topographical map for environmental protection, developed on the example of wetlands’ image, is substantiated. Such areas are protected by a number of international organizations and conventions. The requirements for them from a number of related areas of the economy, scientific research, for arrangement of rational environmental management, using specialized maps and protection of natural resources are determined. The concept of the map is formulated, in accordance with which the sections of its content are developed; they characterize the natural, disturbed state, and environmental protection of wetlands. The program of geographical characteristics is presented as an addition to the original map. Samples of images of bog complexes are proposed, showing the physiognomic varieties of swamps in various latitudinal zones. The general system and structure of the map content, conventional signs, samples of bog complexes are illustrated

Apomixis occurs frequently along the entire American Cordillera

Abstract Apomictic plants mostly occur at higher latitudes and higher elevations, where they tend to occupy deglaciated areas. By analysing samples of the alpine floras of different latitudinal zones of the Americas (Argentina, Bolivia, Ecuador, USA), we investigated whether the proportion of gametophytic apomixis is comparable between the temperate alpine zones of the Northern Hemisphere and the Southern Hemisphere and whether the proportion of apomictic species increases from the alpine tropics towards the temperate alpine zone. The reproductive systems of 196 species and 275 individuals were determined by a flow-cytometric seed screening of 999 seeds. Phylogenetic logistic regression was used to evaluate differences in the proportion of apomictic species in samples of regional alpine floras. The apomictic embryo:endosperm ratio was determined for 33 species (two pseudogamous species and 31 species with autonomous apomixis) belonging to 28 genera of 13 families. The probability of a species being apomictic did not significantly differ between the regions. The highest probability of a species being apomictic was estimated for the northern temperate zone (29.6%), followed by the tropical zone (12.5%), and the southern temperate zone (11.9%). Our results show that asexual plant reproduction by apomixis is not restricted to the alpine zone of the Northern Hemisphere and its representation in alpine floras of the Southern Hemisphere, including the alpine tropics, has been substantially underestimated.