Tropical Latitudes Research Articles

Half a century of thermal tolerance studies in springtails (Collembola): A review of metrics, spatial and temporal trends.

Global changes in soil surface temperatures are altering the abundances and distribution ranges of invertebrate species worldwide, including effects on soil microarthropods such as springtails (Collembola), which are vital for maintaining soil health and providing ecosystem services. Studies of thermal tolerance limits in soil invertebrates have the potential to provide information on demographic responses to climate change and guide assessments of possible impacts on the structure and functioning of ecosystems. Here, we review the state of knowledge of thermal tolerance limits in Collembola. Thermal tolerance metrics have diversified over time, which should be taken into account when conducting large-scale comparative studies. A temporal trend shows that the estimation of 'Critical Thermal Limits' (CTL) is becoming more common than investigations of 'Supercooling Point' (SCP), despite the latter being the most widely used metric. Indeed, most studies (66%) in Collembola have focused on cold tolerance; fewer have assessed heat tolerance. The majority of thermal tolerance data are from temperate and polar regions, with fewer assessments from tropical and subtropical latitudes. While the hemiedaphic life form represents the majority of records at low latitudes, euedaphic and epedaphic groups remain largely unsampled in these regions compared to the situation in temperate and high latitude regions, where sampling records show a more balanced distribution among the different life forms. Most CTL data are obtained during the warmest period of the year, whereas SCP and 'Lethal Temperature' (LT) show more variation in terms of the season when the data were collected. We conclude that more attention should be given to understudied zoogeographical regions across the tropics, as well as certain less-studied clades such as the family Neanuridae, to identify the role of thermal tolerance limits in the redistribution of species under changing climates.

Thermal sensitivity in dual‐breathing ectotherms: Embryos and mothers determine species' vulnerability to climate change

AbstractUnderstanding the life‐stage specific vulnerability of ectotherms to temperature increases is crucial to accurately predicting the consequences of current and future global climate change. Here, we examined ontogeny‐specific thermal vulnerability of three intertidal, bimodal (i.e., air and water) breathing crabs from tropical and warm temperate latitudes to address this issue. Spawning females and embryos of intertidal crabs from warm temperate latitudes were more vulnerable to temperature increases than tropical conspecifics, particularly in water. Our findings do not fully support the Climate Variability Hypothesis for setting upper thermal limits, but correspond with the Oxygen‐ and Capacity‐Limited Thermal Tolerance hypothesis, suggesting ontogeny‐specific aerobic capacity dictates overall species' thermal sensitivity. Bimodal breathing efficiency as an evolutionary adaptation, ontogenetic stage and local climate adaptation are therefore significant factors to consider when evaluating the vulnerability of intertidal ectotherms to temperature increases and the consequences of climate changes for intertidal organisms, populations and communities.

Statistical analysis of negative cloud-to-ground lightning characteristics in Bogota, Colombia based on electric field measurements

This paper studies the electric field parameters of negative cloud-to-ground (CG) lightning flashes in the Bogota savanna (a large plateau located in central Colombia), and its comparison with other regions. This work is the first of its kind in the country where the parameters of lightning-generated electric fields are analyzed in detail. A total of 329 CG lightning flashes had been examined. These flashes were recorded within 4–250 km from the measuring station during the period August–November 2016. From observations, negative CG flashes comprised 93% of total events registered. It has been found that negative lightning discharges occurred along the plateau (4250 km2 at 2550 m altitude) exhibit some different characteristics compared with measurements carried out in several regions (tropical, subtropical and temperate latitudes). In this study, it was found that 64.7% of the negative CG flashes are multiple strokes with an average multiplicity of 2.58 strokes per flash. In addition, the mean interval between 789 negative return strokes (306 first- and 483 subsequent strokes) was 61.3 ± 51.9 ms, while the arithmetic mean of the total duration for 198 multiple-stroke flashes was 149.5 ms. Other lightning flash features such as relation between the interstroke interval and the return stroke order, the ratio of the subsequent stroke peak field to the corresponding first one and the maximum multiplicity are also analyzed.

Characterizing the Long-Term, Wide-Band and Deep-Water Soundscape Off Hawai’i

Many animals use sound for communication, navigation, and foraging, particularly in deep water or at night when light is limited, so describing the soundscape is essential for understanding, protecting, and managing these species and their environments. The nearshore deep-water acoustic environment off the coast of Kona, Hawai’i, is not well documented but is expected to be strongly influenced by anthropogenic activities such as fishing, tourism, and other vessel activity. To characterize the deep-water soundscape in this area we used High-frequency Acoustic Recording Packages (HARPs) to record acoustic data year-round at a 200 or 320 kHz sampling rate. We analyzed data spanning more than 10 years (2007-2018) by producing measurements of frequency-specific energy and using a suite of detectors and classifiers for general and specific sound sources. This provided a time series for sounds coming from biological, anthropogenic and physical sources. The soundscape in this location is dominated by signals generated by humans and odontocete cetaceans (mostly delphinids), generally alternating on a diel cycle. During daylight hours the dominant sound sources are vessels and echosounders, with strong signals ranging from 10 Hz to 80 kHz and above, while during the night the clicks from odontocetes dominate the soundscape in mid-to-high frequencies, generally between 10 and 90 kHz. Winter-resident humpback whales are present seasonally and produce calls in lower frequencies (200-2,000 Hz). Overall, seasonal variability is relatively subtle, which is unsurprising given the tropical latitude and deep-water environment. These results, and particularly the inclusion of sounds from frequencies above 2 kHz, represent the first long-term analysis of a marine soundscape in the North Pacific, and the first assessment of the intense, daily presence of manmade noise at this site. The decadal time series allows us to characterize the dynamic nature of this location, and to begin to identify changes in the soundscape over time. This type of analysis facilitates protection of natural resources and effective management of human activities in an ecologically important area.

The high‐frequency variability of Antarctic sea ice and polar cold air incursions over Amazonia

AbstractThe cold air incursion over South America is associated with the frontal systems generated in the Antarctic region, and sea ice cover plays an important role in its formation. Little is known about how the high‐frequency variability of the coupled ocean–cryosphere‐atmosphere system affects weather conditions in South America, especially in the Amazon region ‐ in tandem with the largest tropical forest on the planet and a key region of the global climate system. The results presented here suggest that the high‐frequency variability of the expansion of Antarctic sea ice extent (SIE) extremes, in the Ross Sea and Indian Ocean, modulate the cold air incursion over the Amazon in the southern winter 4 and 2 days after the expansion of SIE extremes, respectively. The SIE extremes can couple with the atmosphere, inducing Rossby waves that propagate and undergo amplification downstream from the Ross Sea and Indian Ocean during such extremes. In this way, the atmospheric wave train acquires a more southern spread over South America, reaching tropical latitudes after the SIE extremes. In non‐SIE extreme periods, the atmospheric wave train has a more zonal spread and reaches only the extratropical latitudes of the continent.

Anomalous weathering trends indicate accelerated erosion of tropical basaltic landscapes during the Permo-Triassic warming

Weathering of basalt in tropical environments is sensitive to climate change and considered to play a significant role in regulating climate evolution. Though extensively studied on the modern Earth and hypothesized for the geological past, basalt weathering is difficult to directly track in geological archives. We here focus on the basaltic sediments derived from the Emeishan large igneous province (LIP) in South China and determined their organic carbon content and isotope, mineral and geochemical compositions. Based on the newly obtained high-precision zircon U-Pb age of 251.79 ± 0.12/0.13/0.36 Ma, we establish temporal variations of weathering intensity for the Emeishan LIP basaltic landscapes in the tropical latitudes through the Permo-Triassic rapid climate warming periods. Analysis of weathering trends indicates a significant decrease in weathering intensity across the Permo-Triassic transition. This decrease in intensity is anomalous considering its coincidence with the climate warming at the Permo-Triassic transition, which tends to elevate chemical weathering rate of basalts and produce sediments with high chemical weathering intensity. Combining these weathering trends with present-day basalt weathering-temperature relationship and reported paleo-temperatures, total erosion rate is quantitatively estimated to increase from 282 ± 43 t/km2/yr in the latest Permian to > 1618 ± 187 t/km2/yr in the Early Triassic. This massive erosion in the Early Triassic is plausibly related to amplified extreme precipitation associated with intensification of the hydrological cycle in the Early Triassic hothouse climate. This study underlines the weathering responses of tropical landscapes to rapid climate warming.

Temperature Affects the Time Required to Discern the Relationship between Primary Production and Export Production in the Ocean

Knowledge of the relationship between net primary production (NPP) and export production (EP) in the ocean is required to estimate how the ocean’s biological pump is likely to respond to climate change effects. Here, we show with a theoretical food web model that the relationship between NPP and EP is obscured by the following phenomena: (1) food web dynamics, which cause EP to be a weighted average of new production (NP) over a previous temperature-dependent time interval that can vary between several weeks at 25 °C to several months at 0 °C and, hence, to be much less temporally variable than NP and (2) the temperature dependence of the resiliency of the food web to perturbations, which causes the return to equilibrium to vary from roughly 50 days at 0 °C to 5–10 days at 25 °C. The implication is that the relationship between NPP and EP can be discerned at tropical and subtropical latitudes if measurements of NPP and EP are averages or climatologies over a timeframe of roughly one month. At high latitudes, however, measurements may need to be averaged over a timeframe of roughly one year because the food webs at high latitudes are very likely far from equilibrium with respect to NPP and EP much of the time, and the model can describe only the average behavior of such physically dynamic systems.

Biogeographical affinity shapes relationships between ecological and phylogenetic mammal diversity and associations with their environmental correlates in the Americas.

We evaluate the role of biogeographical affinity in shaping relationships between ecological diversity as a proxy of functional diversity and phylogenetic diversity and their association with environmental variation, across tropical and temperate latitudes of the Americas. If environmental niches are evolutionarily conserved, high mammal taxa of tropical and temperate affinity will show consistent differences in these relationships. Accordingly, mammal groups of tropical affinity (old-autochthonous: marsupials and xenarthrans; and mid-Cenozoic immigrants: hystricognaths and primates) show stronger positive correlations between ecological and phylogenetic diversity within the tropics than those from extra-tropical latitudes where newcomers from North America (artiodactyls) show the strongest positive correlations. The other group of newcomers (carnivorans), however, show a peak in the association that include both tropical and extra-tropical latitudes of South America. Climate predominates over topographic relief in structuring the spatial variation of ecological and phylogenetic mammal diversity. The environmental structuring of ecological and phylogenetic mammal diversity across the Americas is more complex than expected from a latitudinal diversity gradient. Dry seasonal tropical habitats generated considerable heterogeneity in relationships between ecological and phylogenetic diversity and their association with environmental correlates. We conclude that biogeographical affinity and regional associations between the different components of diversity and the environment should be considered for a comprehensive explanation of covariation between ecological and phylogenetic diversity on a continental scale.

Middle Miocene (∼14 Ma) and Late Miocene (∼6 Ma) Paleogeographic Boundary Conditions

AbstractDuring the Miocene, major global cooling occurred during two intervals: the middle Miocene (∼14–13 Ma) and the late Miocene (∼7‐6 Ma). The Antarctic Ice Sheet expanded substantially at ∼14–13 Ma, and glaciation in the Northern Hemisphere was initiated at ∼7–6 Ma. Although the causes of these two global cooling events remain unclear, paleoclimate modeling provides an important approach for investigating the mechanisms. However, paleoclimate modeling relies on paleogeographic boundary conditions, and many uncertainties remain regarding the land–sea distribution, topography, and bathymetry of the Miocene; specifically, previous published paleogeographic reconstructions for the middle and late Miocene show several discrepancies with each other. Here, we present two new sets of global topographic and bathymetric boundary conditions for the middle Miocene (∼14 Ma) and late Miocene (∼6 Ma). Our new reconstructions use a published plate kinematics model, oceanic lithospheric paleo‐ages, and oceanic sediment thicknesses and incorporate global fossil records, stratigraphy, lithofacies, paleoenvironment, and paleoelevation data. With these data, we further constrain the conditions of several important intercontinental and marginal seas surrounding Eurasia and the Arctic, the depth of major seaways in tropical latitudes and middle‐high latitudes of the Northern Hemisphere, and global paleotopography, especially that of the Tibetan Plateau and the Andes.

Properties of Mesoscale Convective Systems Throughout Their Lifetimes Using IMERG, GPM, WWLLN, and a Simplified Tracking Algorithm

AbstractMesoscale convective systems (MCSs) occur frequently over the tropics and mid‐latitudes and have a large impact on the local precipitation amounts as well as large‐scale circulation through their modulation of the vertical diabatic heating profile. To fully understand and quantify these effects, MCSs must be studied throughout their lifetimes at both mid‐ and tropical latitudes, over both land and ocean. This can be accomplished by tracking the storm using a global scale data set of precipitation and using this information to composite collocated active sensor measurements to produce a detailed analysis of storm properties along the lifetime of the MCS. To do this, we utilize precipitation features (PFs) produced using observations from the Global Precipitation Measurement (GPM) mission's core satellite and from Integrated Multi‐satellitE Retrievals for GPM data by grouping contiguous raining pixels in both data sets. We propose a simplified tracking algorithm to track systems throughout their lifetimes. Lightning data from the World Wide Lightning Location Network are collocated to these tracks along with GPM PFs. These are then composited relative to the time step along the track that has the greatest number of lightning flashes, which is used as a proxy for MCSs with lightning reaching the maximum convective intensity. We then examine various radar variables for tropical and mid‐latitude systems of varying lifetimes over both land and ocean in order to determine the differences and similarities between these types of systems.

Dust and water ice variability and their interaction pattern during Martian low-dust and high-dust periods

Analysis of dust and water ice variation is carried out using observations from the Mars Climate Sounder (MCS), which includes the data for six years (during Martian years 29–34). This study only used the nighttime observations, as these profiles extend closer to the surface compared to the daytime. The correlation between dust opacity and water ice opacity is found to switch sign between the low-dust northern spring and summer (LS ​= ​0°–180°) and high-dust southern spring and summer seasons (LS ​= ​180°–360°). Density-scaled opacity profiles show the correlation between dust and water ice variability over the southern hemisphere and the tropics, which alters between 20 and 40 ​km altitudes. The positive correlation during the low-dust period over the latitudes 40–80°S is mainly controlled by the water ice cycle in the south polar hood clouds. Whereas the water ice cycle within the tropical cloud belt (TCB) serves as a primary controlling factor, and the presence of atmospheric dust prevails only in its formation stage within the latitudes -20 – 40°N. During the high-dust period, at southern latitudes, significant dust lifting and the associated temperature change are found to be the reason for the strong negative correlation with ice clouds. And in tropical latitudes, the significant positive relationship at relatively high altitudes (∼40 ​km) is possibly due to the presence of thin or haze clouds. The global dust storm occurrence only modulates the correlation behavior during the high-dust period, and the influence is seen above ∼40 ​km altitude that indicates an enhanced vertical advection sustained till late northern winter. Based on analysis of observational data and simulations with the MarsWRF model, it is found that the difference in correlation behavior between low and high-dust seasons could be explained from the variations in the planetary boundary layer height. Moreover, the dust and water ice interaction pattern has a prominent seasonal variation that is influenced by the water ice cycle, dust cycle, or the dust-ice microphysical relationship. It also has an altitudinal dependency, which changes between low-dust, high-dust, or global dust storm scenarios.

Efficient measurement of large-scale decadal shoreline change with increased accuracy in tide-dominated coastal environments with Google Earth Engine

Most of the worlds’ population relies on the processes and ecosystems in the coastal zone. Understanding the long-term change of coastlines is critical for the effective management of these complex, and heavily utilised regions. There has been a recent increase of studies focused on large-scale shoreline change mapping. However, most current methods are optimized for extracting shorelines of wave-dominated sandy beaches, which are only 30% of the global coasts, resulting in uncertainty for other environments such as tidal flats and bedrock. Here, we propose a new shoreline change mapping workflow, using the Landsat archive and Google Earth Engine, which increases compute efficiency and is suitable for retrieving shoreline changes for various coastal landforms at high tide instead of mean sea level. By validating against regional and continental datasets in Australia, we found the approach here produced high mapping accuracy and showed particularly better performance at tide-dominated coasts, where tidal flats and intertidal bars and ridges are present, when compared to past approaches. This is an important step forward since tide-dominated and tide-modified coasts are widely distributed at tropical low latitudes. We also explored the global application of the proposed method and derived hotspots of shoreline erosion and accretion that agreed with multiple regional studies across the world. Most of these hotspots were related to river sediment discharge and human intervention on the coast, as expected. Although it requires further validation, the global application of our method demonstrates the significance of this approach in identifying potential threats to coastal zones, especially in complex tide-dominated environments, which can facilitate effective coastal management.

Observation of Terrestrial Gamma‐Ray Flashes at Mid Latitude

AbstractWe present a sample of Terrestrial Gamma‐ray Flashes (TGFs) observed at mid latitudes by the Atmosphere Space Interaction Monitor (ASIM). The events were detected between June 2018 and August 2020 in the latitude bands between 35° and 51° in both hemispheres, which we hereafter refer to as “mid latitudes.” The sample includes the first observations above and consists of 14 events clustered in four geographical regions: north‐west Atlantic and eastern USA; Mediterranean Sea; the ocean around South Africa; and north‐eastern China and Siberia. We examine the characteristics of each event, both standalone and in the context of the global ASIM TGF data set, and we find that our sample is consistent with the global population concerning the number of counts, but shows significantly shorter durations. We analyze the meteorological context and the general evolution of the parent storms and we show that the storms are not extreme in terms of total duration and extension. Whenever possible, we also include the radio sferics and the peak current of the parent stroke. Finally, we present an estimation of the TGF occurrence rate at mid latitudes, based on ASIM's exposure, the local flash rate and tropopause altitude, and we show that it is outside but very close to two standard deviation from the rate of production at tropical latitudes, corrected by the higher atmospheric absorption of higher latitudes. This means that atmospheric absorption plays a major role in the detection of TGFs at mid latitudes, but we cannot rule out other factors.

Yukon to the Yucatan: Habitat partitioning in North American Late Pleistocene ground sloths (Xenarthra, Pilosa)

The late Pleistocene mammalian fauna of North America included seven genera of ground sloth, representing four families. This cohort of megaherbivores had an extensive geographic range in North America from the Yukon in Canada to the Yucatan Peninsula in Mexico and inhabited a variety of biomes. Within this latitudinal range there are taxa with a distribution limited to temperate latitudes while others have a distribution restricted to tropical latitudes. Some taxa are better documented than others and more is known about their palaeoecology and habitat preferences, while our knowledge of the palaeoecology of taxa more recently discovered remains limited. In order to better understand what aspects of their palaeoecology allowed their dispersal from South America, long–term success in North America and ultimately the underlying causes for their extinction at the end of the Pleistocene more information is needed. A summary overview of the differences in the palaeoecology of the late Pleistocene sloths in North America and their preferred habitats is presented based on different data sources.

100Identification of a latitude gradient in the prevalence of Primary Biliary Cholangitis in Australia

Abstract Background Primary biliary cholangitis (PBC) is an autoimmune destructive condition of the gall bladder, with environmental factors like sun exposure implicated in its aetiology, similar to multiple sclerosis. PBC prevalence varies significantly and appears to have a positive latitudinal gradient. To determine whether there was a latitudinal gradient of PBC prevalence in Australia using two methods of prevalence estimation: private pathology anti-mitochondrial antibody (AMA) results, the primary diagnostic test for PBC, and ursodeoxycholic acid (UDCA) prescriptions, the sole pharmacological treatment for PBC. Methods We investigated the latitudinal variation in PBC prevalence across the states and territories of Australia (latitudinal range 18.0° to 42.7°S) using pathology-based (private pathology AMA results search (three of the major private pathology companies in Australia which cover 77% of all private pathology testing) and PBC-specific prescription databases (prescriptions for UDCA). Results Pathology-based PBC prevalence was significantly increased with latitude, such that the postcodes in the highest quintile of latitude (encompassing the south coastal areas of the Australian mainland and insular Tasmania (latitude range -37.75 to -42.72)) had 1.83-times higher frequencies than those in the lowest quintile (encompassing tropical and southern Queensland (latitude range -18.02 to -27.59). Analogous results were seen for state-based UDCA prescriptions, being 2.31-times higher in Tasmania than Queensland. Conclusions We have found for the first time that the prevalence of PBC significantly varies with latitude in Australia. While the most immediate mediating factors underlying this association would be ultraviolet radiation and vitamin D levels, studies to substantiate this mechanism are needed. Key messages In line with some other autoimmune conditions, PBC shows a significant positive latitudinal gradient, with nearly 2-times higher prevalence in the southernmost state than the northernmost.

Quaternary equatorial Atlantic deep-sea ostracodes: evidence for a distinct tropical fauna in the deep sea

AbstractLow-latitude, deep-sea faunas remain poorly understood and described. Here, we systematically describe Quaternary deep-sea ostracodes from the Ocean Drilling Program (ODP) Site 925 (Ceara Rise; 4°12.2'N, 43°29.3′W; 3040 m water depth) in the equatorial Atlantic Ocean. Twenty-six genera and 52 species were examined and illustrated with high-resolution scanning electron microscopy images. Six new species are described herein:Pseudocythere spinae,Hemiparacytheridea zarikiani,Pedicythere canis,Xylocythere denticulata,Paracytherois obtusa, andPoseidonamicus sculptus. The results show that deep-sea ostracodes have a tropical faunal element that is distinctive from higher latitude ostracodes, and that is globally distributed in low latitudes. This tropical faunal component is possibly a Tethyan legacy of a fauna that was widely distributed in tropical and extratropical latitudes in deep waters during greenhouse conditions in the Cretaceous and early Cenozoic. Global cooling thereafter shrank its distribution, limiting it to tropical latitudes, perhaps with the relatively warm uppermost bathyal area acting as the source or refuge of this faunal component. Because similar present-day biogeographic patterns (i.e., presence and wide distribution of tropical deep-sea fauna) are known in other deep-sea benthic groups, this scenario might be applicable to the deep-sea benthos more broadly.UUID:http://zoobank.org/552d4cb2-c0db-463a-ae3f-b2efcc0985df.

Basal metabolic rate in free-ranging tropical birds lacks long-term repeatability and is influenced by ambient temperature.

Tropical birds live longer, have smaller clutches and invest more resources into self-maintenance than temperate species. These "slow" life-histories in tropical birds are accompanied by low basal metabolic rate (BMR). It has recently been suggested that the low BMR of tropical species may be related not to their slow "pace of life" or high ambient temperatures (Ta ) in tropical latitudes, but to the stability of environmental conditions in tropics. Since the repeatability of metabolic traits is higher in stable environments, such as laboratory conditions, we predicted that long-term repeatability of BMR in a tropical climate should be higher than in a temperate one. Contrary to our predictions, the repeatability of mass-independent BMR in 64 individuals of free-living tropical birds from Vietnam was low and insignificant after the species affiliation was taken into account. It indicates that BMR cannot be used as an individual long-term characteristic of tropical birds. On the other hand, tropical birds showed consistent differences in their mass-independent BMR at the interspecific level. Using BMR measurements from 1543 individuals of 134 species, we also found that different characteristics of Ta within the week preceding BMR measurements had a significant impact on the mass-independent BMR of tropical birds. The most significant effect was the difference between the absolute maximum and minimum Ta within a single week. Our results indicate that the physiology of tropical birds is more subject to changes than would be expected based on the notion of the stability of climatic conditions in the tropics.

Transport and Variability of Tropospheric Ozone over Oceania and Southern Pacific during the 2019–20 Australian Bushfires

The present study contributes to the scientific effort for a better understanding of the potential of the Australian biomass burning events to influence tropospheric trace gas abundances at the regional scale. In order to exclude the influence of the long-range transport of ozone precursors from biomass burning plumes originating from Southern America and Africa, the analysis of the Australian smoke plume has been driven over the period December 2019 to January 2020. This study uses satellite (IASI, MLS, MODIS, CALIOP) and ground-based (sun-photometer, FTIR, ozone radiosondes) observations. The highest values of aerosol optical depth (AOD) and carbon monoxide total columns are observed over Southern and Central Australia. Transport is responsible for the spatial and temporal distributions of aerosols and carbon monoxide over Australia, and also the transport of the smoke plume outside the continent. The dispersion of the tropospheric smoke plume over Oceania and Southern Pacific extends from tropical to extratropical latitudes. Ozone radiosonde measurements performed at Samoa (14.4°S, 170.6°W) and Lauder (45.0°S, 169.4°E) indicate an increase in mid-tropospheric ozone (6–9 km) (from 10% to 43%) linked to the Australian biomass burning plume. This increase in mid-tropospheric ozone induced by the transport of the smoke plume was found to be consistent with MLS observations over the tropical and extratropical latitudes. The smoke plume over the Southern Pacific was organized as a stretchable anticyclonic rolling which impacted the ozone variability in the tropical and subtropical upper-troposphere over Oceania. This is corroborated by the ozone profile measurements at Samoa which exhibit an enhanced ozone layer (29%) in the upper-troposphere. Our results suggest that the transport of Australian biomass burning plumes have significantly impacted the vertical distribution of ozone in the mid-troposphere southern tropical to extratropical latitudes during the 2019–20 extreme Australian bushfires.

Molecular phylogeny of European Runcinida (Gastropoda, Heterobranchia): the discover of an unexpected pool of complex species, with special reference to the case ofRuncina coronata

AbstractRuncinida is a small heterobranch order of sea slugs with 61 known species distributed worldwide across temperate and tropical latitudes with two established families (Ilbiidae and Runcinidae). Little is known about the phylogenetic relationships within Runcinida. Here, we present the first molecular phylogeny of the order with an emphasis on European species and we discuss the taxonomic status of the type species Runcina coronata. Molecular phylogenetics based on the mitochondrial genes cytochrome c oxidase subunit I and 16S rRNA and nuclear gene histone H3 is used to investigate relationships between species. Detailed morpho-anatomical worked was additionally employed to study Runcina coronata. Our results suggest the monophyly of Runcinida and showed that Runcina coronata is a complex of four species, namely: R. coronata proper, R. aurata and two new species here formally described (R. caletensis sp. nov. and R. tingensis sp. nov.).

Synoptic comparison between two cases of subtropical cyclones in the South coast of Brazil

Subtropical Cyclones are low-pressure systems that occur in tropical or subtropical latitudes and that have characteristics of both tropical cyclones and extratropical cyclones. The subtropical class also has a thermodynamic forcing near the surface resulting from heat and humidity flows from the warm ocean. The objective of this study is to make a comparison between two cases of subtropical cyclones that occurred on the south coast of Brazil during the end of spring and summer periods in the Southern Hemisphere. The chosen cases were SC Cari and SC Eçai, which occurred respectively from March 10th to 13th of 2015 and from December 3rd to 6th of 2016. This study was carried out through the analysis of meteorological fields employing the ERA5 reanalysis data along with GOES-13 satellite imagery. In spite of both systems occurring on a similar spatial domain, their different atmospheric characteristics have an important part in their origin, intensity and trajectory. Their trajectories were of interest because of their uncommonness, where Cari moved at first towards the continent presenting risks to the society and only later moving towards the ocean till its dissipation. And Eçai formed over the land as a thermal low that moved towards the ocean gaining strength as it found warm waters, finding a new and more favorable environment.