Search results for "Amazon basin"
showing 7 items of 7 documents
Cryptic diversity within three South American whip spider species (Arachnida, Amblypygi)
2020
4 pages; International audience; Cryptic diversity (CD), the presence of highly divergent phylogenetic lineages within closed morphological species, has been documented for many taxa. Great arachnid orders such as Araneae or Scorpiones are well studied and many cases of CD have been described therein; to date, however, related research on smaller arachnid orders, such as whip spiders (Amblypygi), remains lacking. In the current study, we investigated CD based on cytochrome oxidase 1 (COI) in three nominal species of the genus Heterophrynus (H. alces, H. batesii, and H. longicornis), represented by 65 specimens. The sequences were compared using three different methods. All three species sho…
Influx of African biomass burning aerosol during the Amazonian dry season through layered transatlantic transport of black carbon-rich smoke
2020
Black carbon (BC) aerosols influence the Earth's atmosphere and climate, but their microphysical properties, spatiotemporal distribution, and long-range transport are not well constrained. This study presents airborne observations of the transatlantic transport of BC-rich African biomass burning (BB) smoke into the Amazon Basin using a Single Particle Soot Photometer (SP2) as well as several complementary techniques. We base our results on observations of aerosols and trace gases off the Brazilian coast onboard the HALO (High Altitude and LOng range) research aircraft during the ACRIDICON-CHUVA campaign in September 2014. During flight AC19 over land and ocean at the northeastern coastline …
Further evidence for CCN aerosol concentrations determining the height of warm rain and ice initiation in convective clouds over the Amazon basin
2017
We have investigated how aerosols affect the height above cloud base of rain and ice hydrometeor initiation and the subsequent vertical evolution of cloud droplet size and number concentrations in growing convective cumulus. For this purpose we used in situ data of hydrometeor size distributions measured with instruments mounted on HALO aircraft during the ACRIDICON–CHUVA campaign over the Amazon during September 2014. The results show that the height of rain initiation by collision and coalescence processes (Dr, in units of meters above cloud base) is linearly correlated with the number concentration of droplets (Nd in cm−3) nucleated at cloud base (Dr ≈ 5 ⋅ Nd). Additional cloud processes…
Quantifying the spatial extent and intensity of recent extreme drought events in the Amazon rainforest and their impacts on the carbon cycle
2020
Over the last decades, the Amazon rainforest was hit by multiple severe drought events. Here we assess the severity and spatial extent of the extreme drought years 2005, 2010, and 2015/2016 in the Amazon region and their impacts on the carbon cycle. As an indicator of drought stress in the Amazon rainforest, we use the widely applied maximum cumulative water deficit (ΔMCWD). Evaluating an ensemble of ten state-of-the-art precipitation datasets for the Amazon region, we find that the spatial extent of the drought in 2005 ranges from 2.8 to 4.2 (mean = 3.2) million km2 (46–71 % of the Amazon basin, mean = 53 %) where ΔMCWD indicates at le…
Do organics contribute to small particle formation in the Amazonian upper troposphere?
2008
3-D cloud-resolving model simulations including explicit aerosol physics and chemistry are compared with observations of upper tropospheric (12 km) aerosol size distributions over the Amazon Basin. ...
Another New Riparian Dendrobatid Frog Species from the Upper Amazon Basin of Peru
2003
A new dendrobatid frog of the genus Colostethus is described from the Cordillera El Sira, an isolated mountain ridge in the upper Amazon basin of central Peru. It has bright yellowish dorsolateral stripes thus resembling Colostethus exasperatus, Colostethus sp. (cf. exasperatus), and Colostethus nexipus, all from the upper Amazon basin of Ecuador and Peru. In morphology, the new species is most similar to Colostethus mcdiarmidi from the eastern Andean slopes of Bolivia and Colostethus alessandroi from the eastern Andean slopes of Peru. The new species can be distinguished from all these taxa on the basis of coloration including the color of the ring around pupil in life, adult male size, le…
Description and phylogenetic relationships of a new species of treefrog of theOsteocephalus buckleyispecies group (Anura: Hylidae)
2020
The Osteocephalus buckleyi species group is widely distributed in primary and secondary forests of the Amazon Basin and Guiana Region. Based on integrative analysis, including morphological and genetic data, we estimate the phylogenetic relationships and species boundaries among populations of the Osteocephalus buckleyi group from the Ecuadorian Amazon, focusing on the O. verruciger-O. cannatellai species complex. Our results uncovered the existence of one confirmed candidate species from Sangay National Park and one unconfirmed candidate species. Here, we describe the new species which is morphologically and ecologically distinct from other Osteocephalus species. The new species is unusual…