More Like this

1. The South American Tropopause Aerosol Layer (SATAL)

   https://doi.org/10.1175/BAMS-D-23-0074.1  

   Bresciani, Caroline; Herdies, Dirceu Luis; Figueroa, Silvio Nilo; Buchard, Virginie; da Silva, Arlindo M.; Jones, Charles; Carvalho, Leila M. (January 2024, Bulletin of the American Meteorological Society)

   Abstract The presence of an aerosol layer in the upper troposphere/lower stratosphere (UT/LS) in South America was identified with the Modern-Era Retrospective Analysis for Research and Applications version 2 (MERRA-2). This layer, which we shall refer to as the South American tropopause aerosol layer (SATAL), was identified over the Amazon basin at altitudes between 11 and 14 km. It exhibits a seasonal behavior similar to the Asian tropopause aerosol layer (ATAL) and the North American tropopause aerosol layer (NATAL). The SATAL is observed from October to March, coinciding with the presence of the South American monsoon. It forms first in the eastern Amazon basin in October, then moves to the southern Amazon, where it weakens in December–January and finally dissipates in February–March. We hypothesize that two main factors influence the SATAL formation in the UT/LS: 1) the source of aerosols from Africa and 2) the updraft mass flux from deep convective systems during the active phase of the South American monsoon system that transports aerosols to the UT/LS. Further satellite observations of aerosols and field campaigns are needed to provide useful information to find the origin and composition of the aerosols in the UT/LS during the South American monsoon. 

   more » « less
2. How Amazonian Transpiration Affects South American Climate

   Ukaonu, C. (January 2022, AGU Fall Meeting Abstract)
3. Subtropical South American Hailstorm Characteristics and Environments

   https://doi.org/10.1175/MWR-D-19-0011.1  

   Bruick, Zachary S.; Rasmussen, Kristen L.; Cecil, Daniel J. (November 2019, Monthly Weather Review)

   Abstract Hailstorms in subtropical South America are known to be some of the most frequent anywhere in the world, causing significant damage to the local agricultural economy every year. Convection in this region tends to be orographically forced, with moisture supplied from the Amazon rain forest by the South American low-level jet. Previous climatologies of hailstorms in this region have been limited to localized and sparse observational networks. Because of the lack of sufficient ground-based radar coverage, objective radar-derived hail climatologies have also not been produced for this region. As a result, this study uses a 16-yr dataset of TRMM Precipitation Radar and Microwave Imager observations to identify possible hailstorms remotely, using 37-GHz brightness temperature as a hail proxy. By combining satellite instruments and ERA-Interim reanalysis data, this study produces the first objective study of hailstorms in this region. Hailstorms in subtropical South America have an extended diurnal cycle, often occurring in the overnight hours. In addition, they tend to be multicellular in nature, rather than discrete. High-probability hailstorms (≥50% probability of containing hail) tend to be deeper by 1–2 km and horizontally larger by greater than 15 000 km2 than storms having a low probability of containing hail (<25% probability of containing hail). Hailstorms are supported synoptically by strong upper- and lower-level jets, anomalously warm and moist low levels, and enhanced instability. The findings of this study will support the forecasting of these severe storms and mitigation of their damage within this region. 

   more » « less
4. Accurate predictive modeling of conservation status in animal species using supervised learning

   https://doi.org/10.21203/rs.3.rs-3471388/v1  

   Aoki, Anais; Sethuraman, Arun (October 2023, Research Square)

   Abstract Conservation management to mitigate extinction of wildlife becomes more crucial than ever as global impacts due to anthropogenic activities and climate change continue to create devastation for species around the globe. Despite ongoing efforts to understand species constantly changing population dynamics due to anthropogenic stressors, there is a strong disconnect between conservation research and conservation policy, what is known as the “Conservation Gap”. The International Union of Conservation of Nature, the IUCN, is a globally recognized organization that works to sustain biodiversity by maintaining a ranking of species known as their Red List. However, the IUCN does not currently utilize genetic information to assess species conservation status despite the availability of molecular data. Here we use over 7300 studies collated from the MacroPopGen database, and over 450 published articles from the public repository DataDryad, focused on conservation and population genetics, sampling across a variety of invertebrate and vertebrate taxa, and using IUCN classifications to predict species endangerment using machine learning. Our models were able to accurately predict species threat level classified by the IUCN using both measures of genetic diversity and differentiation with IUCN assessment criteria. Our goal is to use these models to help determine and communicate conservation status to practitioners that takes into consideration all available species-specific information. 

   more » « less
5. Conservation needs to integrate knowledge across scales

   https://doi.org/10.1038/s41559-021-01605-x  

   Chaplin-Kramer, Rebecca; Brauman, Kate A.; Cavender-Bares, Jeannine; Díaz, Sandra; Duarte, Gabriela Teixeira; Enquist, Brian J.; Garibaldi, Lucas A.; Geldmann, Jonas; Halpern, Benjamin S.; Hertel, Thomas W.; et al (January 2021, Nature Ecology & Evolution)