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Sample records for agricultura tropical ciat

  1. Genomic basis of broad host range and environmental adaptability of Rhizobium tropici CIAT 899 and Rhizobium sp. PRF 81 which are used in inoculants for common bean (Phaseolus vulgaris L.)

    PubMed Central

    2012-01-01

    Background Rhizobium tropici CIAT 899 and Rhizobium sp. PRF 81 are α-Proteobacteria that establish nitrogen-fixing symbioses with a range of legume hosts. These strains are broadly used in commercial inoculants for application to common bean (Phaseolus vulgaris) in South America and Africa. Both strains display intrinsic resistance to several abiotic stressful conditions such as low soil pH and high temperatures, which are common in tropical environments, and to several antimicrobials, including pesticides. The genetic determinants of these interesting characteristics remain largely unknown. Results Genome sequencing revealed that CIAT 899 and PRF 81 share a highly-conserved symbiotic plasmid (pSym) that is present also in Rhizobium leucaenae CFN 299, a rhizobium displaying a similar host range. This pSym seems to have arisen by a co-integration event between two replicons. Remarkably, three distinct nodA genes were found in the pSym, a characteristic that may contribute to the broad host range of these rhizobia. Genes for biosynthesis and modulation of plant-hormone levels were also identified in the pSym. Analysis of genes involved in stress response showed that CIAT 899 and PRF 81 are well equipped to cope with low pH, high temperatures and also with oxidative and osmotic stresses. Interestingly, the genomes of CIAT 899 and PRF 81 had large numbers of genes encoding drug-efflux systems, which may explain their high resistance to antimicrobials. Genome analysis also revealed a wide array of traits that may allow these strains to be successful rhizosphere colonizers, including surface polysaccharides, uptake transporters and catabolic enzymes for nutrients, diverse iron-acquisition systems, cell wall-degrading enzymes, type I and IV pili, and novel T1SS and T5SS secreted adhesins. Conclusions Availability of the complete genome sequences of CIAT 899 and PRF 81 may be exploited in further efforts to understand the interaction of tropical rhizobia with common bean

  2. Effect of leguminous lectins on the growth of Rhizobium tropici CIAT899.

    PubMed

    de Vasconcelos, Mayron Alves; Cunha, Cláudio Oliveira; Arruda, Francisco Vassiliepe Sousa; Carneiro, Victor Alves; Bastos, Rafaela Mesquita; Mercante, Fábio Martins; do Nascimento, Kyria Santiago; Cavada, Benildo Sousa; dos Santos, Ricardo Pires; Teixeira, Edson Holanda

    2013-05-17

    Rhizobium tropici is a Gram-negative bacterium that induces nodules and fixed atmospheric nitrogen in symbiotic association with Phaseolus vulgaris (common bean) and some other leguminous species. Lectins are proteins that specifically bind to carbohydrates and, consequently, modulate different biological functions. In this study, the d-glucose/ d-mannose-binding lectins (from seeds of Dioclea megacarpa, D. rostrata and D. violacea) and D-galactose-binding lectins (from seeds of Bauhinia variegata, Erythina velutina and Vatairea macrocarpa) were purified using chromatographic techniques and evaluated for their effect on the growth of R. tropici CIAT899. All lectins were assayed with a satisfactory degree of purity according to SDS-PAGE analysis, and stimulated bacterial growth; in particular, the Dioclea rostrata lectin was the most active among all tested proteins. As confirmed in the present study, both d-galactose- and d-glucose/d-mannose-binding lectins purified from the seeds of leguminous plants may be powerful biotechnological tools to stimulate the growth of R. tropici CIAT99, thus improving symbiotic interaction between rhizobia and common bean and, hence, the production of this field crop.

  3. NrcR, a New Transcriptional Regulator of Rhizobium tropici CIAT 899 Involved in the Legume Root-Nodule Symbiosis

    PubMed Central

    del Cerro, Pablo; Rolla-Santos, Amanda A. P.; Valderrama-Fernández, Rocío; Gil-Serrano, Antonio; Bellogín, Ramón A.; Gomes, Douglas Fabiano; Pérez-Montaño, Francisco; Megías, Manuel; Hungría, Mariangela; Ollero, Francisco Javier

    2016-01-01

    The establishment of nitrogen-fixing rhizobium-legume symbioses requires a highly complex cascade of events. In this molecular dialogue the bacterial NodD transcriptional regulators in conjunction with plant inducers, mostly flavonoids, are responsible for the biosynthesis and secretion of Nod factors which are key molecules for successful nodulation. Other transcriptional regulators related to the symbiotic process have been identified in rhizobial genomes, including negative regulators such as NolR. Rhizobium tropici CIAT 899 is an important symbiont of common bean (Phaseolus vulgaris L.), and its genome encompasses intriguing features such as five copies of nodD genes, as well as other possible transcriptional regulators including the NolR protein. Here we describe and characterize a new regulatory gene located in the non-symbiotic plasmid pRtrCIAT899c, that shows homology (46% identity) with the nolR gene located in the chromosome of CIAT 899. The mutation of this gene, named nrcR (nolR-like plasmid c Regulator), enhanced motility and exopolysaccharide production in comparison to the wild-type strain. Interestingly, the number and decoration of Nod Factors produced by this mutant were higher than those detected in the wild-type strain, especially under salinity stress. The nrcR mutant showed delayed nodulation and reduced competitiveness with P. vulgaris, and reduction in nodule number and shoot dry weight in both P. vulgaris and Leucaena leucocephala. Moreover, the mutant exhibited reduced capacity to induce the nodC gene in comparison to the wild-type CIAT 899. The finding of a new nod-gene regulator located in a non-symbiotic plasmid may reveal the existence of even more complex mechanisms of regulation of nodulation genes in R. tropici CIAT 899 that may be applicable to other rhizobial species. PMID:27096734

  4. Tropical Whitefly IPM Project.

    PubMed

    Morales, Francisco J

    2007-01-01

    The Tropical Whitefly IPM Project (TWFP) is an initiative of the Systemwide IPM Programme of the Consultative Group on International Agricultural Research (CGIAR), financed by the Department for International Development (DFID) of the United Kingdom, the Danish International Development Agency (DANIDA), the United States Department of Agriculture (USDA) and Agency for International Development (USAID), the Australian Centre for International Agricultural Research (ACIAR), and the New Zealand Agency for International Development (NZAID), to manage whitefly pests and whitefly-transmitted viruses in the Tropics. Participating CGIAR and other international centers include the Centre for International Tropical Agriculture (CIAT); the International Institute of Tropical Agriculture (IITA); The International Potato Centre (CIP); the Asian Vegetable Research and Development Centre (AVRDC); and the International Centre of Insect Physiology and Ecology (ICIPE), in close collaboration with the National Resources Institute (NRI-UK); national agricultural research institutions; agricultural universities; and advanced agricultural research laboratories in Africa, Asia, Europe, the Pacific Region, and the Americas. The TWFP was launched in 1996 as five separate but closely linked subprojects targeting: (1) Bemisia tabaci as a vector of viruses affecting cassava and sweet potato in sub-Saharan Africa (IITA, NRI, CIP, CIAT); (2) B. tabaci as a vector of viruses in mixed cropping systems of Mexico, Central America, and the Caribbean (CIAT); (3) B. tabaci as a vector of viruses in mixed cropping systems of eastern and southern Africa (ICIPE, AVRDC); (4) B. tabaci as a vector of viruses in mixed cropping systems of Southeast Asia (AVRDC); (5) Trialeurodes vaporariorum as a pest in mixed cropping systems of the Andean highlands (CIAT); and (6) whiteflies as pests of cassava in South America (CIAT). Diagnostic surveys conducted in Phase I (1997-2000) clearly showed that the two main

  5. The structure and molecular mechanics calculations of the cyclic (1 → 2)-β- D-glucan secreted by Rhizobium tropici CIAT 899

    NASA Astrophysics Data System (ADS)

    Gil Serrano, Antonio M.; Franco-Rodríguez, Guillermo; González-Jiménez, Isabel; Tejero-Mateo, Pilar; Molina, José Molina; Dobado, J. A.; Megías, Manuel; Romero, Maria Jesús

    1993-12-01

    The structure of the extracellular cyclic (1 → 2)-β- D-glucan secreted by Rhizobium tropici CIAT 899 has been studied by methylation analysis, 1D and 2D NMR experiments, HPLC and FAB-MS. Molecular mechanics (MM2) and theoretical 3JHH coupling constants calculations were performed.

  6. Prediction of Tropical Cyclone Rapid Intensification Events

    DTIC Science & Technology

    1990-05-03

    intensification. "STR" is the subtropical ridge, "SER" the subequatorial ridge, and "TUTT" is the tropical upper tropospheric trough (Elsberry et al., 1987...161 8.2 Illustration of the effect (relative to storm motion) dual outflow channels asso- ciated with mid-latitude troughs and TUTTs have in...Rapid intensification in the NWPAC occurs mainly in the Philippine Sea region west of the Marianas Islands, east of the Philippines, and south of 25°N

  7. Tropical malabsorption

    PubMed Central

    Ramakrishna, B S; Venkataraman, S; Mukhopadhya, A

    2006-01-01

    Malabsorption is an important clinical problem both in visitors to the tropics and in native residents of tropical countries. Infections of the small intestine are the most important cause of tropical malabsorption. Protozoal infections cause malabsorption in immunocompetent hosts, but do so more commonly in the setting of immune deficiency. Helminth infections occasionally cause malabsorption or protein‐losing enteropathy. Intestinal tuberculosis, chronic pancreatitis and small‐bowel bacterial overgrowth are important causes of tropical malabsorption. In recent years, inflammatory bowel disease and coeliac disease have become major causes of malabsorption in the tropics. Sporadic tropical sprue is still an important cause of malabsorption in adults and in children in South Asia. Investigations to exclude specific infective, immunological or inflammatory causes are important before considering tropical sprue as a diagnosis. This article briefly reviews the management of tropical sprue and presents an algorithm for its investigation and management. PMID:17148698

  8. Tropical Rainforests.

    ERIC Educational Resources Information Center

    Nigh, Ronald B.; Nations, James D.

    1980-01-01

    Presented is a summary of scientific knowledge about the rainforest environment, a tropical ecosystem in danger of extermination. Topics include the current state of tropical rainforests, the causes of rainforest destruction, and alternatives of rainforest destruction. (BT)

  9. Tropical malabsorption.

    PubMed

    Ramakrishna, B S; Venkataraman, S; Mukhopadhya, A

    2006-12-01

    Malabsorption is an important clinical problem both in visitors to the tropics and in native residents of tropical countries. Infections of the small intestine are the most important cause of tropical malabsorption. Protozoal infections cause malabsorption in immunocompetent hosts, but do so more commonly in the setting of immune deficiency. Helminth infections occasionally cause malabsorption or protein-losing enteropathy. Intestinal tuberculosis, chronic pancreatitis and small-bowel bacterial overgrowth are important causes of tropical malabsorption. In recent years, inflammatory bowel disease and coeliac disease have become major causes of malabsorption in the tropics. Sporadic tropical sprue is still an important cause of malabsorption in adults and in children in South Asia. Investigations to exclude specific infective, immunological or inflammatory causes are important before considering tropical sprue as a diagnosis. This article briefly reviews the management of tropical sprue and presents an algorithm for its investigation and management.

  10. Tropical myelopathies.

    PubMed

    Román, Gustavo C

    2014-01-01

    A large number of causal agents produce spinal cord lesions in the tropics. Most etiologies found in temperate regions also occur in the tropics including trauma, herniated discs, tumors, epidural abscess, and congenital malformations. However, infectious and nutritional disorders occur with higher prevalence in tropical regions. Among the most common infectious etiologies are tuberculous Pott's disease, brucellosis, and neuroborreliosis. Parasitic diseases such as schistosomiasis, neurocysticercosis, and eosinophilic meningitis are frequent causes of nontraumatic paraplegia. The retrovirus HTLV-1 is a cause of tropical spastic paraparesis. Nutritional causes of paraparesis include deficiencies of vitamin B12 and folate; endemic clusters of konzo and tropical ataxic myeloneuropathy are associated in Africa with malnutrition and excessive consumption of cyanide-containing bitter cassava. Other toxic etiologies of tropical paraplegia include lathyrism and fluorosis. Nutritional forms of myelopathy are associated often with optic and sensory neuropathy, hence the name tropical myeloneuropathies. Acute transverse myelopathy is seen in association with vaccination, infections, and fibrocartilaginous embolism of the nucleus pulposus. Multiple sclerosis and optic myelopathy occur in the tropics but with lesser prevalence than in temperate regions. The advent of modern imaging in the tropics, including computed tomography and magnetic resonance imaging, has allowed better diagnosis and treatment of these conditions that are a frequent cause of death and disability.

  11. Tropical Deforestation.

    ERIC Educational Resources Information Center

    Raven, Peter H.

    1988-01-01

    Outlines the deforestation problem and some efforts for solving the problem. Considers the impact of population growth, poverty, and ignorance. Includes a discussion of the current rapid decline in tropical forests, the consequences of destruction, and an outlook for the future. (YP)

  12. In vitro anthelmintic activity of five tropical legumes on the exsheathment and motility of Haemonchus contortus infective larvae.

    PubMed

    von Son-de Fernex, Elke; Alonso-Díaz, Miguel Angel; Valles-de la Mora, Braulio; Capetillo-Leal, Concepción M

    2012-08-01

    This study investigated the in vitro anthelmintic (AH) activity of five tropical legume plants [Arachis pintoi CIAT 22160 (A.p. 22160), Gliricidia sepium, Cratylia argentea (C.a. Yacapani), C. argentea CIAT 22386 (C.a. 22386), C. argentea Veranera (C.a. Veranera)] against Haemonchus contortus infective larvae and the role of tannins/polyphenolic compounds in the AH effect. Lyophilized leaf extracts of each plant were evaluated using the Larval Exsheathment Inhibition Assay (LEIA) and the larval migration inhibition assay (LMIA). The role of tannins/polyphenolic compounds in the AH effect was evaluated in both assays using polyethylene glycol (PEG) to remove tannins from the solutions. At the highest concentration (1200μg of extract/ml), A. pintoi 22160, C.a. Yacapani, C.a. Veranera and C.a. 22386 completely inhibited the exsheathment process of H. contortus (P<0.01). At the same concentration (1200μg of extract/ml), the inhibition of larval migration for C.a. 22386, C.a. Veranera and G. sepium was 66.0%, 35.9% and 39.2% (relative to the PBS control), respectively. In both bioassays (LEIA and LMIA), the AH effect shown by each plant was blocked after the addition of polyethylene glycol (PEG), corroborating the role of tannins/polyphenolic compounds.

  13. Morpho-anatomical adaptations to waterlogging by germplasm accessions in a tropical forage grass

    PubMed Central

    Cardoso, Juan Andrés; Rincón, Joisse; Jiménez, Juan de la Cruz; Noguera, Diana; Rao, Idupulapati M.

    2013-01-01

    Soil waterlogging reduces gas exchange between the soil and the atmosphere, leading to oxygen deprivation in the rhizosphere. Brachiaria spp. are the most widely sown forage grasses in tropical America. Among commercial Brachiaria grasses, B. humidicola shows superior tolerance to waterlogged soils based on maintenance of growth and reduced leaf chlorophyll loss and senescence. However, little is known about the underlying traits of waterlogging tolerance in B. humidicola or their intraspecific variation. For this purpose, an outdoor study was conducted using 12 germplasm accessions of B. humidicola that were grown in soil cylinders under drained or waterlogged soil conditions for 21 days. Dry mass production and morpho-anatomical responses (aerenchyma in shoots and roots, root diameter, proportional area of stele in roots, number of nodal and lateral roots, and length of the longest root) were determined. All accessions showed shorter roots and reduced root dry mass under waterlogged soil conditions. All accessions showed aerenchyma in shoots and roots under drained conditions but were further increased under waterlogging. All accessions showed a reduction in the proportional area of stele of roots in response to waterlogging. The accession (CIAT 26570) that showed a higher proportion of aerenchyma in shoots and roots and an increased number of nodal roots (with higher diameter and a reduction in the number of lateral roots) showed longer roots, less reduction in root dry mass and increased shoot growth under waterlogged conditions. We conclude that superior growth of one accession (CIAT 26570) under waterlogged soil conditions is probably a result of morpho-anatomical traits acting together to enhance root aeration and shoot ventilation. Further research is needed to test the ability to recover from waterlogging in B. humidicola accessions.

  14. Tropical forests

    SciTech Connect

    Not Available

    1985-01-01

    Major international aid and nongovernmental groups have agreed on a strategy to conserve tropical forests. Their plan calls for a $5.3 billion, five-year program for the 56 most critically affected countries. This report consists of three parts. The Plan details the costs of deforestation in both developing and industrialized countries, uncovers its real causes, and outlines a five-part action plan. Case Studies reviews dozens of detailed accounts of successful forest management projects from around the world, covering wide-ranging ecological conditions and taking into account the economics of forest products in different marketing situations. Country Investment Profiles spell out country-by-country listings of what should be done, who should do it, and how much it will cost.

  15. Tropical Convection's Roles in Tropical Tropopause Cirrus

    NASA Technical Reports Server (NTRS)

    Boehm, Matthew T.; Starr, David OC.; Verlinde, Johannes; Lee, Sukyoung

    2002-01-01

    The results presented here show that tropical convection plays a role in each of the three primary processes involved in the in situ formation of tropopause cirrus. First, tropical convection transports moisture from the surface into the upper troposphere. Second, tropical convection excites Rossby waves that transport zonal momentum toward the ITCZ, thereby generating rising motion near the equator. This rising motion helps transport moisture from where it is detrained from convection to the cold-point tropopause. Finally, tropical convection excites vertically propagating tropical waves (e.g. Kelvin waves) that provide one source of large-scale cooling near the cold-point tropopause, leading to tropopause cirrus formation.

  16. Tropical Cyclone Report, 1993

    DTIC Science & Technology

    1993-01-01

    Office of Naval Research (;rant AN00014-914J1721 STAFF JOINT TYPHOON WARNING CENTER LCDR ANTHONY A. MARTINEZ USN TDO. DEPUTY DIRECTOR LCDR TERESA M...OEJFN TDA. GRAPHICS AGAN ANDRESG.GRANT USN TDA, GRAPHICS UNIVERSITY OF GUAM / JTWC RESEARCH LIAISON DR MARK A. LANDER TROPICAL CYCLONE RESEARCH MR...CHARLES P. GUARD TROPICAL CYCLONE RESEARCH * TRANSFERRED DURING 1993 ** ACTIVE DUTY TRAINING S~ii FOREWORD The Annual Tropical Cyclone Report is past four

  17. Deforestation in the Tropics

    SciTech Connect

    Repetto, R. )

    1990-04-01

    Government policies that encourage exploitation--in particular excessive logging and clearing for ranches and farms--are largely to blame for the accelerating destruction of tropical forests. This paper surveys the problem in detail and briefly recommends potential solutions.

  18. Tropical Cyclone Nargis: 2008

    NASA Video Gallery

    This new animation, developed with the help of NASA's Pleiades supercomputer, illustrates how tropical cyclone Nargis formed in the Indian Ocean's Bay of Bengal over several days in late April 2008...

  19. Tropical Storm Faxai

    NASA Video Gallery

    NASA/JAXA's TRMM Satellite provided data of developing Tropical Storm Faxai to make this 3-D image that showed some towering thunderstorms in the area were reaching altitudes of up to 15.5km/~9.6 m...

  20. Tropical Storm Don

    NASA Video Gallery

    GOES-13 data was compiled into an animation by the NASA GOES Project at NASA Goddard that shows the development of Tropical Storm Don in the southern Gulf of Mexico, west of Cuba. The animation run...

  1. Tropical Storm Dolly Develops

    NASA Video Gallery

    This animation from NOAA's GOES-East satellite from Aug. 31-Sept. 2 shows the movement of a low pressure area from the western Caribbean Sea over the Yucatan Peninsula as it becomes Tropical Storm ...

  2. Tropical Cyclone Report, 1988

    DTIC Science & Technology

    1988-01-01

    TAIWAN NAVPGSCOL LIBRARY CITIES SERVICES OIL GAS CORP NAVPOLAROCEANCEN SUITLAND CIUDAD UNIVERSITARIA , MEXICO NAVAL RESEARCH LAB CIVIL DEFENSE, SAIPAN...The system software has been provided An effort is now underway to develop a to OAO Corporation for inclusion in the JTWC series of examples...winds in the range of 34 to speed, typically within one degree of the center of a 63 kt (17 to 32 m/sec) inclusive . tropical cyclone. TROPICAL UPPER

  3. Neglected Tropical Diseases outside the Tropics

    PubMed Central

    Norman, Francesca F.; Pérez de Ayala, Ana; Pérez-Molina, José-Antonio; Monge-Maillo, Begoña; Zamarrón, Pilar; López-Vélez, Rogelio

    2010-01-01

    Background The neglected tropical diseases (NTDs) cause significant morbidity and mortality worldwide. Due to the growth in international travel and immigration, NTDs may be diagnosed in countries of the western world, but there has been no specific focus in the literature on imported NTDs. Methods Retrospective study of a cohort of immigrants and travelers diagnosed with one of the 13 core NTDs at a Tropical Medicine Referral Unit in Spain during the period April 1989-December 2007. Area of origin or travel was recorded and analyzed. Results There were 6168 patients (2634 immigrants, 3277 travelers and 257 VFR travelers) in the cohort. NTDs occurred more frequently in immigrants, followed by VFR travelers and then by other travelers (p<0.001 for trend). The main NTDs diagnosed in immigrants were onchocerciasis (n = 240, 9.1%) acquired mainly in sub-Saharan Africa, Chagas disease (n = 95, 3.6%) in immigrants from South America, and ascariasis (n = 86, 3.3%) found mainly in immigrants from sub-Saharan Africa. Most frequent NTDs in travelers were: schistosomiasis (n = 43, 1.3%), onchocerciasis (n = 17, 0.5%) and ascariasis (n = 16, 0.5%), and all were mainly acquired in sub-Saharan Africa. The main NTDs diagnosed in VFR travelers were onchocerciasis (n = 14, 5.4%), and schistosomiasis (n = 2, 0.8%). Conclusions The concept of imported NTDs is emerging as these infections acquire a more public profile. Specific issues such as the possibility of non-vectorial transmission outside endemic areas and how some eradication programmes in endemic countries may have an impact even in non-tropical western countries are addressed. Recognising NTDs even outside tropical settings would allow specific prevention and control measures to be implemented and may create unique opportunities for research in future. PMID:20668546

  4. [Research in tropical medicine].

    PubMed

    Dumas, Michel; Preux, Pierre-Marie

    2013-10-01

    In France, research in tropical medicine is carried out by the Institute for Research and Development (IRD), university-affiliated institutes, and other research organizations such as INSERM, CNRS and the Pasteur Institute. Currently, this research is highly fragmented and therefore inefficient. As a result, despite significant financial means, French research in this field is not sufficiently competitive. This research activity should be coordinated by creating a "federation ", that would 1) facilitate the sharing of material and human resources, thereby improving efficiency and resulting in cost savings; 2) valorize French research in tropical medicine and its expert know-how, thus favoring the nomination of French experts in large international research programs (French experts in tropical medicine are currently under-recognized); 3) attract young researchers from France and elsewhere; and 4) adapt to the ongoing demographic and economic evolution of tropical countries. The creation of a Federation of French researchers would also make research in tropical medicine more visible. The objectives to which it leads already must include 1) a better understanding of the priorities of countries in the southern hemisphere, taking into account the social, cultural and economic contexts and ensuring the consistency of current and future projects ; 2) strengthening of research networks in close and equal partnership with researchers in the southern hemisphere, with pooling of resources (scientific, human and material) to reach the critical mass required for major projects ; 3) promoting the emergence of centers of excellence for health research in tropical countries ; and 4) contributing more effectively to training, because there can be no training without research, and no research without training This consolidation will help to empower research in tropical medicine, as in other Western countries, and will allow France to recover the place it deserves. The specific

  5. Grey swan tropical cyclones

    NASA Astrophysics Data System (ADS)

    Lin, Ning; Emanuel, Kerry

    2016-01-01

    We define `grey swan’ tropical cyclones as high-impact storms that would not be predicted based on history but may be foreseeable using physical knowledge together with historical data. Here we apply a climatological-hydrodynamic method to estimate grey swan tropical cyclone storm surge threat for three highly vulnerable coastal regions. We identify a potentially large risk in the Persian Gulf, where tropical cyclones have never been recorded, and larger-than-expected threats in Cairns, Australia, and Tampa, Florida. Grey swan tropical cyclones striking Tampa, Cairns and Dubai can generate storm surges of about 6 m, 5.7 m and 4 m, respectively, with estimated annual exceedance probabilities of about 1/10,000. With climate change, these probabilities can increase significantly over the twenty-first century (to 1/3,100-1/1,100 in the middle and 1/2,500-1/700 towards the end of the century for Tampa). Worse grey swan tropical cyclones, inducing surges exceeding 11 m in Tampa and 7 m in Dubai, are also revealed with non-negligible probabilities, especially towards the end of the century.

  6. Tropical cyclone formation

    SciTech Connect

    Montgomery, M.T.; Farrell, B.F. )

    1993-01-15

    The physics of tropical cyclone formation is not well understood, and more is known about the mature hurricane than the formative mechanisms that produce it. It is believed part of the reason for this can be traced to insufficient upper-level atmospheric data. Recent observations suggest that tropical cyclones are initiated by asymmetric interactions associated with migratory upper-level potential vorticity disturbances and low-level disturbances. Favored theories of cyclones formation, however, focus on internal processes associated with cumulus convection and/or air-sea interaction. This work focuses on external mechanisms of cyclone formation and, using both a two- and three-dimensional moist geostrophic momentum model, investigates the role of upper-level potential vorticity disturbances on the formation process. A conceptual model of tropical cyclone formation is proposed, and implications of the theory are discussed. 71 refs., 5 figs., 1 tab.

  7. Tropical forecasting - Predictability perspective

    NASA Technical Reports Server (NTRS)

    Shukla, J.

    1989-01-01

    Results are presented of classical predictability studies and forecast experiments with observed initial conditions to show the nature of initial error growth and final error equilibration for the tropics and midlatitudes, separately. It is found that the theoretical upper limit of tropical circulation predictability is far less than for midlatitudes. The error growth for a complete general circulation model is compared to a dry version of the same model in which there is no prognostic equation for moisture, and diabatic heat sources are prescribed. It is found that the growth rate of synoptic-scale errors for the dry model is significantly smaller than for the moist model, suggesting that the interactions between dynamics and moist processes are among the important causes of atmospheric flow predictability degradation. Results are then presented of numerical experiments showing that correct specification of the slowly varying boundary condition of SST produces significant improvement in the prediction of time-averaged circulation and rainfall over the tropics.

  8. Tropical Rainfall Measuring Mission

    NASA Technical Reports Server (NTRS)

    1999-01-01

    Tropical rainfall affects the lives and economics of a majority of the Earth's population. Tropical rain systems, such as hurricanes, typhoons, and monsoons, are crucial to sustaining the livelihoods of those living in the tropics. Excess rainfall can cause floods and great property and crop damage, whereas too little rainfall can cause drought and crop failure. The latent heat release during the process of precipitation is a major source of energy that drives the atmospheric circulation. This latent heat can intensify weather systems, affecting weather thousands of kilometers away, thus making tropical rainfall an important indicator of atmospheric circulation and short-term climate change. Tropical forests and the underlying soils are major sources of many of the atmosphere's trace constituents. Together, the forests and the atmosphere act as a water-energy regulating system. Most of the rainfall is returned to the atmosphere through evaporation and transpiration, and the atmospheric trace constituents take part in the recycling process. Hence, the hydrological cycle provides a direct link between tropical rainfall and the global cycles of carbon, nitrogen, and sulfur, all important trace materials for the Earth's system. Because rainfall is such an important component in the interactions between the ocean, atmosphere, land, and the biosphere, accurate measurements of rainfall are crucial to understanding the workings of the Earth-atmosphere system. The large spatial and temporal variability of rainfall systems, however, poses a major challenge to estimating global rainfall. So far, there has been a lack of rain gauge networks, especially over the oceans, which points to satellite measurement as the only means by which global observation of rainfall can be made. The Tropical Rainfall Measuring Mission (TRMM), jointly sponsored by the National Aeronautics and Space Administration (NASA) of the United States and the National Space Development Agency (NASDA) of

  9. Rain Forests: Tropical Treasures.

    ERIC Educational Resources Information Center

    Braus, Judy, Ed.

    1989-01-01

    Ranger Rick's NatureScope is a creative education series dedicated to inspiring in children an understanding and appreciation of the natural world while developing the skills they will need to make responsible decisions about the environment. The topic of this issue is "Rain Forests: Tropical Treasures." Contents are organized into the…

  10. NRL Tropical Exposure Facilities

    DTIC Science & Technology

    1947-04-01

    canal. To the east, on the opposite side of Limon Bay, lies Cristobal , Coco Solo, and Colon . Travel between Fort Sherman and Cristobal is accomplished...precision equipment. I 4 NRL TROPICAL EXPOSURE FACILITIES 5 Accessibility Proximity of the station to the port of Cristobal and to the Naval Air Station

  11. Assessing Tropical Cyclone Damage

    NASA Astrophysics Data System (ADS)

    Done, J.; Czajkowski, J.

    2012-12-01

    Landfalling tropical cyclones impact large coastal and inland areas causing direct damage due to winds, storm-surge flooding, tornadoes, and precipitation; as well as causing substantial indirect damage such as electrical outages and business interruption. The likely climate change impact of increased tropical cyclone intensity, combined with increases in exposure, bring the possibility of increased damage in the future. A considerable amount of research has focused on modeling economic damage due to tropical cyclones, and a series of indices have been developed to assess damages under climate change. We highlight a number of ways this research can be improved through a series of case study analyses. First, historical loss estimates are revisited to properly account for; time, impacted regions, the source of damage by type, and whether the damage was direct/indirect and insured/uninsured. Second, the drivers of loss from both the socio-economic and physical side are examined. A case is made to move beyond the use of maximum wind speed to more stable metrics and the use of other characteristics of the wind field such as direction, degree of gustiness, and duration is explored. A novel approach presented here is the potential to model losses directly as a function of climate variables such as sea surface temperature, greenhouse gases, and aerosols. This work is the first stage in the development of a tropical cyclone loss model to enable projections of losses under scenarios of both socio-economic change (such as population migration or altered policy) and physical change (such as shifts in tropical cyclone activity one from basin to another or within the same basin).

  12. Advances in commercial application of gamma radiation in tropical fruits at Brazil

    NASA Astrophysics Data System (ADS)

    Sabato, S. F.; Silva, J. M.; Cruz, J. N.; Broisler, P. O.; Rela, P. R.; Salmieri, S.; Lacroix, M.

    2009-07-01

    All regions of Brazil are potential areas for growing tropical fruits. As this country is already a great producer and exporter of tropical fruits, ionizing radiation has been the subject of studies in many commodities. An important project has been carried out to increase the commercial use of gamma radiation in our country. Instituto de Pesquisas Energeticas e Nucleares (IPEN)-CNEN/SP together with field producers in northeast region and partners like International Atomic Energy Agency (IAEA), CIC, Empresa Brasileira Pesquisa na Agricultura (EMBRAPA) joined to demonstrate this technology, its application and commercial feasibility. The objective of this study is to show advances in feasibility demonstrate the quality of the irradiated fruits in an international consignment from Brazil to Canada. In this work, Tommy Atkins mangoes harvested in northeast region of Brazil were sent to Canada. The fruits were treated in a gamma irradiation facility at doses 0.4 and 1.0 kGy. The control group was submitted to hydrothermal treatment (46 °C for 110 min). The fruits were stored at 11 °C for 10 days until the international transportation and kept at an environmental condition (22 °C) for 12 days, where their physical-chemical and sensorial properties were evaluated. The financial part of the feasibility study covers the scope of the investment, including the net working capital and production costs.

  13. Seasonal Variation of Ozone in the Tropical Lower Stratosphere: Southern Tropics are Different from Northern Tropics

    NASA Technical Reports Server (NTRS)

    Stolarski, Richard S.; Waugh, Darryn W.; Wang, Lei,; Oman, Luke D.; Douglass, Anne R.; Newman, Paul A.

    2014-01-01

    We examine the seasonal behavior of ozone by using measurements from various instruments including ozonesondes, Aura Microwave Limb Sounder, and Stratospheric Aerosol and Gas Experiment II. We find that the magnitude of the annual variation in ozone, as a percentage of the mean ozone, exhibits a maximum at or slightly above the tropical tropopause. The maximum is larger in the northern tropics than in the southern tropics, and the annual maximum of ozone in the southern tropics occurs 2 months later than that in the northern tropics, in contrast to usual assumption that the tropics can be treated as a horizontally homogeneous region. The seasonal cycles of ozone and other species in this part of the lower stratosphere result from a combination of the seasonal variation of the Brewer-Dobson circulation and the seasonal variation of tropical and midlatitude mixing. In the Northern Hemisphere, the impacts of upwelling and mixing between the tropics and midlatitudes on ozone are in phase and additive. In the Southern Hemisphere, they are not in phase. We apply a tropical leaky pipe model independently to each hemisphere to examine the relative roles of upwelling and mixing in the northern and southern tropical regions. Reasonable assumptions of the seasonal variation of upwelling and mixing yield a good description of the seasonal magnitude and phase in both the southern and northern tropics. The differences in the tracers and transport between the northern and southern tropical stratospheres suggest that the paradigm of well-mixed tropics needs to be revised to consider latitudinal variations within the tropics.

  14. Tropical Diabetic Hand Syndrome

    PubMed Central

    Okpara, TC; Ezeala-Adikaibe, BA; Omire, O; Nwonye, E; Maluze, J

    2015-01-01

    Any adult with diabetes in the tropics with hand cellulitis, infection and gangrene qualifies for tropical diabetic hand syndrome (TDHS). We reviewed a 39-year-old woman with a 3-week history of swelling of the left index finger following an insect bite. The swelling progressively increased in size, was very painful, and extended to the palm. There was no history or symptoms suggestive of chronic complications of diabetes. Random blood sugar on presentation was above 600 mg/dl using a glucometer. Examination revealed an edematous left palm draining pus from multiple sinuses, necrotic and gangrenous left index finger extending down to just above the thenar eminence. A diagnosis of TDHS in a patient with hyperosmolar state was made. She was managed accordingly and subsequently underwent aggressive debridement and desloughing. Two fingers were amputated and the wound was allowed to heal by secondary intention. PMID:27057390

  15. Tuberculosis in tropical Africa

    PubMed Central

    Roelsgaard, E.; Iversen, E.; Bløcher, C.

    1964-01-01

    Up to the end of the nineteenth century the tubercle bacillus apparently had little opportunity of disseminating among the rather isolated tribes of tropical Africa. With the creation of large centres of trade and industry in the wake of European colonization, tuberculosis seems to have spread rapidly over the continent and is today found everywhere. In a number of tuberculosis prevalence surveys conducted by WHO during 1955-60, randomly selected population groups were tuberculin tested, X-rayed and had sputa examined by direct microscopy. The three methods of examination were applied independently of one another. Data collected during the surveys have been analysed with a view to discovering common epidemiological features of tuberculosis in tropical Africa, assessing the reliability of the diagnostic methods employed and discussing their usefulness in future tuberculosis control programmes. PMID:14178027

  16. Tropical Cyclone Report, 1986.

    DTIC Science & Technology

    1986-01-01

    following: would be unwarranted at lower risk levels. A rule for deciding such actions can be derived on an expected outcome basis (e.g. cost/ benefits ...responsi- Changes to this year’s publication include: raw bility. fix data files usually printed in Annex A, plus the raw warning, forecast and best...for this report; to the Navy represents data obtained by the tropical cyclone Publications and Printing Service Branch Office, satellite surveillance

  17. Tropical ecotoxicology: The state of the environment in the tropics

    SciTech Connect

    Lacher, T.E. Jr. |; Goldstein, M.I.

    1995-12-31

    Ecotoxicology has focused almost exclusively on temperate zone countries and ecosystems. Tropical ecosystems, including rain forest, tropical dry forest, savanna, wetlands and freshwater ecosystems, have been neglected. These ecosystems combined might contain as much as 75% of global biodiversity. Tropical ecosystems are under increasing threat of development and alteration. The major causes of habitat degradation in the tropics include population growth and urbanization, agricultural expansion, deforestation, and mining. Some of these activities (in particular agriculture, mining, and the manufacturing and chemical industries) also lead to the release of toxic substances into the environment. Little research in ecotoxicology has been done in tropical environments and techniques and procedures developed for temperate environments are often applied, even though physical and chemical environmental parameters in the tropics can be very different. The regulatory environment also varies from country to country. The authors present an extensive literature review of tropical ecotoxicology, with a focus on Latin America and the Caribbean. Most research has focused on water quality and aquatic toxicology. Virtually no research has been done on the effects of toxic substance on tropical wildlife. They present a protocol for tropical ecotoxicology that addresses the special problems associated with doing ecotoxicological research in the tropics. The authors discuss the issue of adapting temperate zone principles and methods to tropical environments. Finally, they discuss priority areas for immediate research. These include large scale agricultural activities, especially bananas, pineapples, and soybeans and gold mining with the associated heavy use of mercury. The authors also present a prioritization of tropical wildlife that appear to be at highest risk of exposure to toxic substances.

  18. Tropical fevers: Management guidelines.

    PubMed

    Singhi, Sunit; Chaudhary, Dhruva; Varghese, George M; Bhalla, Ashish; Karthi, N; Kalantri, S; Peter, J V; Mishra, Rajesh; Bhagchandani, Rajesh; Munjal, M; Chugh, T D; Rungta, Narendra

    2014-02-01

    Tropical fevers were defined as infections that are prevalent in, or are unique to tropical and subtropical regions. Some of these occur throughout the year and some especially in rainy and post-rainy season. Concerned about high prevalence and morbidity and mortality caused by these infections, and overlapping clinical presentations, difficulties in arriving at specific diagnoses and need for early empiric treatment, Indian Society of Critical Care Medicine (ISCCM) constituted an expert committee to develop a consensus statement and guidelines for management of these diseases in the emergency and critical care. The committee decided to focus on most common infections on the basis of available epidemiologic data from India and overall experience of the group. These included dengue hemorrhagic fever, rickettsial infections/scrub typhus, malaria (usually falciparum), typhoid, and leptospira bacterial sepsis and common viral infections like influenza. The committee recommends a 'syndromic approach' to diagnosis and treatment of critical tropical infections and has identified five major clinical syndromes: undifferentiated fever, fever with rash / thrombocytopenia, fever with acute respiratory distress syndrome (ARDS), fever with encephalopathy and fever with multi organ dysfunction syndrome. Evidence based algorithms are presented to guide critical care specialists to choose reliable rapid diagnostic modalities and early empiric therapy based on clinical syndromes.

  19. TROPICAL COLLECTOR URCHIN, TRIPNEUSTES ...

    EPA Pesticide Factsheets

    This document describes a fertilization method to estimate the chronic toxicity of effluents and receiving waters to the gametes of the tropical sea urchin (Tripneustes gratilla). This toxicity test measures the fertilizing capacity of sperm following a static, non-renewal 60-minute exposure and a subsequent 20-minute exposure period following the addition of eggs. The purpose of the test is to determine the concentrations of a test substance diluted in sea water that reduce fertilization of exposed gametes relative to that of the control. This method was developed to provide an assessment of the toxicity of materials discharged into the marine environment, using biota indigenous to tropical Pacific regions, including Hawaii. This method provides an assessment of the toxicity to indigenous biota of materials discharged into the tropical Pacific marine environment. The use of this method contributes to risk based determinations, and the scientific foundation they provide for regulatory criteria at the state, regional or national levels. General impacts from this contribution include improved understanding by managers and scientists of links between human activities, natural dynamics, ecological stressors and ecosystem condition.

  20. 1989 Annual Tropical Cyclone Report

    DTIC Science & Technology

    2007-11-02

    z TYPHOON GAY (32W) The fust tropical cyclone of November turned out to be the worst tropical cyclone to affect the Malay Peninsula in 35 years... Gay developed in the Gulf of Thailand, crossed the Malay Peninsula into the Bay of Bengal and slammed into India with peak sustained winds of 140 kt...70 rn/see). Unique because of its small size, intensity, and point of origin, Gay challenged forecasters by crossing two different tropical cyclone

  1. The EEG of tropical encephalopathies.

    PubMed

    Mallewa, Macpherson; Birbeck, Gretchen L

    2013-10-01

    In addition to encountering most of the conditions treated by clinicians in the West, clinicians in the tropics are faced with unique tropical encephalopathies. These are largely but not entirely infectious in nature. Despite the relatively low cost of EEG technology, it remains unavailable in many low-income tropical settings even at the tertiary care level. Where available, the EEG recordings and interpretation are often of unacceptable quality. Nonetheless, there are existing data on the EEG patterns seen in malaria and a number of tropical viral, bacterial, and parasitic infestations.

  2. Energetics of tropical hibernation.

    PubMed

    Dausmann, K H; Glos, J; Heldmaier, G

    2009-04-01

    In this field study, the energetic properties of tropical hibernation were investigated by measuring oxygen consumption and body temperature of the Malagasy primate Cheirogaleus medius in their natural hibernacula. These lemurs use tree holes with extremely varying insulation capacities as hibernacula. In poorly insulated tree holes, tree hole temperature and body temperature fluctuated strongly each day (between 12.8 and 34.4 degrees C). The metabolic rate under these conditions also showed large daily fluctuations between about 29.0 ml O(2)/h and 97.9 ml O(2)/h in parallel with changes in body temperature. In well insulated tree holes in very large trees on the other hand, tree hole temperature and body temperature remained relatively constant at about 25 degrees C. Lemurs hibernating in these tree holes showed a more constant metabolic rate at an intermediate level, but hibernation was interrupted by repeated arousals with peak metabolic rates up to 350 ml O(2)/h. The occurrence of these spontaneous arousals proved that the ability for thermoregulation persists during hibernation. Arousals were energetically costly, but much less so than in temperate and arctic hibernators. Despite the decisive influence of tree hole properties on the pattern of body temperature and metabolic rate during hibernation, the choice of the hibernaculum does not seem to be of energetic importance. The overall energetic savings by tropical hibernation amounted to about 70% as compared to the active season (31.5 vs. 114.3 kJ/d). Therefore, tropical hibernation in C. medius is an effective, well-regulated adaptive response to survive unfavourable seasons.

  3. Atlantic tropical cyclones revisited

    NASA Astrophysics Data System (ADS)

    Mann, Michael E.; Emanuel, Kerry A.; Holland, Greg J.; Webster, Peter J.

    Vigorous discussions have taken place recently in Eos [e.g., Mann and Emanuel, 2006; Landsea, 2007] and elsewhere [Emanuel, 2005; Webster et al., 2005; Hoyos et al., 2006; Trenberth and Shea, 2006; Kossin et al., 2007] regarding trends in North Atlantic tropical cyclone (TC) activity and their potential connection with anthropogenic climate change. In one study, for example [Landsea, 2007], it is argued that a substantial underestimate of Atlantic tropical cyclone counts in earlier decades arising from insufficient observing systems invalidates the conclusion that trends in TC behavior may be connected to climate change. Here we argue that such connections are in fact robust with respect to uncertainties in earlier observations.Several recent studies have investigated trends in various measures of TC activity. Emanuel [2005] showed that a measure of total power dissipation by TCs (the power dissipation index, or PDI) is highly correlated with August-October sea surface temperatures (SST) over the main development region (MDR) for Atlantic TCs over at least the past half century. Some support for this conclusion was provided by Sriver and Ruber [2006]. Webster et al. [2005] demonstrated a statistically significant increase in recent decades in both the total number of the strongest category cyclones (categories 4 and 5) and the proportion of storms reaching hurricane intensity. Hoyos et al. [2006] showed that these increases were closely tied to warming trends in tropical Atlantic SST, while, for example, the modest decrease in vertical wind shear played a more secondary role. Kossin et al. [2007] called into question some trends in other basins, based on a reanalysis of past TC data, but they found the North Atlantic trends to be robust.

  4. Seven Guideposts for Tropical Rain Forest Education.

    ERIC Educational Resources Information Center

    Rillero, Peter

    1999-01-01

    Identifies seven guideposts for tropical rain forest education. Aids teachers in finding structure and creating educational experiences that promote more complete understanding of tropical rain forests. (CCM)

  5. Combating tropical deforestation in Haiti

    SciTech Connect

    Pellek, R.

    1990-09-01

    This article outlines the findings of Tropical Forestry Action Plan (TFAP), which was part of an international initiative on tropical deforestation. Ten specific recommendations are addressed. Haiti has lost more than 97% of its forestland, so emphasis should be placed on replenishing the forest cover.

  6. Tropical Rainforest Education. ERIC Digest.

    ERIC Educational Resources Information Center

    Rillero, Peter

    This digest provides four guideposts for tropical rainforest education: (1) structure; (2) location and climate; (3) importance; and (4) conservation of resources. Research is cited and background information provided about the layers of life and the adaptations of life within the tropical rain forest. Aspects of life within and near rain forests…

  7. Tropical Soda Apple (Solanum viarum)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Tropical soda apple (Solanum viarum Dunal), a perennial shrub, is a Federal Noxious Weed that continues to spread at an alarming rate in the southeastern United States. Information is provided on the impact of tropical soda apple on agricultural and natural areas, federal regulations for restricted...

  8. Botany, Chemistry, and Tropical Development.

    ERIC Educational Resources Information Center

    Headrick, Daniel R.

    1996-01-01

    Examines the role played by botany and chemistry in the development, exploitation, and later deterioration of tropical economies. Although near equals in 19th-century international trade, the development of synthetics by European scientists in the early 20th century crippled the tropical economies. Research, innovation, and investment protected…

  9. Tropical Cyclone Information System

    NASA Technical Reports Server (NTRS)

    Li, P. Peggy; Knosp, Brian W.; Vu, Quoc A.; Yi, Chao; Hristova-Veleva, Svetla M.

    2009-01-01

    The JPL Tropical Cyclone Infor ma tion System (TCIS) is a Web portal (http://tropicalcyclone.jpl.nasa.gov) that provides researchers with an extensive set of observed hurricane parameters together with large-scale and convection resolving model outputs. It provides a comprehensive set of high-resolution satellite (see figure), airborne, and in-situ observations in both image and data formats. Large-scale datasets depict the surrounding environmental parameters such as SST (Sea Surface Temperature) and aerosol loading. Model outputs and analysis tools are provided to evaluate model performance and compare observations from different platforms. The system pertains to the thermodynamic and microphysical structure of the storm, the air-sea interaction processes, and the larger-scale environment as depicted by ocean heat content and the aerosol loading of the environment. Currently, the TCIS is populated with satellite observations of all tropical cyclones observed globally during 2005. There is a plan to extend the database both forward in time till present as well as backward to 1998. The portal is powered by a MySQL database and an Apache/Tomcat Web server on a Linux system. The interactive graphic user interface is provided by Google Map.

  10. Cardiomegaly in tropical Africa.

    PubMed

    Tomaszewski, Ryszard

    2012-01-01

    The term "cardiomegaly" is found in 5-7% of chest X-ray film evaluations in tropical Africa. However, "cardiomegaly" is a descriptive term, devoid of any aetiological meaning. Therefore, providing information about the aetiological factors leading to heart enlargement in a group of Africans (Nigerians) was the purpose of this study. In the years 2002-2011, 170 subjects (aged 17-80 years, mean age 42 years) in whom "cardiomegaly" was revealed by chest radiographs were studied at the Madonna University Teaching Hospital, Elele. The patients underwent echocardiography, electrocardiography, and several appropriate laboratory tests. Arterial hypertension was found to be most frequently associated with heart enlargement (39.4%), followed by dilated cardiomyopathy (21.76%), endomyocardial fibrosis (14.1%), valvular defects (9.4%), cardiac enlargement in the course of sickle-cell anaemia (6.47%), and schistosomal cor pulmonale (3.52%). This study is a contribution to a better aetiological elucidation of "cardiomegaly" in the tropics and emphasizes the importance of arterial hypertension as one of its causative factors. The dire need for effective treatment of hypertensive patients becomes evident. A high prevalence of elevated blood pressure seems to reflect an impact of civilization-related factors on the African communities.

  11. Tropical pediatrics: 2002 to 2015.

    PubMed

    Santos Ocampo, Perla D; Santos Ocampo-Padilla, Cynthia

    2003-01-01

    It also presents the challenges that confront children in the tropics and their effects on the health of these children. These challenges include the technology divide, economic disparity, ecological changes, urbanization and industrialization, globalization, political instability, population explosion, and gender inequality. The paper paints a scenario of tropical pediatrics into the year 2015. Problems brought about by both underdevelopment and modernization, with urbanization and industrialization, will persist. Infectious diseases will continue to be the leading causes of deaths. The paper presents some significant achievements in the fight against tropical diseases and tries to predict what future progress will contribute to the alleviation of such diseases. The paper also outlines the commitment of the International Society of Tropical Pediatrics (ISTP) to improve the state of tropical pediatrics in the next 15 years.

  12. Intensive rainfall recharges tropical groundwaters

    NASA Astrophysics Data System (ADS)

    Jasechko, Scott; Taylor, Richard G.

    2015-12-01

    Dependence upon groundwater to meet rising agricultural and domestic water needs is expected to increase substantially across the tropics where, by 2050, over half of the world’s population is projected to live. Rare, long-term groundwater-level records in the tropics indicate that groundwater recharge occurs disproportionately from heavy rainfalls exceeding a threshold. The ubiquity of this bias in tropical groundwater recharge to intensive precipitation is, however, unknown. By relating available long-term records of stable-isotope ratios of O and H in tropical precipitation (15 sites) to those of local groundwater, we reveal that groundwater recharge in the tropics is near-uniformly (14/15 sites) biased to intensive monthly rainfall, commonly exceeding the ∼70th intensity decile. Our results suggest that the intensification of precipitation brought about by global warming favours groundwater replenishment in the tropics. Nevertheless, the processes that transmit intensive rainfall to groundwater systems and enhance the resilience of tropical groundwater storage in a warming world, remain unclear.

  13. Micro irrigation of tropical fruit crops

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In most tropical regions, tropical fruits are grown either in wet-and-dry climates characterized by erratic rainfall patterns and prolonged dry periods or in fertile but semiarid lands under irrigation. Little is known about water requirements of tropical crops grown in the tropics. This book chapt...

  14. Cloudsat Dissects Tropical Storm Ileana

    NASA Video Gallery

    NASA's CloudSat satellite's Cloud Profiling Radar captured a sideways look across Tropical Storm Ileana on Aug. 27 at 20:40 UTC. The colors indicate intensity of reflected radar energy. The blue ar...

  15. GPM: Hurricanes Beyond the Tropics

    NASA Video Gallery

    NASA's Global Precipitation Measurement mission, or GPM, a joint NASA/JAXA mission, will provide rainfall data on storms and hurricanes like Irene that move out of the tropics. The data will be ava...

  16. Tropical Storm Lee to Newfoundland

    NASA Video Gallery

    This video shows Tropical Storm Lee as it made landfall in Louisiana and Mississippi on September 4, 2011. This storm produced flooding and tornadoes to the southern states all the way to flooding ...

  17. Ecology: The Tropical Deforestation Debt.

    PubMed

    Norris, Ken

    2016-08-22

    Tropical deforestation is a significant cause of global carbon emissions and biodiversity loss. A new study shows that deforestation today leaves a carbon and biodiversity debt to be paid over subsequent years. This has potentially profound implications for forest conservation.

  18. Tropical Storm Faxai's Rainfall Rates

    NASA Video Gallery

    This animation shows Tropical Storm Faxai's rainfall rates on March 2 from a TRMM TMI/PR rainfall analysis being faded in over infrared cloud data from the TRMM VIRS instrument. Credit: SSAI/NASA, ...

  19. Annual Tropical Cyclone Report 2011

    DTIC Science & Technology

    2012-05-24

    the southern tip of Honshu as it completed extra-tropical transition, bringing heavy rainfall and flooding to mainland Japan. Table 1-5. JTWC and...with the outer spiral bands produced flash floods and landslides across the Northern Philippines resulting in four fatalities1 (Figure 1-9...weakened and underwent extra-tropical transition, it continued to produce heavy rain and flooding with 13 fatalities5 reported in mainland Japan. In the

  20. Paradigms for Tropical Cyclone Intensification

    DTIC Science & Technology

    2014-03-01

    Tang and Emanuel 2010 and references), it is imperative to have a firm understanding of the physical processes of intensity change for...defensible when studying the basic physics of tropical cyclone intensification (Nguyen et al. 2008, section 3.2.1), but not, of course, for tropical...They recalled that the premise underlying all physical parameteriszations is that some aspect of the chaotic microscale process is in statistical

  1. 1993 Annual Tropical Cyclone Report

    DTIC Science & Technology

    1995-01-01

    Cover Caption: As viewed on 301604Z September by the Andersen AFB, Guam Next Generation (Doppler W-ther) Radar ( NEXRAD ), the bands of precipitation...basis for our analyses, forecasts and post analyses; the staff at National Oceanic and Atmospheric Administration ( NOAA ) National Environmental Satellite...Doppler Weather Radar’s ( NEXRAD ) introduction to tropical meteorology. Depicted on the cover graphic is Tropical Storm Ed seen from the Guam NEXRAD

  2. Treatment of tropical mycoses.

    PubMed

    Restrepo, A

    1994-09-01

    Several subcutaneous and deep-seated mycoses are either observed more frequently in the tropical areas or are restricted to certain regions within the tropics. These mycoses include sporotichosis, chromoblastomycosis, entomophthoromycosis, eumycetoma, lobomycosis, and paracoccidioidomycosis. In sporotrichosis and paracoccidioidomycosis, therapy often results in either complete resolution or marked improvement. For decades sporotrichosis has been treated successfully with potassium iodide, but recently the triazole compounds, especially itraconazole, have proved effective and free of major side effects. The usual therapy for paracoccidioidomycosis is sulfonamides or amphotericin B; the former requires prolonged treatment, whereas the latter causes a significant degree of toxicity. Various azole derivatives (ketoconazole, fluconazole, saperconazole, and itraconazole) allow shorter treatment courses, can be given orally, and are more effective. Presently, itraconazole is the drug of choice. Chromoblastomycosis is a difficult condition to treat, especially if it is caused by Fonsecaea pedrosoi. Several therapeutic approaches have been used, including heat, surgery, cryotherapy, thiabendazole, amphotericin B combined with flucytosine, and azole derivatives, but their success has been modest. A 65% response rate has been obtained with itraconazole given for periods of 6 to 19 months; in limited trials, saperconazole appears to be more effective and requires shorter treatment courses. Only a few patients with eumycetoma respond to therapy; 70% of patients with Madurella mycetomatis respond to prolonged treatment with ketoconazole. Griseofulvin has been tried in nonresponders with partial success. Limited data in patients with Fusarium species eumycetoma indicate good responses to itraconazole. Eumycetoma caused by Pseudallescheria boydii or Acremonium species has been refractory to therapy. Therapy of entomophthoromycosis is also difficult because the diagnosis is usually

  3. Tropical Cyclone Gonu

    NASA Technical Reports Server (NTRS)

    2007-01-01

    You might expect to see a storm with near-perfect symmetry and a well-defined eye hovering over the warm waters of the Caribbean or in the South Pacific, but Tropical Cyclone Gonu showed up in an unusual place. On June 4, 2007, when the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA's Aqua satellite captured this image, Tropical Cyclone Gonu was approaching the northeastern shore of Oman, a region better known for hot desert conditions. Though rare, cyclones like Gonu are not unheard of in the northern Indian Ocean basin. Most cyclones that form in the region form over the Bay of Bengal, east of India. Those that take shape over the Arabian Sea, west of the Indian peninsula, tend to be small and fizzle out before coming ashore. Cyclone Gonu is a rare exception. As of June 4, 2007, the powerful storm had reached a dangerous Category Four status, and it was forecast to graze Oman's northeastern shore, following the Gulf of Oman. According to storm statistics maintained on Unisys Weather, the last storm of this size to form over the Arabian Sea was Cyclone 01A, which tracked northwest along the coast of India between May 21 and May 28, 2001. Unlike Gonu's forecasted track, Cyclone 01A never came ashore. MODIS acquired this photo-like image at 12:00 p.m. local time (9:00 UTC), a few hours after the Joint Typhoon Warning Center estimated Gonu's sustained winds to be over 240 kilometers per hour (145 miles per hour). The satellite image confirms that Gonu was a super-powerful cyclone. The storm has the hallmark tightly wound arms that spiral around a well-defined, circular eye. The eye is surrounded by a clear wall of towering clouds that cast shadows on the surrounding clouds. Called hot towers, these clouds are a sign of the powerful uplift that feeds the storm. The symmetrical spirals, clear eye, and towering clouds are all features regularly seen in satellite images of other particularly powerful cyclones, which are also known as typhoons or hurricanes

  4. Climate Adaptation of Tropical Cattle.

    PubMed

    Barendse, W

    2017-02-08

    There is sustained growth in the number of tropical cattle, which represent more than half of all cattle worldwide. By and large, most research in tropical areas is still focused on breeds of cattle, their particular advantages or disadvantages in tropical areas, and the tropical forages or feeds that could be usefully fed to them. A consistent issue for adaptation to climate is the heat of tropical environments. Changing the external characteristics of the animal, such as color and coat characteristics, is one way to adapt, and there are several major genes for these traits. However, further improvement in heat tolerance and other adaptation traits will need to use the entire genome and all physical and physiological systems. Apart from the response to heat, climate forcing through methane emission identifies dry season weight loss as an important if somewhat neglected trait in climate adaptation of cattle. The use of genome-estimated breeding values in tropical areas is in its infancy and will be difficult to implement, but will be essential for rapid, coordinated genetic improvement. The difficulty of implementation cannot be exaggerated and may require major improvements in methodology.

  5. Animation of Flood Potential from Two Australian Tropical Cyclones

    NASA Video Gallery

    Merged precipitation data from NASA-JAXA's Tropical Rainfall Measuring Mission (TRMM) and other satellites was used to calculate flood potential withrainfall from Tropical Cyclone Lam and Tropical ...

  6. Tropical Cyclone Indlala

    NASA Technical Reports Server (NTRS)

    2007-01-01

    On March 14, 2007, storm-weary Madagascar braced for its fourth land-falling tropical cyclone in as many months. Cyclone Indlala was hovering off the island's northeast coast when the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA's Aqua satellite captured this photo-like image at 1:40 p.m. local time (10:40 UTC). Just over a hundred kilometers offshore, the partially cloudy eye at the heart of the storm seems like a vast drain sucking in a disk of swirling clouds. According to reports from the Joint Typhoon Warning Center issued less than three hours after MODIS captured this image, Indlala had winds of 115 knots (132 miles per hour), with gusts up to 140 knots (161 mph). Wave heights were estimated to be 36 feet. At the time of the report, the storm was predicted to intensify through the subsequent 12-hour period, to turn slightly southwest, and to strike eastern Madagascar as a Category 4 storm with sustained winds up to 125 knots (144 mph), and gusts up to 150 knots (173 mph). According to Reuters AlertNet news service, Madagascar's emergency response resources were taxed to their limit in early March 2007 as a result of extensive flooding in the North, drought and food shortages in the South, and three previous hits from cyclones in the preceding few months: Bondo in December 2006, Clovis in January 2007, and Gamede in February.

  7. Tropical cyclone activity over the Southwest Tropical Indian Ocean

    NASA Astrophysics Data System (ADS)

    Burns, Jessica M.; Subrahmanyam, Bulusu; Nyadjro, Ebenezer S.; Murty, V. S. N.

    2016-08-01

    The Southwest Tropical Indian Ocean (SWTIO) is a key region for air-sea interaction. Tropical cyclones (TCs) regularly form over the SWTIO and subsurface ocean variability influences the cyclogenesis of this region. Tropical cyclone days for this region span from November through April, and peak in January and February during austral summer. Past research provides evidence for more tropical cyclone days over the SWTIO during austral summer (December-June) with a deep thermocline ridge than in austral summer with a shallow thermocline ridge. We have analyzed the Argo temperature data and HYbrid Coordinate Ocean Model (HYCOM) outputs while focusing on the austral summer of 2012/2013 (a positive Indian Ocean Dipole (IOD) year and neutral El Niño Southern Oscillation (ENSO) year) when seven named tropical cyclones developed over the SWTIO region. This study reveals that the climatic events like the IOD and ENSO influence the cyclonic activity and number of TC days over the SWTIO. We ascertain that the IOD events have linkages with the Barrier Layer Thickness (BLT) in the SWTIO region through propagating Rossby waves, and further show that the BLT variability influences the cyclonic activity in this region.

  8. Where will tropical cyclogenesis occur around a preexisting tropical cyclone?

    NASA Astrophysics Data System (ADS)

    Shi, Wenli; Fei, Jianfang; Huang, Xiaogang; Ma, Zhanhong

    2017-01-01

    An observational study focusing on the locations of tropical cyclogenesis induced by tropical cyclone energy dispersion (TCED) in the western North Pacific is conducted. Statistical results indicate that the cyclogenesis cases associated with TCED widely occur around preexisting tropical cyclones (TCs). In addition to the typical scenario of cyclogenesis to the southeast of a preexisting TC, new TCs can even form in the east or southwest directions at distances ranging from 1000 km to 3500 km. Further analyses reveal that the locations of cyclogenesis are mainly governed by large-scale environments via regulating the patterns of Rossby wave trains. The observational relationships between wave train regimes and the structures of environmental flows are revealed, which are broadly consistent with previous idealized numerical simulations. The results in this study provide a valuable reference for the prediction of cyclogenesis considering the TCED mechanism.

  9. Tropical Cyclogenesis in a Tropical Wave Critical Layer: Easterly Waves

    NASA Technical Reports Server (NTRS)

    Dunkerton, T. J.; Montgomery, M. T.; Wang, Z.

    2009-01-01

    The development of tropical depressions within tropical waves over the Atlantic and eastern Pacific is usually preceded by a "surface low along the wave" as if to suggest a hybrid wave-vortex structure in which flow streamlines not only undulate with the waves, but form a closed circulation in the lower troposphere surrounding the low. This structure, equatorward of the easterly jet axis, is identified herein as the familiar critical layer of waves in shear flow, a flow configuration which arguably provides the simplest conceptual framework for tropical cyclogenesis resulting from tropical waves, their interaction with the mean flow, and with diabatic processes associated with deep moist convection. The recirculating Kelvin cat's eye within the critical layer represents a sweet spot for tropical cyclogenesis in which a proto-vortex may form and grow within its parent wave. A common location for storm development is given by the intersection of the wave's critical latitude and trough axis at the center of the cat's eye, with analyzed vorticity centroid nearby. The wave and vortex live together for a time, and initially propagate at approximately the same speed. In most cases this coupled propagation continues for a few days after a tropical depression is identified. For easterly waves, as the name suggests, the propagation is westward. It is shown that in order to visualize optimally the associated Lagrangian motions, one should view the flow streamlines, or stream function, in a frame of reference translating horizontally with the phase propagation of the parent wave. In this co-moving frame, streamlines are approximately equivalent to particle trajectories. The closed circulation is quasi-stationary, and a dividing streamline separates air within the cat's eye from air outside.

  10. Maize, tropical (Zea mays L.).

    PubMed

    Assem, Shireen K

    2015-01-01

    Maize (Zea mays L.) is the third most important food crop globally after wheat and rice. In sub-Saharan Africa, tropical maize has traditionally been the main staple of the diet; 95 % of the maize grown is consumed directly as human food and as an important source of income for the resource-poor rural population. The biotechnological approach to engineer biotic and abiotic traits implies the availability of an efficient plant transformation method. The production of genetically transformed plants depends both on the ability to integrate foreign genes into target cells and the efficiency with which plants are regenerated. Maize transformation and regeneration through immature embryo culture is the most efficient system to regenerate normal transgenic plants. However, this system is highly genotype dependent. Genotypes adapted to tropic areas are difficult to regenerate. Therefore, transformation methods used with model genotypes adapted to temperate areas are not necessarily efficient with tropical lines. Agrobacterium-mediated transformation is the method of choice since it has been first achieved in 1996. In this report, we describe a transformation method used successfully with several tropical maize lines. All the steps of transformation and regeneration are described in details. This protocol can be used with a wide variety of tropical lines. However, some modifications may be needed with recalcitrant lines.

  11. APR-2 Tropical Cyclone Observations

    NASA Technical Reports Server (NTRS)

    Durden, S. L.; Tanelli, S.

    2011-01-01

    The Second Generation Airborne Precipitation Radar (APR-2) participated in the Genesis and Rapid Intensification Processes (GRIP) experiment in August and September of 2010, collecting a large volume of data in several tropical systems, including Hurricanes Earl and Karl. Additional measurements of tropical cyclone have been made by APR-2 in experiments prior to GRIP (namely, CAMEX-4, NAMMA, TC4); Table 1 lists all the APR-2 tropical cyclone observations. The APR-2 observations consist of the vertical structure of rain reflectivity at 13.4 and 35.6 GHz, and at both co-polarization and crosspolarization, as well as vertical Doppler measurements and crosswind measurements. APR-2 normally flies on the NASA DC-8 aircraft, as in GRIP, collecting data with a downward looking, cross-track scanning geometry. The scan limits are 25 degrees on either side of the aircraft, resulting in a roughly 10-km swath, depending on the aircraft altitude. Details of the APR-2 observation geometry and performance can be found in Sadowy et al. (2003).The multiparameter nature of the APR-2 measurements makes the collection of tropical cyclone measurements valuable for detailed studies of the processes, microphysics and dynamics of tropical cyclones, as well as weaker systems that are associated with tropical cyclone formation. In this paper, we give a brief overview of how the APR-2 data are processed. We also discuss use of the APR-2 cross-track winds to estimate various quantities of interest in in studies of storm intensification. Finally, we show examples of the standard products and derived information.

  12. Structure of Developing Tropical Cyclones

    NASA Astrophysics Data System (ADS)

    Molinari, J. E.

    2006-12-01

    Considerable progress has been made in the numerical modeling of tropical cyclones. The very high resolution now routinely used in research models allows realistic simulation of eyewall structure and breakdown, vortex Rossby waves, and numerous other processes that were beyond the capability of previous generations of models. At least one aspect of tropical cyclones, however, has not been reproduced in the current generation of models: early development (or lack of development) during tropical depression and early tropical storm stages. During such times, vertical wind shear often plays a critical role. In this presentation, details of the structure of four tropical cyclones at early stages will be given: Claudette (2003), Danny (1997), Gabrielle (2001), and Edouard (2002). The first three contained intense vortices that formed within downshear convection. Deep-layer vertical wind shear ranged from 8-15 m/s in the storms. In Claudette, a hurricane formed that lasted only 6 hours. In Danny and Gabrielle, the downshear vortices became the new storm center. One became a hurricane and one did not. In Edouard, vertical shear was even larger. Convection fluctuated between downshear of the center and over the center, with analogous intensity changes. This behavior is known to forecasters, but the causes of such fluctuations remain uncertain. The evolving structure of these four storms will be shown, with emphasis on the variation of convection, equivalent potential temperature in the lower troposphere, and azimuthal asymmetries of wind and circulation. Contrast will be made between the structure of forming tropical cyclones in nature and those seen in mesoscale numerical models. Some remarks will be given on the key physical processes that must be simulated.

  13. Tropical Depression Alex hits Yucatan Peninsula

    NASA Video Gallery

    NASA's TRMM spacecraft observed this view of Tropical Depression Alex on June 27, 2010 at 2214 UTC (6:14 PM EST). Tropical depression Alex was near the western coast of Mexico's Yucatan Peninsula. ...

  14. Satellite Sees Birth of Tropical Storm Gordon

    NASA Video Gallery

    An animation of satellite observations from August 13-16, 2012, shows the birth of the Atlantic Ocean hurricane season's eighth tropical depression that strengthens into Tropical Storm Gordon. This...

  15. Tropical Storm Debby Moves into Atlantic

    NASA Video Gallery

    An animation of satellite observations shows the progression of Tropical Storm Debby from June 25-27, 2012. The animation shows that Tropical Storm Debby's center move from the northeastern Gulf of...

  16. Anthocyanins Present in Some Tropical Fruits.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Many tropical fruits are rich in anthocyanins, though limited information is available about the characterization and quantification of these anthocyanins. The identification of anthocyanin pigments in four tropical fruits was determined by ion trap mass spectrometry. Fruits studied included acero...

  17. Glacial climate in the tropics

    SciTech Connect

    Broecker, W.

    1996-06-28

    New findings have caused ideas about the Earth`s climate during the Pleistocene glaciation to change. A consensus seems to be forming that during times of glaciation, climatic conditions in the tropics were quite different from those today. However still to be explained is why strontium-calcium measurements on corals and moble gas measurements of ground water suggest a tropical cooling of 4-6 C while foraminiferal speciation, oxygen isotope, and alkenone results suggest a cooling of no more than 3 C. This article discusses different aspects of the debate. 9 refs., 1 fig.

  18. Tropical Storm Erin

    NASA Technical Reports Server (NTRS)

    2007-01-01

    Location: The Atlantic Ocean 210 miles south of Galveston, Texas Categorization: Tropical Storm Sustained Winds: 40 mph (60 km/hr)

    [figure removed for brevity, see original site] [figure removed for brevity, see original site] Infrared ImageMicrowave Image

    Infrared Images Because infrared radiation does not penetrate through clouds, AIRS infrared images show either the temperature of the cloud tops or the surface of the Earth in cloud-free regions. The lowest temperatures (in purple) are associated with high, cold cloud tops that make up the top of the storm. In cloud-free areas the AIRS instrument will receive the infrared radiation from the surface of the Earth, resulting in the warmest temperatures (orange/red).

    Microwave Images In the AIRS microwave imagery, deep blue areas in storms show where the most precipitation occurs, or where ice crystals are present in the convective cloud tops. Outside of these storm regions, deep blue areas may also occur over the sea surface due to its low radiation emissivity. On the other hand, land appears much warmer due to its high radiation emissivity.

    Microwave radiation from Earth's surface and lower atmosphere penetrates most clouds to a greater or lesser extent depending upon their water vapor, liquid water and ice content. Precipitation, and ice crystals found at the cloud tops where strong convection is taking place, act as barriers to microwave radiation. Because of this barrier effect, the AIRS microwave sensor detects only the radiation arising at or above their location in the atmospheric column. Where these barriers are not present, the microwave sensor detects radiation arising throughout the air column and down to the surface. Liquid surfaces (oceans, lakes and rivers) have 'low emissivity' (the signal isn't as strong) and their radiation brightness temperature is therefore low. Thus the ocean also appears 'low temperature' in the AIRS microwave images and is assigned the color blue

  19. Black Swan Tropical Cyclones

    NASA Astrophysics Data System (ADS)

    Emanuel, K.; Lin, N.

    2012-12-01

    Virtually all assessments of tropical cyclone risk are based on historical records, which are limited to a few hundred years at most. Yet stronger TCs may occur in the future and at places that have not been affected historically. Such events lie outside the realm of historically based expectations and may have extreme impacts. Their occurrences are also often made explainable after the fact (e.g., Hurricane Katrina). We nickname such potential future TCs, characterized by rarity, extreme impact, and retrospective predictability, "black swans" (Nassim Nicholas Taleb, 2007). As, by definition, black swan TCs have yet to happen, statistical methods that solely rely on historical track data cannot predict their occurrence. Global climate models lack the capability to predict intense storms, even with a resolution as high as 14 km (Emanuel et al. 2010). Also, most dynamic downscaling methods (e.g., Bender et al. 2010) are still limited in horizontal resolution and are too expensive to implement to generate enough events to include rare ones. In this study, we apply a simpler statistical/deterministic hurricane model (Emanuel et al. 2006) to simulate large numbers of synthetic storms under a given (observed or projected) climate condition. The method has been shown to generate realistic extremes in various basins (Emanuel et al. 2008 and 2010). We also apply a hydrodynamic model (ADCIRC; Luettich et al. 1992) to simulate the storm surges generated by these storms. We then search for black swan TCs, in terms of the joint wind and surge damage potential, in the generated large databases. Heavy rainfall is another important TC hazard and will be considered in a future study. We focus on three areas: Tampa Bay in the U.S., the Persian Gulf, and Darwin in Australia. Tampa Bay is highly vulnerable to storm surge as it is surrounded by shallow water and low-lying lands, much of which may be inundated by a storm tide of 6 m. High surges are generated by storms with a broad

  20. Introduction to Biology, Tropical Edition.

    ERIC Educational Resources Information Center

    Mackean, D. G.

    This pupil's reference book is intended to provide biological information, using plants and animals which are suitable for study over a wide range of tropical countries. Its topics are taken mostly from the biology syllabi for the British General Certification of Education at the Ordinary Level and are written principally for pupils in the last…

  1. The future of tropical forests.

    PubMed

    Wright, S Joseph

    2010-05-01

    Five anthropogenic drivers--land use change, wood extraction, hunting, atmospheric change, climate change--will largely determine the future of tropical forests. The geographic scope and intensity of these five drivers are in flux. Contemporary land use change includes deforestation (approximately 64,000 km(2) yr(-1) for the entire tropical forest biome) and natural forests regenerating on abandoned land (approximately 21,500 km(2) yr(-1) with just 29% of the biome evaluated). Commercial logging is shifting rapidly from Southeast Asia to Africa and South America, but local fuelwood consumption continues to constitute 71% of all wood production. Pantropical rates of net deforestation are declining even as secondary and logged forests increasingly replace old-growth forests. Hunters reduce frugivore, granivore and browser abundances in most forests. This alters seed dispersal, seed and seedling survival, and hence the species composition and spatial template of plant regeneration. Tropical governments have responded to these local threats by protecting 7% of all land for the strict conservation of nature--a commitment that is only matched poleward of 40 degrees S and 70 degrees N. Protected status often fails to stop hunters and is impotent against atmospheric and climate change. There are increasing reports of stark changes in the structure and dynamics of protected tropical forests. Four broad classes of mechanisms might contribute to these changes. Predictions are developed to distinguish among these mechanisms.

  2. Tropical Biological Drawings with Notes.

    ERIC Educational Resources Information Center

    Mitchelmore, June A.

    The annotated illustrations of biological specimens useful for illustrating the "tropical" topics dealt with in African secondary school biology courses are designed to serve a two-fold purpose. The diagrams are intended to show the pupil the structures he should be looking for in his laboratory work, with the textual material being an…

  3. Skin Diseases in the Tropics.

    ERIC Educational Resources Information Center

    Mahe, Antoine; And Others

    1994-01-01

    Common skin diseases are prevalent in tropical countries because of extreme weather conditions, mediocre hygiene, and lack of adequate treatment of infectious dermatoses. This guide describes the major endemic skin diseases and their signs for the purpose of helping unspecialized health agents train themselves and determine when a patient should…

  4. Tropical Animal Tour Packet. Metro.

    ERIC Educational Resources Information Center

    Metro Washington Park Zoo, Portland, OR. Educational Services Div.

    This packet is designed to assist teachers in creating a tropical animals lesson plan that centers around a visit to the zoo. A teacher packet is divided into eight parts: (1) goals and objectives; (2) what to expect at the zoo; (3) student activities (preparatory activities, on-site activities, and follow-up activities); (4) background…

  5. Tropical Storms Bud and Dera

    NASA Technical Reports Server (NTRS)

    2001-01-01

    Like dancers pirouetting in opposite directions, the rotational patterns of two different tropical storms are contrasted in this pair of MISR nadir-camera images.

    The left-hand image is of Tropical Storm Bud, acquired on June 17, 2000 (Terra orbit 2656) as the storm was dissipating. Bud was situated in the eastern Pacific Ocean between Socorro Island and the southern tip of Baja California. South of the storm's center is a vortex pattern caused by obstruction of the prevailing flow by tiny Socorro Island. Sonora, Mexico and Baja California are visible at the top of the image.

    The right-hand image is of Tropical Cyclone Dera, acquired on March 12, 2001 (Terra orbit 6552). Dera was located in the Indian Ocean, south of Madagascar. The southern end of this large island is visible in the top portion of this image.

    Northern hemisphere tropical storms, like Bud, rotate in a counterclockwise direction, whereas those in the southern hemisphere, such as Dera, rotate clockwise. The opposite spins are a consequence of Earth's rotation.

    Each image covers a swath approximately 380 kilometers wide.

    MISR was built and is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Office of Earth Science, Washington, DC. The Terra satellite is managed by NASA's Goddard Space Flight Center, Greenbelt, MD. JPL is a division of the California Institute of Technology.

  6. Tropical Storms Bud and Dera

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Like dancers pirouetting in opposite directions, the rotational patterns of two different tropical storms are contrasted in this pair of Multi-angle Imaging Spectroradiometer (MISR) nadir-camera images. The left-hand image is of Tropical Storm Bud, acquired on June 17, 2000 (Terra orbit 2656) as the storm was dissipating. Bud was situated in the eastern Pacific Ocean between Socorro Island and the southern tip of Baja California. South of the storm's center is a vortex pattern caused by obstruction of the prevailing flow by tiny Socorro Island. Sonora, Mexico and Baja California are visible at the top of the image. The right-hand image is of Tropical Cyclone Dera, acquired on March 12, 2001. Dera was located in the Indian Ocean, south of Madagascar. The southern end of this large island is visible in the top portion of this image. Northern hemisphere tropical storms, like Bud, rotate in a counterclockwise direction, whereas those in the southern hemisphere, such as Dera, rotate clockwise. The opposite spins are a consequence of Earth's rotation. Each image covers a swath approximately 380 kilometers wide. Image courtesy NASA/JPL/GSFC/LaRC, MISR Team

  7. Tropical Cyclone Ensemble Data Assimilation

    DTIC Science & Technology

    2012-09-30

    described above, but using a vertical window of influence of 2.0 times the scale hight . Notice that meaningful vertical correlation is found by LETKF...between the scatterometer observation and many points throughout the troposphere. This suggests that for assimilation near tropical cyclones that have

  8. Tropical cyclogenesis in a tropical wave critical layer: easterly waves

    NASA Astrophysics Data System (ADS)

    Dunkerton, T. J.; Montgomery, M. T.; Wang, Z.

    2008-06-01

    The development of tropical depressions within tropical waves over the Atlantic and eastern Pacific is usually preceded by a "surface low along the wave" as if to suggest a hybrid wave-vortex structure in which flow streamlines not only undulate with the waves, but form a closed circulation in the lower troposphere surrounding the low. This structure, equatorward of the easterly jet axis, resembles the familiar critical layer of waves in shear flow, a flow configuration which arguably provides the simplest conceptual framework for tropical cyclogenesis resulting from tropical waves, their interaction with the mean flow, and with diabatic processes associated with deep moist convection. The critical layer represents a sweet spot for tropical cyclogenesis in which a proto-vortex may form and grow within its parent wave. A common location for storm development within the critical layer is given by the intersection of the wave's critical latitude and trough axis, with analyzed vorticity centroid nearby. The wave and vortex live together for a time, and initially propagate at approximately the same speed. In most cases this coupled propagation continues for a few days after a tropical depression is identified. For easterly waves, as the name suggests, the propagation is westward. It is shown that in order to visualize optimally this "marsupial paradigm" one should view the flow streamlines, or stream function, in a frame of reference translating horizontally with the phase propagation of the parent wave. This translation requires an appropriate "gauge" that renders translating streamlines and isopleths of translating stream function approximately equivalent to flow trajectories. In the translating frame, the closed circulation is stationary, and a dividing streamline effectively separates air within the critical layer from air outside. The critical layer equatorward of the easterly jet axis is important to tropical cyclogenesis because it provides (i) a region of

  9. Tropical cyclogenesis in a tropical wave critical layer: easterly waves

    NASA Astrophysics Data System (ADS)

    Dunkerton, T. J.; Montgomery, M. T.; Wang, Z.

    2009-08-01

    The development of tropical depressions within tropical waves over the Atlantic and eastern Pacific is usually preceded by a "surface low along the wave" as if to suggest a hybrid wave-vortex structure in which flow streamlines not only undulate with the waves, but form a closed circulation in the lower troposphere surrounding the low. This structure, equatorward of the easterly jet axis, is identified herein as the familiar critical layer of waves in shear flow, a flow configuration which arguably provides the simplest conceptual framework for tropical cyclogenesis resulting from tropical waves, their interaction with the mean flow, and with diabatic processes associated with deep moist convection. The recirculating Kelvin cat's eye within the critical layer represents a sweet spot for tropical cyclogenesis in which a proto-vortex may form and grow within its parent wave. A common location for storm development is given by the intersection of the wave's critical latitude and trough axis at the center of the cat's eye, with analyzed vorticity centroid nearby. The wave and vortex live together for a time, and initially propagate at approximately the same speed. In most cases this coupled propagation continues for a few days after a tropical depression is identified. For easterly waves, as the name suggests, the propagation is westward. It is shown that in order to visualize optimally the associated Lagrangian motions, one should view the flow streamlines, or stream function, in a frame of reference translating horizontally with the phase propagation of the parent wave. In this co-moving frame, streamlines are approximately equivalent to particle trajectories. The closed circulation is quasi-stationary, and a dividing streamline separates air within the cat's eye from air outside. The critical layer equatorward of the easterly jet axis is important to tropical cyclogenesis because its cat's eye provides (i) a region of cyclonic vorticity and weak deformation by the

  10. Influenza Burden and Transmission in the Tropics.

    PubMed

    Ng, Sophia; Gordon, Aubree

    Each year, influenza causes substantial mortality and morbidity worldwide. It is important to understand influenza in the tropics because of the significant burden in the region and its relevance to global influenza circulation. In this review, influenza burden, transmission dynamics, and their determinants in the tropics are discussed. Environmental, cultural, and social conditions in the tropics are very diverse and often differ from those of temperate regions. Theories that account for and predict influenza dynamics in temperate regions do not fully explain influenza epidemic patterns observed in the tropics. Routine surveillance and household studies have been useful in understanding influenza dynamics in the tropics, but these studies have been limited to only some regions; there is still a lack of information regarding influenza burden and transmission dynamics in many tropical countries. Further studies in the tropics will provide useful insight on many questions that remain.

  11. Remote tropical and sub-tropical responses to Amazon deforestation

    NASA Astrophysics Data System (ADS)

    Badger, Andrew M.; Dirmeyer, Paul A.

    2016-05-01

    Replacing natural vegetation with realistic tropical crops over the Amazon region in a global Earth system model impacts vertical transport of heat and moisture, modifying the interaction between the atmospheric boundary layer and the free atmosphere. Vertical velocity is decreased over a majority of the Amazon region, shifting the ascending branch and modifying the seasonality of the Hadley circulation over the Atlantic and eastern Pacific oceans. Using a simple model that relates circulation changes to heating anomalies and generalizing the upper-atmosphere temperature response to deforestation, agreement is found between the response in the fully-coupled model and the simple solution. These changes to the large-scale dynamics significantly impact precipitation in several remote regions, namely sub-Saharan Africa, Mexico, the southwestern United States and extratropical South America, suggesting non-local climate repercussions for large-scale land use changes in the tropics are possible.

  12. Tropical Cyclone Forecasters Reference Guide 2. Tropical Climatology

    DTIC Science & Technology

    1992-04-01

    tropical circulation and weather patterns, and vice versa. Time-lapsed movies of cloud imageries from geostationary satellites often show cloud bands...intense low tropospheric convergence and moisture, convective cloudiness, and rainfall prevail in and to the east of the trough. Cloud clusters...seen on satellite cloud imageries, are usually associated with the waves. A majority of these waves are cold-core, and the axis of the wave tilts toward

  13. Genital manifestations of tropical diseases

    PubMed Central

    Richens, J

    2004-01-01

    Genital symptoms in tropical countries and among returned travellers can arise from a variety of bacterial, protozoal, and helminthic infections which are not usually sexually transmitted. The symptoms may mimic classic sexually transmitted infections (STIs) by producing ulceration (for example, amoebiasis, leishmaniasis), wart-like lesions (schistosomiasis), or lesions of the upper genital tract (epididymo-orchitis caused by tuberculosis, leprosy, and brucellosis; salpingitis as a result of tuberculosis, amoebiasis, and schistosomiasis). A variety of other genital symptoms less suggestive of STI are also seen in tropical countries. These include hydrocele (seen with filariasis), which can be no less stigmatising than STI, haemospermia (seen with schistosomiasis), and hypogonadism (which may occur in lepromatous leprosy). This article deals in turn with genital manifestations of filariasis, schistosomiasis, amoebiasis, leishmaniasis, tuberculosis and leprosy and gives clinical presentation, diagnosis, and treatment. PMID:14755029

  14. University of the humid tropics

    NASA Astrophysics Data System (ADS)

    The creation of a foundation called the University of the Humid Tropics (UNITROP) was announced by Brazilian atmospheric scientist Luiz Carlos Molion at the AGU Chapman Conference on Global Biomass Burning, held March 23 in Williamsburg, Va. The headquarters for UNITROP is in Manaus, Amazonia, Brazil. UNITROP is not a university in a narrow sense, but an institution created and run by scientists with the purpose of understanding Amazonia and developing it socio-economically in harmony with its environment, Molion said.The scientific objectives of UNITROP are: Research: Promote, organize and fund researchers and research in Amazonia, encompassing all branches of science, from social and aboriginal issues to biogeophysicalchemical processes, and leading to an integrated understanding of the tropical forest environment and its transformation.

  15. Health crusades and tropical diseases.

    PubMed

    Weller, T H

    1980-03-01

    Worldwide attempts to eradicate yaws, malaria, and smallpox have all been effective to varying extents, and all have taught some valuable lessons that should be taken into account as a new global crusade is mounted against tropical diseases. But it should not be forgotten that infectious disease remains a major public health problem in the U.S., and new diseases are arising to replace those already vanquished.

  16. The Dynamics of Tropical Cyclones

    DTIC Science & Technology

    2016-06-07

    include three different representations of cumulus convection . Realistic simulations of hurricanes have been carried out with the model. The model...tropical cyclones. We have completed a study of the convective destabilization by an approaching upper level trough and a joint paper on this topic with a...the study has been accepted for publication (Thorncroft and Jones, 2000). We have prepared a review paper on the role of cumulus convection in

  17. Tropical Timbers of the World,

    DTIC Science & Technology

    1980-04-01

    excelsa reported not resistant to decay while A. indica is rated as durable to moderately durable. Preservation: Heartwood is not treatable but sapwood...Azadirachta indica ) from the Republic of the Sudan. FPRL consignments Nos. 1307 and 1374, Forest Products Research Laboratory, Princes Risborough. 566 .e r...Pahutan (Philippines). Distribution: Throughout tropical Asia, most species found in Malaya. M. indica produces the mango fruit of commerce and has

  18. Annual Tropical Cyclone Report, 1984.

    DTIC Science & Technology

    1984-01-01

    Mauna Kea . Further north, Hong Kong reported Taiwan. The sea level pressure of Lanyu gusts to 60 kt (31 m/s) with the passage of (WMO 46762), located...confirmed by the USS Mauna Kea (AE22) which Luichow Peninsula, and weakened rapidly as inadvertently passed very close to Wynne’s it moved inland. The...China. No forecast . " problems were encountered with Tropical - - The Hong Kong Royal Observatory (WMO Storm Betty since it moved steadily to the 45005

  19. Annual Tropical Cyclone Report 2010

    DTIC Science & Technology

    2010-01-01

    period of rapid intensification. Tropical Cyclone 04B matured as a relatively small cyclone, its upper-level cirrus cloud shield spanning... defined cirrus outflow streak poleward of the low-level circulation center around 22/00Z. These structural changes are evident in the satellite imagery...erratically based on the upper level cloud patterns and convective maxima. It was not until visible imagery became available, that the two low level

  20. Rain from Tropical Storm Noel

    NASA Technical Reports Server (NTRS)

    2007-01-01

    Though not the most powerful storm of the 2007 Atlantic Hurricane season, Tropical Storm Noel was among the most deadly. Only Category 5 Hurricane Felix and its associated flooding had a higher toll. The slow-moving Tropical Storm Noel inundated the Dominican Republic, Haiti, Jamaica, Cuba, and the Bahamas with heavy rain between October 28 and November 1, 2007. The resulting floods and mudslides left at least 115 dead and thousands homeless throughout the Caribbean, reported the Associated Press on November 2, 2007. This image shows the distribution of the rainfall that made Noel a deadly storm. The image shows rainfall totals as measured by the Multi-satellite Precipitation Analysis (MPA) at NASA Goddard Space Flight Center from October 26 through November 1, 2007. The analysis is based on measurements taken by the Tropical Rainfall Measuring Mission (TRMM) satellite. The heaviest rainfall fell in the Dominican Republic and the Bahamas, northeast of Noel's center. Areas of dark red show that rainfall totals over the south-central Dominican Republic and parts of the Bahamas were over 551 millimeters (21 inches). Much of eastern Hispaniola, including both the Dominican Republic and Haiti received at least 200 mm (about 8 inches) of rain, shown in yellow. Rainfall totals over Haiti and Cuba were less, with a range of at least 50 mm (2 inches) to over 200 mm (8 inches).

  1. Recent advances in tropical medicine.

    PubMed

    Solomon, Anthony W; Nayagam, Shevanthi; Pasvol, Geoffrey

    2009-07-01

    There have been significant advances in both the classical and neglected tropical diseases, with Guinea worm looking set to be the next disease after smallpox to be eradicated. Aided by a combination of enhanced understanding of the biology of the pathogens, intensification of immunisation activities or mass drug administration, together with the development of synergies with control programmes for co-endemic tropical diseases, polio, lymphatic filariasis, trachoma and onchocerciasis all appear to be in global decline, with good prospects for eventual successful elimination. While the global incidence of new cases of leprosy continues to decrease, the focus of leprosy control efforts has shifted following more widespread recognition that cure of infection does not necessarily prevent disability. Expansion in funding for HIV/AIDS and malaria provides some grounds for optimism about the control of these diseases. However, ongoing education and access remain essential to increasing the uptake of HIV testing and decreasing transmission. Meanwhile, the rise of drug-resistant tuberculosis and malaria is concerning, and the emergence of the highly pathogenic avian influenza A and re-emergence of viruses such as chikungunya and West Nile virus, without significant recent progress in vaccine development, pose additional ongoing challenges to tropical medicine physicians worldwide.

  2. Medical geochemistry of tropical environments

    NASA Astrophysics Data System (ADS)

    Dissanayake, C. B.; Chandrajith, Rohana

    1999-10-01

    Geochemically, tropical environments are unique. This uniqueness stems from the fact that these terrains are continuously subjected to extreme rainfall and drought with resulting strong geochemical fractionation of elements. This characteristic geochemical partitioning results in either severe depletion of elements or accumulation to toxic levels. In both these situations, the effect on plant, animal and human health is marked. Medical geochemistry involves the study of the relationships between the geochemistry of the environment in which we live and the health of the population living in this particular domain. Interestingly, the relationships between geochemistry and health are most marked in the tropical countries, which coincidentally are among the poorest in the world. The very heavy dependence on the immediate environment for sustainable living in these lands enables the medical geochemist to observe correlations between particular geochemical provinces and the incidence of certain diseases unique to these terrains. The aetiology of diseases such as dental and skeletal fluorosis, iodine deficiency disorders, diseases of humans and animals caused by mineral imbalances among others, lie clearly in the geochemical environment. The study of the chemistry of the soils, water and stream sediments in relation to the incidence of geographically distributed diseases in the tropics has not only opened up new frontiers in multidisciplinary research, but has offered new challenges to the medical profession to seriously focus attention on the emerging field of medical geochemistry with the collaboration of geochemists and epidemiologists.

  3. Ecotoxicology of tropical marine ecosystems

    SciTech Connect

    Peters, E.C.; Gassman, N.J.; Firman, J.C.; Richmond, R.H.; Power, E.A.

    1997-01-01

    The negative effects of chemical contaminants on tropical marine ecosystems are of increasing concern as human populations expand adjacent to these communities. Watershed streams and ground water carry a variety of chemicals from agricultural, industrial, and domestic activities, while winds and currents transport pollutants from atmospheric and oceanic sources to these coastal ecosystems. The implications of the limited information available on impacts of chemical stressors on mangrove forests, seagrass meadows, and coral reefs are discussed in the context of ecosystem management and ecological risk assessment. Three classes of pollutants have received attention: heavy metals, petroleum, and synthetic organics. Heavy metals have been detected in all three ecosystems, causing physiological stress, reduced reproductive success, and outright mortality in associated invertebrates and fishes. Oil spills have been responsible for the destruction of entire coastal shallow-water communities, with recovery requiring years. Herbicides are particularly detrimental to mangroves and seagrasses and adversely affect the animal-algal symbioses in corals. Pesticides interfere with chemical cues responsible for key biological processes, including reproduction and recruitment of a variety of organisms. Information is lacking with regard to long-term recovery, indicator species, and biomarkers for tropical communities. Critical areas that are beginning to be addressed include the development of appropriate benchmarks for risk assessment, baseline monitoring criteria, and effective management strategies to protect tropical marine ecosystems in the face of mounting anthropogenic disturbance.

  4. Tropical forest preservation using economic incentives

    SciTech Connect

    Katzman, M.T. ); Cale, W.G. Jr. )

    1990-12-01

    The authors address the problem of deforestation of the tropical forests in terms of economic factors. They outline the global effects, such as hydrological and climatological changes, that apparently small scale deforestation has, when the forest is destroyed in many different places. The authors suggest that industrialized nations should offer economic incentives for tropical nations to save their forests, since all the world will suffer the effects of tropical deforestation.

  5. Tropical Acne: Clinical and Laboratory Investigations.

    DTIC Science & Technology

    developed in the tropical acne patients were clinically and histopathologically identical to those seen in severe pustular, cystic acne patients. The...Observations were made on the clinical, biochemical, histopathological and microbiological parameters of eleven ’tropical acne patients.’ All...tropical acne patients in the study had a previous history of mild to moderate acne vulgaris prior to their tour in Vietnam. The type of lesions which

  6. An Observational Analysis of Tropical Cyclone Recurvature.

    DTIC Science & Technology

    1991-05-01

    SR = Slowly recurving cyclones TC = Tropical Cyclone TUTT = Tropical Upper Tropospheric Trough W = West WNW = West-Northwest v Chapter 1 INTRODUCTION...latitude at which the cyclone was located. Observations also showed that not all troughs approaching a cyclone caused recurvature. Mid- latitude troughs ...general synoptic conditions which were favorable for tropical cyclone recurvature. These included: 1. High amplitude troughs extending from the westerlies

  7. Problem Oriented Differential Diagnosis of Tropical Diseases

    DTIC Science & Technology

    1989-09-01

    also provided primary care to the local population who were already infected with a variety of tropical diseases. Many biowarfare agents are exotic or... agents of warfare. 1 This manual was written by a primary care physician for primary care physicians to solve a dilema. We are faced with evaluating the...and by presenting signs and symptoms. The tropical medicine texbooks arrange tropical diseases by infectious agent . The indexes of these texts do not

  8. [Tropical medicine/tropical dermatology training in Tanzania and Ghana: Personal experience and selected case reports].

    PubMed

    Völker, K

    2015-05-01

    As a consultant for dermatology with special interested in tropical diseases, I accepted my employers offer (German Armed Forces) to start my training in tropical medicine and tropical dermatology in Africa. The dermatological part of the training was completed at the Regional Dermatology Training Centre (RDTC) in Moshi, Tanzania. This was followed by tropical medicine training at the Presbyterian Hospital in Agogo, Ghana. In this article, I report on my experiences in Africa and present selected case reports.

  9. [Tropical spastic paraparesis in a non tropical region].

    PubMed

    Pias-Peleteiro, L; Pias-Peleteiro, J M; Arias, M

    2015-10-16

    Introduccion. El virus linfotropo humano de celulas T tipo 1 (HTLV-1) es el agente causal de la paraparesia espastica tropical. Su prevalencia, elevada en determinadas areas tropicales, es baja en Europa y Norteamerica. Casos clinicos. Se describen dos casos de paraparesia espastica tropical en varones naturales y residentes en Galicia. Se realizaron estudios analiticos en la sangre y el liquido cefalorraquideo (LCR), examenes neurofisiologicos y resonancia magnetica craneal y medular. En ambos pacientes, la presentacion clinica fue la de una mielopatia cronica, con cuadro torpido y progresivo que evoluciono a paraparesia espastica. Un paciente desarrollo uveitis antes de la clinica neurologica. En los dos casos, el estudio del LCR demostro leve pleocitosis linfoide, ligera hiperproteinorraquia, bandas oligoclonales negativas y anticuerpos anti-HTLV-1 positivos. La reaccion en cadena de la polimerasa para HTLV-1 resulto positiva en ambos casos. La resonancia magnetica raquidea resulto normal en un paciente y mostro en el otro hiperseñal medular dorsal, que desaparecio tras el tratamiento. No se demostraron datos de polineuropatia periferica. Recibieron corticoides e interferon alfa, con leve mejoria y estabilizacion del cuadro clinico. La anamnesis dirigida revelo antecedentes de contactos sexuales de riesgo en regiones endemicas de HTLV-1. Conclusiones. La uveitis asociada a HTLV-1 podria ser predictora de paraparesia espastica tropical. Esta es probablemente una entidad infradiagnosticada (alto porcentaje de portadores asintomaticos, clinica insidiosa y bajo indice de sospecha en areas no endemicas). Debe considerarse su diagnostico en zonas no tropicales que reciben inmigrantes de areas endemicas y tambien en regiones con una tradicional emigracion a regiones tropicales.

  10. Nitrous oxide flux following tropical land clearing

    NASA Technical Reports Server (NTRS)

    Luizao, Flavio; Luizao, Regina; Matson, Pamela; Livingston, Gerald; Vitousek, Peter

    1989-01-01

    The importance of seasonal cycles of N2O flux from tropical ecosystems and the possibility that tropical deforestation could contribute to the ongoing global increase in N2O concentrations were assessed by measuring N2O flux from forest, cleared land, and pasture over an annual cycle in the central Amazon. A pasture that had been converted from tropical forest had threefold greater annual N2O flux than a paired forest site; similar results were obtained in spot measurements in other pastures. If these results are general, such tropical pastures represent a globally significant source of increased N2O.

  11. The ecology of tropical lakes and rivers

    SciTech Connect

    Payne, A.I.

    1986-01-01

    This is self-contained text reviewing tropical limnology. It discusses a number of communities in detail, including plankton, benthic regions, and the water margins. It introduces the characteristic types and assemblies of animals and plants from tropical communities. The measurement and relative magnitude of such quantifiable aspects as abundance, biomass, primary production, secondary production, and decomposition are all outlined, drawing together the diverse threads of freshwater ecology over one of the earth's climatic belts. Deals with use and abuse of water in the tropics and looks at problems of diversity and diversification in tropical waters.

  12. Technologies to sustain tropical forest resources

    SciTech Connect

    Not Available

    1984-03-01

    This report describes the background of tropical forest resource changes, including who is affected, the current status, the visible agents and underlying causes of change, and the organizations involved. Various technologies for resource-sustaining development of tropical forests are discussed. Some are techniques to manage the forests and some are technologies to use forests to protect related resources such as agriculture and water. Issues and options for Congress to promote development and use of technologies that can sustain tropical forest resources globally and within US tropical territories are described. (ACR)

  13. Have we overstated the tropical biodiversity crisis?

    PubMed

    Laurance, William F

    2007-02-01

    Tropical forests are the most biologically diverse and ecologically complex of terrestrial ecosystems, and are disappearing at alarming rates. It has long been suggested that rapid forest loss and degradation in the tropics, if unabated, could ultimately precipitate a wave of species extinctions, perhaps comparable to mass extinction events in the geological history of the Earth. However, a vigorous debate has erupted following a study by Wright and Muller-Landau that challenges the notion of large-scale tropical extinctions, at least over the next century. Here, I summarize this controversy and describe how the debate is stimulating a serious examination of the causes and biological consequences of future tropical deforestation.

  14. Interactions between climate and tropical cyclones

    NASA Astrophysics Data System (ADS)

    Webster, P. J.

    2007-05-01

    For the last 50 years, there have been two major thrusts in tropical cyclone research: determining the state of the atmosphere and ocean that is suitable for the formation of tropical storms (the genesis criteria) and short-term forecasting of the track and intensity of storms. Efforts to forecast seasonal storm activity, especially in the North Atlantic Ocean, have been undertaken through empirical means and, more recently, using low-resolution climate models. Climate model results have been exceptionally encouraging suggesting that the tropical cyclogenesis factors are predictable and are part of the large scale tropical circulation. During the last few years, a spate of papers has noted the relationship between changes in sea-surface temperature (SST) and tropical cyclone intensity and frequency. A critical issue is determining to what degree the frequency of hurricanes, as well as their intensity distribution, will change in a warming world. We discuss recent research regarding the interactions of the climate system with tropical cyclones, including the role of climate in determining the genesis of tropical cyclones and the role of tropical cyclones in the heat balance of the planet. Specifically: (i) We re-examine the genesis criteria of tropical cyclones and add two new criteria based on the behavior of waves in a flow varying in longitude and the inertial instability of equatorial flow in a cross-equatorial pressure gradient environment. Tropical cyclones are seen to form where the stretching deformation is negative and where large-scale waves transform into tight smaller and highly energetic scale vortices. We also discuss the tendency for storms to develop and intensify where the near-equatorial flow is inertially unstable. (ii) Tropical cyclones act to cool the tropical oceans by > 1K/year by evaporation of ocean surface water and by entrainment mixing with cooler water from below the mixed layer. We suggest that tropical cyclones are important part of

  15. The Role of the Tropics in Abrupt Climate Changes

    SciTech Connect

    Fedorov, Alexey

    2013-12-07

    Topics addressed include: abrupt climate changes and ocean circulation in the tropics; what controls the ocean thermal structure in the tropics; a permanent El Niño in paleoclimates; the energetics of the tropical ocean.

  16. Methane Emission from Tropical Rivers

    NASA Astrophysics Data System (ADS)

    Sawakuchi, H. O.; Rasera, M. F. F. L.; Krusche, A. V.; Ballester, M. V. R.

    2012-04-01

    Inland water is already known as an important source of methane to atmosphere. Methane is produced in anaerobic environments usually find in lakes and floodplain bottom sediment. It is the main reason that almost all information regarding methane flux come from this environments. However, while floodplain dries during low water season reducing methanogenesis, rivers keep the capacity to emit methane throughout the year. Here we present preliminary results of CH4 flux measurements done in 6 large tropical rivers within the Amazon basin. We measured 17 areas using floating chamber during dry (low water) season, between September and November of 2011, in Amazon river mainstem, Araguaia, Xingu, Tapajós, Madeira, and Negro Rivers. Measured fluxes of all rivers ranged from 59.3 to 2974.4 mmol m-2 yr-1. Geomorphologic structure of channels is one important factor that contributes to this high heterogeneity due to development of low flow velocity depositional settings allowing formation of anoxic zones in rivers. Hydraulic and sediment barriers in the confluence of river channels promote the generation of natural dams which function as a trap for the suspension load favoring the deposition of organic rich muds. This kind of environment is very different from common river channels and has a stronger potential of methane emission. Average values of our flux measurements for this two river environments show that depositional areas can have much higher fluxes than the main channel, 1089.6 and 163.1 mmol m-2 yr-1, respectively. Hence, CH4 flux from these depositional zones is similar to some tropical floodplain lakes and reservoirs. Although the low flux from channel, the area covered by water is very large resulting in a significant contribution to the regional methane emission to the atmosphere. Moreover, mapping the area of these depositional river zones will give us a better idea of the magnitude of methane flux from tropical rivers.

  17. Predictability of Sheared Tropical Cyclones

    NASA Astrophysics Data System (ADS)

    Zhang, F.; Tao, D.

    2015-12-01

    Predictability of the formation, rapid intensification and eyewall replacement of sheared tropical cyclones (TCs) are explored through a series of convection-permitting ensemble simulations using the Weather Research and Forecasting (WRF) model with different environmental vertical wind shear, sea-surface temperature (SST), and ambient moisture conditions. It is found that the intrinsic predictability of the RI onset time is more limited with increasing shear magnitude until the shear magnitude is large enough to prevent the TC formation. Based on ensemble sensitivity and correlation analysis, the RI onset timing within one set is largely related to the vortex tilt magnitude, the diabatic heating distribution and the strength of the primary vortex circulation. Systematic differences amongst the ensemble members begin to arise right after the initial burst of moist convection associated with the incipient vortex. This difference from the randomness inherent in moist convection in terms of both location and intensity first changes the TC vortex structure subtly and then leads to the deviations in system scales and eventually in the development (and precession) of the TC. On average, a higher SST has a positive effect on the TC formation and reduces the uncertainty of development under all shear conditions, while a drier environment has a negative impact on the TCs development and either broadens the ensemble spread of RI onset time or prevents the storm from forming when the shear-induced tilt is large. Nevertheless, the uncertainty in environmental shear magnitudes may dominate over the effect of randomness in moist convection in terms of TC formation and predictability. A byproduct of tropical cyclones under vertical wind shear is the secondary eyewall formation (SEF). It is found that the eyewall formation is more often observed in TCs with moderate to high shear, which was inherently more unpredictable. The inward contraction/axisymmeterization of shear

  18. Brachioradial pruritus: a tropical dermopathy.

    PubMed

    Walcyk, P J; Elpern, D J

    1986-08-01

    Data on 42 patients with brachioradial pruritus seen in Hawaii over a 2-year period are presented. In contrast to previous reports, the sex ratio was 1:1 with a preponderance of patients in the younger age groups. All patients had developed the disorder after having lived in Hawaii for at least one year. More than half the cases had no history of neck trauma or arthritis, ruling out a peripheral neuropathy as the cause. Radiographs of 15 patients showed changes only in the patients in the older, arthritis-age groups. Brachioradial pruritus appears to be peculiar to the tropics.

  19. Zinc requirements of tropical legume cover crops

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Tropical soils are deficient in essential plant nutrients, including zinc (Zn). Using cover crops in cropping systems is an important option to improve soil fertility for sustainable crop production. However, success of cover crops in highly weathered tropical infertile acid soils is greatly influen...

  20. Genomics of Tropical Fruit Tree Crops

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The genetic improvement of tropical fruit trees is limited when compared to progress achieved in temperate fruit trees and annual crops. Tropical fruit tree breeding programs require significant resources to develop new cultivars that are adapted to modern shipping and storage requirements. The use...

  1. Use of tropical maize for bioethanol production

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Tropical maize is an alternative energy crop being considered as a feedstock for bioethanol production in the North Central and Midwest United States. Tropical maize is advantageous because it produces large amounts of soluble sugars in its stalks, creates a large amount of biomass, and requires lo...

  2. Tropical Forests. Global Issues Education Packet.

    ERIC Educational Resources Information Center

    Holm, Amy E.

    Tropical forests provide the world with many products and an incredible diversity of plant and animal life. These forests also provide watershed areas, soil control, climate regulation, and winter homes for migrating birds from North America. It is believed that about 40% of tropical forests have already been destroyed in the last 20-30 years,…

  3. Heterotrophy in tropical scleractinian corals.

    PubMed

    Houlbrèque, Fanny; Ferrier-Pagès, Christine

    2009-02-01

    The dual character of corals, that they are both auto- and heterotrophs, was recognized early in the twentieth Century. It is generally accepted that the symbiotic association between corals and their endosymbiotic algae (called zooxanthellae) is fundamental to the development of coral reefs in oligotrophic tropical oceans because zooxanthellae transfer the major part of their photosynthates to the coral host (autotrophic nutrition). However, numerous studies have confirmed that many species of corals are also active heterotrophs, ingesting organisms ranging from bacteria to mesozooplankton. Heterotrophy accounts for between 0 and 66% of the fixed carbon incorporated into coral skeletons and can meet from 15 to 35% of daily metabolic requirements in healthy corals and up to 100% in bleached corals. Apart from this carbon input, feeding is likely to be important to most scleractinian corals, since nitrogen, phosphorus, and other nutrients that cannot be supplied from photosynthesis by the coral's symbiotic algae must come from zooplankton capture, particulate matter or dissolved compounds. A recent study showed that during bleaching events some coral species, by increasing their feeding rates, are able to maintain and restore energy reserves. This review assesses the importance and effects of heterotrophy in tropical scleractinian corals. We first provide background information on the different food sources (from dissolved organic matter to meso- and macrozooplankton). We then consider the nutritional inputs of feeding. Finally, we review feeding effects on the different physiological parameters of corals (tissue composition, photosynthesis and skeletal growth).

  4. Bridges to sustainable tropical health

    PubMed Central

    Singer, Burton H.; de Castro, Marcia Caldas

    2007-01-01

    Ensuring sustainable health in the tropics will require bridge building between communities that currently have a limited track record of interaction. It will also require new organizational innovation if much of the negative health consequences of large-scale economic development projects are to be equitably mitigated, if not prevented. We focus attention on three specific contexts: (i) forging linkages between the engineering and health communities to implement clean water and sanitation on a broad scale to prevent reworming, after the current deworming-only programs, of people by diverse intestinal parasites; (ii) building integrated human and animal disease surveillance infrastructure and technical capacity in tropical countries on the reporting and scientific evidence requirements of the sanitary and phytosanitary agreement under the World Trade Organization; and (iii) developing an independent and equitable organizational structure for health impact assessments as well as monitoring and mitigation of health consequences of economic development projects. Effective global disease surveillance and timely early warning of new outbreaks will require a far closer integration of veterinary and human medicine than heretofore. Many of the necessary surveillance components exist within separate animal- and human-oriented organizations. The challenge is to build the necessary bridges between them. PMID:17913894

  5. Mission Investigates Tropical Cirrus Clouds

    NASA Astrophysics Data System (ADS)

    Jenson, Eric; Starr, David; Toon, Owen B.

    2004-02-01

    It has been a year since NASA conducted the highly successful Cirrus Regional Study of Tropical Anvils and Cirrus Layers-Florida Area Cirrus Experiment Study (CRYSTAL-FACE). The measurement campaign was designed to investigate the physical properties and formation processes of tropical cirrus clouds. CRYSTAL-FACE was sponsored by NASA's Earth Science Enterprise as an integral component of its Earth observation research strategy, and included substantial collaboration with the National Oceanic and Atmospheric Administration, the National Science Foundation, the Department of Energy, and the Naval Research Laboratory. During July 2002, the mission's six aircraft (NASA ER-2, NASA WB-57, Scaled Composites Proteus, University of North Dakota Citation, NSF-supported NRL P-3, and NRL Twin Otter) operated from the Key West Naval Air Facility. In addition, ground sites were located at the Tamiami airport on the east coast of Florida and near Everglades City on the west coast of Florida. Aircraft and ground site measurements are listed in Table 1. Data archiving is complete, and the data are now available to the general scientific community. Detailed instrument descriptions as well as the final data can be found on the CRYSTAL-FACE Web site (http://cloud1.arc.nasa.gov/crystalface/).

  6. Simulation of Tropical Biomass Burning

    NASA Technical Reports Server (NTRS)

    Hamill, Patrick; Guo, Zitian

    1998-01-01

    The work proposed was carried out as planned. The work described in this final report formed the basis for a follow-on research grant research grant from NASA Ames Research Center. The research objectives that were achieved during the course of our studies include the following: (1) the evaluation of several components of MM5 (Meteorological Model 5 version 2) and the Global/Regional Atmospheric Chemistry Event Simulator (GRACES) combined modeling system; (2) improved calculations of the transport of tracers for both NASA airborne missions, Study of Ozone and Nitrogen oxides experiment (SONEX) and Pacific Exploratory MIssion in the Tropics (PEM-Tropics); (3) improved source strength estimates for isoprene, dust and similar emissions from the Earth's surface. This required the use of newly available databases on the Earth's surface and vegetation; (4) completed atmospheric chemistry simulations of radicals and nitrogen oxide species; (5)improved the handling of cumulonimbus convection by modifying the existing scheme; (6) identified the role of the African Intertropical Front, using MM5's nesting capability to refine model resolution in crucial areas; modified the MM5 trajectory program to allow it to work much better for a parcel crossing the west/east boundaries.

  7. Plate tectonics drive tropical reef biodiversity dynamics

    NASA Astrophysics Data System (ADS)

    Leprieur, Fabien; Descombes, Patrice; Gaboriau, Théo; Cowman, Peter F.; Parravicini, Valeriano; Kulbicki, Michel; Melián, Carlos J.; de Santana, Charles N.; Heine, Christian; Mouillot, David; Bellwood, David R.; Pellissier, Loïc

    2016-05-01

    The Cretaceous breakup of Gondwana strongly modified the global distribution of shallow tropical seas reshaping the geographic configuration of marine basins. However, the links between tropical reef availability, plate tectonic processes and marine biodiversity distribution patterns are still unknown. Here, we show that a spatial diversification model constrained by absolute plate motions for the past 140 million years predicts the emergence and movement of diversity hotspots on tropical reefs. The spatial dynamics of tropical reefs explains marine fauna diversification in the Tethyan Ocean during the Cretaceous and early Cenozoic, and identifies an eastward movement of ancestral marine lineages towards the Indo-Australian Archipelago in the Miocene. A mechanistic model based only on habitat-driven diversification and dispersal yields realistic predictions of current biodiversity patterns for both corals and fishes. As in terrestrial systems, we demonstrate that plate tectonics played a major role in driving tropical marine shallow reef biodiversity dynamics.

  8. Plate tectonics drive tropical reef biodiversity dynamics.

    PubMed

    Leprieur, Fabien; Descombes, Patrice; Gaboriau, Théo; Cowman, Peter F; Parravicini, Valeriano; Kulbicki, Michel; Melián, Carlos J; de Santana, Charles N; Heine, Christian; Mouillot, David; Bellwood, David R; Pellissier, Loïc

    2016-05-06

    The Cretaceous breakup of Gondwana strongly modified the global distribution of shallow tropical seas reshaping the geographic configuration of marine basins. However, the links between tropical reef availability, plate tectonic processes and marine biodiversity distribution patterns are still unknown. Here, we show that a spatial diversification model constrained by absolute plate motions for the past 140 million years predicts the emergence and movement of diversity hotspots on tropical reefs. The spatial dynamics of tropical reefs explains marine fauna diversification in the Tethyan Ocean during the Cretaceous and early Cenozoic, and identifies an eastward movement of ancestral marine lineages towards the Indo-Australian Archipelago in the Miocene. A mechanistic model based only on habitat-driven diversification and dispersal yields realistic predictions of current biodiversity patterns for both corals and fishes. As in terrestrial systems, we demonstrate that plate tectonics played a major role in driving tropical marine shallow reef biodiversity dynamics.

  9. Plate tectonics drive tropical reef biodiversity dynamics

    PubMed Central

    Leprieur, Fabien; Descombes, Patrice; Gaboriau, Théo; Cowman, Peter F.; Parravicini, Valeriano; Kulbicki, Michel; Melián, Carlos J.; de Santana, Charles N.; Heine, Christian; Mouillot, David; Bellwood, David R.; Pellissier, Loïc

    2016-01-01

    The Cretaceous breakup of Gondwana strongly modified the global distribution of shallow tropical seas reshaping the geographic configuration of marine basins. However, the links between tropical reef availability, plate tectonic processes and marine biodiversity distribution patterns are still unknown. Here, we show that a spatial diversification model constrained by absolute plate motions for the past 140 million years predicts the emergence and movement of diversity hotspots on tropical reefs. The spatial dynamics of tropical reefs explains marine fauna diversification in the Tethyan Ocean during the Cretaceous and early Cenozoic, and identifies an eastward movement of ancestral marine lineages towards the Indo-Australian Archipelago in the Miocene. A mechanistic model based only on habitat-driven diversification and dispersal yields realistic predictions of current biodiversity patterns for both corals and fishes. As in terrestrial systems, we demonstrate that plate tectonics played a major role in driving tropical marine shallow reef biodiversity dynamics. PMID:27151103

  10. [Training in tropical medicine in France].

    PubMed

    Touze, Jean-Étienne; Laroche, Roland

    2013-10-01

    Tropical medicine was a key element of the medical structures provided by France to our former colonies and, later; to countries within the scope of our international cooperation. hI recent decades, France has drastically reduced its bilateral commitments to countries in the tropics, and especially in sub-Saharan Africa. At the same time, the teaching of tropical medicine, which was highly regarded even beyond our borders, has lost a good deal of its expertise. Initially available in a few large French centers, and ensured by teachers with extensive field experience, training in tropical medicine is now offered in many universities. However; their programs and educational objectives, focusing mainly on infectious and parasitic diseases, no longer meet the healthcare priorities of southern countries, which are facing an epidemiological transition and the rise of non communicable diseases. Few teachers now have recognized expertise in tropical medicine. These changes have had negative consequences for research programs in tropical medicine and for the image of French assistance to developing countries. In this context, the followving perspectives should be considered: 1) training in tropical medicine should be enhanced by the creation of a national diploma recognized by international bodies. 2) The creation of a doctoral course in tropical medicine is a prerequisite for achieving this goal, and the future diploma must include a significant research component. 3) Teaching in tropical medicine must become more practical and be ensured by teachers with extensive field experience. 4) Training in tropical medicine should be part of a bilateral relationship with countries in the tropics, each party contributing its expertise while respecting that of its partners. 5) Training in tropical medicine should be backed uip by high-level scientific research based on enhanced synergy of our current networks (Institute for Research and Development, Network of overseas Pasteur

  11. Microphysical Characteristics of Tropical Clouds

    NASA Technical Reports Server (NTRS)

    Grainger, Cedric A.; Anderson, Nicholas

    2004-01-01

    This report summarizes the analysis of data collected by the University of North Dakota Citation II measurement platform during three TRMM Field measurement campaigns. The Citation II made cloud measurements during TEFLUN B in Florida, the LBA program in Brazil, and KWAJEX in Kwajalein. The work performed can be divided into two parts. The first part consisted of reformatting the Citation data into a form more easily used to compare to the satellite information. The second part consisted of examination of the cloud data in order to characterize the properties of the tropical clouds. The reformatting of the Citation data was quite labor intensive and, due to the fact that the aircraft was involved in three of the field campaigns, it required a substantial number of person-hours to complete. Much of the analysis done on the second part was done in conjunction with the thesis work of Nicholas Anderson, then a graduate student at the University of North Dakota.

  12. 1995 Annual Tropical Cyclone Report

    DTIC Science & Technology

    1995-01-01

    BAILEY JASON E. ECCLES ROBERT M. GIGUERE DAVID J. CORREA , JR. JORDAN S. KELLY VINCENT L. PETRASEK JEFFREY L. WILKERSON TIMOTHY C. WILLlAMS CLARK D. WILSON...07W TY Gary 08W TY Helen 09W TS Irving 10W TS Janis lIW TD 12W STY Kent 13W TY Lois 14W TY Mark 15W TS Nina 16W TD 17W STY Oscar Individual Tropical...14W TY MARK 15W TS NINA 16W TD 17W STY OSCAR 18W TY POLLY 19W STY RYAN 20W TY SIBYL 21W TD 22W TD 23w TD 24W TY TED 25W TS VAL 26W STY WARD 27w TY

  13. Tropical parasitic diseases and women.

    PubMed

    Okwa, O O

    2007-12-01

    Tropical parasitic diseases constitute the greatest threat to the health and socio-economic status of women as a gender and social group. There are some gender specific ways in which parasitic diseases affect women in contrast to men due to differences in exposure, occupational risk, sociocultural behavior, gender roles and practices. These parasitic diseases confer some social stigma, which affects the health seeking behavior of women. Women are therefore important in the control of these parasitic diseases and they are key agents of change, if they are included in community control programs. Women need more attention in endemic areas as a group that had been neglected. This deprived and excluded group have got vital role to play, as discussed in this review.

  14. Predictability of the tropical atmosphere

    NASA Technical Reports Server (NTRS)

    Shukla, J.

    1981-01-01

    An examination of the deterministic predictability for tropics and middle-latitudes separately indicates that the theoretical upper limit of deterministic predictability for low latitudes is shorter than that for middle latitudes. Variability of time averages in low latitudes is mainly determined by the location and intensity of the large-scale Hadley and Walker circulations. Since these are largely influenced by the slowly varying boundary conditions of sea surface temperature and soil moisture, and since synoptic instabilities are not strong enough to change drastically the large scale flow, there is larger potential for predictability of monthly and seasonal means in low latitudes. It is conjectured that for short and medium range deterministic prediction, a prescribed diabatic heating field due to moist convection may be more useful than their explicit calculation from the evolving flow.

  15. Southeast Asian tropical medicine and parasitology network.

    PubMed

    Waikagul, Jitra

    2006-01-01

    The SEAMEO TROPMED Network is a regional cooperative network established in 1967 for education, training and research in tropical medicine and public health under the Southeast Asia Ministers of Education Organization. The Network operates through four Regional Centers with respective areas of specialization and host institutions: Community Nutrition/Tropmed Indonesia; Microbiology, Parasitology and Entomology/Tropmed Malaysia; Public Health/Tropmed Philippines; and Tropical Medicine/Tropmed Thailand. To train health workers, to support research on endemic and newly emerging diseases, and to advocate relevant health policies are the main functions of these centers. SEAMEO TROPMED Network in collaboration with the Faculty of Tropical Medicine, Mahidol University and other institutions has regularly organized the Seminar on Food-borne Parasitic Zoonoses every 3-5 years over the past 15 years. The Faculty of Tropical Medicine has organized the annual Joint International Tropical Medicine Meeting since 1996. Full papers of the presentations at these two meetings have been published as supplementary issues to the Southeast Asian Journal of Tropical Medicine and Public Health, an in-house journal of SEAMEO TROPMED Network. Recently, the Parasitology Association of ASEAN Countries has rotated the hosting of the ASEAN Congress of Parasitology and Tropical Medicine. These institutional and conference networks will enable closer links, to promote the health of people in the Southeast Asian region.

  16. Acute kidney injury in the tropics

    PubMed Central

    Mathew, Ashish Jacob; George, Jacob

    2011-01-01

    Acute kidney injury (AKI) is one of the most challenging problems faced by clinicians in the tropics owing to its fast-changing burden. AKI in the tropics is strikingly different from that in the developed world in terms of etiology and presentation. In addition, there is a stark contrast between well-developed and poor areas in the tropics. The true epidemiological picture of AKI in the tropics is not well understood due to the late presentation of patients to tertiary centers. Infections remain the major culprit in most cases of AKI, with high mortality rates in the tropics. Human immunodeficiency virus–related AKI, related to nephrotoxicity due to antiretroviral therapy, is on the rise. Acute tubular necrosis and thrombotic microangiopathy are the most common mechanisms of AKI. A notable problem in the tropics is the scarcity of resources in health centers to support patients who require critical care due to AKI. This article reviews the unique and contrasting nature of AKI in the tropics and describes its management in each situation. PMID:21911980

  17. Acute kidney injury in the tropics.

    PubMed

    Mathew, Ashish Jacob; George, Jacob

    2011-01-01

    Acute kidney injury (AKI) is one of the most challenging problems faced by clinicians in the tropics owing to its fast-changing burden. AKI in the tropics is strikingly different from that in the developed world in terms of etiology and presentation. In addition, there is a stark contrast between well-developed and poor areas in the tropics. The true epidemiological picture of AKI in the tropics is not well understood due to the late presentation of patients to tertiary centers. Infections remain the major culprit in most cases of AKI, with high mortality rates in the tropics. Human immunodeficiency virus-related AKI, related to nephrotoxicity due to antiretroviral therapy, is on the rise. Acute tubular necrosis and thrombotic microangiopathy are the most common mechanisms of AKI. A notable problem in the tropics is the scarcity of resources in health centers to support patients who require critical care due to AKI. This article reviews the unique and contrasting nature of AKI in the tropics and describes its management in each situation.

  18. Renal stones in the tropics.

    PubMed

    Robertson, William G

    2003-01-01

    Urolithiasis is a problem that is generally increasing in the tropics as it is in most Western countries. There are 2 main types of the disorder-bladder stones in children, a form of the disorder that disappeared from Europe in the late 19th and early 20th centuries, and upper urinary tract stones in adults. The former has been decreasing in most countries in the so-called endemic bladder stone belt with gradual improvements in levels of nutrition. However, as living standards increase, particularly in the urban areas of the more affluent developing countries, so the incidence of upper urinary tract stones in adults is increasing. The types of stones formed depend mainly on the composition of urine, which, in turn, reflects the type of diet consumed in the countries concerned. The main factor that leads to the formation of bladder stones in children is a nutritionally poor diet that is low in animal protein, calcium, and phosphate, but high in cereal and is acidogenic. This leads to the formation of urine with a relatively high content of ammonium and urate ions and consequently to the formation of ammonium acid urate crystals and stones. In countries where there is also a high intake of oxalate from local leaves and vegetables, urinary oxalate is increased and, as a result, the ammonium acid urate stones often contain calcium oxalate as well. The stone problem in the tropics is compounded by low urine volumes resulting in some areas from poor drinking water, which causes chronic diarrhea, and in others from the hot climate and fluid losses through the skin. As nutrition improves in these countries, the formation of bladder stones gives way to upper urinary tract stones consisting of calcium oxalate, often mixed with calcium phosphate or uric acid, such as are formed in most Western countries.

  19. Equatorial refuge amid tropical warming

    NASA Astrophysics Data System (ADS)

    Karnauskas, Kristopher B.; Cohen, Anne L.

    2012-07-01

    Upwelling across the tropical Pacific Ocean is projected to weaken in accordance with a reduction of the atmospheric overturning circulation, enhancing the increase in sea surface temperature relative to other regions in response to greenhouse-gas forcing. In the central Pacific, home to one of the largest marine protected areas and fishery regions in the global tropics, sea surface temperatures are projected to increase by 2.8°C by the end of this century. Of critical concern is that marine protected areas may not provide refuge from the anticipated rate of large-scale warming, which could exceed the evolutionary capacity of coral and their symbionts to adapt. Combining high-resolution satellite measurements, an ensemble of global climate models and an eddy-resolving regional ocean circulation model, we show that warming and productivity decline around select Pacific islands will be mitigated by enhanced upwelling associated with a strengthening of the equatorial undercurrent. Enhanced topographic upwelling will act as a negative feedback, locally mitigating the surface warming. At the Gilbert Islands, the rate of warming will be reduced by 0.7+/-0.3°C or 25+/-9% per century, or an overall cooling effect comparable to the local anomaly for a typical El Niño, by the end of this century. As the equatorial undercurrent is dynamically constrained to the Equator, only a handful of coral reefs stand to benefit from this equatorial island effect. Nevertheless, those that do face a lower rate of warming, conferring a significant advantage over neighbouring reef systems. If realized, these predictions help to identify potential refuges for coral reef communities from anticipated climate changes of the twenty-first century.

  20. Rain on small tropical islands

    NASA Astrophysics Data System (ADS)

    Sobel, A. H.; Burleyson, C. D.; Yuter, S. E.

    2011-04-01

    A high-resolution rainfall climatology based on observations from the Tropical Rainfall Measuring Mission's Precipitation Radar (PR) instrument is used to evaluate the influence of small tropical islands on climatological rainfall. Islands with areas between one hundred and several thousand km2 are considered in both the Indo-Pacific Maritime Continent and Caribbean regions. Annual mean climatological (1997-2007) rainfall over each island is compared with that over the surrounding ocean region, and the difference is expressed as a percentage. In addition to total rainfall, rain frequency and intensity are also analyzed. Results are stratified into two 12 h halves of the diurnal cycle as well as eight 3 h periods, and also by a measure of each island's topographic relief. In both regions, there is a clear difference between larger islands (areas of a few hundred km2 or greater) and smaller ones. Both rain frequency and total rainfall are significantly enhanced over larger islands compared to the surrounding ocean. For smaller islands the enhancement is either negligibly small, statistically insignificant, or, in the case of Caribbean rain frequency, negative. The enhancement in total rainfall over larger islands is partly attributable to greater frequency and partly to greater intensity. A diurnal cycle in island enhancement is evident in frequency but not intensity, except over small Caribbean islands where the converse is true. For the larger islands, higher orography is associated with greater rainfall enhancements. The orographic effect is larger (percentagewise) in the Caribbean than in the Maritime Continent. Orographic precipitation enhancement manifests more strongly as increased frequency of precipitation rather than increased intensity and is present at night as well as during the day. The lack of a clear diurnal cycle in orographic enhancement suggests that much of the orographic rainfall enhancement is attributable to mechanically forced upslope flow

  1. New strategies for conserving tropical forests.

    PubMed

    Butler, Rhett A; Laurance, William F

    2008-09-01

    In an interval of just 1-2 decades, the nature of tropical forest destruction has changed. Rather than being dominated by rural farmers, tropical deforestation now is substantially driven by major industries and economic globalization, with timber operations, oil and gas development, large-scale farming and exotic-tree plantations being the most frequent causes of forest loss. Although instigating serious challenges, such changes are also creating important new opportunities for forest conservation. Here we argue that, by increasingly targeting strategic corporations and trade groups with public-pressure campaigns, conservation interests could have a much stronger influence on the fate of tropical forests.

  2. Tropical medicine: Telecommunications and technology transfer

    NASA Technical Reports Server (NTRS)

    Legters, Llewellyn J.

    1991-01-01

    The potential for global outbreaks of tropical infectious diseases, and our ability to identify and respond to such outbreaks is a major concern. Rapid, efficient telecommunications is viewed as part of the solution to this set of problems - the means to link a network of epidemiological field stations via satellite with U.S. academic institutions and government agencies, for purposes of research, training in tropical medicine, and observation of and response to epidemic emergencies. At a workshop, telecommunications and technology transfer were addressed and applications of telecommunications technology in long-distance consultation, teaching and disaster relief were demonstrated. Applications in teaching and consultation in tropical infectious diseases is discussed.

  3. Dealing with diversity: The Smithsonian tropical research Institute and tropical biology.

    PubMed

    Rubinoff, I; Leigh, E G

    1990-04-01

    Despite unprecedented research attention in recent years, the tropics remain an unexplored frontier. To achieve a better understanding of tropical ecosystems in the face of rapid and irrevocable destruction, it is essential to develop and improve field facilities for long-term comparative research worldwide. This article describes the work of one such facility - the Smithsonian Tropical Research Institute in Panama - as model for future investigations.

  4. The Tropical Disease Priority Review Voucher: A Game-Changer for Tropical Disease Products

    PubMed Central

    Berman, Jonathan; Radhakrishna, Tanya

    2017-01-01

    The Neglected Tropical Disease Voucher Program is a Congressionally-mandated program intended to promote approval of products for tropical diseases because it provides spectacular financial compensation consequent to FDA approval of a priority product. Three drug approvals–artemether/lumifantrine for malaria, bedaquiline for multidrug resistant tuberculosis, miltefosine for leishmaniasis–have received Tropical Disease Vouchers to date. We give our view of the type of products that might qualify for a Tropical Disease Voucher, financial considerations in venturing capital to support product development, clinical ramifications of a successful product approval, and an overall evaluation of the Program. PMID:27573627

  5. Tropical deep convective cloud morphology

    NASA Astrophysics Data System (ADS)

    Igel, Matthew R.

    A cloud-object partitioning algorithm is developed. It takes contiguous CloudSat cloudy regions and identifies various length scales of deep convective clouds from a tropical, oceanic subset of data. The methodology identifies a level above which anvil characteristics become important by analyzing the cloud object shape. Below this level in what is termed the pedestal region, convective cores are identified based on reflectivity maxima. Identifying these regions allows for the assessment of length scales of the anvil and pedestal of the deep convective clouds. Cloud objects are also appended with certain environmental quantities from the ECMWF reanalysis. Simple geospatial and temporal assessments show that the cloud object technique agrees with standard observations of local frequency of deep-convective cloudiness. Additionally, the nature of cloud volume scale populations is investigated. Deep convection is seen to exhibit power-law scaling. It is suggested that this scaling has implications for the continuous, scale invariant, and random nature of the physics controlling tropical deep convection and therefore on the potentially unphysical nature of contemporary convective parameterizations. Deep-convective clouds over tropical oceans play important roles in Earth's climate system. The response of tropical, deep convective clouds to sea surface temperatures (SSTs) is investigated using this new data set. Several previously proposed feedbacks are examined: the FAT hypothesis, the Iris hypothesis, and the Thermostat hypothesis. When the data are analyzed per cloud object, each hypothesis is broadly found to correctly predict cloud behavior in nature, although it appears that the FAT hypothesis needs a slight modification to allow for cooling cloud top temperatures with increasing SSTs. A new response that shows that the base temperature of deep convective anvils remains approximately constant with increasing SSTs is introduced. These cloud-climate feedbacks are

  6. Cutaneous manifestations of systemic tropical parasitic diseases.

    PubMed

    Fernandes, Neil F; Kovarik, Carrie L

    2009-01-01

    Tropical diseases continue to cause significant health problems in developing nations. An overview of illnesses with notable cutaneous findings caused by protozoans and helminthes is provided. The role of the health care provider in disease management is described.

  7. Tropical Cyclone Jack in Satellite 3-D

    NASA Video Gallery

    This 3-D flyby from NASA's TRMM satellite of Tropical Cyclone Jack on April 21 shows that some of the thunderstorms were shown by TRMM PR were still reaching height of at least 17 km (10.5 miles). ...

  8. Human influence on tropical cyclone intensity

    NASA Astrophysics Data System (ADS)

    Sobel, Adam H.; Camargo, Suzana J.; Hall, Timothy M.; Lee, Chia-Ying; Tippett, Michael K.; Wing, Allison A.

    2016-07-01

    Recent assessments agree that tropical cyclone intensity should increase as the climate warms. Less agreement exists on the detection of recent historical trends in tropical cyclone intensity. We interpret future and recent historical trends by using the theory of potential intensity, which predicts the maximum intensity achievable by a tropical cyclone in a given local environment. Although greenhouse gas-driven warming increases potential intensity, climate model simulations suggest that aerosol cooling has largely canceled that effect over the historical record. Large natural variability complicates analysis of trends, as do poleward shifts in the latitude of maximum intensity. In the absence of strong reductions in greenhouse gas emissions, future greenhouse gas forcing of potential intensity will increasingly dominate over aerosol forcing, leading to substantially larger increases in tropical cyclone intensities.

  9. GPM Video of Tropical Depression Ida

    NASA Video Gallery

    NASA's GPM Analyzes Rainfall in Tropical Storm Ida This flyover animation was created from data taken on Sept. 24, when NASA/JAXA's GPM satellite saw some storms in Ida were dropping heavy rainfall...

  10. GMI Rainfall Data on Tropical Storm Adjali

    NASA Video Gallery

    This animation shows GMI rainfall data on Tropical Storm Adjali on Nov. 19, 2014 combined with cloud data from the METEOSAT-7 satellite. Rainfall was found to be falling at a rate of over 69 mm/hr ...

  11. GPM Flyby of Tropical Cyclone Uriah

    NASA Video Gallery

    On Feb. 15, GPM saw rain was falling at a rate of over 127 mm (5 inches) per hour in a band of intense storms south of Tropical Cyclone Uriah's center. Thunderstorms moving around the southwestern ...

  12. Tropical Deforestation in the Bolivian Amazon

    NASA Technical Reports Server (NTRS)

    Tucker, Compton J.; Steininger, Marc K.; Townshend, John R. G.; Killeen, Timothy R.; Desch, Arthur

    2000-01-01

    Landsat satellite images from the mid-1980s and early 1990s were used to map tropical forest extent and deforestation in approximately 800,000 sq km of Amazonian Bolivia. Forest cover extent, including tropical deciduous forest, totalled 472,000 sq km while the area of natural non-forest formations totalled 298,000 sq km. The area deforested totalled 15,000 sq km in the middle 1980s and 28,800 sq km by the early 1990s. The rate of tropical deforestation in the >1,000 mm/y precipitation forest zone of Bolivia was 2,200 sq km/y from 1985-1986 to 1992-1994. We document a spatially-concentrated "deforestation zone" in Santa Cruz Department where >60% of the Bolivian deforestation is occurring at an accelerating rate in areas of tropical deciduous dry forest.

  13. GPM Flyby of Tropical Storm Dineo

    NASA Video Gallery

    This flyby animation of rainfall data within Tropical Cyclone Dineo was taken from NASA/JAXA's GPM satellite on Feb.16. Storms over Swaziland were dropping precipitation at a rate of over 86 mm (3....

  14. Tropical Storm Wali Seen by GOESWest

    NASA Video Gallery

    This animation of infrared and visible imagery from NOAA's GOES-West satellite from July 15 to 18 shows the birth of Tropical Storm Wali southeast of the Big Island of Hawaii on July 17. Credit: NA...

  15. Tropical Storm Gil - July 31, 2013

    NASA Video Gallery

    NASA's TRMM satellite traveled above intensifying Tropical Storm Gil on July 31 at 12:55 a.m. EDT. The TRMM satellite pass showed that Gil was already very well organized with intense bands of rain...

  16. Tropical Storm Gilma in Eastern Pacific

    NASA Video Gallery

    An animation of satellite observations shows the progression of Tropical Storm Gilma from August 7-10, 2012, along the coast of the Eastern Pacific Ocean. This visualization was created by the NASA...

  17. Tropical deforestation in the Bolivian Amazon

    NASA Astrophysics Data System (ADS)

    Tucker, Compton J., III; Steininger, Marc K.; Townshend, John R. G.; Killeen, Timothy R.; Desch, Arthur

    2000-04-01

    Landsat satellite images from the mid-1980s and early 1990s were used to map tropical forest extent and deforestation in approximately 800,000 km2 of Amazonian Bolivia. Forest cover extent, including tropical deciduous forest, totaled 472,000 km2 while the area of natural non-forest formation totaled 298,000 km2. The area deforested totaled 15,000 km2 in the middle 1980s and 28,800 km2 by the early 1900s. The rate of tropical deforestation in the > 1,000 mm y-1 precipitation forest zone of Bolivia was 2,200 km2 y-1 from 1985-1986 to 1992-1994. We document a spatially-concentrated 'deforestation zone' in Santa Cruz Department where > 60 percent of the Bolivian deforestation is occurring at an accelerating rate in areas of tropical deciduous dry forest.

  18. Fly me, I'm tropical.

    PubMed

    May, A

    1994-03-24

    Leprosy, malaria and jigger fleas are all in a week's work for London's Hospital for Tropical Diseases. But some fear that the internal market could bring its 170-year history to a close, reports Annabelle May.

  19. Global barotropic response to a tropical forcing

    NASA Technical Reports Server (NTRS)

    Zhang, Yuxia; Mcguirk, James P.

    1993-01-01

    Zonally varying flow has been used to initialize numerical models and has been shown to play an important role in strong localized responses both in extratropics and the tropics. In this study, a climatological 200 mb January mean is used as a steady basic state of a barotropical model which consists of shallow water equations and a mass source centered at 4 deg S/120 deg E to simulate convective heating over Indonesia region. In the experiment, tropical responses appear not only over the western Pacific, where the forcing is located, but also over the eastern Pacific where the response is related to the zonally varying basic state. The westward propagating equatorial Rossby waves excited by the forcing interact with waves out of and into the tropics and the positive and negative phase of the Rossby waves result in blocking circulation over North America and tropical plumes over equatorial eastern Pacific, respectively.

  20. GOES Movie of Tropical Storm Danielle

    NASA Video Gallery

    This animation NOAA's GOES-East satellite imagery from June 18 to 20 shows the development and movement Tropical Storm Danielle from the western Caribbean Sea into the Bay of Campeche/Gulf of Mexic...

  1. GOES video of Tropical Storm Andrea

    NASA Video Gallery

    This NOAA GOES-East satellite animation shows the development of System 91L into Tropical Storm Andrea over the course of 3 days from June 4 to June 6, just after Andrea was officially designated a...

  2. Human Influence on Tropical Cyclone Intensity

    NASA Technical Reports Server (NTRS)

    Sobel, Adam H.; Camargo, Suzana J.; Hall, Timothy M.; Lee, Chia-Ying; Tippett, Michael K.; Wing, Allison A.

    2016-01-01

    Recent assessments agree that tropical cyclone intensity should increase as the climate warms. Less agreement exists on the detection of recent historical trends in tropical cyclone intensity.We interpret future and recent historical trends by using the theory of potential intensity, which predicts the maximum intensity achievable by a tropical cyclone in a given local environment. Although greenhouse gas-driven warming increases potential intensity, climate model simulations suggest that aerosol cooling has largely canceled that effect over the historical record. Large natural variability complicates analysis of trends, as do poleward shifts in the latitude of maximum intensity. In the absence of strong reductions in greenhouse gas emissions, future greenhouse gas forcing of potential intensity will increasingly dominate over aerosol forcing, leading to substantially larger increases in tropical cyclone intensities.

  3. Human influence on tropical cyclone intensity.

    PubMed

    Sobel, Adam H; Camargo, Suzana J; Hall, Timothy M; Lee, Chia-Ying; Tippett, Michael K; Wing, Allison A

    2016-07-15

    Recent assessments agree that tropical cyclone intensity should increase as the climate warms. Less agreement exists on the detection of recent historical trends in tropical cyclone intensity. We interpret future and recent historical trends by using the theory of potential intensity, which predicts the maximum intensity achievable by a tropical cyclone in a given local environment. Although greenhouse gas-driven warming increases potential intensity, climate model simulations suggest that aerosol cooling has largely canceled that effect over the historical record. Large natural variability complicates analysis of trends, as do poleward shifts in the latitude of maximum intensity. In the absence of strong reductions in greenhouse gas emissions, future greenhouse gas forcing of potential intensity will increasingly dominate over aerosol forcing, leading to substantially larger increases in tropical cyclone intensities.

  4. Internal Influences on Tropical Cyclone Formation

    DTIC Science & Technology

    2006-01-01

    scales. This is evident in Fig. 2. Another hypothesis in the top-down category is what we call the “ shower - head” theory by Bister and Emanuel...extra-tropical precursors. Quart. J. Roy. Meteor . Soc. (coming soon). Dickinson, M.J., and J. Molinari, 2002: Mixed Rossby-gravity waves and...1998: The formation of Tropical Cyclones. Meteor . Atmos. Phys. 67, 37—69. Harr, P. A., M. S. Kalafsky and R. L. Elsberry, 1996a: Environmental

  5. Phenology of temperate trees in tropical climates.

    PubMed

    Borchert, Rolf; Robertson, Kevin; Schwartz, Mark D; Williams-Linera, Guadalupe

    2005-09-01

    Several North American broad-leaved tree species range from the northern United States at approximately 47 degrees N to moist tropical montane forests in Mexico and Central America at 15-20 degrees N. Along this gradient the average minimum temperatures of the coldest month (T (Jan)), which characterize annual variation in temperature, increase from -10 to 12 degrees C and tree phenology changes from deciduous to leaf-exchanging or evergreen in the southern range with a year-long growing season. Between 30 and 45 degrees N, the time of bud break is highly correlated with T (Jan) and bud break can be reliably predicted for the week in which mean minimum temperature rises to 7 degrees C. Temperature-dependent deciduous phenology-and hence the validity of temperature-driven phenology models-terminates in southern North America near 30 degrees N, where T (Jan)>7 degrees C enables growth of tropical trees and cultivation of frost-sensitive citrus fruits. In tropical climates most temperate broad-leaved species exchange old for new leaves within a few weeks in January-February, i.e., their phenology becomes similar to that of tropical leaf-exchanging species. Leaf buds of the southern ecotypes of these temperate species are therefore not winter-dormant and have no chilling requirement. As in many tropical trees, bud break of Celtis, Quercus and Fagus growing in warm climates is induced in early spring by increasing daylength. In tropical climates vegetative phenology is determined mainly by leaf longevity, seasonal variation in water stress and day length. As water stress during the dry season varies widely with soil water storage, climate-driven models cannot predict tree phenology in the tropics and tropical tree phenology does not constitute a useful indicator of global warming.

  6. Monitoring tropical environments with Space Shuttle photography

    NASA Technical Reports Server (NTRS)

    Helfert, Michael R.; Lulla, Kamlesh P.

    1989-01-01

    Orbital photography from the Space Shuttle missions (1981-88) and earlier manned spaceflight programs (1962-1975) allows remote sensing time series to be constructed for observations of environmental change in selected portions of the global tropics. Particular topics and regions include deforestation, soil erosion, supersedimentation in streams, lacustrine, and estuarine environments, and desertification in the greater Amazon, tropical Africa and Madagascar, South and Southeast Asia, and the Indo-Pacific archipelagoes.

  7. Promoting the confluence of tropical cyclone research.

    PubMed

    Marler, Thomas E

    2015-01-01

    Contributions of biologists to tropical cyclone research may improve by integrating concepts from other disciplines. Employing accumulated cyclone energy into protocols may foster greater integration of ecology and meteorology research. Considering experienced ecosystems as antifragile instead of just resilient may improve cross-referencing among ecological and social scientists. Quantifying ecosystem capital as distinct from ecosystem services may improve integration of tropical cyclone ecology research into the expansive global climate change research community.

  8. Promoting the confluence of tropical cyclone research

    PubMed Central

    Marler, Thomas E

    2015-01-01

    Contributions of biologists to tropical cyclone research may improve by integrating concepts from other disciplines. Employing accumulated cyclone energy into protocols may foster greater integration of ecology and meteorology research. Considering experienced ecosystems as antifragile instead of just resilient may improve cross-referencing among ecological and social scientists. Quantifying ecosystem capital as distinct from ecosystem services may improve integration of tropical cyclone ecology research into the expansive global climate change research community. PMID:26480001

  9. Observed Climate Properties of Tropical Precipitating Convection

    NASA Technical Reports Server (NTRS)

    DelGenio, Anthony

    2002-01-01

    Conflicting theories about the contribution of convective systems to cloud feedback highlight the need for observational constraints on the properties of these storms. The NASA Tropical Rainfall Measuring Mission (TRMM) satellite provides unprecedented information on the hydrological properties and energetics of tropical convection. We present an analysis of almost 9,000 TRMM storms, focusing on how convection strength affects storm cloud properties and rainfall, and what this implies for the opposing "adaptive iris" and "thermostat" hypotheses.

  10. Objective classification of historical tropical cyclone intensity

    NASA Astrophysics Data System (ADS)

    Chenoweth, Michael

    2007-03-01

    Preinstrumental records of historical tropical cyclone activity require objective methods for accurately categorizing tropical cyclone intensity. Here wind force terms and damage reports from newspaper accounts in the Lesser Antilles and Jamaica for the period 1795-1879 are compared with wind speed estimates calculated from barometric pressure data. A total of 95 separate barometric pressure readings and colocated simultaneous wind force descriptors and wind-induced damage reports are compared. The wind speed estimates from barometric pressure data are taken as the most reliable and serve as a standard to compare against other data. Wind-induced damage reports are used to produce an estimated wind speed range using a modified Fujita scale. Wind force terms are compared with the barometric pressure data to determine if a gale, as used in the contemporary newspapers, is consistent with the modern definition of a gale. Results indicate that the modern definition of a gale (the threshold point separating the classification of a tropical depression from a tropical storm) is equivalent to that in contemporary newspaper accounts. Barometric pressure values are consistent with both reported wind force terms and wind damage on land when the location, speed and direction of movement of the tropical cyclone are determined. Damage reports and derived wind force estimates are consistent with other published results. Biases in ships' logbooks are confirmed and wind force terms of gale strength or greater are identified. These results offer a bridge between the earlier noninstrumental records of tropical cyclones and modern records thereby offering a method of consistently classifying storms in the Caribbean region into tropical depressions, tropical storms, nonmajor and major hurricanes.

  11. Next-Generation Tropical Cyclone Model

    DTIC Science & Technology

    2016-06-07

    goal of this project is to develop a robust and hardened high-resolution air- ocean coupled tropical cyclone (TC) data assimilation and prediction...mechanical interchanges with the underlying ocean and land surfaces, shallow and deep atmospheric convection in the convectively unstable tropical...shown to be able to reproduce rapid intensification in case studies involving complex upper tropospheric and oceanic conditions in a carefully

  12. Tropical Climate Dynamics and Civilizations

    NASA Astrophysics Data System (ADS)

    Haug, G. H.; Yancheva, G.; Peterson, L. C.

    2005-12-01

    Dr. James P. Kennett has been a leader in the area of rapid climate change. Jim and his son Douglas J. Kennett, a scientific archeologist, were among the first to make a serious effort to combine high-quality climate data with archeological information to study the impact of climate on societies. They argued about the 'strong relationship between climatically induced changes in environmental conditions and social, political, and economic responses' in coastal California during the past 2 millennia. One tropical climate archive with an appropriate memory for the most relevant sub-centennial to sub-decadal scale climate swings is the anoxic Cariaco Basin off northern Venezuela. Millimeter to micrometer-scale geochemical data in the laminated sediments of the Cariaco Basin have been interpreted to reflect variations in the hydrological cycle and the mean annual position of the Intertropical Convergence Zone (ITCZ) over tropical South America during the past millennia. These data with decadal to (sub)annual resolution show that the Terminal Collapse of the Classic Maya civilization occurred during an extended dry period. In detail, the Cariaco record reveals evidence for three separate droughts during the period of Maya downfall, each lasting a decade or less. These data suggest that climate change was potentially one immediate cause of the demise of Mayan civilization, with a century-scale decline in rainfall putting a general strain on resources and several multi-year events of more intense drought pushing Mayan society over the edge. Here, we present a new data set of comparable quality and resolution from Southern China. In the sediments of lake Huguang Maar in coastal southeast China, the titanium content and redox-sensitive magnetic properties record the strength of winter monsoon winds at subdecadal resolution over the last 16 thousand years. The record indicates a stronger winter monsoon prior to the Boelling-Alleroed warming, during the Younger Dryas, and

  13. Tropical convection and climate sensitivity

    NASA Astrophysics Data System (ADS)

    Williams, Ian Nobuo

    Surface temperature has become a popular measure of climate change, but it does not provide the most critical test of climate models. This thesis presents new methods to evaluate climate models based on processes determining the climate sensitivity to radiative forcing from atmospheric greenhouse gases. Cloud radiative feedbacks depend on temperature and relative humidity profiles in addition to surface temperature, through the dependence of cloud type on boundary layer buoyancy. Buoyancy provides a reference to which the onset of deep convection is invariant, and gives a compact description of sea surface temperature changes and cloud feedbacks suitable for diagnostics and as a basis for simplified climate models. This thesis also addresses uncertainties in climate sensitivity involving terrestrial ecosystem responses to global warming. Different diagnostics support different conclusions about atmospheric transport model errors that could imply either stronger or weaker northern terrestrial carbon sinks. Equilibrium boundary layer concepts were previously used in idealized tropical climate models, and are extended here to develop a diagnostic of boundary layer trace gas transport and mixing. Hypotheses linking surface temperature to climate and precipitation sensitivity were tested in this thesis using comprehensive and idealized climate model simulations, and observational datasets. The results do not support the thermostat hypothesis that predicts deep cloud cover will increase with radiative forcing and limit sea surface temperatures to the maximum present-day warm pool temperature. Warm pool temperatures increased along with or even faster than the tropical average over the past several decades, while diagnosed deep cloud cover has not significantly increased, in agreement with global warming simulations. Precipitation sensitivity also depends on more than surface temperature alone, including thermodynamic profiles and air-sea temperature differences. The

  14. Which statistics should tropical biologists learn?

    PubMed

    Loaiza Velásquez, Natalia; González Lutz, María Isabel; Monge-Nájera, Julián

    2011-09-01

    Tropical biologists study the richest and most endangered biodiversity in the planet, and in these times of climate change and mega-extinctions, the need for efficient, good quality research is more pressing than in the past. However, the statistical component in research published by tropical authors sometimes suffers from poor quality in data collection; mediocre or bad experimental design and a rigid and outdated view of data analysis. To suggest improvements in their statistical education, we listed all the statistical tests and other quantitative analyses used in two leading tropical journals, the Revista de Biología Tropical and Biotropica, during a year. The 12 most frequent tests in the articles were: Analysis of Variance (ANOVA), Chi-Square Test, Student's T Test, Linear Regression, Pearson's Correlation Coefficient, Mann-Whitney U Test, Kruskal-Wallis Test, Shannon's Diversity Index, Tukey's Test, Cluster Analysis, Spearman's Rank Correlation Test and Principal Component Analysis. We conclude that statistical education for tropical biologists must abandon the old syllabus based on the mathematical side of statistics and concentrate on the correct selection of these and other procedures and tests, on their biological interpretation and on the use of reliable and friendly freeware. We think that their time will be better spent understanding and protecting tropical ecosystems than trying to learn the mathematical foundations of statistics: in most cases, a well designed one-semester course should be enough for their basic requirements.

  15. Tracer exchange between tropics and middle latitudes

    NASA Technical Reports Server (NTRS)

    Rood, Richard; Douglass, Anne; Weaver, Clark

    1992-01-01

    The interaction between the tropics and middle latitudes is studied using a tracer emitted at 50 hPa along a great circle route between Los Angeles, USA and Sydney, Australia. Though designed to examine the impact of stratospheric aircraft, the study more generally addresses the transport between tropics and middle latitudes for a three month period from January through March 1989. The results show that air is transported from the tropics to middle latitudes by planetary scale and tropospheric cyclonic scale waves. Except for intrusions by these wave events, the tropics are substantially isolated throughout the lower stratosphere. These waves draw material out of the tropics which ends up in the middle latitude westerly jets, with little material entering the winter polar latitudes prior to the springtime transition. The summer Southern Hemisphere is characterized by tracer being drawn out in streamers that extend from north and west to south and east. The material in the tropics is zonally asymmetric. The material that reaches the troposphere comes down in the synoptic scale eddies and is concentrated in the middle latitude jet stream. These characteristics are similar to those observed during the dispersion of volcanic clouds.

  16. Tropical skin diseases in British military personnel.

    PubMed

    Bailey, Mark S

    2013-09-01

    Skin complaints are common in travellers to foreign countries and are responsible for up to 25% of medical consultations by military personnel during deployments in the tropics. They also have relatively high rates of field hospital admission, medical evacuation and referral to UK Role 4 healthcare facilities. Non-infectious tropical skin diseases include sunburn, heat rash, arthropod bites, venomous bites, contact dermatitis and phytophotodermatitis. During tropical deployments skin infections that commonly occur in military personnel may become more frequent, severe and difficult to treat. Several systemic tropical infections have cutaneous features that can be useful in making early diagnoses. Tropical skin infections such as cutaneous larva migrans, cutaneous myiasis, cutaneous leishmaniasis and leprosy do occur in British troops and require specialist clinical management. This illustrated review focuses on the most significant tropical skin diseases that have occurred in British military personnel in recent years. Clinical management of these conditions on deployments would be improved and medical evacuations could be reduced if a military dermatology 'reach-back' service (including a telemedicine facility) was available.

  17. Characterization of clouds in Titan's tropical atmosphere

    USGS Publications Warehouse

    Griffith, C.A.; Penteado, P.; Rodriguez, S.; Le, Mouelic S.; Baines, K.H.; Buratti, B.; Clark, R.; Nicholson, P.; Jaumann, R.; Sotin, C.

    2009-01-01

    Images of Titan's clouds, possible over the past 10 years, indicate primarily discrete convective methane clouds near the south and north poles and an immense stratiform cloud, likely composed of ethane, around the north pole. Here we present spectral images from Cassini's Visual Mapping Infrared Spectrometer that reveal the increasing presence of clouds in Titan's tropical atmosphere. Radiative transfer analyses indicate similarities between summer polar and tropical methane clouds. Like their southern counterparts, tropical clouds consist of particles exceeding 5 ??m. They display discrete structures suggestive of convective cumuli. They prevail at a specific latitude band between 8??-20?? S, indicative of a circulation origin and the beginning of a circulation turnover. Yet, unlike the high latitude clouds that often reach 45 km altitude, these discrete tropical clouds, so far, remain capped to altitudes below 26 km. Such low convective clouds are consistent with the highly stable atmospheric conditions measured at the Huygens landing site. Their characteristics suggest that Titan's tropical atmosphere has a dry climate unlike the south polar atmosphere, and despite the numerous washes that carve the tropical landscape. ?? 2009. The American Astronomical Society.

  18. LCSs in tropical cyclone genesis

    NASA Astrophysics Data System (ADS)

    Rutherford, B.; Montgomery, M. T.

    2011-12-01

    The formation of tropical cyclones in the Atlantic most often occurs at the intersection of the wave trough axis of a westward propagating African easterly wave and the wave critical latitude. Viewed in a moving reference frame with the wave, a cat's eye region of cyclonic recirculation can be seen in streamlines prior to genesis. The cat's eye recirculation region has little strain deformation and its center serves as the focal point for aggregation of convectively generated vertical vorticity. Air inside the cat's eye is repeatedly moistened by convection and is protected from the lateral intrusion of dry air. Since the flow is inherently time-dependent, we contrast the time-dependent structures with Eulerian structures of the wave-relative frame. Time-dependence complicates the kinematic structure of the recirculation region as air masses from the outer environment are allowed to interact with the interior of the cat's eye. LCSs show different boundaries of the cat's eye than the streamlines in the wave-relative frame. These LCSs are particularly important for showing the pathways of air masses that interact with the developing vortex, as moist air promotes development by supporting deep convection, while interaction with dry air impedes development. We primarily use FTLEs to locate the LCSs, and show the role of LCSs in both developing and non-developing storms. In addition, we discuss how the vertical coherence of LCSs is important for resisting the effects of vertical wind shear.

  19. Tropical infections in the ICU.

    PubMed

    Kothari, Vatsal M; Karnad, Dilip R; Bichile, Lata S

    2006-04-01

    Certain arthropod-borne infections are common in tropical regions because of favorable climatic conditions. Water-borne infections like leptospirosis are common due to contamination of water especially during the monsoon floods. Infections like malaria, leptospirosis, dengue fever and typhus sometimes cause life threatening organ dysfunction and have several overlapping features. Most patients present with classicial clinical syndromes: fever and thrombocytopenia are common in dengue, malaria and leptospirosis; coagulopathy is frequent in leptospirosis and viral hepatitis. Hepatorenal syndrome is seen in leptospirosis, falciparum malaria and scrub typhus. The pulmonary renal syndrome is caused by falciparium malaria, leptospirosis, Hantavirus infection and scrub typhus. Fever with altered mental status is produced by bacterial meningitis, Japanese B encephalitis, cerebral malarial, typhoid encephalopathy and fulminant hepatic failure due to viral hepatitis. Subtle differences in features of the organ failure exist among these infections. The diagnosis in some of these diseases is made by demonstration of antibodies in serum, and these may be negative in the first week of the illness. Hence empiric therapy for more than one disorder may be justified in a small proportion of cases. In addition to specific anti-infective therapy, management of organ dysfunction includes use of mechanical ventilation, vasopressor drugs, continuous renal replacement therapy and blood products. Timely transfer of these patients to well-equipped ICUs with experience in managing these cases can considerably decrease mortality and morbidity.

  20. Thermal Performance of Tropical Atrium

    NASA Astrophysics Data System (ADS)

    Baharvand, Mohammad; Bin Ahmad, Mohd Hamdan; Safikhan, Tabassom; Mirmomtaz, Sayyed Mohammad Mahdi

    2013-12-01

    Atrium is a popular architectural feature utilized widely by building designers and owners to bring various benefits such as adequate daylight, circulation spaces and surfaces for landscape applications. But atrium problems in tropical climates such as excessive daylight, glare and high temperature, which lead to increase building energy demand, have been reported. To avoid and reduce these unpleasant features, a side-lit atrium has been suggested. Although researchers proposed side-lit atrium to prevent common problems of atria, the lack of precedent research on this issue compels these authors to study atrium performance in hot and humid climate. So the research aims to examine two different atrium roof form types in terms of temperature and ventilation impacts in hot and humid climate of Malaysia using DesignBuilder as a simulation program. The results indicate lower temperature of side-lit model with better airflow pattern in comparison with top-lit model while the top-lit model provides higher air velocity at the air inlet and outlet.

  1. Climatic Variability In Tropical Countries

    NASA Astrophysics Data System (ADS)

    Seneviratne, L. W.

    2003-04-01

    Introduction Droughts in tropical countries are proved as periodic and its occurrence is shown remarkable in 9.25 year cycles as explained by the author. These cycles exist as soon or late around the central point. In the tropical regions monsoons or trade winds has a definite origin and pattern of advancing towards land mass. Ocean evaporation is the main source of rain clouds, which is drifted on to low vapour pressure zones. In the drought situation low vapour pressure zones are reduced and high vapour pressure zones are increased. Evaporation is reduced and incident solar radiation (insolation) is relatively reduced. Wind effect needed to form a cloud is low. Dry wind is passing along the land mass. Most rainy lands are subjected to prolonged droughts and hence cultivation is affected. Drought impacts create severe losses to irrigation projects. Civilization is affected by lack of food production. Lack of drinking water entirely eliminates the living animals and creatures. Eco system slowly changes to dried jungles and abandoned skeletons. Tropical conditions Sri Lanka experienced drought in 2001. Hambanthota District suffered for entire year 2000 with low rainfall. This area is not in line with monsoons and mountain ranges are not available to form dynamic cooling of air. So as the Puttalam and Mannar Districts Rainfall is very low in these areas. Drought continued for 2001 and half of 2002 in the main land. Hambanthota District is still continuing with low rainfall. The central mountains are well placed to bring monsoon rains. This position is not purely effective to form sufficient precipitation in drought years. The reason is highly stable atmosphere in this region. Due to global warming of 1deg C in 60 years and high carbon dioxide gas creating high density in low atmospheres, evaporation and rainmaking has a general reduction. It is identified by the author that the common plane episode of Moon and Earth, which occurs in 9.25 years is creating stable

  2. [Dangerous sharks in tropical seas].

    PubMed

    Maslin, J; Menard, G; Drouin, C; Pollet, L

    2000-01-01

    Sightseeing travel in tropical zones is a growing industry. The risks incurred by travelers depend on the destination, duration of stay, individual behavior, and type of leisure activity. Water sports expose visitors to encounters with dangerous marine animals. Shark attacks are rare but always serious occurrences. Divers should handle any shark, regardless of size, with due precaution. Prevention of shark attack depends on avoiding encounters by not attracting the attention of the shark and knowing the proper attitude to adopt in case an encounter should occur. Active and passive protection can be used, but each method has advantages and disadvantages depending on the situation. Rescue operations are difficult due to the gravity of injuries and their occurrence in a marine environment. This along with the nature of the aggressor explain that many attacks are immediately fatal. Wounds are often deep with involvement of bone, blood vessels, and nerves. A possible source of complication in survivors is infection, which can involve uncommon microorganisms associated with bacteria in sharks mouth or marine environment.

  3. Disaggregating tropical disease prevalence by climatic and vegetative zones within tropical West Africa

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Tropical infectious disease prevalence is dependent on many socio-cultural determinants. However, rainfall and temperature frequently underlie overall prevalence, particularly for vector-borne diseases. As a result these diseases have increased prevalence in tropical as compared to temperate regions...

  4. Tropical deforestation and the global carbon budget

    SciTech Connect

    Melillo, J.M.; Kicklighter, D.W.; Houghton, R.A.; McGuire, A.D.

    1996-12-31

    The CO{sub 2} concentration of the atmosphere has increased by almost 30% since 1800. This increase is due largely to two factors: the combustion of fossil fuel and deforestation to create croplands and pastures. Deforestation results in a net flux of carbon to the atmospheric because forests contain 20--50 times more carbon per unit area than agricultural lands. In recent decades, the tropics have been the primary region of deforestation.The annual rate of CO{sub 2} released due to tropical deforestation during the early 1990s has been estimated at between 1.2 and 2.3 gigatons C. The range represents uncertainties about both the rates of deforestation and the amounts of carbon stored in different types of tropical forests at the time of cutting. An evaluation of the role of tropical regions in the global carbon budget must include both the carbon flux to the atmosphere due to deforestation and carbon accumulation, if any, in intact forests. In the early 1990s, the release of CO{sub 2} from tropical deforestation appears to have been mostly offset by CO{sub 2} uptake occurring elsewhere in the tropics, according to an analysis of recent trends in the atmospheric concentrations of O{sub 2} and N{sub 2}. Interannual variations in climate and/or CO{sub 2} fertilization may have been responsible for the CO{sub 2} uptake in intact forests. These mechanisms are consistent with site-specific measurements of net carbon fluxes between tropical forests and the atmosphere, and with regional and global simulations using process-based biogeochemistry models. 86 refs., 1 fig., 6 tabs.

  5. Methyl Chloride Emission from Tropical Plants

    NASA Astrophysics Data System (ADS)

    Yokouchi, Y.; Ikeda, M.; Ikeda, M.; Inuzuka, Y.; Yukawa, T.

    2001-12-01

    We studied CH3Cl emissions from tropical plants in Tropical Rainforest Glasshouse (25 m x 20 m x 10-24 m high) in Tsukuba Botanical Gardens, where more than 200 representative species from lowland tropical forests of Southeast Asia grow. CH3Cl concentrations were always higher in the glasshouse than outside and increased significantly when the windows were closed. The fluxes of CH3Cl from the tropical rainforest system in the glasshouse were calculated from the averages of their accumulation rates when the windows were closed (average; 142 pptv”h-1) with the dimension of the glasshouse. Emission rates per unit area for CH3Cl was 5.4 mg m-2 h-1. In order to determine which of the plants or whether the soil is responsible for the increase of CH3Cl, flux measurements were done by using an enclosure method. The soil was found to take up CH3Cl at a small rate. On the other hand, some plants from the Marattiaceae, Cyatheaceae (tree fern), Dicksoniaceae, and Dipterocarpaceae families were found to significantly emit CH3Cl. The first three families are ferns commonly growing in tropical forests, and Dipterocarpaceae species are dominant in the tropical rainforests of Southeast Asia. The average CH3Cl emission rate from the 9 plants in these families was around 0.5 mg (g dry leaf)-1”h-1. As for Cyatheaceae, we conducted a flux measurement from Cyathea lepifera E.Copel. in a subtropical forest in Okinawa and detected high emissions of CH3Cl amounting to 1.1 mg (g dry leaf)-1”h-1. Strong emissions of CH3Cl from tropical forests raises questions about the trends of chlorine compounds in the future and in the past.

  6. The tropical cyclone diurnal cycle

    NASA Astrophysics Data System (ADS)

    Dunion, Jason P.

    The research presented in this thesis explores a phenomenon referred to as the tropical cyclone (TC) diurnal cycle (TCDC) and presents satellite, numerical modeling, and observational perspectives pertaining to how it can be monitored, its evolution in time and space, its relevance to TC structure and intensity, and how it manifests in numerical simulations of TCs. Infrared satellite imagery was developed and used to investigate diurnal oscillations in TCs and finds a diurnal pulsing pattern that occurs with notable regularity through a relatively deep layer from the inner core to the surrounding environment. A combination of satellite, numerical model simulations, and aircraft observations found diurnal signals in operationally analyzed radii of 50 kt winds in TCs and in satellite intensity estimates from the Advanced Dvorak Technique and spawned the development of a 24-hr conceptual clock that approximates the temporal and spatial evolution of the TCDC each day. TC diurnal pulses are revealed to significantly impact the thermodynamics and winds in the TC environment and appear as narrow, convectively active rings of high radar reflectivity in NOAA aircraft radar data and are hundreds of kilometers in length. Enhanced nighttime radiational cooling that is particularly favored in the TC outflow layer acts to pre-condition the TC environment in a way that favors triggering of the TCDC and TC diurnal pulses, while in the daytime, the stabilizing effects of shortwave warming begins to suppress TCDC processes in the storm, leading to the culmination of the TCDC each day. Schematics are presented that summarize many of the main findings in this work, including descriptions of the basic state of the TC environment as the TCDC evolves during its early and later stages each day and a TCDC-centric daytime evolution of a TC diurnal pulse, associated squall lines and gust fronts, and radial and vertical winds in the lower and upper levels of the storm. The TCDC represents a

  7. Raindrop Size Distribution Measurements in Tropical Cyclones

    NASA Technical Reports Server (NTRS)

    Tokay, Ali; Bashor, Paul G.; Habib, Emad; Kasparis, Takis

    2008-01-01

    Characteristics of the raindrop size distribution in seven tropical cyclones have been studied through impact-type disdrometer measurements at three different sites during the 2004-06 Atlantic hurricane seasons. One of the cyclones has been observed at two different sites. High concentrations of small and/or midsize drops were observed in the presence or absence of large drops. Even in the presence of large drops, the maximum drop diameter rarely exceeded 4 mm. These characteristics of raindrop size distribution were observed in all stages of tropical cyclones, unless the storm was in the extratropical stage where the tropical cyclone and a midlatitude frontal system had merged. The presence of relatively high concentrations of large drops in extratropical cyclones resembled the size distribution in continental thunderstorms. The integral rain parameters of drop concentration, liquid water content, and rain rate at fixed reflectivity were therefore lower in extratropical cyclones than in tropical cyclones. In tropical cyclones, at a disdrometercalculated reflectivity of 40 dBZ, the number concentration was 700 plus or minus 100 drops m(sup -3), while the liquid water content and rain rate were 0.90 plus or minus 0.05 g m(sup -3) and 18.5 plus or minus 0.5 mm h(sup -1), respectively. The mean mass diameter, on the other hand, was 1.67 plus or minus 0.3 mm. The comparison of raindrop size distributions between Atlantic tropical cyclones and storms that occurred in the central tropical Pacific island of Roi-Namur revealed that the number density is slightly shifted toward smaller drops, resulting in higher-integral rain parameters and lower mean mass and maximum drop diameters at the latter site. Considering parameterization of the raindrop size distribution in tropical cyclones, characteristics of the normalized gamma distribution parameters were examined with respect to reflectivity. The mean mass diameter increased rapidly with reflectivity, while the normalized

  8. Drought-mortality relationships for tropical forests.

    PubMed

    Phillips, Oliver L; van der Heijden, Geertje; Lewis, Simon L; López-González, Gabriela; Aragão, Luiz E O C; Lloyd, Jon; Malhi, Yadvinder; Monteagudo, Abel; Almeida, Samuel; Dávila, Esteban Alvarez; Amaral, Iêda; Andelman, Sandy; Andrade, Ana; Arroyo, Luzmila; Aymard, Gerardo; Baker, Tim R; Blanc, Lilian; Bonal, Damien; de Oliveira, Atila Cristina Alves; Chao, Kuo-Jung; Cardozo, Nallaret Dávila; da Costa, Lola; Feldpausch, Ted R; Fisher, Joshua B; Fyllas, Nikolaos M; Freitas, Maria Aparecida; Galbraith, David; Gloor, Emanuel; Higuchi, Niro; Honorio, Eurídice; Jiménez, Eliana; Keeling, Helen; Killeen, Tim J; Lovett, Jon C; Meir, Patrick; Mendoza, Casimiro; Morel, Alexandra; Vargas, Percy Núñez; Patiño, Sandra; Peh, Kelvin S-H; Cruz, Antonio Peña; Prieto, Adriana; Quesada, Carlos A; Ramírez, Fredy; Ramírez, Hirma; Rudas, Agustín; Salamão, Rafael; Schwarz, Michael; Silva, Javier; Silveira, Marcos; Slik, J W Ferry; Sonké, Bonaventure; Thomas, Anne Sota; Stropp, Juliana; Taplin, James R D; Vásquez, Rodolfo; Vilanova, Emilio

    2010-08-01

    *The rich ecology of tropical forests is intimately tied to their moisture status. Multi-site syntheses can provide a macro-scale view of these linkages and their susceptibility to changing climates. Here, we report pan-tropical and regional-scale analyses of tree vulnerability to drought. *We assembled available data on tropical forest tree stem mortality before, during, and after recent drought events, from 119 monitoring plots in 10 countries concentrated in Amazonia and Borneo. *In most sites, larger trees are disproportionately at risk. At least within Amazonia, low wood density trees are also at greater risk of drought-associated mortality, independent of size. For comparable drought intensities, trees in Borneo are more vulnerable than trees in the Amazon. There is some evidence for lagged impacts of drought, with mortality rates remaining elevated 2 yr after the meteorological event is over. *These findings indicate that repeated droughts would shift the functional composition of tropical forests toward smaller, denser-wooded trees. At very high drought intensities, the linear relationship between tree mortality and moisture stress apparently breaks down, suggesting the existence of moisture stress thresholds beyond which some tropical forests would suffer catastrophic tree mortality.

  9. Neuropsychiatric manifestations of some tropical diseases.

    PubMed

    Moryś, Joanna M; Jeżewska, Maria; Korzeniewski, Krzysztof

    2015-01-01

    Some tropical diseases are the direct cause of severe disturbances of cerebral function while others affect only finer cerebral systems controlling fears, anxiety and personality traits. The mechanisms by which psychiatric symptoms are produced in tropical disorders are not any different from the mechanisms that relate to any physical disorders. Neuropsychiatric symptoms may be caused by a number of different mechanisms including bacterial toxins, release of cytokines, hyperthermia, shock (poor perfusion), acute renal insufficiency, pulmonary failure (shock lung), coagulopathy, disruption of the blood-brain barrier, and/or the nest of pathogens into the central nervous system. The following tropical illnesses can be associated with neuropsychiatric symptoms: neurocysticercosis, malaria, trypanosomiasis, dengue, and schistosomiasis. Neurological and psychiatric impairments induced by tropical diseases both represent a major category of invalidating disorders, which cause profound changes in the nervous system functions, often associated with severe sequels or late-onset disturbances. It is therefore important to disseminate knowledge of the neuropsychiatric symptoms accompanying tropical diseases in order to increase the awareness of these problems and challenges.

  10. Mercury in tropical and subtropical coastal environments

    PubMed Central

    Costa, Monica F.; Landing, William M.; Kehrig, Helena A.; Barletta, Mário; Holmes, Christopher D.; Barrocas, Paulo R. G.; Evers, David C.; Buck, David G.; Vasconcellos, Ana Claudia; Hacon, Sandra S.; Moreira, Josino C.; Malm, Olaf

    2012-01-01

    Anthropogenic activities influence the biogeochemical cycles of mercury, both qualitatively and quantitatively, on a global scale from sources to sinks. Anthropogenic processes that alter the temporal and spatial patterns of sources and cycling processes are changing the impacts of mercury contamination on aquatic biota and humans. Human exposure to mercury is dominated by the consumption of fish and products from aquaculture operations. The risk to society and to ecosystems from mercury contamination is growing, and it is important to monitor these expanding risks. However, the extent and manner to which anthropogenic activities will alter mercury sources and biogeochemical cycling in tropical and sub-tropical coastal environments is poorly understood. Factors as (1) lack of reliable local/regional data; (2) rapidly changing environmental conditions; (3) governmental priorities and; (4) technical actions from supra-national institutions, are some of the obstacles to overcome in mercury cycling research and policy formulation. In the tropics and sub-tropics, research on mercury in the environment is moving from an exploratory “inventory” phase towards more process-oriented studies. Addressing biodiversity conservation and human health issues related to mercury contamination of river basins and tropical coastal environments are an integral part of paragraph 221 paragraph of the United Nations document “The Future We Want” issued in Rio de Janeiro in June 2012. PMID:22901765

  11. Extinction risk escalates in the tropics.

    PubMed

    Vamosi, Jana C; Vamosi, Steven M

    2008-01-01

    The latitudinal biodiversity gradient remains one of the most widely recognized yet puzzling patterns in nature. Presently, the high level of extinction of tropical species, referred to as the "tropical biodiversity crisis", has the potential to erode this pattern. While the connection between species richness, extinction, and speciation has long intrigued biologists, these interactions have experienced increased poignancy due to their relevancy to where we should concentrate our conservation efforts. Natural extinction is a phenomenon thought to have its own latitudinal gradient, with lower extinction rates in the tropics being reported in beetles, birds, mammals, and bivalves. Processes that have buffered ecosystems from high extinction rates in the past may also buffer ecosystems against disturbance of anthropogenic origin. While potential parallels between historical and present-day extinction patterns have been acknowledged, they remain only superficially explored and plant extinction patterns have been particularly neglected. Studies on the disappearances of animal species have reached conflicting conclusions, with the rate of extinction appearing either higher or lower in species richness hotspots. Our global study of extinction risk in vascular plants finds disproportionately higher extinction risk in tropical countries, even when indicators of human pressure (GDP, population density, forest cover change) are taken into account. Our results are at odds with the notion that the tropics represent a museum of plant biodiversity (places of historically lowered extinction) and we discuss mechanisms that may reconcile this apparent contradiction.

  12. Particularities of allergy in the Tropics.

    PubMed

    Caraballo, Luis; Zakzuk, Josefina; Lee, Bee Wah; Acevedo, Nathalie; Soh, Jian Yi; Sánchez-Borges, Mario; Hossny, Elham; García, Elizabeth; Rosario, Nelson; Ansotegui, Ignacio; Puerta, Leonardo; Sánchez, Jorge; Cardona, Victoria

    2016-01-01

    Allergic diseases are distributed worldwide and their risk factors and triggers vary according to geographical and socioeconomic conditions. Allergies are frequent in the Tropics but aspects of their prevalence, natural history, risk factors, sensitizers and triggers are not well defined and some are expected to be different from those in temperate zone countries. The aim of this review is to investigate if allergic diseases in the Tropics have particularities that deserve special attention for research and clinical practice. Such information will help to form a better understanding of the pathogenesis, diagnosis and management of allergic diseases in the Tropics. As expected, we found particularities in the Tropics that merit further study because they strongly affect the natural history of common allergic diseases; most of them related to climate conditions that favor permanent exposure to mite allergens, helminth infections and stinging insects. In addition, we detected several unmet needs in important areas which should be investigated and solved by collaborative efforts led by the emergent research groups on allergy from tropical countries.

  13. The Tropical Rainfall Measuring Mission (TRMM)

    NASA Technical Reports Server (NTRS)

    Simpson, Joanne; Kummerow, Christian D.; Meneghini, Robert; Hou, Arthur; Adler, Robert F.; Huffman, George; Barkstrom, Bruce; Wielicki, Bruce; Goodman, Steven J.; Christian, Hugh; Einaudi, Franco (Technical Monitor)

    1999-01-01

    Recognizing the importance of rain in the tropics and the accompanying latent heat release, NASA for the U.S. and NASDA for Japan have partnered in the design, construction and flight of an Earth Probe satellite to measure tropical rainfall and calculate the associated heating. Primary mission goals are: 1) the understanding of crucial links in climate variability by the hydrological cycle, 2) improvement in the large-scale models of weather and climate, and 3) improvement in understanding cloud ensembles and their impacts on larger scale circulations. The linkage with the tropical oceans and landmasses are also emphasized. The Tropical Rainfall Measuring Mission (TRMM) satellite was launched in November 1997 with fuel enough to obtain a four to five year data set of rainfall over the global tropics from 37 deg N to 37 deg S. This paper reports progress from launch date through the spring of 1999. The data system and its products and their access is described, as are the algorithms used to obtain the data. Some exciting early results from TRMM are described. Some important algorithm improvements are shown. These will be used in the first total data reprocessing, scheduled to be complete in early 2000. The reader is given information on how to access and use the data.

  14. Forty years experience in developing and using rainfall simulators under tropical and Mediterranean conditions

    NASA Astrophysics Data System (ADS)

    Pla-Sentís, Ildefonso; Nacci, Silvana

    2010-05-01

    obtained with small size 500-1000 cm2, easily dismantled, drop former simulators, than with larger, nozzle, or more sophisticated equipments. In this contribution there are presented some of the rainfall simulators developed and used by the main author, and some of the results obtained in different studies of practical problems under tropical and Mediterranean conditions. References Pla, I.,G.Campero, y R.Useche.1974.Physical degradación of agricultural soils in the Western Plains of Venezuela. "Trans.10th Int.Cong.Soil.Sci.Soc". 1:231-240. .Moscú Pla, I. 1975.Effects of bitumen emulsion and polyacrilamide on some physical properties of Venezuelan soils. En "Soil Sci. Soc. Am. Special Publication"• 7. 35-46. Madison. Wisconsin . (USA). Pla, I. 1977.Aggregate size and erosion control on sloping land treated with hydrophobic bitumen emulsion."Soil Conservation and Management in the Humid Tropics".109-115. John Wiley & Sons. Pla, I.1981.Simuladores de lluvia para el estudio de relaciones suelo-agua bajo agricultura de secano en los trópicos. Rev. Fac. Agron. XII(1-2):81-93.Maracay (Venezuela) Pla, I. 1986.A routine laboratory index to predict the effects of soil sealing on soil and water conservation. En "Assesment of Soil Surface Sealing and Crusting". 154-162.State Univ. of Ghent.Gante (Bélgica Pla, I., M.C. Ramos, S. Nacci, F. Fonseca y X. Abreu. 2005. Soil moisture regime in dryland vineyards of Catalunya (Spain) as influenced by climate, soil and land management. "Integrated Soil and Water Management for Orchard Development". FAO Land and Water Bulletin 10. 41-49. Roma (Italia).

  15. The influence of the tropics on the prediction of ultralong waves. I - Tropical wind field

    NASA Technical Reports Server (NTRS)

    Baker, W. E.; Paegle, J.

    1983-01-01

    The effects of tropical wind data from the FGGE and tropical latent heating on numerical modeling of ultralong waves are considered in a two-part study. The model studied is the global fourth-order GLAS general circulation model, an energy-conserving format with horizontal differences calculated with fourth-order accuracy. Data assimilation experiments were performed with and without the wind data, with account taken of eastward and northward wind components, the geopotential height, and the relative humidity, all over pressure surfaces. The initial conditions were used to generate six pairs of forecasts, and the tropical wind error decreased after two days of prediction when the initial conditions contained the wind data. The deviations from the measured planetary wave data were attributed to differences in the initial rotational wind field, which varied on a three-day basis. The latent heat initial data had a five-day period and extended its influence beyond the tropical zone. The tropical heat sources sustained the tropical westerlies in the GLAS model, and removal of the tropical heat sources reversed the wind to easterlies.

  16. Monitoring tropical vegetation succession with LANDSAT data

    NASA Technical Reports Server (NTRS)

    Robinson, V. B. (Principal Investigator)

    1983-01-01

    The shadowing problem, which is endemic to the use of LANDSAT in tropical areas, and the ability to model changes over space and through time are problems to be addressed when monitoring tropical vegetation succession. Application of a trend surface analysis model to major land cover classes in a mountainous region of the Phillipines shows that the spatial modeling of radiance values can provide a useful approach to tropical rain forest succession monitoring. Results indicate shadowing effects may be due primarily to local variations in the spectral responses. These variations can be compensated for through the decomposition of the spatial variation in both elevation and MSS data. Using the model to estimate both elevation and spectral terrain surface as a posteriori inputs in the classification process leads to improved classification accuracy for vegetation of cover of this type. Spatial patterns depicted by the MSS data reflect the measurement of responses to spatial processes acting at several scales.

  17. Tropical Pacific climate trends since 1960

    NASA Technical Reports Server (NTRS)

    Posmentier, Eric S.; Cane, Mark A.; Zebiak, Stephen E.

    1989-01-01

    Merchant ship observations appear to indicate an increase in the strength of the surface winds in the tropical Pacific and elsewhere in recent decades. Here, trends in tropical Pacific sea surface temperature and sea level, which has repeatedly been shown to be closely related to the winds, are investigated. The results suggest that sea levels since 1960 have been rising oceanwide at about 3.5 cm/decade, while simultaneously tilting about 2 cm/decade higher in the east and lower in the west, and that surface temperatures have been rising about 0.6 C/decade. These results are not consistent with the apparent wind change; rather, they support the contention that the apparent wind changes are an artifact introduced by changes in measurement technique, and suggest that tropical Pacific winds may have actually decreased in strength.

  18. Tropical cyclone intensities from satellite microwave data

    NASA Technical Reports Server (NTRS)

    Vonderhaar, T. H.; Kidder, S. Q.

    1980-01-01

    Radial profiles of mean 1000 mb to 250 mb temperature from the Nimbus 6 scanning microwave spectrometer (SCAMS) were constructed around eight intensifying tropical storms in the western Pacific. Seven storms showed distinct inward temperature gradients required for intensification; the eighth displayed no inward gradient and was decaying 24 hours later. The possibility that satellite data might be used to forecast tropical cyclone turning motion was investigated using estimates obtained from Nimbus 6 SCAMS data tapes of the mean 1000 mb to 250 mb temperature field around eleven tropical storms in 1975. Analysis of these data show that for turning storms, in all but one case, the turn was signaled 24 hours in advance by a significant temperature gradient perpendicular to the storm's path, at a distance of 9 deg to 13 deg in front of the storm. A thresholding technique was applied to the North Central U.S. during the summer to estimate precipitation frequency. except

  19. Paleoceanography of the tropical eastern pacific ocean.

    PubMed

    Grigg, R W; Hey, R

    1992-01-10

    The East Pacific Barrier (EPB) is the most effective marine barrier to dispersal of tropical shallow-water fauna in the world today. The fossil record of corals in the eastern Pacific suggests this has been true throughout the Cenozoic. In the Cretaceous, the EPB was apparently less effective in limiting dispersal. Equatorial circulation in the Pacific then appears to have been primarily east to west and the existence of oceanic atolls (now drowned guyots) in the eastern Pacific probably aided dispersal. Similarly, in the middle and early Mesozoic and late Paleozoic, terranes in the central tropical Pacific likely served as stepping stones to dispersal of tropical shelf faunas, reducing the isolating effect of an otherwise wider Pacific Ocean (Panthalassa).

  20. Solar Influence On ENSO And The Tropics?

    NASA Astrophysics Data System (ADS)

    Cane, M. A.; Emile-Geay, J. B.; Seager, R.; Clement, A. C.; Mann, M. E.

    2004-12-01

    We consider the possibility that variations in solar irradiance have a significant impact on the climate of the tropics, including the El Niño-Southern Oscillation (ENSO) cycle. It is well known that ENSO has a large impact on regional climates worldwide, with subsequent impacts on ecosystems and society. Very recent work (Schubert et al. 2004; Seager et al. 2004) has shown that a prime cause of the Dust Bowl droughts of the 1930s is a La Niña-like pattern of decadal mean sea surface temperature anomalies in the Pacific. These anomalies were very small amplitude (<0.5°C everywhere). Decadal anomalies of similar size in the tropical West Pacific and Indian Oceans have been shown to impact the North Atlantic sector (Hoerling et al., 2001); other small amplitude anomalies throughout the tropical Indian and Pacific Oceans appear to be responsible for widespread midlatitude droughts from 1998-2002 (Hoerling and Kumar, 2003). Our recent work (Mann et al. 2004) has shown that coupled ocean-atmosphere interactions in the tropical Pacific generate a significant response to solar and volcanic radiative forcing over the past 1000 years. Here we focus on solar variations. While they are unlikely to have much effect on individual El Niño-Southern Oscillation (ENSO) events, they may influence characteristics of the ENSO cycle by changing the background state. Shifts in the ENSO cycle or the background state of the tropical Pacific could help explain persistent climate anomalies around the world over the last 1000 years. Noise or chaos internal to the climate system clearly is responsible for much of the decade to decade variation in the ENSO cycle, which has caused droughts such as those of the 1930s. But does solar variability also play a role? What is the impact of solar variability on the tropical climate in general, on timescales from decades to millennia?

  1. GOES-West Video of Tropical Storm Blas

    NASA Video Gallery

    This animation of visible and infrared imagery from NOAA's GOES-West satellite from July 9 to July 11 shows Tropical Storm Blas weakening to a remnant (left) followed by a strengthening Tropical Cy...

  2. Satellite Movie Shows Birth of Atlantic's Tropical Storm Lorenzo

    NASA Video Gallery

    This animation of NOAA's GOES-East satellite imagery from Oct. 20 to 22 shows the development and strengthening of Tropical Depression 13L into Tropical Storm Lorenzo in the Atlantic (far right), a...

  3. NASA's 3-D Animation of Tropical Storm Ulika from Space

    NASA Video Gallery

    An animated 3-D flyby of Tropical Storm Ulika using GPM's Radar data showed some strong convective storms inside the tropical storm were dropping precipitation at a rate of over 187 mm (7.4 inches)...

  4. NASA Sees Heavy Rainfall, Hot Towers in Tropical Cyclone Nathan

    NASA Video Gallery

    NASA-JAXA's Tropical Rainfall Measuring Mission or TRMM satellite showed that the heaviest rainfall occurring in Tropical Cyclone Nathan on March 18 at 0758 UTC (3:58 a.m. EDT) was falling at a rat...

  5. Tropical Storm Debby: June 23-25, 2012

    NASA Video Gallery

    An animation of satellite observations shows the progression of Tropical Storm Debby from June 23-25, 2012. The animation begins 12 hours after Debby became a tropical storm in the Gulf of Mexico, ...

  6. NASA Analyzes Rainfall in Strengthening Tropical Depression 2

    NASA Video Gallery

    As Tropical Depression 2 continued to organize and strengthen late on May 27, the GPM core satellite saw Tropical Depression 2 rain falling at a rate of over 57 mm (1.3 inches) per hour in an area ...

  7. Tropical Rainfall Measurement Mission (TRMM) Operation Summary

    NASA Technical Reports Server (NTRS)

    Nio, Tomomi; Saito, Susumu; Stocker, Erich; Pawloski, James H.; Murayama, Yoshifumi; Ohata, Takeshi

    2015-01-01

    The Tropical Rainfall Measurement Mission (TRMM) is a joint U.S. and Japan mission to observe tropical rainfall, which was launched by H-II No. 6 from Tanegashima in Japan at 6:27 JST on November 28, 1997. After the two-month commissioning of TRMM satellite and instruments, the original nominal mission lifetime was three years. In fact, the operations has continued for approximately 17.5 years. This paper provides a summary of the long term operations of TRMM.

  8. The Saptarishis Calendar: 'The Indian tropical Zodiac'!

    NASA Astrophysics Data System (ADS)

    Indrasena, Buddhike S. H.

    2015-07-01

    The Saptarishis Calendar of ancient India is based on precession of the equinoxes. It employs the tropical zodiac of the Greeks and the precessional rate of Hipparchus. The Saptarishis era has to be determined by naked eye observation of the sky. Currently, the line of reference goes through the stars Dubhe and Merak in the constellation of Ursa Major, touching both of them, and crosses the ecliptic in the sidereal Purvaphalguni Nakshatra of Simha Rashi at a point close to the star 59 Leonis. The angular difference between this 'Saptarishis pointer' and the vernal equinox gives the tropical lunar mansion in which Saptarishis resides at a given point in time.

  9. Climatic Teleconnections Recorded By Tropical Mountain Glaciers

    NASA Astrophysics Data System (ADS)

    Thompson, L. G.; Permana, D.; Mosley-Thompson, E.; Davis, M. E.

    2014-12-01

    Information from ice cores from the world's highest mountains in the Tropics demonstrates both local climate variability and a high degree of teleconnectivity across the Pacific basin. Here we examine recently recovered ice core records from glaciers near Puncak Jaya in Papua, Indonesia, which lie on the highest peak between the Himalayas and the South American Andes. These glaciers are located on the western side of the Tropical Pacific warm pool, which is the "center of action" for interannual climate variability dominated by El Niño-Southern Oscillation (ENSO). ENSO either directly or indirectly affects most regions of Earth and their populations. In 2010, two ice cores measuring 32.13 m and 31.25 m were recovered to bedrock from the East Northwall Firn ice field. Both have been analyzed in high resolution (~3 cm sample length, 1156 and 1606 samples, respectively) for stable isotopes, dust, major ions and tritium concentrations. To better understand the controls on the oxygen isotopic (δ18 O) signal for this region, daily rainfall samples were collected between January 2013 and February 2014 at five weather stations over a distance of ~90 km ranging from 9 meters above sea level (masl) on the southern coast up to 3945 masl. The calculated isotopic lapse rate for this region is 0.24 ‰/100m. Papua, Indonesian ice core records are compared to ice core records from Dasuopu Glacier in the central Himalayas and from Quelccaya, Huascarán, Hualcán and Coropuna ice fields in the tropical Andes of Peru on the eastern side of the Pacific Ocean. The composite of the annual isotopic time series from these cores is significantly (R2 =0.53) related to tropical Pacific sea surface temperatures (SSTs), reflecting the strong linkage between tropical Pacific SSTs associated with ENSO and tropospheric temperatures in the low latitudes. New data on the already well-documented concomitant loss of ice on Quelccaya, Kilimanjaro in eastern Africa and the ice fields near Puncak

  10. Further Examination of the Thermodynamic Modification of the Inflow Layer of Tropical Cyclones by Vertical Wind Shear

    DTIC Science & Technology

    2013-01-11

    the SBC hereafter. The SBC and the asso- ciated downdraft pattern extends outwards to approximately 150–180 km. On account of the swirling winds, the...updrafts within the SBC rise along a helical path. A simple kinematic model (Riemer and Montgomery, 2011) suggests that, at low levels above the...Evaporative cooling of precipitation falling out of the SBC , and into this unsaturated air, most likely drives the strong and persistent, vortex-scale

  11. Augmentation of Early Intensity Forecasting in Tropical Cyclones

    DTIC Science & Technology

    2012-09-30

    1 Augmentation of Early Intensity Forecasting in Tropical Cyclones J. Scott Tyo College of Optical Sciences University of Arizona Tucson, AZ...automatic intensity estimator of Tropical Cyclones (TCs) based on satellite infrared (IR) imagery. The proposed methodology analyzes the TC’s structure to...procedure to objectively estimate the intensity of tropical cyclones . The level of axisymmetry of tropical cyclones is quantified by calcualting the

  12. EDITORIAL: Tropical deforestation and greenhouse gas emissions

    NASA Astrophysics Data System (ADS)

    Gibbs, Holly K.; Herold, Martin

    2007-10-01

    Carbon emissions from tropical deforestation have long been recognized as a key component of the global carbon budget, and more recently of our global climate system. Tropical forest clearing accounts for roughly 20% of anthropogenic carbon emissions and destroys globally significant carbon sinks (IPCC 2007). Global climate policy initiatives are now being proposed to address these emissions and to more actively include developing countries in greenhouse gas mitigation (e.g. Santilli et al 2005, Gullison et al 2007). In 2005, at the Conference of the Parties (COP) in Montreal, the United Nations Framework Convention on Climate Change (UNFCCC) launched a new initiative to assess the scientific and technical methods and issues for developing policy approaches and incentives to reduce emissions from deforestation and degradation (REDD) in developing countries (Gullison et al 2007). Over the last two years the methods and tools needed to estimate reductions in greenhouse gas emissions from deforestation have quickly evolved, as the scientific community responded to the UNFCCC policy needs. This focus issue highlights those advancements, covering some of the most important technical issues for measuring and monitoring emissions from deforestation and forest degradation and emphasizing immediately available methods and data, as well as future challenges. Elements for effective long-term implementation of a REDD mechanism related to both environmental and political concerns are discussed in Mollicone et al. Herold and Johns synthesize viewpoints of national parties to the UNFCCC on REDD and expand upon key issues for linking policy requirements and forest monitoring capabilities. In response to these expressed policy needs, they discuss a remote-sensing-based observation framework to start REDD implementation activities and build historical deforestation databases on the national level. Achard et al offer an assessment of remote sensing measurements across the world

  13. Ensemble Data Assimilation and Predictability of Tropical Cyclones

    DTIC Science & Technology

    2012-09-30

    on comparing and coupling the ensemble and variational data assimilation methods for tropical cyclone applications. Mr. Melhauser, who started to work...understanding of tropical cyclone predictability and further developed ensemble-based data assimilation methods for tropical cyclones. Now that we have

  14. Ensemble Data Assimilation and Predictability of Tropical Cyclones

    DTIC Science & Technology

    2013-09-30

    comparing and coupling the ensemble and variational data assimilation methods for tropical cyclone applications using past field campaign observations...understanding of tropical cyclone predictability and further developed ensemble-based data assimilation methods for tropical cyclones. Now that we have

  15. Augmentation of Early Intensity Forecasting in Tropical Cyclones

    DTIC Science & Technology

    2012-09-30

    Rodriguez- Herrera, Matthew E. Kucas, and James W. E. Darlow, “A Web-based Interactive Interface for Researching and Forecasting Tropical Cyclone ...Augmentation of Early Intensity Forecasting in Tropical Cyclones J. Scott Tyo College of Optical Sciences...an objective and automatic intensity estimator of Tropical Cyclones (TCs) based on satellite infrared (IR) imagery. The proposed methodology analyzes

  16. Does Biodiversity-Ecosystem Function Literature Neglect Tropical Ecosystems?

    PubMed

    Clarke, David A; York, Paul H; Rasheed, Michael A; Northfield, Tobin D

    2017-03-06

    Current evidence suggests that there is a positive relationship between biodiversity and ecosystem functioning, but few studies have addressed tropical ecosystems where the highest levels of biodiversity occur. We develop two hypotheses for the implications of generalizing from temperate studies to tropical ecosystems, and discuss the need for more tropical research.

  17. Trampling resistance of tropical rainforest soils and vegetation in the wet tropics of north east Australia.

    PubMed

    Talbot, L M; Turton, S M; Graham, A W

    2003-09-01

    Controlled trampling was conducted to investigate the trampling resistance of contrasting high fertility basaltic and low fertility rhyolitic soils and their associated highland tropical rainforest vegetation in north east Australia's Wet Tropics. Although this approach has been taken in numerous studies of trampling in a variety of ecosystem types (temperate and subtropical forest, alpine shrubland, coral reef and seagrass beds), the experimental method does not appear to have been previously applied in a tropical rainforest context. Ground vegetation cover and soil penetration resistance demonstrated variable responses to trampling. Trampling, most noticeably after 200 and 500 passes reduced organic litter cover. Bulk density increased with trampling intensity, particularly on basalt soils as rhyolite soils appeared somewhat resistant to the impacts of trampling. The permeability of the basalt and rhyolite soils decreased markedly with increased trampling intensity, even after only 75 passes. These findings suggest physical and hydrological changes may occur rapidly in tropical rainforest soils following low levels of trampling, particularly on basalt soils.

  18. Reanalyzing Tropical Cyclone Intensities with Citizen Scientists

    NASA Astrophysics Data System (ADS)

    Schreck, C. J.; Hennon, C. C.; Knapp, K.; Stevens, S. E.

    2012-12-01

    Tropical cyclones are among the most destructive weather phenomena. Whenever possible, the intensities of these storms have been determined from in situ data or aircraft reconnaissance. More often, however, they are estimated subjectively from satellite data using the Dvorak technique. Heterogeneities are introduced into the historical record with the evolution of operational procedures, personnel, and observing platforms. In some cases, multiple agencies even arrive at different estimates for the same storm. These uncertainties impede our ability to identify the relationship between tropical cyclone intensities and climate change. NOAA's NCDC has produced a 30-year (1979-2008) homogeneous dataset (HURSAT) of tropical cyclone imagery from geostationary satellites. This dataset has the potential to address some of the uncertainties in the recent tropical cyclone record. However, it would take nearly 40 years for a trained expert, working nonstop, to apply the Dvorak technique to all 200,000 images. Harnessing the power of thousands of Citizen Scientists, the same task can be completed in a matter of months. This presentation will explain how the Dvorak technique was adapted for Citizen Scientists, and how their skill will be evaluated relative to the operational analyses by trained experts.

  19. Travelers' diarrhea in children visiting tropical countries.

    PubMed

    Silva, Filipe Glória; Figueiredo, António; Varandas, Luis

    2009-01-01

    We studied a group of 174 Portuguese children (aged 2 mo-16 y) who mostly traveled to tropical Portuguese-speaking countries and found an attack rate of 21.8% for travelers' diarrhea, much lower than previously described. We also showed that African rate analysis by region may hide significant differences between countries.

  20. Citation patterns in tropical medicine journals.

    PubMed

    Schoonbaert, Dirk

    2004-11-01

    Selections of most important journals in the field of tropical medicine have previously been identified with the help of resources such as bibliographical and citation databases. This article uses ISI's Journal Citation Reports (JSR) for 2002 to analyse the citation characteristics of the Tropical Medicine category. According to these data, this small but diverse group of 12 journals bestows some 40% more citations than it receives. Its six typical core journals tend to cite one another heavily, but they also refer a lot to multidisciplinary science and general medicine journals, and to infectious diseases and parasitology journals. Looking at the sources from which JCR's tropical medicine journals derive their citations, it is clear that in this reverse direction, the specialty's literature is still more concentrated. Apart from the typical core, this JCR category also contains a number of journals with more idiosyncratic citing patterns, focused on specialties such as paediatrics, a single disease (leprosy) and a representative of Latin American and Francophone biomedical science each. Implications of concentrated citedness and language biases are discussed briefly. This paper features a selection of bibliometric parameters relating to the tropical medicine journals and lists of the 80 journals most citing and cited by them.

  1. Defaunation affects carbon storage in tropical forests.

    PubMed

    Bello, Carolina; Galetti, Mauro; Pizo, Marco A; Magnago, Luiz Fernando S; Rocha, Mariana F; Lima, Renato A F; Peres, Carlos A; Ovaskainen, Otso; Jordano, Pedro

    2015-12-01

    Carbon storage is widely acknowledged as one of the most valuable forest ecosystem services. Deforestation, logging, fragmentation, fire, and climate change have significant effects on tropical carbon stocks; however, an elusive and yet undetected decrease in carbon storage may be due to defaunation of large seed dispersers. Many large tropical trees with sizeable contributions to carbon stock rely on large vertebrates for seed dispersal and regeneration, however many of these frugivores are threatened by hunting, illegal trade, and habitat loss. We used a large data set on tree species composition and abundance, seed, fruit, and carbon-related traits, and plant-animal interactions to estimate the loss of carbon storage capacity of tropical forests in defaunated scenarios. By simulating the local extinction of trees that depend on large frugivores in 31 Atlantic Forest communities, we found that defaunation has the potential to significantly erode carbon storage even when only a small proportion of large-seeded trees are extirpated. Although intergovernmental policies to reduce carbon emissions and reforestation programs have been mostly focused on deforestation, our results demonstrate that defaunation, and the loss of key ecological interactions, also poses a serious risk for the maintenance of tropical forest carbon storage.

  2. Defaunation affects carbon storage in tropical forests

    PubMed Central

    Bello, Carolina; Galetti, Mauro; Pizo, Marco A.; Magnago, Luiz Fernando S.; Rocha, Mariana F.; Lima, Renato A. F.; Peres, Carlos A.; Ovaskainen, Otso; Jordano, Pedro

    2015-01-01

    Carbon storage is widely acknowledged as one of the most valuable forest ecosystem services. Deforestation, logging, fragmentation, fire, and climate change have significant effects on tropical carbon stocks; however, an elusive and yet undetected decrease in carbon storage may be due to defaunation of large seed dispersers. Many large tropical trees with sizeable contributions to carbon stock rely on large vertebrates for seed dispersal and regeneration, however many of these frugivores are threatened by hunting, illegal trade, and habitat loss. We used a large data set on tree species composition and abundance, seed, fruit, and carbon-related traits, and plant-animal interactions to estimate the loss of carbon storage capacity of tropical forests in defaunated scenarios. By simulating the local extinction of trees that depend on large frugivores in 31 Atlantic Forest communities, we found that defaunation has the potential to significantly erode carbon storage even when only a small proportion of large-seeded trees are extirpated. Although intergovernmental policies to reduce carbon emissions and reforestation programs have been mostly focused on deforestation, our results demonstrate that defaunation, and the loss of key ecological interactions, also poses a serious risk for the maintenance of tropical forest carbon storage. PMID:26824067

  3. Nitrogen availability in tropical forests of Brazil

    NASA Astrophysics Data System (ADS)

    Martinelli, L. A.

    2015-12-01

    Nitrogen availability is considered to be high in tropical forest, especially in relation to temperate forests. However, there is among tropical forest a significant variability in nutrient concentrations and stocks either in soils as well as in the vegetation. Here we review the nitrogen distribution and availability in more than 60 forest sites encompassing different soil types and precipitation regimes of the two main tropical forests biomes of Brazil: the Amazon and the Atlantic Forest. We aimed to determine factors that control nitrogen availability in these forests, using as a proxy of such availability parameters like: foliar and soil nitrogen concentrations, nitrogen stable isotopic composition, and foliar nitrogen:phosphorus ratio. Our main hypothesis is that nitrogen availability will be higher in forest where dry-season precipitation is low and/or weathered old soils prevailed. On the contrary, tropical forests over young soils and/or precipitation is high over the year will have a lower nitrogen availability and will be more phosphorus than nitrogen limited.

  4. The Origins of Tropical Rainforest Hyperdiversity.

    PubMed

    Pennington, R Toby; Hughes, Mark; Moonlight, Peter W

    2015-11-01

    Traditional models for tropical species richness contrast rainforests as "museums" of old species or "cradles" of recent speciation. High plant species diversity in rainforests may be more likely to reflect high episodic evolutionary turnover of species--a scenario implicating high rates of both speciation and extinction through geological time.

  5. Climate Science: Tropical Expansion by Ocean Swing

    SciTech Connect

    Lu, Jian

    2014-04-01

    The tropical belt has become wider over the past decades, but climate models fall short of capturing the full rate of the expansion. The latest analysis of the climate simulations suggests that a long-term swing of the Pacific Decadal Oscillation is the main missing cause.

  6. Satellite Views Tropical Storm Katia in Atlantic

    NASA Video Gallery

    An animation of satellite observations from Aug. 27 at 10:45 p.m. EDT through Aug. 31 at 10:45 a.m. EDT shows the birth of Tropical Storm Katia. Katia began as an area of low pressure that moved aw...

  7. Mean Atmospheric Conditions - Australian Tropical Operating Conditions.

    DTIC Science & Technology

    1981-10-01

    The ARDU mean tropical atmosphere differs significantly from the ICAO standard atmosphere and is based upon data gathered prior to 1965. More recent...atmosphere and the ICAO atmosphere to describe mean conditions in their respective regions of application. It is recommended, however, that where extreme

  8. Tropical forests and the genus Homo.

    PubMed

    Roberts, Patrick; Boivin, Nicole; Lee-Thorp, Julia; Petraglia, Michael; Stock, Jay

    2016-11-01

    Tropical forests constitute some of the most diverse and complex terrestrial ecosystems on the planet. From the Miocene onward, they have acted as a backdrop to the ongoing evolution of our closest living relatives, the great apes, and provided the cradle for the emergence of early hominins, who retained arboreal physiological adaptations at least into the Late Pliocene. There also now exists growing evidence, from the Late Pleistocene onward, for tool-assisted intensification of tropical forest occupation and resource extraction by our own species, Homo sapiens. However, between the Late Pliocene and Late Pleistocene there is an apparent gap in clear and convincing evidence for the use of tropical forests by hominins, including early members of our own genus. In discussions of Late Pliocene and Early Pleistocene hominin evolution, including the emergence and later expansion of Homo species across the globe, tropical forest adaptations tend to be eclipsed by open, savanna environments. Thus far, it is not clear whether this Early-Middle Pleistocene lacuna in Homo-rainforest interaction is real and representative of an adaptive shift with the emergence of our species or if it is simply reflective of preservation bias.

  9. Raindrop Size Distribution Measurements in Tropical Cyclones

    NASA Astrophysics Data System (ADS)

    Tokay, A.; Bashor, P. G.; Habib, E.; Kasparis, T. C.

    2006-12-01

    Measurements of the raindrop size distribution (RSD) have been collected in tropical cyclones and hurricanes with an impact type disdrometer during the past three Atlantic hurricane seasons. The measurements were taken at Wallops Island, Virginia, Lafayette, Louisiana, and Orlando, Florida. The RSDs from the remnants of tropical cyclones or hurricanes at 40 dBZ agreed well with each other where the mean mass diameter was 1.65-1.7 mm, and the total concentration had a range of 600 to 800 drops/m3. Assuming the normalized gamma size distribution, the shape parameter will be 5-8 to satisfy the observed rain rate of 18-20 mm/hr. If the observations were taken during the extratropical phase of the storm where the tropical cyclone merges with a frontal system, the composite spectra at 40 dBZ include more large drops and less small to mid-size drops, typical for continental thunderstorms. Thus, the mean mass diameter was larger, while total concentration, and rain rate was less in extratropical cyclones than in tropical cyclones.

  10. Hurricane Emilia Chases Tropical Storm Daniel

    NASA Video Gallery

    An animation of satellite observations from July 8 (6:00 p.m. EDT) to July 11 (1:30 p.m. EDT), 2012, shows Hurricane Daniel as it loses its hurricane eye and become a tropical storm as it heads tow...

  11. TRMM Satellite Flyby of Tropical Storm Halong

    NASA Video Gallery

    NASA's TRMM Satellite 3-D Flyby of Tropical Storm Halong On July 31, NASA's TRMM Satellite showed rain was falling at a rate of over 85.6 mm (about 3.4 inches) per hour in bands wrapping around Hal...

  12. Precipitation: Sub-tropical drying explained

    NASA Astrophysics Data System (ADS)

    Chadwick, Robin

    2017-01-01

    The sub-tropics are some of Earth's driest regions, and are expected to get even drier under climate change. Now research overturns our previous understanding of this drying, and suggests that it will affect the oceans much more than the land.

  13. Modelling tropical forests response to logging

    NASA Astrophysics Data System (ADS)

    Cazzolla Gatti, Roberto; Di Paola, Arianna; Valentini, Riccardo; Paparella, Francesco

    2013-04-01

    Tropical rainforests are among the most threatened ecosystems by large-scale fragmentation due to human activity such as heavy logging and agricultural clearance. Although, they provide crucial ecosystem goods and services, such as sequestering carbon from the atmosphere, protecting watersheds and conserving biodiversity. In several countries forest resource extraction has experienced a shift from clearcutting to selective logging to maintain a significant forest cover and understock of living biomass. However the knowledge on the short and long-term effects of removing selected species in tropical rainforest are scarce and need to be further investigated. One of the main effects of selective logging on forest dynamics seems to be the local disturbance which involve the invasion of open space by weed, vines and climbers at the expense of the late-successional state cenosis. We present a simple deterministic model that describes the dynamics of tropical rainforest subject to selective logging to understand how and why weeds displace native species. We argue that the selective removal of tallest tropical trees carries out gaps of light that allow weeds, vines and climbers to prevail on native species, inhibiting the possibility of recovery of the original vegetation. Our results show that different regime shifts may occur depending on the type of forest management adopted. This hypothesis is supported by a dataset of trees height and weed/vines cover that we collected from 9 plots located in Central and West Africa both in untouched and managed areas.

  14. Tropics of Arrangement: A Theory of "Dispositio."

    ERIC Educational Resources Information Center

    D'Angelo, Frank J.

    1990-01-01

    Proposes a theoretical model of organizing texts that uses four "master" tropes (metaphor, metonymy, synecdoche, and irony) as a conceptual framework to represent the processes of selecting, ordering, and placing words, ideas, and images into a text. Discusses possible practical application of tropical operations to nonfictional…

  15. Distribution of tropical tropospheric water vapor

    NASA Technical Reports Server (NTRS)

    Sun, De-Zheng; Lindzen, Richard S.

    1993-01-01

    Utilizing a conceptual model for tropical convection and observational data for water vapor, the maintenance of the vertical distribution of the tropical tropospheric water vapor is discussed. While deep convection induces large-scale subsidence that constrains the turbulent downgradient mixing to within the convective boundary layer and effectively dries the troposphere through downward advection, it also pumps hydrometeors into the upper troposphere, whose subsequent evaporation appears to be the major source of moisture for the large-scale subsiding motion. The development of upper-level clouds and precipitation from these clouds may also act to dry the outflow, thus explaining the low relative humidity near the tropopause. A one-dimensional model is developed to simulate the mean vertical structure of water vapor in the tropical troposphere. It is also shown that the horizontal variation of water vapor in the tropical troposphere above the trade-wind boundary layer can be explained by the variation of a moisture source that is proportional to the amount of upper-level clouds. Implications for the nature of water vapor feedback in global warming are discussed.

  16. Tropical ataxic neuropathy - A century old enigma.

    PubMed

    Netto, Archana B; Netto, Clare M; Mahadevan, Anita; Taly, Arun B; Agadi, J B

    2016-01-01

    Tropical ataxic neuropathy, which is prevalent in the tropics causes significant disability as well as increased mortality and remains an enigmatic disease with no effective treatment or cure, even a century after its identification. The syndrome, first described in Jamaica in 1897 and christened as tropical ataxic neuropathy in 1959, is a constellation of bilateral optic atrophy, bilateral sensory neural deafness, predominant posterior column involvement and pyramidal tract myelopathy, with ataxic polyneuropathy. The exact etiopathogenesis remains unresolved, and several factors have been proposed including malnutrition, vitamin B deficiencies, malabsorption, poor protein consumption, chronic cyanide, and nitrile toxicity, with a strong geospatial endemic prevalence in areas of cassava cultivation. In this review, we summarize the history, epidemiology, clinical features, and controversies regarding the pathogenesis and differential diagnosis of the disease and identify the potential areas for further research concerning this debilitating disorder that is common in the tropics. Its multifactorial etiopathogenesis provides potential opportunities for research and international collaboration to identify novel avenues for treatment.

  17. GPM Rain Rates in Tropical Cyclone Pam

    NASA Video Gallery

    NASA-JAXA's GPM Satellite Close-up of Cyclone Pam's Rainfall NASA-JAXA's GPM core satellite captured rain rates in Tropical Cyclone Pam at 03:51 UTC (2:51 p.m. local time) on March 14, 2015. Heavie...

  18. TRMM (Tropical Rainfall Measuring Mission): A satellite mission to measure tropical rainfall

    NASA Technical Reports Server (NTRS)

    Simpson, Joanne (Editor)

    1988-01-01

    The Tropical Rainfall Measuring Mission (TRMM) is presented. TRMM is a satellite program being studied jointly by the United States and Japan which would carry out the systematic study of tropical rainfall required for major strides in weather and climate research. The scientific justification for TRMM is discussed. The implementation process for the scientific community, NASA management, and the other decision-makers and advisory personnel who are expected to evaluate the priority of the project is outlined.

  19. Tropical pacing of Antarctic sea ice increase

    NASA Astrophysics Data System (ADS)

    Schneider, D. P.

    2015-12-01

    One reason why coupled climate model simulations generally do not reproduce the observed increase in Antarctic sea ice extent may be that their internally generated climate variability does not sync with the observed phases of phenomena like the Pacific Decadal Oscillation (PDO) and ENSO. For example, it is unlikely for a free-running coupled model simulation to capture the shift of the PDO from its positive to negative phase during 1998, and the subsequent ~15 year duration of the negative PDO phase. In previously presented work based on atmospheric models forced by observed tropical SSTs and stratospheric ozone, we demonstrated that tropical variability is key to explaining the wind trends over the Southern Ocean during the past ~35 years, particularly in the Ross, Amundsen and Bellingshausen Seas, the regions of the largest trends in sea ice extent and ice season duration. Here, we extend this idea to coupled model simulations with the Community Earth System Model (CESM) in which the evolution of SST anomalies in the central and eastern tropical Pacific is constrained to match the observations. This ensemble of 10 "tropical pacemaker" simulations shows a more realistic evolution of Antarctic sea ice anomalies than does its unconstrained counterpart, the CESM Large Ensemble (both sets of runs include stratospheric ozone depletion and other time-dependent radiative forcings). In particular, the pacemaker runs show that increased sea ice in the eastern Ross Sea is associated with a deeper Amundsen Sea Low (ASL) and stronger westerlies over the south Pacific. These circulation patterns in turn are linked with the negative phase of the PDO, characterized by negative SST anomalies in the central and eastern Pacific. The timing of tropical decadal variability with respect to ozone depletion further suggests a strong role for tropical variability in the recent acceleration of the Antarctic sea ice trend, as ozone depletion stabilized by late 1990s, prior to the most

  20. Effect of Convection on the Tropical Tropopause Layer over the Tropical Americas

    NASA Technical Reports Server (NTRS)

    Pittman, Jasna; Robertson, Franklin

    2007-01-01

    Water vapor and ozone are the most important gases that regulate the radiative balance of the Tropical Tropopause Layer (TTL). Their radiative contribution dictates the height within the TTL and the rate at which air either ascends into the tropical stratosphere or subsides back to the tropical troposphere. The details of the mechanisms that control their concentration, however, are poorly understood. One of such mechanisms is convection that reaches into the TTL. ill this study, we will present evidence from space-borne observations of the impact that convection has on water vapor, ozone, and temperature in the TTL over the Tropical Americas where deep and overshooting convection have the highest frequency of occurrence in the tropics. We explore the effect of convective systems such as hurricanes during the 2005 season using the Microwave Limb Sounder (MLS) on Aura version 1.5 data and more recent tropical systems using the newly released version 2 data with higher vertical resolution. ill order to provide the horizontal extent and the vertical structure of the convective systems, we use data from the Moderate Resolution Imaging Spectroradiometer (MODIS) on Aqua, the Microwave Humidity Sensor (MHS) on NOAA18, and CloudSat when available.

  1. Tropical thermostats and low cloud clover

    SciTech Connect

    Miller, R.L.

    1997-03-01

    The ability of subtropical stratus low cloud cover to moderate amplify the tropical response to climate forcing such as increased CO{sub 2} is considered. Cloud radiative forcing over the subtropics is parameterized using an empirical relation between stratus cloud cover and the difference in potential temperature between 700 mb (a level that is above the trade inversion) and the surface. This relation includes the empirical negative correlation between SST and low cloud cover and is potentially a positive feedback to climate forcing. Since potential temperature above the trade inversion varies in unison across the Tropics as a result of the large-scale circulation and because moist convection relates tropospheric temperature within the convecting region to variations in surface temperature and moisture, the subtropical potential temperature at 700 mb depends upon surface conditions within the convecting region. As a result, subtropical stratus cloud cover and the associated feedback depend upon the entire tropical climate and not just the underlying SST. A simple tropical model is constructed, consisting of separate budgets of dry static energy and moisture for the convecting region (referred to as the {open_quotes}warm{close_quotes} pool) and the subtropical descending region (the {open_quotes}cold{close_quotes} pool). The cold pool is the location of stratus low clouds in the model. Dynamics is implicitly included through the assumption that temperature above the boundary layer is horizontally uniform as a result of the large-scale circulation. The tropropause and warm pool surface are shown to be connected by a moist adiabat in the limit of vanishingly narrow convective updrafts. Stratus low cloud cover is found to be a negative feedback, increasing in response to doubled CO{sub 2} and reducing the tropically averaged warming in comparison to the warming with low cloud cover held fixed. 72 refs., 13 figs., 2 tabs.

  2. Tropical cyclone rainfall area controlled by relative sea surface temperature

    PubMed Central

    Lin, Yanluan; Zhao, Ming; Zhang, Minghua

    2015-01-01

    Tropical cyclone rainfall rates have been projected to increase in a warmer climate. The area coverage of tropical cyclones influences their impact on human lives, yet little is known about how tropical cyclone rainfall area will change in the future. Here, using satellite data and global atmospheric model simulations, we show that tropical cyclone rainfall area is controlled primarily by its environmental sea surface temperature (SST) relative to the tropical mean SST (that is, the relative SST), while rainfall rate increases with increasing absolute SST. Our result is consistent with previous numerical simulations that indicated tight relationships between tropical cyclone size and mid-tropospheric relative humidity. Global statistics of tropical cyclone rainfall area are not expected to change markedly under a warmer climate provided that SST change is relatively uniform, implying that increases in total rainfall will be confined to similar size domains with higher rainfall rates. PMID:25761457

  3. [Tropical veterinary medicine and education in The Netherlands].

    PubMed

    Uilenberg, Gerrit

    2008-01-01

    in this lecture an overview is given of the development of tropical veterinary medicine and education in The Netherlands after the Dutch colonial period. The starting point is the development of tropical veterinary medicine in general, especially in Europe and Africa. It is pointed out that just now it is very important to have specialists in tropical diseases not only in the tropics but also in the western world since globalization involves the import of a lot of tropical diseases. The speaker is an advocate of a course on tropical veterinary medicine on an European level, but at the same time he is sceptical about it. In the second part he gives an overview of the education programme on tropical veterinary medicine from the foundation of the Institute at Utrecht University in 1948 until its decline.

  4. Geographical Variablity of the Width of the Tropical Belt

    NASA Astrophysics Data System (ADS)

    Currey, B.

    2014-12-01

    A number of recent studies have found evidence for a widening of the earth's tropical belt (Seidel et al). Most studies focus on the annual mean zonal mean tropical belt width. The purpose of this research, however, is to determine the longitudinal variability of the width of the tropical belt. We study how well defined the boundaries of the tropical belt are in both hemispheres as a function of longitude as well as season. The sharpness of the tropical boundaries as a function of longitude can provide information, which is otherwise hidden in the more commonly studied zonal averages. Localized widening of the tropical belt is expected to have a bigger climatic impact for a very sharp tropical boundary encompassing a drastic distinction between the climates of the tropics versus the subtropics. An improved understanding of the morphology of the tropical belt can help us determine any changes regarding these regions surrounding the edges of the tropics. By locating the subtropical tropopause break, a region where the tropopauses' altitude drastically shifts, the boundaries of the tropical belt can be observed. By finding the gradient of the tropopause break, we can determine the sharpness of the tropical boundaries. It was found that during each hemisphere's respective summer season the tropical belt edge over the Pacific and Atlantic oceans can display a tendency to be very fickle and thus poorly defined. For all times of the year, however, it is shown that the tropopause break in each hemisphere's respective winter and over land has the tendency to create a well-defined and sharp tropical edge.

  5. Comparison of AC electronic monitoring and field data for estimating tolerance to Empoasca kraemeri (Homoptera: Cicadellidae) in common bean genotypes.

    PubMed

    Serrano, M S; Backus, E A; Cardona, C

    2000-12-01

    Two methods for estimating the tolerance of common bean genotypes to Empoasca kraemeri Ross & Moore were compared, using a yield trial carried out at Centro Internacional de Agricultura Tropical (CIAT), Cali, Colombia, versus stylet penetration tactics measured by AC electronic feeding monitors. A stylet penetration index was devised based on principal component scores of three penetration tactics identified (pulsing laceration, cell rupturing, and lancing sap ingestion), combined with knowledge of the hopperburn symptoms caused by each tactic. Tolerant genotypes, as classified by the CIAT yield index, showed significantly more unprotected yield and lower hopperburn scores than the susceptible control. They also induced performance of less pulsing laceration (the tactic considered most damaging to the plant), and more of the other two, mitigating tactics, especially cell rupturing. When index values were calculated for each genotype, stylet penetration index values matched those of the yield index for three out of five genotypes: two EMP-coded tolerant lines ('EMP 385' and 'EMP 392') and the susceptible control 'BAT 41'. Thus, for these three genotypes, all subsequent hoppereburn symptoms are predictable by the type of feeding behavior performed on them. 'Porrillo Sintético' and 'EMP 84', considered borderline genotypes by the yield index, were overestimated and underestimated respectively, by the stylet penetration index. We postulate that, for these two genotypes, plant physiological responses to feeding (either compensatory or heightened sensitivity, respectively) synergize with type of feeding performed to generate the overall hopperburn condition. This multivariate analysis of electronic monitoring data was successfully used to devise an index of resistance. The implications of using the stylet penetration index and the advantages of using electronic monitoring in a bean-breeding program are discussed.

  6. Effects of unionised ammonia on tropical freshwater organisms: Implications on temperate-to-tropic extrapolation and water quality guidelines.

    PubMed

    Wang, Zhen; Leung, Kenneth M Y

    2015-10-01

    Unionised ammonia (NH3) is highly toxic to freshwater organisms. Yet, most of the available toxicity data on NH3 were predominantly generated from temperate regions, while toxicity data on NH3 derived from tropical species were limited. To address this issue, we first conducted standard acute toxicity tests on NH3 using ten tropical freshwater species. Subsequently, we constructed a tropical species sensitivity distribution (SSD) using these newly generated toxicity data and available tropical toxicity data of NH3, which was then compared with the corresponding temperate SSD constructed from documented temperate acute toxicity data. Our results showed that tropical species were generally more sensitive to NH3 than their temperate counterparts. Based on the ratio between temperate and tropical hazardous concentration 10% values, we recommend an extrapolation factor of four to be applied when surrogate temperate toxicity data or temperate water quality guidelines of NH3 are used for protecting tropical freshwater ecosystems.

  7. The psychiatric aspects of tropical disorders.

    PubMed

    German, G A

    1979-01-01

    The nature of psychiatric disorders in tropical regions is affected much more by the effect on the patient of certain environmental and cultural factors than by any specific features of tropical diseases. In places where the standards of health care and health education are not yet fully developed, abnormalities of physical development, particularly those affecting the development of the cerebral cortex, are of great importance. For example, protein-energy malnutrition may result in deficits in cerebral maturation and efficiency that reduce the capacity of the brain to manage its behavioural functions and may give rise to impaired capacities for concentration, foresight, and judgement and impairment of inhibitory control over intensely experienced emotions. In addition, certain cultural attitudes that are widespread in pre-literate societies influence the type of secondary reaction to disease: for example, acute symptoms tend to be florid and uninhibited, and violently experienced and externalized emotions such as hilarity, terror, anger, and grief are the rule rather than the exception.Certain tropical diseases are, however, the direct cause of severe disturbance of cerebral functioning, while others affect only the finer cerebral controls so that normally controlled fears, anxieties, and other personality traits emerge. These specific brain syndromes may be acute or chronic and may be triggered by an apparently trivial physical cause. Acute brain syndromes appear to be more common in tropical countries perhaps because in the adult the cerebral cortical reserve is less than it ought to be because of the prevalence of earlier minimal brain damage. Formal psychiatric reactions are, of course, also seen in tropical countries, but the expression of, for example, schizophrenia, hypomanic and manic states, and depression is coloured by the underlying personality and the cultural background of the patient. Perhaps in no other setting is the intimate relationship between

  8. Diagnostic radiology in the tropics: technical considerations.

    PubMed

    Ng, Kwan-Hoong; McLean, Ian Donald

    2011-11-01

    An estimated two thirds of the world's population is currently without access to diagnostic radiology services, and most of them live in resource-limited tropical regions with harsh environments. Most patients are diagnosed and treated in poorly equipped government-funded hospitals and clinics that have insufficiently trained staff and are barely operational. Any available imaging equipment is likely to be functioning suboptimally and be poorly maintained. The root of the problem is usually a lack of know-how and a quality culture, combined with insufficient basic equipment and infrastructure. Radiological imaging is an essential aspect of primary care and used in the critical diagnosis and management of trauma, tuberculosis, pneumonia, acquired immunodeficiency syndrome, cancer, and other respiratory and abdominal diseases. Considerations such as quality management and infrastructure, personnel, equipment, and radiation protection and safety are important to ensure the proper functioning and rational use of a diagnostic radiology facility in the tropics.

  9. Experiment to Characterize Tropical Cloud Systems

    SciTech Connect

    May, Peter T.; Mather, Jim H.; Jakob, Christian

    2005-08-02

    A major experiment to study tropical convective cloud systems and their impacts will take place around Darwin, Northern Australia in early 2006. The Tropical Warm Pool International Cloud Experiment (TWP-ICE) is a collaboration including the DOE ARM (Atmospheric Radiation Measurement) and ARM-UAV programs, NASA centers, the Australian Bureau of Meteorology, CSIRO, and universities in the USA, Australia, Japan, the UK, and Canada. TWP-ICE will be preceded in November/December 2004 by a collaborating European aircraft campaign involving the EU SCOUT-O3 and UK NERC ACTIVE projects. Detailed atmospheric measurements will be made in the Darwin area through the whole Austral summer, giving unprecedented coverage through the pre-monsoon and monsoon periods.

  10. Impacts of warming on tropical lowland rainforests.

    PubMed

    Corlett, Richard T

    2011-11-01

    Before the end of this century, tropical rainforests will be subject to climatic conditions that have not existed anywhere on Earth for millions of years. These forests are the most species-rich ecosystems in the world and play a crucial role in regulating carbon and water feedbacks in the global climate system; therefore, it is important that the probable impacts of anthropogenic climate change are understood. However, the recent literature shows a striking range of views on the vulnerability of tropical rainforests, from least to most concern among major ecosystems. This review, which focuses on the impact of rising temperatures, examines the evidence for and against high vulnerability, identifies key research needs for resolving current differences and suggests ways of mitigating or adapting to potential impacts.

  11. [Medical aspects of diving in the tropics].

    PubMed

    Muth, C M; Müller, P; Kemmer, A

    2005-07-07

    Scuba diving vacations in tropical surroundings belong to the repertoire of most divers. In addition to carefully making travel plans and taking care of the necessary vaccinations and appropriate malaria prophylaxis, the following points also must be observed. The flight itself affects diving safety. In particular, a too short time interval between diving and the return flight can lead to decompression problems. Because most of the diving areas are reached by ship, many divers need a prophylaxis against motion sickness. Moreover, external otitis occurs more frequently while diving in the tropics. Finally, there is potential danger from the sea inhabitants, primarily from scorpion fishes, Portuguese Man-of-Wars, box jellyfishes as well as cone snails.

  12. Tropical marine neurotoxins: venoms to drugs.

    PubMed

    Watters, Michael R

    2005-09-01

    Neurotoxic venoms are common among tropical marine creatures, which have specialized apparatuses for delivery of the venoms. These include jellyfish and anemones, venomous cone snails, venomous fish, stingrays, sea snakes, and venomous octopuses. Numerous toxic neuropeptides are found within these venoms, and some can discriminate between closely related intracellular targets, a characteristic that makes them useful to define cation channels and attractive for drug development. A synthetic derivative of an omega-conotoxin is now available, representing a new class of analgesics. In general, toxic marine venoms contain proteins that are heat labile, providing opportunity for therapeutic intervention following envenomation, while ingestible seafood toxins are thermostable toxins. Ingestible toxins found in the tropics include those associated with reef fish, pufferfish, and some shellfish, which serve as food-chain vectors for toxins produced by marine microorganisms.

  13. Quaternary Tipping Points in Tropical Northern Australia

    NASA Astrophysics Data System (ADS)

    Moss, Patrick; Dunbar, Gavin; Croke, Jacky; Katunar, Rosie

    2016-04-01

    Tropical northern Queensland, particularly the volcanic Atherton Tableland, contains some of the most detailed and longest terrestrial palaeoenvironmental archives in Australia and when combined with adjacent marine sediment records provides key insight into potential environmental 'tipping points' for the entire Quaternary period and beyond. This presentation will provide an overview of some of the key tipping points (i.e. significant landscape transformation) that have occurred within the tropical northern Australian region over the Quaternary, as well as discussing potential causes and subsequent impacts of these transformation episodes. These events include the development of the Great Barrier Reef, transition from obliquity to eccentricity dominated glacial-interglacial cycles, the Mid-Brunhes event, the Oxygen Isotope Stage 6 episode, the arrival of people into the region, Last Glacial-Interglacial Transition and European settlement.

  14. Beta-Diversity in Tropical Forest Trees

    NASA Astrophysics Data System (ADS)

    Condit, Richard; Pitman, Nigel; Leigh, Egbert G.; Chave, Jérôme; Terborgh, John; Foster, Robin B.; Núñez V., Percy; Aguilar, Salomón; Valencia, Renato; Villa, Gorky; Muller-Landau, Helene C.; Losos, Elizabeth; Hubbell, Stephen P.

    2002-01-01

    The high alpha-diversity of tropical forests has been amply documented, but beta-diversity-how species composition changes with distance-has seldom been studied. We present quantitative estimates of beta-diversity for tropical trees by comparing species composition of plots in lowland terra firme forest in Panama, Ecuador, and Peru. We compare observations with predictions derived from a neutral model in which habitat is uniform and only dispersal and speciation influence species turnover. We find that beta-diversity is higher in Panama than in western Amazonia and that patterns in both areas are inconsistent with the neutral model. In Panama, habitat variation appears to increase species turnover relative to Amazonia, where unexpectedly low turnover over great distances suggests that population densities of some species are bounded by as yet unidentified processes. At intermediate scales in both regions, observations can be matched by theory, suggesting that dispersal limitation, with speciation, influences species turnover.

  15. New Permian fauna from tropical Gondwana

    PubMed Central

    Cisneros, Juan C.; Marsicano, Claudia; Angielczyk, Kenneth D.; Smith, Roger M. H.; Richter, Martha; Fröbisch, Jörg; Kammerer, Christian F.; Sadleir, Rudyard W.

    2015-01-01

    Terrestrial vertebrates are first known to colonize high-latitude regions during the middle Permian (Guadalupian) about 270 million years ago, following the Pennsylvanian Gondwanan continental glaciation. However, despite over 150 years of study in these areas, the biogeographic origins of these rich communities of land-dwelling vertebrates remain obscure. Here we report on a new early Permian continental tetrapod fauna from South America in tropical Western Gondwana that sheds new light on patterns of tetrapod distribution. Northeastern Brazil hosted an extensive lacustrine system inhabited by a unique community of temnospondyl amphibians and reptiles that considerably expand the known temporal and geographic ranges of key subgroups. Our findings demonstrate that tetrapod groups common in later Permian and Triassic temperate communities were already present in tropical Gondwana by the early Permian (Cisuralian). This new fauna constitutes a new biogeographic province with North American affinities and clearly demonstrates that tetrapod dispersal into Gondwana was already underway at the beginning of the Permian. PMID:26537112

  16. Salinity fronts in the tropical Pacific Ocean.

    PubMed

    Kao, Hsun-Ying; Lagerloef, Gary S E

    2015-02-01

    This study delineates the salinity fronts (SF) across the tropical Pacific, and describes their variability and regional dynamical significance using Aquarius satellite observations. From the monthly maps of the SF, we find that the SF in the tropical Pacific are (1) usually observed around the boundaries of the fresh pool under the intertropical convergence zone (ITCZ), (2) stronger in boreal autumn than in other seasons, and (3) usually stronger in the eastern Pacific than in the western Pacific. The relationship between the SF and the precipitation and the surface velocity are also discussed. We further present detailed analysis of the SF in three key tropical Pacific regions. Extending zonally around the ITCZ, where the temperature is nearly homogeneous, we find the strong SF of 1.2 psu from 7° to 11°N to be the main contributor of the horizontal density difference of 0.8 kg/m(3). In the eastern Pacific, we observe a southward extension of the SF in the boreal spring that could be driven by both precipitation and horizontal advection. In the western Pacific, the importance of these newly resolved SF associated with the western Pacific warm/fresh pool and El Niño southern oscillations are also discussed in the context of prior literature. The main conclusions of this study are that (a) Aquarius satellite salinity measurements reveal the heretofore unknown proliferation, structure, and variability of surface salinity fronts, and that (b) the fine-scale structures of the SF in the tropical Pacific yield important new information on the regional air-sea interaction and the upper ocean dynamics.

  17. The underestimated biodiversity of tropical grassy biomes.

    PubMed

    Murphy, Brett P; Andersen, Alan N; Parr, Catherine L

    2016-09-19

    For decades, there has been enormous scientific interest in tropical savannahs and grasslands, fuelled by the recognition that they are a dynamic and potentially unstable biome, requiring periodic disturbance for their maintenance. However, that scientific interest has not translated into widespread appreciation of, and concern about threats to, their biodiversity. In terms of biodiversity, grassy biomes are considered poor cousins of the other dominant biome of the tropics-forests. Simple notions of grassy biomes being species-poor cannot be supported; for some key taxa, such as vascular plants, this may be valid, but for others it is not. Here, we use an analysis of existing data to demonstrate that high-rainfall tropical grassy biomes (TGBs) have vertebrate species richness comparable with that of forests, despite having lower plant diversity. The Neotropics stand out in terms of both overall vertebrate species richness and number of range-restricted vertebrate species in TGBs. Given high rates of land-cover conversion in Neotropical grassy biomes, they should be a high priority for conservation and greater inclusion in protected areas. Fire needs to be actively maintained in these systems, and in many cases re-introduced after decades of inappropriate fire exclusion. The relative intactness of TGBs in Africa and Australia make them the least vulnerable to biodiversity loss in the immediate future. We argue that, like forests, TGBs should be recognized as a critical-but increasingly threatened-store of global biodiversity.This article is part of the themed issue 'Tropical grassy biomes: linking ecology, human use and conservation'.

  18. Tropic Test of Bradley Fighting Vehicle Systems.

    DTIC Science & Technology

    2014-09-26

    operation of the M2/M3 system in a humid tropic environment in terms of materiel degradation and performance, in accordance with the Basic Climatic ...Factors Test of Weapon Systems Loading is contained in Appendix G. 1.3.2 Two 10 week storage periods are planned to achieve the Basic Climate conditions...maintainability for further testing. 1.3.3 The Basic Climatic Conditions (Variable and Constant High Humidity Daily Cycles) are accomplished by utilizing two

  19. Cloud Radiative Forcing in the Tropics

    NASA Technical Reports Server (NTRS)

    Christopher, Sundar Anand

    1995-01-01

    Understanding the role of clouds is one of the highest priority science objectives in the global climate change program. In particular there has been a renewed interest in understanding the cloud radiative interactions in the tropical regions. Although a number of studies have emphasized the importance of cloud optical properties on the earth's radiative energy balance, information concerning cloud optical depth and particle size as a function of cloud type is lacking.

  20. Biophysical Feedbacks in the Tropical Pacific.

    NASA Astrophysics Data System (ADS)

    Marzeion, Ben; Timmermann, Axel; Murtugudde, Ragu; Jin, Fei-Fei

    2005-01-01

    This study explores the influence of phytoplankton on the tropical Pacific heat budget. A hybrid coupled model for the tropical Pacific that is based on a primitive equation reduced-gravity multilayer ocean model, a dynamic ocean mixed layer, an atmospheric mixed layer, and a statistical atmosphere is used. The statistical atmosphere relates deviations of the sea surface temperature from its mean to wind stress anomalies and allows for the rectification of the annual cycle and the El Niño-Southern Oscillation (ENSO) phenomenon through the positive Bjerknes feedback. Furthermore, a nine-component ecosystem model is coupled to the physical variables of the ocean. The simulated chlorophyll concentrations can feed back onto the ocean heat budget by their optical properties, which modify solar light absorption in the surface layers. It is shown that both the surface layer concentration as well as the vertical profile of chlorophyll have a significant effect on the simulated mean state, the tropical annual cycle, and ENSO. This study supports a previously suggested hypothesis (Timmermann and Jin) that predicts an influence of phytoplankton concentration of the tropical Pacific climate mean state and its variability. The bioclimate feedback diagnosed here works as follows: Maxima in the subsurface chlorophyll concentrations lead to an enhanced subsurface warming due to the absorption of photosynthetically available shortwave radiation. This warming triggers a deepening of the mixed layer in the eastern equatorial Pacific and eventually a reduction of the surface ocean currents (Murtugudde et al.). The weakened south-equatorial current generates an eastern Pacific surface warming, which is strongly enhanced by the Bjerknes feedback. Because of the deepening of the mixed layer, the strength of the simulated annual cycle is also diminished. This in turn leads to an increase in ENSO variability.

  1. Poverty and corruption compromise tropical forest reserves.

    PubMed

    Wright, S Joseph; Sanchez-Azofeifa, G Arturo; Portillo-Quintero, Carlos; Davies, Diane

    2007-07-01

    We used the global fire detection record provided by the satellite-based Moderate Resolution Imaging Spectroradiometer (MODIS) to determine the number of fires detected inside 823 tropical and subtropical moist forest reserves and for contiguous buffer areas 5, 10, and 15 km wide. The ratio of fire detection densities (detections per square kilometer) inside reserves to their contiguous buffer areas provided an index of reserve effectiveness. Fire detection density was significantly lower inside reserves than in paired, contiguous buffer areas but varied by five orders of magnitude among reserves. The buffer: reserve detection ratio varied by up to four orders of magnitude among reserves within a single country, and median values varied by three orders of magnitude among countries. Reserves tended to be least effective at reducing fire frequency in many poorer countries and in countries beset by corruption. Countries with the most successful reserves include Costa Rica, Jamaica, Malaysia, and Taiwan and the Indonesian island of Java. Countries with the most problematic reserves include Cambodia, Guatemala, Paraguay, and Sierra Leone and the Indonesian portion of Borneo. We provide fire detection density for 3964 tropical and subtropical reserves and their buffer areas in the hope that these data will expedite further analyses that might lead to improved management of tropical reserves.

  2. Anomalous cold in the Pangaean tropics

    USGS Publications Warehouse

    Soreghan, G.S.; Soreghan, M.J.; Poulsen, C.J.; Young, R.A.; Eble, C.F.; Sweet, D.E.; Davogustto, O.C.

    2008-01-01

    The late Paleozoic archives the greatest glaciation of the Phanerozoic. Whereas high-latitude Gondwanan strata preserve widespread evidence for continental ice, the Permo-Carboniferous tropics have long been considered analogous to today's: warm and shielded from the highlatitude cold. Here, we report on glacial and periglacial indicators that record episodes of freezing continental temperatures in western equatorial Pangaea. An exhumed glacial valley and associated deposits record direct evidence for glaciation that extended to low paleoelevations in the ancestral Rocky Mountains. Furthermore, the Permo-Carboniferous archives the only known occurrence of widespread tropical loess in Earth's history; the volume, chemistry, and provenance of this loess(ite) is most consistent with glacial derivation. Together with emerging indicators for cold elsewhere in low-latitude Pangaea, these results suggest that tropical climate was not buffered from the high latitudes and may record glacial-interglacial climate shifts of very large magnitude. Coupled climate-ice sheet model simulations demonstrate that low atmospheric CO2 and solar luminosity alone cannot account for such cold, and that other factors must be considered in attempting to explain this 'best-known' analogue to our present Earth. ?? 2008 The Geological Society of America.

  3. [Biomedical research in Revista de Biologia Tropical].

    PubMed

    Gutiérrez, José María

    2002-01-01

    The contributions published in Revista de Biología Tropical in the area of Biomedical Sciences are reviewed in terms of number of contributions and scope of research subjects. Biomedical Sciences, particularly Parasitology and Microbiology, constituted the predominant subject in the Revista during the first decade, reflecting the intense research environment at the School of Microbiology of the University of Costa Rica and at Hospital San Juan de Dios. The relative weight of Biomedicine in the following decades diminished, due to the outstanding increment in publications in Biological Sciences; however, the absolute number of contributions in Biomedical Sciences remained constant throughout the last decades, with around 80 contributions per decade. In spite of the predominance of Parasitology as the main biomedical subject, the last decades have witnessed the emergence of new areas of interest in the Revista, such as Pharmacology of natural products, Toxinology, especially related to snake venoms, and Human Genetics. This retrospective analysis evidences that Biomedical Sciences, particularly those related to Tropical Medicine, were a fundamental component during the first years of Revista de Biología Tropical, and have maintained a significant presence in the scientific output of this journal, the most relevant scientific publication in biological sciences in Central America.

  4. Vaccines to combat the neglected tropical diseases

    PubMed Central

    Bethony, Jeffrey M.; Cole, Rhea N.; Guo, Xiaoti; Kamhawi, Shaden; Lightowlers, Marshall W.; Loukas, Alex; Petri, William; Reed, Steven; Valenzuela, Jesus G.; Hotez, Peter J.

    2012-01-01

    Summary The neglected tropical diseases (NTDs) represent a group of parasitic and related infectious diseases such as amebiasis, Chagas disease, cysticercosis, echinococcosis, hookworm, leishmaniasis, and schistosomiasis. Together, these conditions are considered the most common infections in low- and middle-income countries, where they produce a level of global disability and human suffering equivalent to better known conditions such as human immunodeficiency virus/acquired immunodeficiency syndrome and malaria. Despite their global public health importance, progress on developing vaccines for NTD pathogens has lagged because of some key technical hurdles and the fact that these infections occur almost exclusively in the world’s poorest people living below the World Bank poverty line. In the absence of financial incentives for new products, the multinational pharmaceutical companies have not embarked on substantive research and development programs for the neglected tropical disease vaccines. Here, we review the current status of scientific and technical progress in the development of new neglected tropical disease vaccines, highlighting the successes that have been achieved (cysticercosis and echinococcosis) and identifying the challenges and opportunities for development of new vaccines for NTDs. Also highlighted are the contributions being made by non-profit product development partnerships that are working to overcome some of the economic challenges in vaccine manufacture, clinical testing, and global access. PMID:21198676

  5. Citizen scientists analyzing tropical cyclone intensities

    NASA Astrophysics Data System (ADS)

    Hennon, Christopher C.

    2012-10-01

    A new crowd sourcing project called CycloneCenter enables the public to analyze historical global tropical cyclone (TC) intensities. The primary goal of CycloneCenter, which launched in mid-September, is to resolve discrepancies in the recent global TC record arising principally from inconsistent development of tropical cyclone intensity data. The historical TC record is composed of data sets called "best tracks," which contain a forecast agency's best assessment of TC tracks and intensities. Best track data have improved in quality since the beginning of the geostationary satellite era in the 1960s (because TCs could no longer disappear from sight). However, a global compilation of best track data (International Best Track Archive for Climate Stewardship (IBTrACS)) has brought to light large interagency differences between some TC best track intensities, even in the recent past [Knapp et al., 2010Knapp et al., 2010]. For example, maximum wind speed estimates for Tropical Cyclone Gay (1989) differed by as much as 70 knots as it was tracked by three different agencies.

  6. Epilepsy in the tropics: Emerging etiologies.

    PubMed

    Carrizosa Moog, Jaime; Kakooza-Mwesige, Angelina; Tan, Chong Tin

    2017-01-01

    Epilepsy is considered by the World Health Organization a public health priority with more than 50 million human beings affected by the disease. More than 80% of persons with epilepsy live in low and middle income countries and most of them in tropical areas. Several emerging, re-emerging and neglected diseases are symptomatic etiologies that jointly contribute to the enormous global burden of epilepsy. Besides the clinical strengths to reduce diagnostic and treatment gaps, other strategies in social, economic, cultural, educational and health policies are needed to prevent and treat appropriately vulnerable and affected persons with epilepsy. From the public health point of view, several of those strategies could be more effective in reducing the incidence and burden of the disease than the clinical approach of diagnosis and treatment. Special attention has to be given to stigma reduction and promotion of human rights. Several aspects mentioned in this abstract slip away the scope of the article, but it is a remainder to approach epilepsy in an inter- and transdisciplinary manner, an integral and pertinent approach needed and requested in tropical counties. The article focuses only on emergent and re-emergent etiologies of epilepsy in the tropics like malaria, HIV, neurocysticercosis, viral encephalitis and traumatic brain injury.

  7. Quality of Reanalyses in the Tropics.

    NASA Astrophysics Data System (ADS)

    Trenberth, Kevin E.; Stepaniak, David P.; Hurrell, James W.; Fiorino, Michael

    2001-04-01

    Broad vertical layer-averaged temperatures from the microwave sounder unit (MSU) are used as a quasi-independent validation of temperature fields from the U.S. National Centers for Environmental Prediction-National Center for Atmospheric Research (NCEP-NCAR) and the European Centre for Medium-Range Weather Forecasts (ECMWF) reanalyses. While the MSU and NCEP-NCAR temperatures show fairly good agreement overall, large discrepancies with ECMWF temperatures indicate that changes in the satellite observing system may have adversely affected the ECMWF reanalyses, especially in the Tropics. Two spurious discontinuities are present in tropical temperatures with jumps to warmer values throughout the Tropics below 500 mb in late 1986 and early 1989, and further spurious interannual variability is also present. These features are also reflected in the specific humidity fields. The temperature discrepancies have a complex vertical structure with height that is not fully understood, although it seems that the problems partly arise from positive reinforcement of biases in satellite radiances with those of the assimilating model first guess. Changes in the observing system provide a limit to the usefulness of the reanalyses in some climate studies.

  8. Current Trends of Tropical Fruit Waste Utilization.

    PubMed

    Cheok, Choon Yoong; Adzahan, Noranizan Mohd; Rahman, Russly Abdul; Abedin, Nur Hanani Zainal; Hussain, Norhayati; Sulaiman, Rabiha; Chong, Gun Hean

    2016-05-31

    Recent rapid growth of the world's population has increased food demands. This phenomenon poses a great challenge for food manufacturers in maximizing the existing food or plant resources. Nowadays, the recovery of health benefit bioactive compounds from fruit wastes is a research trend not only to help minimize the waste burden, but also to meet the intensive demand from the public for phenolic compounds which are believed to have protective effects against chronic diseases. This review is focused on polyphenolic compounds recovery from tropical fruit wastes and its current trend of utilization. The tropical fruit wastes include in discussion are durian (Durio zibethinus), mangosteen (Garcinia mangostana L.), rambutan (Nephelium lappaceum), mango (Mangifera indica L.), jackfruit (Artocarpus heterophyllus), papaya (Carica papaya), passion fruit (Passiflora edulis), dragon fruit (Hylocereus spp), and pineapple (Ananas comosus). Highlights of bioactive compounds in different parts of a tropical fruit are targeted primarily for food industries as pragmatic references to create novel innovative health enhancement food products. This information is intended to inspire further research ideas in areas that are still under-explored and for food processing manufacturers who would like to minimize wastes as the norm of present day industry (design) objective.

  9. Sensitivity of tropical cyclone intensity to sea surface temperature

    SciTech Connect

    Evans, J.L. )

    1993-06-01

    Increased occurrence of more intense tropical storms intruding further poleward has been foreshadowed as one of the potential consequences of global warming. This scenario is based almost entirely on the general circulation model predictions of warmer sea surface temperature (SST) with increasing levels of atmospheric CO[sub 2] and some theories of tropical cyclone intensification that support the notion of more intense systems with warmer SST. Whether storms are able to achieve this theoretically determined more intense state depends on whether the temperature of the underlying water is the dominant factor in tropical cyclone intensification. An examination of the historical data record in a number of ocean basins is used to identify the relative importance of SST in the tropical cyclone intensification process. The results reveal that SST alone is an inadequate predictor of tropical cyclone intensity. Other factors known to affect tropical cyclone frequency and intensity are discussed. 16 refs., 6 figs., 3 tabs.

  10. Disaggregating Tropical Disease Prevalence by Climatic and Vegetative Zones within Tropical West Africa

    PubMed Central

    Beckley, Carl S.; Shaban, Salisu; Palmer, Guy H.; Hudak, Andrew T.; Noh, Susan M.; Futse, James E.

    2016-01-01

    Tropical infectious disease prevalence is dependent on many socio-cultural determinants. However, rainfall and temperature frequently underlie overall prevalence, particularly for vector-borne diseases. As a result these diseases have increased prevalence in tropical as compared to temperate regions. Specific to tropical Africa, the tendency to incorrectly infer that tropical diseases are uniformly prevalent has been partially overcome with solid epidemiologic data. This finer resolution data is important in multiple contexts, including understanding risk, predictive value in disease diagnosis, and population immunity. We hypothesized that within the context of a tropical climate, vector-borne pathogen prevalence would significantly differ according to zonal differences in rainfall, temperature, relative humidity and vegetation condition. We then determined if these environmental data were predictive of pathogen prevalence. First we determined the prevalence of three major pathogens of cattle, Anaplasma marginale, Babesia bigemina and Theileria spp, in the three vegetation zones where cattle are predominantly raised in Ghana: Guinea savannah, semi-deciduous forest, and coastal savannah. The prevalence of A. marginale was 63%, 26% for Theileria spp and 2% for B. bigemina. A. marginale and Theileria spp. were significantly more prevalent in the coastal savannah as compared to either the Guinea savanna or the semi-deciduous forest, supporting acceptance of the first hypothesis. To test the predictive power of environmental variables, the data over a three year period were considered in best subsets multiple linear regression models predicting prevalence of each pathogen. Corrected Akaike Information Criteria (AICc) were assigned to the alternative models to compare their utility. Competitive models for each response were averaged using AICc weights. Rainfall was most predictive of pathogen prevalence, and EVI also contributed to A. marginale and B. bigemina prevalence

  11. The Tropical Ecology, Assessment and Monitoring (TEAM) Network: An early warning system for tropical rain forests.

    PubMed

    Rovero, Francesco; Ahumada, Jorge

    2017-01-01

    While there are well established early warning systems for a number of natural phenomena (e.g. earthquakes, catastrophic fires, tsunamis), we do not have an early warning system for biodiversity. Yet, we are losing species at an unprecedented rate, and this especially occurs in tropical rainforests, the biologically richest but most eroded biome on earth. Unfortunately, there is a chronic gap in standardized and pan-tropical data in tropical forests, affecting our capacity to monitor changes and anticipate future scenarios. The Tropical Ecology, Assessment and Monitoring (TEAM) Network was established to contribute addressing this issue, as it generates real time data to monitor long-term trends in tropical biodiversity and guide conservation practice. We present the Network and focus primarily on the Terrestrial Vertebrates protocol, that uses systematic camera trapping to detect forest mammals and birds, and secondarily on the Zone of Interaction protocol, that measures changes in the anthroposphere around the core monitoring area. With over 3 million images so far recorded, and managed using advanced information technology, TEAM has created the most important data set on tropical forest mammals globally. We provide examples of site-specific and global analyses that, combined with data on anthropogenic disturbance collected in the larger ecosystem where monitoring sites are, allowed us to understand the drivers of changes of target species and communities in space and time. We discuss the potential of this system as a candidate model towards setting up an early warning system that can effectively anticipate changes in coupled human-natural system, trigger management actions, and hence decrease the gap between research and management responses. In turn, TEAM produces robust biodiversity indicators that meet the requirements set by global policies such as the Aichi Biodiversity Targets. Standardization in data collection and public sharing of data in near real time

  12. Disaggregating Tropical Disease Prevalence by Climatic and Vegetative Zones within Tropical West Africa.

    PubMed

    Beckley, Carl S; Shaban, Salisu; Palmer, Guy H; Hudak, Andrew T; Noh, Susan M; Futse, James E

    2016-01-01

    Tropical infectious disease prevalence is dependent on many socio-cultural determinants. However, rainfall and temperature frequently underlie overall prevalence, particularly for vector-borne diseases. As a result these diseases have increased prevalence in tropical as compared to temperate regions. Specific to tropical Africa, the tendency to incorrectly infer that tropical diseases are uniformly prevalent has been partially overcome with solid epidemiologic data. This finer resolution data is important in multiple contexts, including understanding risk, predictive value in disease diagnosis, and population immunity. We hypothesized that within the context of a tropical climate, vector-borne pathogen prevalence would significantly differ according to zonal differences in rainfall, temperature, relative humidity and vegetation condition. We then determined if these environmental data were predictive of pathogen prevalence. First we determined the prevalence of three major pathogens of cattle, Anaplasma marginale, Babesia bigemina and Theileria spp, in the three vegetation zones where cattle are predominantly raised in Ghana: Guinea savannah, semi-deciduous forest, and coastal savannah. The prevalence of A. marginale was 63%, 26% for Theileria spp and 2% for B. bigemina. A. marginale and Theileria spp. were significantly more prevalent in the coastal savannah as compared to either the Guinea savanna or the semi-deciduous forest, supporting acceptance of the first hypothesis. To test the predictive power of environmental variables, the data over a three year period were considered in best subsets multiple linear regression models predicting prevalence of each pathogen. Corrected Akaike Information Criteria (AICc) were assigned to the alternative models to compare their utility. Competitive models for each response were averaged using AICc weights. Rainfall was most predictive of pathogen prevalence, and EVI also contributed to A. marginale and B. bigemina prevalence

  13. Chilly ice-age tropics could signal climate sensitivity

    SciTech Connect

    Kerr, R.A.

    1995-02-17

    A classic 1976 study, CLIMAP, indicated that the tropical ocean cooled less than 2C during the worst of the last ice age while the rest of the world experienced a 5C chill. However, this climatic buffering in the tropics has come under attack with new evidence and possible errors in the original study. This article discusses new evidence about climate sensitivity in the tropics and reinterpertation in climate models.

  14. Explosive supercell growth - A possible indicator for tropical storm intensification?

    NASA Technical Reports Server (NTRS)

    Venne, Monique G.; Lyons, Walter A.; Keen, Cecil S.; Black, Peter G.; Gentry, R. Cecil

    1989-01-01

    Several tropical storm observations are discussed which support the hypothesis that bursts of cloud-to-ground lightning near the center of a developing tropical storm (also called convective exhaust clouds and supercells), indicative of organized deep convection, could provide a valuable diagnostic for intensification over the next 12-36 hours. It is emphasized that further research is required in order to establish the exact role of supercells in tropical storm intensification.

  15. Evolution of Tropical Cyclone Characteristics and Forecast Assessment

    DTIC Science & Technology

    2016-06-07

    structure, which is important to understanding the motion of the tropical cyclone, is dependent on the growth, evolution, and decay of mesoscale convective ...MCS structural characteristics such as convective and stratiform cloud amounts, percent coverage, and rain rates. Furthermore, co- located microwave...tropical cyclone features (e.g., convective activity, inner-core structure), midlatitude circulation into which the tropical cyclone is moving, and

  16. Tropical boundary layer equilibrium in the last ice age

    NASA Technical Reports Server (NTRS)

    Betts, Alan K.; Ridgway, W.

    1992-01-01

    A radiative-convective boundary layer model is used to assess the effect of changing sea surface temperature, pressure, wind speed, and the energy export from the tropics on the boundary layer equilibrium equivalent potential temperature. It remains difficult to reconcile the observations that during the last glacial maximum (18,000 yr BP) the snowline on the tropical mountains fell 950 m, while the tropical sea surface temperatures fell only 1-2 K.

  17. An Improved Analytical Method for Atmospheric Chlorides in Tropic Tests

    DTIC Science & Technology

    1975-07-01

    Chloride Electrode Chloride Analysis Methodology Tropic Regions Diphenylcarbazone- Panama Canal Zone Tropic Test Center Bromphenol Blue Salt Wet Candle 20...ambient salt has been measured for corrosion studies by wet- candle sampling and determining water-soluble chlorides by manual mercuric nitrate titration...of total chloride in wet- candle samplers. For the past 8 years atmospheric salt has been measured at tropic test sites by the wet- candle method

  18. Dynamic Ocean-Atmosphere Coupling: A Thermostat for the Tropics

    PubMed

    Sun; Liu

    1996-05-24

    The ocean currents connecting the western tropical Pacific Ocean with the eastern tropical Pacific Ocean are driven by surface winds. The surface winds are in turn driven by the sea-surface temperature (SST) differences between these two regions. This dynamic coupling between the atmosphere and ocean may limit the SST in the tropical Pacific Ocean to below 305 kelvin even in the absence of cloud feedbacks.

  19. Diversity and carbon storage across the tropical forest biome.

    PubMed

    Sullivan, Martin J P; Talbot, Joey; Lewis, Simon L; Phillips, Oliver L; Qie, Lan; Begne, Serge K; Chave, Jerôme; Cuni-Sanchez, Aida; Hubau, Wannes; Lopez-Gonzalez, Gabriela; Miles, Lera; Monteagudo-Mendoza, Abel; Sonké, Bonaventure; Sunderland, Terry; Ter Steege, Hans; White, Lee J T; Affum-Baffoe, Kofi; Aiba, Shin-Ichiro; de Almeida, Everton Cristo; de Oliveira, Edmar Almeida; Alvarez-Loayza, Patricia; Dávila, Esteban Álvarez; Andrade, Ana; Aragão, Luiz E O C; Ashton, Peter; Aymard C, Gerardo A; Baker, Timothy R; Balinga, Michael; Banin, Lindsay F; Baraloto, Christopher; Bastin, Jean-Francois; Berry, Nicholas; Bogaert, Jan; Bonal, Damien; Bongers, Frans; Brienen, Roel; Camargo, José Luís C; Cerón, Carlos; Moscoso, Victor Chama; Chezeaux, Eric; Clark, Connie J; Pacheco, Álvaro Cogollo; Comiskey, James A; Valverde, Fernando Cornejo; Coronado, Eurídice N Honorio; Dargie, Greta; Davies, Stuart J; De Canniere, Charles; Djuikouo K, Marie Noel; Doucet, Jean-Louis; Erwin, Terry L; Espejo, Javier Silva; Ewango, Corneille E N; Fauset, Sophie; Feldpausch, Ted R; Herrera, Rafael; Gilpin, Martin; Gloor, Emanuel; Hall, Jefferson S; Harris, David J; Hart, Terese B; Kartawinata, Kuswata; Kho, Lip Khoon; Kitayama, Kanehiro; Laurance, Susan G W; Laurance, William F; Leal, Miguel E; Lovejoy, Thomas; Lovett, Jon C; Lukasu, Faustin Mpanya; Makana, Jean-Remy; Malhi, Yadvinder; Maracahipes, Leandro; Marimon, Beatriz S; Junior, Ben Hur Marimon; Marshall, Andrew R; Morandi, Paulo S; Mukendi, John Tshibamba; Mukinzi, Jaques; Nilus, Reuben; Vargas, Percy Núñez; Camacho, Nadir C Pallqui; Pardo, Guido; Peña-Claros, Marielos; Pétronelli, Pascal; Pickavance, Georgia C; Poulsen, Axel Dalberg; Poulsen, John R; Primack, Richard B; Priyadi, Hari; Quesada, Carlos A; Reitsma, Jan; Réjou-Méchain, Maxime; Restrepo, Zorayda; Rutishauser, Ervan; Salim, Kamariah Abu; Salomão, Rafael P; Samsoedin, Ismayadi; Sheil, Douglas; Sierra, Rodrigo; Silveira, Marcos; Slik, J W Ferry; Steel, Lisa; Taedoumg, Hermann; Tan, Sylvester; Terborgh, John W; Thomas, Sean C; Toledo, Marisol; Umunay, Peter M; Gamarra, Luis Valenzuela; Vieira, Ima Célia Guimarães; Vos, Vincent A; Wang, Ophelia; Willcock, Simon; Zemagho, Lise

    2017-01-17

    Tropical forests are global centres of biodiversity and carbon storage. Many tropical countries aspire to protect forest to fulfil biodiversity and climate mitigation policy targets, but the conservation strategies needed to achieve these two functions depend critically on the tropical forest tree diversity-carbon storage relationship. Assessing this relationship is challenging due to the scarcity of inventories where carbon stocks in aboveground biomass and species identifications have been simultaneously and robustly quantified. Here, we compile a unique pan-tropical dataset of 360 plots located in structurally intact old-growth closed-canopy forest, surveyed using standardised methods, allowing a multi-scale evaluation of diversity-carbon relationships in tropical forests. Diversity-carbon relationships among all plots at 1 ha scale across the tropics are absent, and within continents are either weak (Asia) or absent (Amazonia, Africa). A weak positive relationship is detectable within 1 ha plots, indicating that diversity effects in tropical forests may be scale dependent. The absence of clear diversity-carbon relationships at scales relevant to conservation planning means that carbon-centred conservation strategies will inevitably miss many high diversity ecosystems. As tropical forests can have any combination of tree diversity and carbon stocks both require explicit consideration when optimising policies to manage tropical carbon and biodiversity.

  20. [Common tropical infections with protozoans, worms and ectoparasites].

    PubMed

    Schliemann, S

    2014-10-01

    Infectious diseases of the skin have become rarer in industrialized nations, but they still affect a considerable part of the population in tropical regions. Skin diseases induced by protozoa, worms and ectoparasites are among the 17 "neglected tropical diseases" defined by the WHO (leishmaniasis, dracunculiasis, lymphatic filariasis, onchocerciasis). Skin symptoms in travellers returning from the tropics may challenge dermatologists in Germany regarding differential diagnostic assessment and therapy. Among the 12 most frequent skin diseases in travellers are cutaneous larva migrans, leishmaniasis and myiasis. In this review, diagnosis, treatment and prevention of some the most relevant tropical dermatoses due to protozoa, worms and ectoparasites are discussed.

  1. Detecting Trends in Tropical Rainfall Characteristics, 1979-2003

    NASA Technical Reports Server (NTRS)

    Lau, K. M.; Wu, H. T.

    2006-01-01

    From analyses of blended space-based and ground-based global rainfall data, we found increasing trends in the occurrence of extreme heavy and light rain events, coupled to a decreasing trend in moderate rain events in the tropics during 1979-2003. The trends are consistent with a shift in the large-scale circulation associated with a) a relatively uniform increase in warm rain over the tropical oceans, b) enhanced ice-phase rain over the near-equatorial oceans, and c) reduced mixed-phase rain over the tropical ocean and land regions. Due to the large compensation among different rain categories, the total tropical rainfall trend remained undetectable.

  2. 12. View north of Tropic Chamber. Natick Research & ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    12. View north of Tropic Chamber. - Natick Research & Development Laboratories, Climatic Chambers Building, U.S. Army Natick Research, Development & Engineering Center (NRDEC), Natick, Middlesex County, MA

  3. Diversity and carbon storage across the tropical forest biome

    PubMed Central

    Sullivan, Martin J. P.; Talbot, Joey; Lewis, Simon L.; Phillips, Oliver L.; Qie, Lan; Begne, Serge K.; Chave, Jerôme; Cuni-Sanchez, Aida; Hubau, Wannes; Lopez-Gonzalez, Gabriela; Miles, Lera; Monteagudo-Mendoza, Abel; Sonké, Bonaventure; Sunderland, Terry; ter Steege, Hans; White, Lee J. T.; Affum-Baffoe, Kofi; Aiba, Shin-ichiro; de Almeida, Everton Cristo; de Oliveira, Edmar Almeida; Alvarez-Loayza, Patricia; Dávila, Esteban Álvarez; Andrade, Ana; Aragão, Luiz E. O. C.; Ashton, Peter; Aymard C., Gerardo A.; Baker, Timothy R.; Balinga, Michael; Banin, Lindsay F.; Baraloto, Christopher; Bastin, Jean-Francois; Berry, Nicholas; Bogaert, Jan; Bonal, Damien; Bongers, Frans; Brienen, Roel; Camargo, José Luís C.; Cerón, Carlos; Moscoso, Victor Chama; Chezeaux, Eric; Clark, Connie J.; Pacheco, Álvaro Cogollo; Comiskey, James A.; Valverde, Fernando Cornejo; Coronado, Eurídice N. Honorio; Dargie, Greta; Davies, Stuart J.; De Canniere, Charles; Djuikouo K., Marie Noel; Doucet, Jean-Louis; Erwin, Terry L.; Espejo, Javier Silva; Ewango, Corneille E. N.; Fauset, Sophie; Feldpausch, Ted R.; Herrera, Rafael; Gilpin, Martin; Gloor, Emanuel; Hall, Jefferson S.; Harris, David J.; Hart, Terese B.; Kartawinata, Kuswata; Kho, Lip Khoon; Kitayama, Kanehiro; Laurance, Susan G. W.; Laurance, William F.; Leal, Miguel E.; Lovejoy, Thomas; Lovett, Jon C.; Lukasu, Faustin Mpanya; Makana, Jean-Remy; Malhi, Yadvinder; Maracahipes, Leandro; Marimon, Beatriz S.; Junior, Ben Hur Marimon; Marshall, Andrew R.; Morandi, Paulo S.; Mukendi, John Tshibamba; Mukinzi, Jaques; Nilus, Reuben; Vargas, Percy Núñez; Camacho, Nadir C. Pallqui; Pardo, Guido; Peña-Claros, Marielos; Pétronelli, Pascal; Pickavance, Georgia C.; Poulsen, Axel Dalberg; Poulsen, John R.; Primack, Richard B.; Priyadi, Hari; Quesada, Carlos A.; Reitsma, Jan; Réjou-Méchain, Maxime; Restrepo, Zorayda; Rutishauser, Ervan; Salim, Kamariah Abu; Salomão, Rafael P.; Samsoedin, Ismayadi; Sheil, Douglas; Sierra, Rodrigo; Silveira, Marcos; Slik, J. W. Ferry; Steel, Lisa; Taedoumg, Hermann; Tan, Sylvester; Terborgh, John W.; Thomas, Sean C.; Toledo, Marisol; Umunay, Peter M.; Gamarra, Luis Valenzuela; Vieira, Ima Célia Guimarães; Vos, Vincent A.; Wang, Ophelia; Willcock, Simon; Zemagho, Lise

    2017-01-01

    Tropical forests are global centres of biodiversity and carbon storage. Many tropical countries aspire to protect forest to fulfil biodiversity and climate mitigation policy targets, but the conservation strategies needed to achieve these two functions depend critically on the tropical forest tree diversity-carbon storage relationship. Assessing this relationship is challenging due to the scarcity of inventories where carbon stocks in aboveground biomass and species identifications have been simultaneously and robustly quantified. Here, we compile a unique pan-tropical dataset of 360 plots located in structurally intact old-growth closed-canopy forest, surveyed using standardised methods, allowing a multi-scale evaluation of diversity-carbon relationships in tropical forests. Diversity-carbon relationships among all plots at 1 ha scale across the tropics are absent, and within continents are either weak (Asia) or absent (Amazonia, Africa). A weak positive relationship is detectable within 1 ha plots, indicating that diversity effects in tropical forests may be scale dependent. The absence of clear diversity-carbon relationships at scales relevant to conservation planning means that carbon-centred conservation strategies will inevitably miss many high diversity ecosystems. As tropical forests can have any combination of tree diversity and carbon stocks both require explicit consideration when optimising policies to manage tropical carbon and biodiversity. PMID:28094794

  4. Evolution of tropical plumes in VAS water vapor imagery

    NASA Technical Reports Server (NTRS)

    Mcguirk, James P.; Ulsh, David J.

    1990-01-01

    Synoptic scale tropical plumes are analyzed using satellite data and outgoing longwave radiation data. The evolution of plumes is described and their precursor signals are examined. The horizontal moisture patterns of the plumes are compared with nonplume climatology, and the predictability of plumes based solely on satellite imagery is assessed. The results show that a plume evolves as a stationary, tropical, dry or moist dipole, separated by an exceptionally strong cloud or moisture gradient. Tropical plume evolution is accompanied by a systematic drying of the tropical eastern Pacific atmosphere before development, and moistening and increased cloudiness with development.

  5. Ocean barrier layers' effect on tropical cyclone intensification.

    PubMed

    Balaguru, Karthik; Chang, Ping; Saravanan, R; Leung, L Ruby; Xu, Zhao; Li, Mingkui; Hsieh, Jen-Shan

    2012-09-04

    Improving a tropical cyclone's forecast and mitigating its destructive potential requires knowledge of various environmental factors that influence the cyclone's path and intensity. Herein, using a combination of observations and model simulations, we systematically demonstrate that tropical cyclone intensification is significantly affected by salinity-induced barrier layers, which are "quasi-permanent" features in the upper tropical oceans. When tropical cyclones pass over regions with barrier layers, the increased stratification and stability within the layer reduce storm-induced vertical mixing and sea surface temperature cooling. This causes an increase in enthalpy flux from the ocean to the atmosphere and, consequently, an intensification of tropical cyclones. On average, the tropical cyclone intensification rate is nearly 50% higher over regions with barrier layers, compared to regions without. Our finding, which underscores the importance of observing not only the upper-ocean thermal structure but also the salinity structure in deep tropical barrier layer regions, may be a key to more skillful predictions of tropical cyclone intensities through improved ocean state estimates and simulations of barrier layer processes. As the hydrological cycle responds to global warming, any associated changes in the barrier layer distribution must be considered in projecting future tropical cyclone activity.

  6. 'Combating' tropical diseases in the German colonial press.

    PubMed

    Correa, Sílvio Marcus de Souza

    2013-03-01

    This article shows how much certain German language newspapers were a vehicule for reporting to the lay public on 'combating' tropical diseases. Through the press, immigrants and their descendents in Brazil were informed not only about the diseases which afflicted German colonists in Africa, but also about measures concerning sanitation, prophylaxis and experiments with tropical medicine, etc. Based on hemerographic sources, it shows how successful the overseas German communities were in sharing their experiences regarding health in tropical and/or sub-tropical regions.

  7. Diversity and carbon storage across the tropical forest biome

    NASA Astrophysics Data System (ADS)

    Sullivan, Martin J. P.; Talbot, Joey; Lewis, Simon L.; Phillips, Oliver L.; Qie, Lan; Begne, Serge K.; Chave, Jerôme; Cuni-Sanchez, Aida; Hubau, Wannes; Lopez-Gonzalez, Gabriela; Miles, Lera; Monteagudo-Mendoza, Abel; Sonké, Bonaventure; Sunderland, Terry; Ter Steege, Hans; White, Lee J. T.; Affum-Baffoe, Kofi; Aiba, Shin-Ichiro; de Almeida, Everton Cristo; de Oliveira, Edmar Almeida; Alvarez-Loayza, Patricia; Dávila, Esteban Álvarez; Andrade, Ana; Aragão, Luiz E. O. C.; Ashton, Peter; Aymard C., Gerardo A.; Baker, Timothy R.; Balinga, Michael; Banin, Lindsay F.; Baraloto, Christopher; Bastin, Jean-Francois; Berry, Nicholas; Bogaert, Jan; Bonal, Damien; Bongers, Frans; Brienen, Roel; Camargo, José Luís C.; Cerón, Carlos; Moscoso, Victor Chama; Chezeaux, Eric; Clark, Connie J.; Pacheco, Álvaro Cogollo; Comiskey, James A.; Valverde, Fernando Cornejo; Coronado, Eurídice N. Honorio; Dargie, Greta; Davies, Stuart J.; de Canniere, Charles; Djuikouo K., Marie Noel; Doucet, Jean-Louis; Erwin, Terry L.; Espejo, Javier Silva; Ewango, Corneille E. N.; Fauset, Sophie; Feldpausch, Ted R.; Herrera, Rafael; Gilpin, Martin; Gloor, Emanuel; Hall, Jefferson S.; Harris, David J.; Hart, Terese B.; Kartawinata, Kuswata; Kho, Lip Khoon; Kitayama, Kanehiro; Laurance, Susan G. W.; Laurance, William F.; Leal, Miguel E.; Lovejoy, Thomas; Lovett, Jon C.; Lukasu, Faustin Mpanya; Makana, Jean-Remy; Malhi, Yadvinder; Maracahipes, Leandro; Marimon, Beatriz S.; Junior, Ben Hur Marimon; Marshall, Andrew R.; Morandi, Paulo S.; Mukendi, John Tshibamba; Mukinzi, Jaques; Nilus, Reuben; Vargas, Percy Núñez; Camacho, Nadir C. Pallqui; Pardo, Guido; Peña-Claros, Marielos; Pétronelli, Pascal; Pickavance, Georgia C.; Poulsen, Axel Dalberg; Poulsen, John R.; Primack, Richard B.; Priyadi, Hari; Quesada, Carlos A.; Reitsma, Jan; Réjou-Méchain, Maxime; Restrepo, Zorayda; Rutishauser, Ervan; Salim, Kamariah Abu; Salomão, Rafael P.; Samsoedin, Ismayadi; Sheil, Douglas; Sierra, Rodrigo; Silveira, Marcos; Slik, J. W. Ferry; Steel, Lisa; Taedoumg, Hermann; Tan, Sylvester; Terborgh, John W.; Thomas, Sean C.; Toledo, Marisol; Umunay, Peter M.; Gamarra, Luis Valenzuela; Vieira, Ima Célia Guimarães; Vos, Vincent A.; Wang, Ophelia; Willcock, Simon; Zemagho, Lise

    2017-01-01

    Tropical forests are global centres of biodiversity and carbon storage. Many tropical countries aspire to protect forest to fulfil biodiversity and climate mitigation policy targets, but the conservation strategies needed to achieve these two functions depend critically on the tropical forest tree diversity-carbon storage relationship. Assessing this relationship is challenging due to the scarcity of inventories where carbon stocks in aboveground biomass and species identifications have been simultaneously and robustly quantified. Here, we compile a unique pan-tropical dataset of 360 plots located in structurally intact old-growth closed-canopy forest, surveyed using standardised methods, allowing a multi-scale evaluation of diversity-carbon relationships in tropical forests. Diversity-carbon relationships among all plots at 1 ha scale across the tropics are absent, and within continents are either weak (Asia) or absent (Amazonia, Africa). A weak positive relationship is detectable within 1 ha plots, indicating that diversity effects in tropical forests may be scale dependent. The absence of clear diversity-carbon relationships at scales relevant to conservation planning means that carbon-centred conservation strategies will inevitably miss many high diversity ecosystems. As tropical forests can have any combination of tree diversity and carbon stocks both require explicit consideration when optimising policies to manage tropical carbon and biodiversity.

  8. Medical Imaging of Neglected Tropical Diseases of the Americas.

    PubMed

    Jones, Patrick; Mazal, Jonathan

    2016-01-01

    Neglected tropical diseases are a group of protozoan, parasitic, bacterial, and viral diseases endemic in 149 countries causing substantial illness globally. Extreme poverty and warm tropical climates are the 2 most potent forces promoting the spread of neglected tropical diseases. These forces are prevalent in Central and South America, as well as the U.S. Gulf Coast. Advanced cases often require specialized medical imaging for diagnosis, disease staging, and follow-up. This article offers a review of epidemiology, pathophysiology, clinical manifestations, diagnosis (with special attention to medical imaging), and treatment of neglected tropical diseases specific to the Americas.

  9. What do fecal coliforms indicate in tropical waters

    SciTech Connect

    Hazen, T.C.

    1988-01-01

    High densities of total and fecal coliform bacteria have been detected in pristine streams and in ground water samples collected from many tropical parts of the world, even in epiphytic vegetation 10 m above ground in the rain forest of Puerto Rico. Nucleic acid (DNA) analyses of Escherichia coli from pristine tropical environs has indicated that they are identical to clinical isolates of E. coli. Many tropical source waters have been shown to have enteric pathogens in the complete absence of coliforms. Diffusion chamber studies with E. coli at several tropical sites reveal that this bacterium can survive indefinitely in most freshwaters in Puerto Rico. An evaluation of methods for the enumeration of fecal coliforms showed that currently used media have poor reliability as a result of large numbers of false positive and false negative results when applied to tropical water samples. Total and fecal coliform bacteria are not reliable indicators of recent biological contamination of waters in tropical areas. Fecal streptococci and coliphages in tropical waters, violate the same under lying assumptions of indicator assays as the coliforms. Anaerobic bacteria like Bifidobacterium spp. and Clostridium perfringens show some promise in terms of survival but not in ease of enumeration and media specificity. The best course at present lies in using current techniques for direct enumeration of pathogens by fluorescent staining and nucleic acid analysis and developing tropical maximum containmant levels for certain resistant pathogens in tropical waters. 66 refs.

  10. Tropical disturbances in relation to general circulation modeling

    NASA Technical Reports Server (NTRS)

    Estoque, M. A.

    1982-01-01

    The initial results of an evaluation of the performance of the Goddard Laboratory of Atmospheric Simulation general circulation model depicting the tropical atmosphere during the summer are presented. Because the results show the existence of tropical wave disturbances throughout the tropics, the characteristics of synoptic disturbances over Africa were studied and a synoptic case study of a selected disturbance in this area was conducted. It is shown that the model is able to reproduce wave type synoptic disturbances in the tropics. The findings show that, in one of the summers simulated, the disturbances are predominantly closed vortices; in another summer, the predominant disturbances are open waves.

  11. Tropical birds have a slow pace of life

    PubMed Central

    Wiersma, Popko; Muñoz-Garcia, Agustí; Walker, Amy; Williams, Joseph B.

    2007-01-01

    Tropical birds are relatively long-lived and produce few offspring, which develop slowly and mature relatively late in life, the slow end of the life-history axis, whereas temperate birds lie at the opposite end of this continuum. We tested the hypothesis that tropical birds have evolved a reduced basal metabolic rate (BMR). We measured BMR of 69 species of tropical birds, the largest data set amassed on metabolic rates of tropical birds, and compared these measurements with 59 estimates of BMR for temperate birds. Our analyses included conventional least squares regression, regressions based on phylogenetic independent contrasts, and a comparison of BMR of 13 phylogenetically matched pairs, one species from the tropics and one from northerly temperate areas. Our triptych showed that tropical birds had a reduced BMR, compelling evidence for a connection between the life history of tropical birds and a slow pace of life. Further, tropical migrants breeding in temperate habitats had a lower BMR than did temperate residents, suggesting that these migrants have physiological traits consistent with a slow pace of life. In addition, we determined that tropical birds had a lower cold-induced peak metabolic rate and thermogenic metabolic scope than temperate species, a finding that is consistent with the hypothesis that their environment has not selected for high levels of thermogenesis, or alternatively, that a slow pace of life may be incompatible with high thermogenic capacity. We conclude that physiological function correlates with the suite of life-history traits. PMID:17517640

  12. Ocean Barrier Layers’ Effect on Tropical Cyclone Intensification

    SciTech Connect

    Balaguru, Karthik; Chang, P.; Saravanan, R.; Leung, Lai-Yung R.; Xu, Zhao; Li, M.; Hsieh, J.

    2012-09-04

    Improving a tropical cyclone's forecast and mitigating its destructive potential requires knowledge of various environmental factors that influence the cyclone's path and intensity. Herein, using a combination of observations and model simulations, we systematically demonstrate that tropical cyclone intensification is significantly affected by salinity-induced barrier layers, which are 'quasi-permanent' features in the upper tropical oceans. When tropical cyclones pass over regions with barrier layers, the increased stratification and stability within the layer reduce storm-induced vertical mixing and sea surface temperature cooling. This causes an increase in enthalpy flux from the ocean to the atmosphere and, consequently, an intensification of tropical cyclones. On average, the tropical cyclone intensification rate is nearly 50% higher over regions with barrier layers, compared to regions without. Our finding, which underscores the importance of observing not only the upper-ocean thermal structure but also the salinity structure in deep tropical barrier layer regions, may be a key to more skillful predictions of tropical cyclone intensities through improved ocean state estimates and simulations of barrier layer processes. As the hydrological cycle responds to global warming, any associated changes in the barrier layer distribution must be considered in projecting future tropical cyclone activity.

  13. [Micronutrients and tropical viral infections: one aspect of pathogenic complexity in tropical medicine].

    PubMed

    Malvy, D

    1999-01-01

    In tropical zones, uncertain living conditions, inadequate food intake, and poor medical facilities enhance unnecessary morbidity and mortality especially involving infants and young children. In addition to protein-caloric malnutrition, deficiencies in essential micronutrients have a specific health impact. Such deficiencies can be the direct cause of disease such as vitamin A deficiency and blindness or have a promoting effect by compromising immune status and increasing susceptibility to and severity of infectious diseases especially of viral origin. The promoting effect of micronutrient deficiency plays a significant role in measles, rotavirus-related diarrhea, and, to a certain extent, progression of HIV infection. Several examples are described to illustrate the relationship between tropical viral infection and micronutrients including vitamin A, selenium, and various other antioxidants. These examples highlight the effect of infectious disease on micronutritional status (vitamin A and measles) and the need to develop reliable, practical tools to evaluate the relevance and effectiveness of dietary supplementation. In any case, improving living conditions and health programs such as the Expanded Vaccination Program are required and illustrate a transverse approach for prevention of infectious and non-infectious tropical disease. The relationship between micronutrients and infection is only one aspect of the multifactorial reality that must be dealt with in tropical medicine.

  14. Stratospheric tropical warming event and its impact on the polar and tropical troposphere

    NASA Astrophysics Data System (ADS)

    Kodera, Kunihiko; Eguchi, Nawo; Mukougawa, Hitoshi; Nasuno, Tomoe; Hirooka, Toshihiko

    2017-01-01

    Stratosphere-troposphere coupling is investigated in relation to middle atmospheric subtropical jet (MASTJ) variations in boreal winter. An exceptional strengthening of the MASTJ occurred in association with a sudden equatorward shift of the stratospheric polar night jet (PNJ) in early December 2011. This abrupt transformation of the MASTJ and PNJ had no apparent relation to the upward propagation of planetary waves from the troposphere. The impact of this stratospheric event penetrated into the troposphere in two regions: in the northern polar region and the tropics. Due to the strong MASTJ, planetary waves at higher latitudes were deflected and trapped in the northern polar region. Trapping of the planetary waves resulted in amplification of zonal wave number 1 component, which appeared in the troposphere as the development of a trough over the Atlantic sector and a ridge over the Eurasian sector. A strong MASTJ also suppressed the equatorward propagation of planetary waves, which resulted in weaker tropical stratospheric upwelling and produced anomalous warming in the tropical stratosphere. In the tropical tropopause layer (TTL), however, sublimation of ice clouds kept the temperature change minor. In the troposphere, an abrupt termination of a Madden-Julian Oscillation (MJO) event occurred following the static stability increase in the TTL. This termination suggests that the stratospheric event affected the convective episode in the troposphere.

  15. Helping Children in the Humid Tropics: Water Education. IHP Humid Tropics Programme Series, No. 11.

    ERIC Educational Resources Information Center

    Brelet-Rueff, Claudine

    Considering that, of the 250 million new cases of water-associated diseases reported every year, 75% occur in tropical, poor, rural areas and slum-outskirts of big cities, it becomes clear that water education is a priority. This booklet illustrates that early water education can benefit the entire community. Since habits related to water use are…

  16. The Tropical Fruit Research Program of the USDA-ARS Tropical Agriculture Research Station

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Tropical and subtropical fruit crops are of major importance in commercial and subsistence agriculture. The globalization of the economy and the increased demand for healthy and more diverse food products have opened a large market for many of these fruit crops. Despite this fact, increased produc...

  17. Precipitation, Elevation and Relief in the Tropics

    NASA Astrophysics Data System (ADS)

    Anders, A. M.; Nesbitt, S. W.; Gemperline, J.

    2011-12-01

    TRMM (Tropical Rainfall Measuring Mission) satellite precipitation radar data indicate that near-surface precipitation rates vary as a function of elevation in distinct ways in different mountain ranges across the tropics. Regional maximum precipitation rates are found at very low elevation in India's Western Ghats, Hawaii, and Eastern Australia. In New Guinea, the Northern Andes, and Taiwan, the locally maximum precipitation rates occur at moderate elevations (~1000 m). Regional maximum precipitation rates occur at very high elevation (>2000 m) in the African Rift Valley and Mexico's Sierra Madre Occidental. We present a simple model to explain the occurrence of these different relationships between precipitation and elevation as a function of large-scale atmospheric conditions, including those related to flow, moisture, and lower-tropospheric static stability. Additionally, we note that spatial variability in precipitation corresponds with spatial variability in ridge-valley relief in several tropical mountain ranges. We examine topography derived from SRTM (Shuttle Radar Topography Mission) data and precipitation patterns in swaths cutting perpendicular to the strike of these mountain ranges. Ridge-valley relief is defined as the standard deviation of topographic elevation parallel to the strike of the range. Ridge-valley relief varies systematically across several mountain ranges in concert with annual average precipitation. Where precipitation rates are high, ridge-valley relief is diminished and where precipitation rates are low, ridge-valley relief is maximized. The correspondence of precipitation and relief suggest a dynamic interaction between orographic precipitation and topographic development and confirms the predictions of an idealized numerical model of the co-evolution of precipitation and topography.

  18. Precipitation controls isoprene emissions from tropical ecosystems

    NASA Astrophysics Data System (ADS)

    Potosnak, M. J.; Gatti, L. V.; Guenther, A. B.; Karl, T.; Trostdorf, C. R.; Martins, W. C.; Rinne, H. J.; Yamazaki, A.

    2003-12-01

    Isoprene emissions from tropical regions account for a majority of isoprene produced globally. Current estimates of global isoprene emissions use meteorological inputs (temperature and light), ecosystem leaf area, and a time invariant, ecosystem specific emissions factor. This approach has been verified to work well for deciduous mid-latitude forests, but the approach has not been tested for tropical ecosystems where seasonality is induced by precipitation. Recent flux studies at two field stations in the tropics found strong effects of precipitation regime (dry vs. wet season) on isoprene emissions. A flux study conducted during the wet season (October 1999) at the La Selva Biological Station (10° 26' N, 83° 59' W, precipitation 4000 mm yr{-1}) found whole system isoprene emissions rates between 2--10 mg C m-2 h-1, while a second campaign during the dry season (April 2003) found values ranging 8--16 mg C m-2 h-1. This difference could not be explained by changes in ambient temperature or light using established emissions algorithms. The second field site near Santarém, Brazil in the Floresta Nacional do Tapajós (2° 51' S, 54° 58' W, precipitation 2000 mm yr{-1}), part of the Large scale Biosphere-atmosphere experiment in Amazônia (LBA), showed a similar pattern. Additionally, a 13 month isoprene concentration record at this station found a 4 fold increase during the dry season. Application of a one dimensional chemistry model predicts a similar change in isoprene source strength. A standard emission model using temperature and light could not account for these seasonal changes, but adding an empirical term that accounted for previous precipitation greatly enhanced the fit.

  19. Lessons learnt from tropical cyclone losses

    NASA Astrophysics Data System (ADS)

    Honegger, Caspar; Wüest, Marc; Zimmerli, Peter; Schoeck, Konrad

    2016-04-01

    Swiss Re has a long history in developing natural catastrophe loss models. The tropical cyclone USA and China model are examples for event-based models in their second generation. Both are based on basin-wide probabilistic track sets and calculate explicitly the losses from the sub-perils wind and storm surge in an insurance portfolio. Based on these models, we present two cases studies. China: a view on recent typhoon loss history Over the last 20 years only very few major tropical cyclones have caused severe insurance losses in the Pearl River Delta region and Shanghai, the two main exposure clusters along China's southeast coast. Several storms have made landfall in China every year but most struck areas with relatively low insured values. With this study, we make the point that typhoon landfalls in China have a strong hit-or-miss character and available insured loss experience is too short to form a representative view of risk. Historical storm tracks and a simple loss model applied to a market portfolio - all from publicly available data - are sufficient to illustrate this. An event-based probabilistic model is necessary for a reliable judgement of the typhoon risk in China. New York: current and future tropical cyclone risk In the aftermath of hurricane Sandy 2012, Swiss Re supported the City of New York in identifying ways to significantly improve the resilience to severe weather and climate change. Swiss Re provided a quantitative assessment of potential climate related risks facing the city as well as measures that could reduce those impacts.

  20. The Tropical Western Hemisphere Warm Pool

    NASA Astrophysics Data System (ADS)

    Wang, C.; Enfield, D. B.

    2002-12-01

    The paper describes and examines variability of the tropical Western Hemisphere warm pool (WHWP) of water warmer than 28.5oC. The WHWP is the second-largest tropical warm pool on Earth. Unlike the Eastern Hemisphere warm pool in the western Pacific, which straddles the equator, the WHWP is entirely north of the equator. At various stages of development the WHWP extends over parts of the eastern North Pacific, the Gulf of Mexico, the Caribbean, and the western tropical North Atlantic. It has a large seasonal cycle and its interannual fluctuations of area and intensity are significant. Surface heat fluxes warm the WHWP through the boreal spring to an annual maximum of SST and WHWP area in the late summer/early fall, associated with eastern North Pacific and Atlantic hurricane activities and rainfall from northern South America to the southern tier of the United States. Observations suggest that a positive ocean-atmosphere feedback operating through longwave radiation and associated cloudiness seems to operate in the WHWP. During winter preceding large warm pool, there is an alteration of the Walker and Hadley circulation cells that serves as a "tropospheric bridge" for transferring Pacific ENSO effects to the Atlantic sector and inducing initial warming of warm pool. Associated with the warm SST anomalies is a decrease in sea level pressure anomalies and an anomalous increase in atmospheric convection and cloudiness. The increase in convective activity and cloudiness results in less net longwave radiation loss from the sea surface, which then reinforces SST anomalies.

  1. Relation between tropical easterly wave convection and tropical cyclogenesis over the Atlantic and East Pacific

    NASA Astrophysics Data System (ADS)

    Leppert, Kenneth D., II

    The characteristics of tropical easterly wave convection and the possible implications of convective structure on tropical cyclogenesis and intensification over the Atlantic Ocean and East Pacific were investigated in this study. Easterly waves were partitioned into northerly, southerly, trough, and ridge phases based on 700-hPa meridional wind data. Waves were subsequently divided according to whether they did or did not develop tropical cyclones (i.e., developing waves [DWs] and non-developing waves [NDWs], respectively), and composites of synoptic-scale and convective-scale variables as a function of wave phase and category were created using Eulerian and Lagrangian frameworks. Results of both the Eulerian and Lagrangian composites indicate that the greatest difference between DWs and NDWs is observed for the fractional coverage by infrared brightness temperatures ≤ 240 K and ≤ 210 K. Indicators of convective intensity (e.g., lightning flash rates, mean convective reflectivity profiles) provide relatively few statistically significant differences between DWs and NDWs, except over the East Pacific. In addition, the Lagrangian composites suggest that as genesis is approached for DWs, the coverage by convection and cold cloudiness increases, while convective intensity decreases. In contrast, convective coverage and intensity both increase with time for NDWs. Thus, the results of both the Lagrangian and Eulerian frameworks suggest that the coverage by cold cloudiness/convection is generally more important than convective intensity for tropical cyclogenesis. In terms of large-scale variables, both types of composites suggest that enhanced upper-level (˜200 hPa) divergence and deep-layer moisture are particularly important for cyclogenesis and for distinguishing DWs from NDWs. The Eulerian composites also suggest that favorable large-scale conditions for cyclogenesis (e.g., significantly greater low-level [˜925 hPa] vorticity) occur for Atlantic DWs relative to

  2. Tropical Atlantic Impacts on the Decadal Climate Variability of the Tropical Ocean and Atmosphere.

    NASA Astrophysics Data System (ADS)

    Li, X.; Xie, S. P.; Gille, S. T.; Yoo, C.

    2015-12-01

    Previous studies revealed atmospheric bridges between the tropical Pacific, Atlantic, and Indian Ocean. In particular, several recent works indicate that the Atlantic sea surface temperature (SST) may contribute to the climate variability over the equatorial Pacific. Inspired by these studies, our work aims at investigating the impact of the tropical Atlantic on the entire tropical climate system, and uncovering the physical dynamics under these tropical teleconnections. We first performed a 'pacemaker' simulation by restoring the satellite era tropical Atlantic SST changes in a fully coupled model - the CESM1. Results reveal that the Atlantic warming heats the Indo-Western Pacific and cools the Eastern Pacific, enhances the Walker circulation and drives the subsurface Pacific to a La Niña mode, contributing to 60-70% of the above tropical changes in the past 30 years. The same pan-tropical teleconnections have been validated by the statistics of observations and 106 CMIP5 control simulations. We then used a hierarchy of atmospheric and oceanic models with different complexities, to single out the roles of atmospheric dynamics, atmosphere-ocean fluxes, and oceanic dynamics in these teleconnections. With these simulations we established a two-step mechanism as shown in the schematic figure: 1) Atlantic warming generates an atmospheric deep convection and induces easterly wind anomalies over the Indo-Western Pacific in the form of Kelvin waves, and westerly wind anomalies over the eastern equatorial Pacific as Rossby waves, in line with Gill's solution. This circulation changes warms the Indo-Western Pacific and cools the Eastern Pacific with the wind-evaporation-SST effect, forming a temperature gradient over the Indo-Pacific basins. 2) The temperature gradient further generates a secondary atmospheric deep convection, which reinforces the easterly wind anomalies over the equatorial Pacific and enhances the Walker circulation, triggering the Pacific to a La Ni

  3. Increasing human dominance of tropical forests.

    PubMed

    Lewis, Simon L; Edwards, David P; Galbraith, David

    2015-08-21

    Tropical forests house over half of Earth's biodiversity and are an important influence on the climate system. These forests are experiencing escalating human influence, altering their health and the provision of important ecosystem functions and services. Impacts started with hunting and millennia-old megafaunal extinctions (phase I), continuing via low-intensity shifting cultivation (phase II), to today's global integration, dominated by intensive permanent agriculture, industrial logging, and attendant fires and fragmentation (phase III). Such ongoing pressures, together with an intensification of global environmental change, may severely degrade forests in the future (phase IV, global simplification) unless new "development without destruction" pathways are established alongside climate change-resilient landscape designs.

  4. Rethinking tropical design: Towards a strategic framework

    SciTech Connect

    Rubio, D.; Martinez, V.; Sanchez, D.; Moran, C.; Machado, M.V.; Mustieles, F.

    1999-07-01

    This paper shows four residential projects, carried out by the third year MGL + P Unit, at the Facultad de Arquitectura Universidad del Zulia, Maracaibo, Venezuela. The projects are adapted to a hot-humid climate, and assume bioclimatical responsibilities, according to an urban concept. This is how the Cinetic house, the Fissure house, the Infinite house and the Free house developed. In these projects, climatic and ecological variables like sunning, ventilation, illumination, thermal comfort, materials and bioclimatic landscape were given special consideration. The models have been tested in a heliodom and a wind tunnel looking for an architecture that conciliates space, climate and ecology in tropical regions of the Third World.

  5. OH vertical column abundance - Tropical measurements

    NASA Astrophysics Data System (ADS)

    Burnett, Clyde R.; Minschwaner, Kenneth R.; Burnett, Elizabeth B.

    1990-09-01

    Measurements of the vertical column abundance of atmospheric hydroxyl (OH) have been made during the period 1987-1989 at the National Weather Service (NWS) station at Moen, Truk, Federated States of Micronesia (7 deg N, 152 deg E). A total of 384 independent data sets was obtained. Tropical OH abundance levels average about 22 percent above corresponding mid-latitude values, with OH levels during late winter and early spring up to 50 percent above those observed at 40 deg N. Stratospheric wind and temperature data obtained from the daily NWS radiosonde data are examined for correlations with the OH results.

  6. OH vertical column abundance - Tropical measurements

    NASA Technical Reports Server (NTRS)

    Burnett, Clyde R.; Minschwaner, Kenneth R.; Burnett, Elizabeth B.

    1990-01-01

    Measurements of the vertical column abundance of atmospheric hydroxyl (OH) have been made during the period 1987-1989 at the National Weather Service (NWS) station at Moen, Truk, Federated States of Micronesia (7 deg N, 152 deg E). A total of 384 independent data sets was obtained. Tropical OH abundance levels average about 22 percent above corresponding mid-latitude values, with OH levels during late winter and early spring up to 50 percent above those observed at 40 deg N. Stratospheric wind and temperature data obtained from the daily NWS radiosonde data are examined for correlations with the OH results.

  7. [The tropical traveling child: risks and prevention].

    PubMed

    Alcoba, G; Chappuis, F

    2015-05-06

    Children increasingly travel to the tropics. Compared with adults, the risks of severe malaria, dehydration due to diarrhea, and the number of infectious episodes, are higher. Paradoxically, children receive less pre-travel advice than adults, and some parents are opposed to vaccinations. The consultation must target essential prevention topics. We present the age-related schedules for immunizations against yellow and typhoid fevers, hepatitis A and B, tick-borne and Japanese encephalitis, and rabies. We discuss the preventive measures for malaria, accidents, altitude, and prescriptions for antimalarial drugs, rehydration solutions and standby antibiotics according to weight.

  8. Emissions from fires in various tropical ecosystems

    SciTech Connect

    Ward, D.E.

    1996-12-31

    Biomass burning is estimated to consume more than 6 Pg of vegetation per year. The estimates suggest that from 10% to as much as 25% of the increase in greenhouse gases in the atmosphere can be attributed to biomass burning with most of this resulting from practices leading to deforestation. For tropical regions, the source strength of emissions from biomass on a regional scale are believed to have profound effects on the atmospheric chemistry during periods when biomass burning is prevalent. The research over the past 7 years has included ecosystems in southern central Africa, Brazil, USA, and Canada.

  9. Ectomycorrhizal symbiosis of tropical African trees.

    PubMed

    Bâ, Amadou M; Duponnois, Robin; Moyersoen, Bernard; Diédhiou, Abdala G

    2012-01-01

    The diversity, ecology and function of ectomycorrhizal (EM) fungi and ectomycorrhizas (ECMs) on tropical African tree species are reviewed here. While ECMs are the most frequent mycorrhizal type in temperate and boreal forests, they concern an economically and ecologically important minority of plants in African tropical forests. In these African tropical forests, ECMs are found mainly on caesalpionioid legumes, Sarcolaenaceae, Dipterocarpaceae, Asterpeiaceae, Phyllantaceae, Sapotaceae, Papilionoideae, Gnetaceae and Proteaceae, and distributed in open, gallery and rainforests of the Guineo-Congolian basin, Zambezian Miombo woodlands of East and South-Central Africa and Sudanian savannah woodlands of the sub-sahara. Overall, EM status was confirmed in 93 (26%) among 354 tree species belonging to EM genera. In addition, 195 fungal taxa were identified using morphological descriptions and sequencing of the ML5/ML6 fragment of sporocarps and ECMs from West Africa. Analyses of the belowground EM fungal communities mostly based on fungal internal transcribed spacer sequences of ECMs from Continental Africa, Madagascar and the Seychelles also revealed more than 350 putative species of EM fungi belonging mainly to 18 phylogenetic lineages. As in temperate forests, the /russula-lactarius and /tomentella-thelephora lineages dominated EM fungal flora in tropical Africa. A low level of host preference and dominance of multi-host fungal taxa on different African adult tree species and their seedlings were revealed, suggesting a potential for the formation of common ectomycorrhizal networks. Moreover, the EM inoculum potential in terms of types and density of propagules (spores, sclerotia, EM root fragments and fragments of mycelia strands) in the soil allowed opportunistic root colonisation as well as long-term survival in the soil during the dry season. These are important characteristics when choosing an EM fungus for field application. In this respect, Thelephoroid fungal sp

  10. Tropical squall lines of the Arizona monsoon

    NASA Technical Reports Server (NTRS)

    Smith, Walter P.; Gall, Robert L.

    1989-01-01

    Three cases of squall lines composed of strong to severe thunderstorms that formed over Arizona, and Sonora (Mexico) on July, 16-17 and 17-18, 1984, and August 2-3, 1986, are examined. Data, which included satellite imagery, VISSR-derived fields, surface data, and records or cloud-to-ground lightning strikes, indicate that the initiation, growth, and dissipation of all three squall lines were very similar. Results indicate that these mesoscale convective systems developed in an environment of relatively strong low-level shear with very weak shear aloft and that they possessed almost all the properties of a typical tropical squall line.

  11. Atmospheric weather regimes over tropical South America

    NASA Technical Reports Server (NTRS)

    Connors, Vickie S.; Garstang, Michael; Nolf, Scott R.

    1991-01-01

    Infrared radiance measurements by the GOES-6 satellite during April 1986 through April 1987 were used to characterize and identify distinct regimes of persistent large-scale cloudiness patterns over the Amazon Basin. It is suggested that the energetics of the tropical troposphere over the Amazon Basin can be directly related to the GOES large-scale cloudiness patterns. The geometry and persistence of the cloud patterns are influenced by shifts in general circulation features and are likely modulated by 4- to 5-day and 40- to 60-day waves. Diurnal forcing effects are more pronounced during weather regimes characterized by prominently clear skies over land areas.

  12. W Photoprotection in Tropical Marine Organisms

    NASA Technical Reports Server (NTRS)

    Armstrong, Roy A.

    1997-01-01

    Increasing levels of ultraviolet (UV) radiation reaching the earth's surface which results from stratospheric ozone depletions could have serious implications for terrestrial plants and for aquatic organisms within the euphotic zone. A documented 9% decline in ozone at mid-latitudes is considered to produce a 12% increase in harmful UV radiation. The biologically damaging effects of higher UV levels, particularly W-B (280-320 rim), could manifest earlier in the tropics because of the relative thinness of the earth's equatorial ozone layer. Tropical marine organisms are also living close to their upper tolerance levels of water temperature, However, despite the large potential effects on plants and animals, little is known about UV effects on tropical ecosystems. Long-term ecological studies are needed to quantify the effects of increased UV radiation on terrestrial and marine ecosystems and to produce reliable data for prediction. Plants have developed several mechanisms to protect themselves from harmful UV radiation, one of which is the production of secondary leaf pigments that absorb W-B radiation (screening pigments). A higher concentration of screening pigments (e.g. flavonoids) in leaves may be interpreted as a natural response to increased W radiation. If higher concentrations of flavonoids filter out the excessive W radiation, no damage will occur, as suggested by Caldwell et al. (1989) and Tevini (1993). Failure to screen all W-B may result in deleterious effects on photosynthesis, plant genetic material, and plant and leaf morphology and growth. Eventually this will have an impact on ecosystem processes, structure, species composition, and productivity. This paper describes an ongoing project that is assessing the responses of mangroves, seagrasses and corals to W radiation by studying pigment concentrations, biophysical parameters, and variations in spectral reflectance in the field and in W-reduction experiments. Preliminary results on the distribution

  13. Tropical Engineering. Design Manual-11.1.

    DTIC Science & Technology

    1980-03-01

    AD-Aug 515 NAVAL FACILITIES EIN9IRNG COMAND ALEXADRA VA Fie 13/413 TROPICAL ENINgZRIM6. DESIGNi MANAL11.1.4UI L )NCLASSIFIE AFA01. IimENAFhChONh1...11N3 (6 copies each) A5 7321 15 A6 (Code L .1) FB31 (Guam only) 11N8 C7 (Brazil and Chile only) FB33 FNI0 FDI FB34 (Kadena only) FIPIB (less Concord...areas. Where appearance is a factor, methacrylate type lacquers conforming to MIL- L -19537 may be used. A minimum of a primer and two competitive coats for

  14. Tropical strains of Ralstonia solanacearum Outcompete race 3 biovar 2 strains at lowland tropical temperatures.

    PubMed

    Huerta, Alejandra I; Milling, Annett; Allen, Caitilyn

    2015-05-15

    Bacterial wilt, caused by members of the heterogenous Ralstonia solanacearum species complex, is an economically important vascular disease affecting many crops. Human activity has widely disseminated R. solanacearum strains, increasing their global agricultural impact. However, tropical highland race 3 biovar 2 (R3bv2) strains do not cause disease in tropical lowlands, even though they are virulent at warm temperatures. We tested the hypothesis that differences in temperature adaptation and competitive fitness explain the uneven geographic distribution of R. solanacearum strains. Using three phylogenetically and ecologically distinct strains, we measured competitive fitness at two temperatures following paired-strain inoculations of their shared host, tomato. Lowland tropical strain GMI1000 was only weakly virulent on tomato under temperate conditions (24°C for day and 19°C for night [24/19°C]), but highland tropical R3bv2 strain UW551 and U.S. warm temperate strain K60 were highly virulent at both 24/19°C and 28°C. Strain K60 was significantly more competitive than both GMI1000 and UW551 in tomato rhizospheres and stems at 28°C, and GMI1000 also outcompeted UW551 at 28°C. The results were reversed at cooler temperatures, at which highland strain UW551 generally outcompeted GMI1000 and K60 in planta. The superior competitive index of UW551 at 24/19°C suggests that adaptation to cool temperatures could explain why only R3bv2 strains threaten highland agriculture. Strains K60 and GMI1000 each produced different bacteriocins that inhibited growth of UW551 in culture. Such interstrain inhibition could explain why R3bv2 strains do not cause disease in tropical lowlands.

  15. Simulated sensitivity of the tropical climate to extratropical thermal forcing: tropical SSTs and African land surface

    NASA Astrophysics Data System (ADS)

    Talento, Stefanie; Barreiro, Marcelo

    2016-08-01

    This study investigates the Intertropical Convergence Zone (ITCZ) response to extratropical thermal forcing applied to an atmospheric general circulation model coupled to slab ocean and land models. We focus on the relative roles of the atmosphere, tropical sea surface temperatures (SSTs) and continental surface temperatures in the ITCZ response to the imposed forcing. The forcing consists of cooling in one hemisphere and warming in the other poleward of 40°, with zero global average. Three sets of experiments are performed: in the first the slab ocean and land models are applied globally; in the second the tropical SSTs are kept fixed while the slab land model is applied globally; in the third, in addition, surface temperatures over Africa are kept fixed. Realistic boundary surface conditions are used. We find that the ITCZ shifts towards the warmer hemisphere and that the stronger the forcing, the larger the shift. When the constraint of fixed tropical SST is imposed we find that the ITCZ response is strongly weakened, but it is still not negligible in particular over the Atlantic Ocean and Africa where the precipitation anomalies are of the order of 20 and 60 %, respectively, of the magnitude obtained without the SST restriction. Finally, when the constraint of the African surface temperature is incorporated we find that the ITCZ response completely vanishes, indicating that the ITCZ response to the extratropical forcing is not possible just trough purely atmospheric processes, but needs the involvement of either the tropical SST or the continental surface temperatures. The clear-sky longwave radiation feedback is highlighted as the main physical mechanism operating behind the land-based extratropical to tropical communication.

  16. Tropical Strains of Ralstonia solanacearum Outcompete Race 3 Biovar 2 Strains at Lowland Tropical Temperatures

    PubMed Central

    Huerta, Alejandra I.; Milling, Annett

    2015-01-01

    Bacterial wilt, caused by members of the heterogenous Ralstonia solanacearum species complex, is an economically important vascular disease affecting many crops. Human activity has widely disseminated R. solanacearum strains, increasing their global agricultural impact. However, tropical highland race 3 biovar 2 (R3bv2) strains do not cause disease in tropical lowlands, even though they are virulent at warm temperatures. We tested the hypothesis that differences in temperature adaptation and competitive fitness explain the uneven geographic distribution of R. solanacearum strains. Using three phylogenetically and ecologically distinct strains, we measured competitive fitness at two temperatures following paired-strain inoculations of their shared host, tomato. Lowland tropical strain GMI1000 was only weakly virulent on tomato under temperate conditions (24°C for day and 19°C for night [24/19°C]), but highland tropical R3bv2 strain UW551 and U.S. warm temperate strain K60 were highly virulent at both 24/19°C and 28°C. Strain K60 was significantly more competitive than both GMI1000 and UW551 in tomato rhizospheres and stems at 28°C, and GMI1000 also outcompeted UW551 at 28°C. The results were reversed at cooler temperatures, at which highland strain UW551 generally outcompeted GMI1000 and K60 in planta. The superior competitive index of UW551 at 24/19°C suggests that adaptation to cool temperatures could explain why only R3bv2 strains threaten highland agriculture. Strains K60 and GMI1000 each produced different bacteriocins that inhibited growth of UW551 in culture. Such interstrain inhibition could explain why R3bv2 strains do not cause disease in tropical lowlands. PMID:25769835

  17. Model finds bigger, stronger tropical cyclones with warming seas

    NASA Astrophysics Data System (ADS)

    Schultz, Colin

    2014-03-01

    In the wake of powerful tropical cyclones such as Hurricanes Sandy and Katrina and Typhoon Haiyan, questions about the likely effect of climate change on tropical cyclone activity are on the public's mind. The interactions between global warming and cyclone activity, however, are complex, with rising sea surface temperatures, changing energy distributions, and altered atmospheric dynamics all having some effect.

  18. An imperative need for global change research in tropical forests.

    PubMed

    Zhou, Xuhui; Fu, Yuling; Zhou, Lingyan; Li, Bo; Luo, Yiqi

    2013-09-01

    Tropical forests play a crucial role in regulating regional and global climate dynamics, and model projections suggest that rapid climate change may result in forest dieback or savannization. However, these predictions are largely based on results from leaf-level studies. How tropical forests respond and feedback to climate change is largely unknown at the ecosystem level. Several complementary approaches have been used to evaluate the effects of climate change on tropical forests, but the results are conflicting, largely due to confounding effects of multiple factors. Although altered precipitation and nitrogen deposition experiments have been conducted in tropical forests, large-scale warming and elevated carbon dioxide (CO2) manipulations are completely lacking, leaving many hypotheses and model predictions untested. Ecosystem-scale experiments to manipulate temperature and CO2 concentration individually or in combination are thus urgently needed to examine their main and interactive effects on tropical forests. Such experiments will provide indispensable data and help gain essential knowledge on biogeochemical, hydrological and biophysical responses and feedbacks of tropical forests to climate change. These datasets can also inform regional and global models for predicting future states of tropical forests and climate systems. The success of such large-scale experiments in natural tropical forests will require an international framework to coordinate collaboration so as to meet the challenges in cost, technological infrastructure and scientific endeavor.

  19. An introductory perspective on non-tropical shelf carbonates

    NASA Astrophysics Data System (ADS)

    Nelson, Campbell S.

    1988-11-01

    This brief account introduces the topic of non-tropical shelf carbonate deposits, both modern and ancient, specific aspects of which are described and discussed in the 22 accompanying papers in this Special Issue of Sedimentary Geology. "Non-tropical" shelves are loosely defined as lying poleward of the present limit of development of hermatypic coral reefs, or beyond the mean annual surface-water isotherm of about 20°C, typically near 30° latitude. Most geoscientists have traditionally regarded shallow-water carbonate formation as a low-latitude phenomenon. However, wherever the rate and extent of terrigenous sediment dilution is small, the potential exists for extensive deposits of skeletal carbonate to accumulate on shelves beyond the (sub)tropics. The facies attributes of the modern non-tropical carbonates are distinctive and contrast significantly with the structural, lithological, faunal, floral, mineralogical and diagenetic character of their tropical counterparts. In the rock record, non-tropical limestones probably occur throughout the Phanerozoic, but generally remain to be identified and/or interpreted as such. They are presently described mainly from the Ordovician, Permian and Tertiary-Quaternary, periods of major continental glaciations and accentuated latitudinal thermal gradients. A uniformitarian approach to the recognition and interpretation of ancient shallow-marine limestones requires acceptance of both tropical and non-tropical carbonate facies models.

  20. Energy content of tropical grasses and legumes grown for bioenergy

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Biomass samples of the tropical grasses Brachiaria brizantha (Hochst. ex A. Rich.) Staph, Brachiaria humidicola (Rendle) Schweick, Brachiaria decumbens Staph, Panicum maximum Jacq., Pennistetum alopecuroides (L.) Spreng and three species of the tropical legume Stylosanthes grown in Mato Grosso do Su...

  1. Successful biological control of tropical soda apple in Florida

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Tropical soda apple, Solanum viarum, is a small shrub native to tropical regions of Brazil, Paraguay, and Argentina. This weed was first found in Florida in 1988. In May 2003, a leaf feeding beetle, Gratiana boliviana, from South America was released in Florida as a biological control agent of tro...

  2. Sherlock Holmes and tropical medicine: a centennial appraisal.

    PubMed

    Sodeman, W A

    1994-01-01

    Sir Arthur Conan Doyle incorporated an unidentified tropical disease as a murder weapon in the Sherlock Holmes story, "The Dying Detective," written in 1913. Documentary and circumstantial evidence suggests that the disease mentioned was melioidosis. The description of the newly identified disease occurred shortly before Doyle's death. Doyle's other works at the time reflect a consistent interest in tropical disease.

  3. Biogas energy production from tropical biomass wastes by anaerobic digestion

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Anaerobic digestion (AD) is an attractive technology in tropical regions for converting locally abundant biomass wastes into biogas which can be used to produce heat, electricity, and transportation fuels. However, investigations on AD of tropical forestry wastes, such as albizia biomass, and food w...

  4. Global Warming Attenuates the Tropical Atlantic-Pacific Teleconnection

    PubMed Central

    Jia, Fan; Wu, Lixin; Gan, Bolan; Cai, Wenju

    2016-01-01

    Changes in global sea surface temperature (SST) since the end of last century display a pattern of widespread warming intercepted by cooling in the eastern equatorial Pacific and western coasts of the American continent. Studies have suggested that the cooling in the eastern equatorial Pacific may be partly induced by warming in the North Atlantic. However, it remains unknown how stable this inter-tropical teleconnection will be under global warming. Here we show that the inter-tropical teleconnection from the tropical Atlantic to Pacific weakens substantially as the CO2 concentration increases. This reduced impact is related to the El Niño-like warming of the tropical Pacific mean state, which leads to limited seasonal migration of the Pacific inter-tropical convergence zone (ITCZ) and weakened ocean heat transport. A fast decay of the tropical Atlantic SST anomalies in a warmer climate also contributes to the weakened teleconnection. Our study suggests that as greenhouse warming continues, the trend in the tropical Pacific as well as the development of ENSO will be less frequently interrupted by the Atlantic because of this attenuation. The weakened teleconnection is also supported by CMIP5 models, although only a few of these models can capture this inter-tropical teleconnection. PMID:26838053

  5. Tropics accelerate the evolution of hybrid male sterility in Drosophila.

    PubMed

    Yukilevich, Roman

    2013-06-01

    Understanding the evolutionary mechanisms that facilitate speciation and explain global patterns of species diversity has remained a challenge for decades. The most general pattern of species biodiversity is the latitudinal gradient, whereby species richness increases toward the tropics. Although such a global pattern probably has a multitude of causes, recent attention has focused on the hypothesis that speciation and the evolution of reproductive isolation occur faster in the tropics. Here, I tested this prediction using a dataset on premating and postzygotic isolation between recently diverged Drosophila species. Results showed that while the evolution of premating isolation was not greater between tropical Drosophila relative to nontropical species, postzygotic isolation evolved faster in the tropics. In particular, hybrid male sterility was much greater among tropical Drosophila compared to nontropical species pairs of similar genetic age. Several testable explanations for the novel pattern are discussed, including greater role for sterility-inducing bacterial endosymbionts in the tropics and more intense sperm-sperm competition or sperm-egg sexual conflict in the tropics. The results imply that processes of speciation in the tropics may evolve at different rates or may even be somewhat different from those at higher latitudes.

  6. Application of satellite data to tropic-subtropic moisture coupling

    NASA Technical Reports Server (NTRS)

    Thompson, Aylmer H.; Mcguirk, James P.

    1987-01-01

    Common tropical synoptic events, called moisture bursts, have been defined in terms of their appearance in infrared satellite imagery. Their synoptic and climatological behavior over the tropical North Pacific Ocean is described using data from four cool seasons, including the 1982 to 1983 El Nino winter and the January and May of 1979.

  7. Tropics, Income, and School Life Expectancy: An Intercountry Study.

    ERIC Educational Resources Information Center

    Ram, Rati

    1999-01-01

    Using UNESCO's recent data, explores effects of a country's income and "tropicality" on school life expectancy. Although income's effect is important, distance from the equator also matters. Effects of tropicality were larger in 1980 than in 1992. Implications are discussed. (13 references) (MLH)

  8. Global Warming Attenuates the Tropical Atlantic-Pacific Teleconnection.

    PubMed

    Jia, Fan; Wu, Lixin; Gan, Bolan; Cai, Wenju

    2016-02-03

    Changes in global sea surface temperature (SST) since the end of last century display a pattern of widespread warming intercepted by cooling in the eastern equatorial Pacific and western coasts of the American continent. Studies have suggested that the cooling in the eastern equatorial Pacific may be partly induced by warming in the North Atlantic. However, it remains unknown how stable this inter-tropical teleconnection will be under global warming. Here we show that the inter-tropical teleconnection from the tropical Atlantic to Pacific weakens substantially as the CO2 concentration increases. This reduced impact is related to the El Niño-like warming of the tropical Pacific mean state, which leads to limited seasonal migration of the Pacific inter-tropical convergence zone (ITCZ) and weakened ocean heat transport. A fast decay of the tropical Atlantic SST anomalies in a warmer climate also contributes to the weakened teleconnection. Our study suggests that as greenhouse warming continues, the trend in the tropical Pacific as well as the development of ENSO will be less frequently interrupted by the Atlantic because of this attenuation. The weakened teleconnection is also supported by CMIP5 models, although only a few of these models can capture this inter-tropical teleconnection.

  9. Fighting desires: Henry Miller's Queer Tropic.

    PubMed

    Hardin, Michael

    2002-01-01

    "Fighting Desires: Henry Miller's Queer Tropic" is an investigation of Tropic of Cancer that investigates the deeply repressed homoerotic desire that periodically surfaces. This reading is dependent upon an interpretation of Eve Sedgwick that proposes male sexuality as a continuum. By looking at the nature of the male-male relationships, as well as the lack of emotion and presence in the male-female relationships, I will show that the most intimate relationships are between men, and that these relationships are expressed through the telling of stories about (heterosexual) sex; this is the function of women within the novel: one has sex with a woman, not for the pleasure that the act brings, but for the pleasure that the recounting of the story to other men brings. Furthermore, I will look at Miller's use of puns within the novel and how they also contribute to a homoerotic reading. None of this is to argue that Miller was not homophobic and sexist--Miller very clearly was--the purpose of this essay is to show the complex nature of sexuality, even within a protagonist who asserts a very defined heterosexuality.

  10. Native carotenoids composition of some tropical fruits.

    PubMed

    Murillo, Enrique; Giuffrida, Daniele; Menchaca, Dania; Dugo, Paola; Torre, Germana; Meléndez-Martinez, Antonio J; Mondello, Luigi

    2013-10-15

    Many tropical fruits can be considered a reservoir of bioactive substances with a special interest due to their possible health-promoting properties. The interest in carotenoids from a nutritional standpoint has recently greatly increased, because of their important health benefits. Here we report the native carotenoids composition in six tropical fruits from Panama, which is considered a region of great biodiversity. The native carotenoid composition was directly investigated by an HPLC-DAD-APCI-MS methodology, for the first time. In Corozo 32 different carotenoids were detected, including a high content of β-carotene and lycopene. Sastra showed the highest content of zeaxanthin among the fruit investigated. In Sapote 22 different carotenoids were detected, including β-carotene and 10 different zeaxanthin-di-esters. Frutita showed a very high content of the apo-carotenoid β-citraurin, and of a number of its esters. In Maracuyà chino 14 carotenoids were detected, including a high amounts of mono-esterified lauric acid with β-cryptoxanthin and with cryptocapsin. Mamey rojo was characterised by ketocarotenoids with κ rings, both hydroxylated and not hydroxylated.

  11. Water surface locomotion in tropical canopy ants.

    PubMed

    Yanoviak, S P; Frederick, D N

    2014-06-15

    Upon falling onto the water surface, most terrestrial arthropods helplessly struggle and are quickly eaten by aquatic predators. Exceptions to this outcome mostly occur among riparian taxa that escape by walking or swimming at the water surface. Here we document sustained, directional, neustonic locomotion (i.e. surface swimming) in tropical arboreal ants. We dropped 35 species of ants into natural and artificial aquatic settings in Peru and Panama to assess their swimming ability. Ten species showed directed surface swimming at speeds >3 body lengths s(-1), with some swimming at absolute speeds >10 cm s(-1). Ten other species exhibited partial swimming ability characterized by relatively slow but directed movement. The remaining species showed no locomotory control at the surface. The phylogenetic distribution of swimming among ant genera indicates parallel evolution and a trend toward negative association with directed aerial descent behavior. Experiments with workers of Odontomachus bauri showed that they escape from the water by directing their swimming toward dark emergent objects (i.e. skototaxis). Analyses of high-speed video images indicate that Pachycondyla spp. and O. bauri use a modified alternating tripod gait when swimming; they generate thrust at the water surface via synchronized treading and rowing motions of the contralateral fore and mid legs, respectively, while the hind legs provide roll stability. These results expand the list of facultatively neustonic terrestrial taxa to include various species of tropical arboreal ants.

  12. Abrupt tropical climate change: past and present.

    PubMed

    Thompson, Lonnie G; Mosley-Thompson, Ellen; Brecher, Henry; Davis, Mary; León, Blanca; Les, Don; Lin, Ping-Nan; Mashiotta, Tracy; Mountain, Keith

    2006-07-11

    Three lines of evidence for abrupt tropical climate change, both past and present, are presented. First, annually and decadally averaged delta(18)O and net mass-balance histories for the last 400 and 2,000 yr, respectively, demonstrate that the current warming at high elevations in the mid- to low latitudes is unprecedented for at least the last 2 millennia. Second, the continuing retreat of most mid- to low-latitude glaciers, many having persisted for thousands of years, signals a recent and abrupt change in the Earth's climate system. Finally, rooted, soft-bodied wetland plants, now exposed along the margins as the Quelccaya ice cap (Peru) retreats, have been radiocarbon dated and, when coupled with other widespread proxy evidence, provide strong evidence for an abrupt mid-Holocene climate event that marked the transition from early Holocene (pre-5,000-yr-B.P.) conditions to cooler, late Holocene (post-5,000-yr-B.P.) conditions. This abrupt event, approximately 5,200 yr ago, was widespread and spatially coherent through much of the tropics and was coincident with structural changes in several civilizations. These three lines of evidence argue that the present warming and associated glacier retreat are unprecedented in some areas for at least 5,200 yr. The ongoing global-scale, rapid retreat of mountain glaciers is not only contributing to global sea-level rise but also threatening freshwater supplies in many of the world's most populous regions.

  13. Stratified coastal ocean interactions with tropical cyclones

    PubMed Central

    Glenn, S. M.; Miles, T. N.; Seroka, G. N.; Xu, Y.; Forney, R. K.; Yu, F.; Roarty, H.; Schofield, O.; Kohut, J.

    2016-01-01

    Hurricane-intensity forecast improvements currently lag the progress achieved for hurricane tracks. Integrated ocean observations and simulations during hurricane Irene (2011) reveal that the wind-forced two-layer circulation of the stratified coastal ocean, and resultant shear-induced mixing, led to significant and rapid ahead-of-eye-centre cooling (at least 6 °C and up to 11 °C) over a wide swath of the continental shelf. Atmospheric simulations establish this cooling as the missing contribution required to reproduce Irene's accelerated intensity reduction. Historical buoys from 1985 to 2015 show that ahead-of-eye-centre cooling occurred beneath all 11 tropical cyclones that traversed the Mid-Atlantic Bight continental shelf during stratified summer conditions. A Yellow Sea buoy similarly revealed significant and rapid ahead-of-eye-centre cooling during Typhoon Muifa (2011). These findings establish that including realistic coastal baroclinic processes in forecasts of storm intensity and impacts will be increasingly critical to mid-latitude population centres as sea levels rise and tropical cyclone maximum intensities migrate poleward. PMID:26953963

  14. Training and Operations Integrated Calendar Scheduler - TROPICS

    SciTech Connect

    J.E. Oppenlander; A.J. Levy; V.A. Arbige; A.H. Shoop

    2003-01-27

    TROPICS is a rule-based scheduling system that optimizes the training experience for students in a power (note this change should be everywhere, i.e. Not reactor) plant environment. The problem is complicated by the condition that plant resources and users' time must be simultaneously scheduled to make best use of both. The training facility is highly constrained in how it is used, and, as in many similar environments, subject to dynamic change with little or no advance notice. The flexibility required extends to changes resulting from students' actions such as absences. Even though the problem is highly constrained by plant usage and student objectives, the large number of possible schedules is a concern. TROPICS employs a control strategy for rule firing to prune the possibility tree and avoid combinatorial explosion. The application has been in use since 1996, first as a prototype for testing and then in production. Training Coordinators have a philosophical aspect to teaching students that has made the rule-based approach much more verifiable and satisfying to the domain experts than other forms of capturing expertise.

  15. Tropical forests and the changing earth system

    PubMed Central

    Lewis, Simon L

    2005-01-01

    Tropical forests are global epicentres of biodiversity and important modulators of the rate of climate change. Recent research on deforestation rates and ecological changes within intact forests, both areas of recent research and debate, are reviewed, and the implications for biodiversity (species loss) and climate change (via the global carbon cycle) addressed. Recent impacts have most likely been: (i) a large source of carbon to the atmosphere, and major loss of species, from deforestation and (ii) a large carbon sink within remaining intact forest, accompanied by accelerating forest dynamism and widespread biodiversity changes. Finally, I look to the future, suggesting that the current carbon sink in intact forests is unlikely to continue, and that the tropical forest biome may even become a large net source of carbon, via one or more of four plausible routes: changing photosynthesis and respiration rates, biodiversity changes in intact forest, widespread forest collapse via drought, and widespread forest collapse via fire. Each of these scenarios risks potentially dangerous positive feedbacks with the climate system that could dramatically accelerate and intensify climate change. Given that continued land-use change alone is already thought to be causing the sixth mass extinction event in Earth's history, should such feedbacks occur, the resulting biodiversity and societal consequences would be even more severe. PMID:16553317

  16. Multiyear predictability of tropical marine productivity

    PubMed Central

    Séférian, Roland; Bopp, Laurent; Gehlen, Marion; Swingedouw, Didier; Mignot, Juliette; Guilyardi, Eric; Servonnat, Jérôme

    2014-01-01

    With the emergence of decadal predictability simulations, research toward forecasting variations of the climate system now covers a large range of timescales. However, assessment of the capacity to predict natural variations of relevant biogeochemical variables like carbon fluxes, pH, or marine primary productivity remains unexplored. Among these, the net primary productivity (NPP) is of particular relevance in a forecasting perspective. Indeed, in regions like the tropical Pacific (30°N–30°S), NPP exhibits natural fluctuations at interannual to decadal timescales that have large impacts on marine ecosystems and fisheries. Here, we investigate predictions of NPP variations over the last decades (i.e., from 1997 to 2011) with an Earth system model within the tropical Pacific. Results suggest a predictive skill for NPP of 3 y, which is higher than that of sea surface temperature (1 y). We attribute the higher predictability of NPP to the poleward advection of nutrient anomalies (nitrate and iron), which sustain fluctuations in phytoplankton productivity over several years. These results open previously unidentified perspectives to the development of science-based management approaches to marine resources relying on integrated physical-biogeochemical forecasting systems. PMID:25071174

  17. Remotely sensed resilience of tropical forests

    NASA Astrophysics Data System (ADS)

    Verbesselt, Jan; Umlauf, Nikolaus; Hirota, Marina; Holmgren, Milena; van Nes, Egbert H.; Herold, Martin; Zeileis, Achim; Scheffer, Marten

    2016-11-01

    Recent work suggests that episodes of drought and heat can bring forests across climate zones to a threshold for massive tree mortality. As complex systems approach a threshold for collapse they tend to exhibit a loss of resilience, as reflected in declining recovery rates from perturbations. Trees may be no exception, as at the verge of drought-induced death, trees are found to be weakened in multiple ways, affecting their ability to recover from stress. Here we use worldwide time series of satellite images to show that temporal autocorrelation, an indicator of slow recovery rates, rises steeply as mean annual precipitation declines to levels known to be critical for tropical forests. This implies independent support for the idea that such forests may have a tipping point for collapse at drying conditions. Moreover, the demonstration that reduced rates of recovery (slowing down) may be detected from satellite data suggests a novel way to monitor resilience of tropical forests, as well as other ecosystems known to be vulnerable to collapse.

  18. A Simplified Model of Tropical Cyclone Intensification

    NASA Astrophysics Data System (ADS)

    Schubert, W. H.

    2015-12-01

    An axisymmetric model of tropical cyclone intensification is presented. The model is based on Salmon's wave-vortex approximation, which can describe flows with high Rossby number and low Froude number. After introducing an additional approximation designed to filter propagating inertia-gravity waves, the problem is reduced to the prediction of potential vorticity (PV) and the inversion of this PV to obtain the balanced wind and mass fields. This PV prediction/inversion problem is solved analytically for two types of forcing: a two-region model in which there is nonzero forcing in the cyclone core and zero forcing in the far-field; a three-region model in which there is non-zero forcing in both the cyclone core and the eyewall, with zero forcing in the far-field. The solutions of the two-region model provide insight into why tropical cyclones can have long incubation times before rapid intensification and how the size of the mature vortex can be influenced by the size of the initial vortex. The solutions of the three-region model provide insight into the formation of hollow PV structures and the inward movement of angular momentum surfaces across the radius of maximum wind.

  19. Climate Change and Tropical Total Lightning

    NASA Technical Reports Server (NTRS)

    Albrecht, R.; Petersen, W.; Buechler, D.; Goodman, S.; Blakeslee, R.; Christian, H.

    2009-01-01

    While global warming is regarded as a fact by many in the scientific community, its future impact remains a challenge to be determined and measured. The International Panel on Climate Change (IPCC) assessment report (IPCC, 2007) shows inconclusive answers on global rainfall trends and general agreement on a future drier climate with increased global warming. The relationship between temperature, humidity and convection is not linear and is strongly dependent on regional scale features, such as topography and land cover. Furthermore, the relationship between convective lightning production (thunderstorms) and temperature is even more complicated, being subjected to the cloud dynamics and microphysics. Total lightning (intracloud and cloud-to-ground) monitoring is a relatively new field of observation. Global and tropical total lightning began to be more extensively measured by satellites in the mid 90s. In this scope, the Lightning Imaging Sensor (LIS) onboard of the Tropical Rainfall Measurement Mission (TRMM) has been operational for over 11 years. Here we address total lightning trends observed by LIS from 1998 to 2008 in different temporal (annual and seasonal) and spatial (large and regional) scales. The observed 11-year trends are then associate to different predicted/hypothesized climate change scenarios.

  20. Tropical forests and the changing earth system.

    PubMed

    Lewis, Simon L

    2006-01-29

    Tropical forests are global epicentres of biodiversity and important modulators of the rate of climate change. Recent research on deforestation rates and ecological changes within intact forests, both areas of recent research and debate, are reviewed, and the implications for biodiversity (species loss) and climate change (via the global carbon cycle) addressed. Recent impacts have most likely been: (i) a large source of carbon to the atmosphere, and major loss of species, from deforestation and (ii) a large carbon sink within remaining intact forest, accompanied by accelerating forest dynamism and widespread biodiversity changes. Finally, I look to the future, suggesting that the current carbon sink in intact forests is unlikely to continue, and that the tropical forest biome may even become a large net source of carbon, via one or more of four plausible routes: changing photosynthesis and respiration rates, biodiversity changes in intact forest, widespread forest collapse via drought, and widespread forest collapse via fire. Each of these scenarios risks potentially dangerous positive feedbacks with the climate system that could dramatically accelerate and intensify climate change. Given that continued land-use change alone is already thought to be causing the sixth mass extinction event in Earth's history, should such feedbacks occur, the resulting biodiversity and societal consequences would be even more severe.

  1. Bioquality Hotspots in the Tropical African Flora.

    PubMed

    Marshall, Cicely A M; Wieringa, Jan J; Hawthorne, William D

    2016-12-05

    Identifying areas of high biodiversity is an established way to prioritize areas for conservation [1-3], but global approaches have been criticized for failing to render global biodiversity value at a scale suitable for local management [4-6]. We assembled 3.1 million species distribution records for 40,401 vascular plant species of tropical Africa from sources including plot data, herbarium databases, checklists, and the Global Biodiversity Information Facility (GBIF) and cleaned the records for geographic accuracy and taxonomic consistency. We summarized the global ranges of tropical African plant species into four weighted categories of global rarity called Stars. We applied the Star weights to summaries of species distribution data at fine resolutions to map the bioquality (range-restricted global endemism) of areas [7]. We generated confidence intervals around bioquality scores to account for the remaining uncertainty in the species inventory. We confirm the broad significance of the Horn of Africa, Guinean forests, coastal forests of East Africa, and Afromontane regions for plant biodiversity but also reveal the variation in bioquality within these broad regions and others, particularly at local scales. Our framework offers practitioners a quantitative, scalable, and replicable approach for measuring the irreplaceability of particular local areas for global biodiversity conservation and comparing those areas within their global and regional context.

  2. Abrupt tropical climate change: Past and present

    PubMed Central

    Thompson, Lonnie G.; Mosley-Thompson, Ellen; Brecher, Henry; Davis, Mary; León, Blanca; Les, Don; Lin, Ping-Nan; Mashiotta, Tracy; Mountain, Keith

    2006-01-01

    Three lines of evidence for abrupt tropical climate change, both past and present, are presented. First, annually and decadally averaged δ18O and net mass-balance histories for the last 400 and 2,000 yr, respectively, demonstrate that the current warming at high elevations in the mid- to low latitudes is unprecedented for at least the last 2 millennia. Second, the continuing retreat of most mid- to low-latitude glaciers, many having persisted for thousands of years, signals a recent and abrupt change in the Earth’s climate system. Finally, rooted, soft-bodied wetland plants, now exposed along the margins as the Quelccaya ice cap (Peru) retreats, have been radiocarbon dated and, when coupled with other widespread proxy evidence, provide strong evidence for an abrupt mid-Holocene climate event that marked the transition from early Holocene (pre-5,000-yr-B.P.) conditions to cooler, late Holocene (post-5,000-yr-B.P.) conditions. This abrupt event, ≈5,200 yr ago, was widespread and spatially coherent through much of the tropics and was coincident with structural changes in several civilizations. These three lines of evidence argue that the present warming and associated glacier retreat are unprecedented in some areas for at least 5,200 yr. The ongoing global-scale, rapid retreat of mountain glaciers is not only contributing to global sea-level rise but also threatening freshwater supplies in many of the world’s most populous regions. PMID:16815970

  3. Who Neglects Neglected Tropical Diseases? - Korean Perspective.

    PubMed

    Choi, Min-Ho; Yu, Jae-Ran; Hong, Sung-Tae

    2015-11-01

    Neglected tropical diseases (NTDs) are a group of tropical infectious diseases of poorest people. Of 17 NTDs managed by WHO, two, guinea worm disease (by 2015) and yaws (by 2020) are targeted for eradication, and four (blinding trachoma, human African trypanosomiasis, leprosy, and lymphatic filariasis) for elimination by 2020. The goals look promising but 11 others are still highly prevalent. Soil-transmitted helminths (STHs) are one NTD which prevail over the world including temperate zones. They had been highly prevalent in Korea but are mostly disappearing at present through systematic and sustainable control activity. The successful experience of STH control enables Korean experts to develop many programs of NTD control in developing countries. Several programs of both official development aid and non-governmental organizations are now targeting NTDs. Most NTDs are low in health priority compared to their health threats because they are chronic, insidious, and of low mortality. No one, including the victims, raised priority of NTD control with a loud voice in the endemic field of the diseases. After the millennium development goals declared disease control over the world, NTDs are becoming less neglected globally. Even with limited resources, beginning a sustainable national program is the key for the control and elimination of NTDs. No more neglect, especially no more self-neglect, can eliminate diseases and upgrade quality of life of the neglected people.

  4. Storms in the tropics of Titan.

    PubMed

    Schaller, E L; Roe, H G; Schneider, T; Brown, M E

    2009-08-13

    Methane clouds, lakes and most fluvial features on Saturn's moon Titan have been observed in the moist high latitudes, while the tropics have been nearly devoid of convective clouds and have shown an abundance of wind-carved surface features like dunes. The presence of small-scale channels and dry riverbeds near the equator observed by the Huygens probe at latitudes thought incapable of supporting convection (and thus strong rain) has been suggested to be due to geological seepage or other mechanisms not related to precipitation. Here we report the presence of bright, transient, tropospheric clouds in tropical latitudes. We find that the initial pulse of cloud activity generated planetary waves that instigated cloud activity at other latitudes across Titan that had been cloud-free for at least several years. These observations show that convective pulses at one latitude can trigger short-term convection at other latitudes, even those not generally considered capable of supporting convection, and may also explain the presence of methane-carved rivers and channels near the Huygens landing site.

  5. Introducing tropical lianas in a vegetation model

    NASA Astrophysics Data System (ADS)

    Verbeeck, Hans; De Deurwaerder, Hannes; Brugnera, Manfredo di Procia e.; Krshna Moorthy Paravathi, Sruthi; Pausenberger, Nancy; Roels, Jana; kearsley, elizabeth

    2016-04-01

    Tropical forests are essential components of the earth system and play a critical role for land surface feedbacks to climate change. These forests are currently experiencing large-scale structural changes, including the increase of liana abundance and biomass. This liana proliferation might have large impacts on the carbon cycle of tropical forests. However no single global vegetation model currently accounts for lianas. The TREECLIMBERS project (ERC starting grant) aims to introduce for the first time lianas into a vegetation model. The project attempts to reach this challenging goal by performing a global meta-analysis on liana data and by collecting new data in South American forests. Those new and existing datasets form the basis of a new liana plant functional type (PFT) that will be included in the Ecosystem Demography model (ED2). This presentation will show an overview of the current progress of the TREECLIMBERS project. Liana inventory data collected in French Guiana along a forest disturbance gradient show the relation between liana abundance and disturbance. Xylem water isotope analysis indicates that trees and lianas can rely on different soil water resources. New modelling concepts for liana PFTs will be presented and in-situ leaf gas exchange and sap flow data are used to parameterize water and carbon fluxes for this new PFT. Finally ongoing terrestrial LiDAR observations of liana infested forest will be highlighted.

  6. The Tropical Warm Pool International Cloud Experiment

    SciTech Connect

    May, Peter T.; Mather, James H.; Vaughan, Geraint; Jakob, Christian; McFarquhar, Greg; Bower, Keith; Mace, Gerald G.

    2008-05-01

    One of the most complete data sets describing tropical convection ever collected will result from the upcoming Tropical Warm Pool International Cloud Experiment (TWP-ICE) in the area around Darwin, Northern Australia in January and February 2006. The aims of the experiment, which will be operated in conjunction with the DOE Atmospheric Radiation Measurement (ARM) site in Darwin, will be to examine convective cloud systems from their initial stages through to the decay of the cirrus generated and to measure their impact on the environment. The experiment will include an unprecedented network of ground-based observations (soundings, active and passive remote sensors) combined with low, mid and high altitude aircraft for in-situ and remote sensing measurements. A crucial outcome of the experiment will be a data set suitable to provide the forcing and evaluation data required by cloud resolving and single column models as well as global climate models (GCMs) with the aim to contribute to parameterization development. This data set will provide the necessary link between the observed cloud properties and the models that are attempting to simulate them. The experiment is a large multi-agency experiment including substantial contributions from the United States DOE ARM program, ARM-UAV program, NASA, the Australian Bureau of Meteorology, CSIRO, EU programs and many universities.

  7. Effects of volcanism on tropical variability

    NASA Astrophysics Data System (ADS)

    Maher, Nicola; McGregor, Shayne; England, Matthew H.; Gupta, Alexander Sen

    2015-07-01

    The effects of large tropical volcanic eruptions on Indo-Pacific tropical variability are investigated using 122 historical ensemble members from the Coupled Model Intercomparison Project 5. Radiative forcing due to volcanic aerosols in the stratosphere is found to increase the likelihood of a model climatic response that projects onto both the El Niño-Southern Oscillation and the Indian Ocean Dipole (IOD). Large eruptions are associated with co-occurring El Niño and positive IOD events in the ensemble means that peak 6-12 months after the volcanic forcing peaks, marking a significant increase in the likelihood of each event occurring in the Southern Hemisphere (SH) spring/summer posteruption. There is also an ensemble mean La Niña-like response in the third SH summer posteruption, which coincides with a significant increase in the likelihood of a La Niña occurring. Taken together with the initial cooling, this La Niña-like response may increase the persistence of the cool global average surface temperature anomaly after an eruption.

  8. Deforestation homogenizes tropical parasitoid-host networks.

    PubMed

    Laliberté, Etienne; Tylianakis, Jason M

    2010-06-01

    Human activities drive biotic homogenization (loss of regional diversity) of many taxa. However, whether species interaction networks (e.g., food webs) can also become homogenized remains largely unexplored. Using 48 quantitative parasitoid-host networks replicated through space and time across five tropical habitats, we show that deforestation greatly homogenized network structure at a regional level, such that interaction composition became more similar across rice and pasture sites compared with forested habitats. This was not simply caused by altered consumer and resource community composition, but was associated with altered consumer foraging success, such that parasitoids were more likely to locate their hosts in deforested habitats. Furthermore, deforestation indirectly homogenized networks in time through altered mean consumer and prey body size, which decreased in deforested habitats. Similar patterns were obtained with binary networks, suggesting that interaction (link) presence-absence data may be sufficient to detect network homogenization effects. Our results show that tropical agroforestry systems can support regionally diverse parasitoid-host networks, but that removal of canopy cover greatly homogenizes the structure of these networks in space, and to a lesser degree in time. Spatiotemporal homogenization of interaction networks may alter coevolutionary outcomes and reduce ecological resilience at regional scales, but may not necessarily be predictable from community changes observed within individual trophic levels.

  9. Who Neglects Neglected Tropical Diseases? - Korean Perspective

    PubMed Central

    Choi, Min-Ho; Yu, Jae-Ran

    2015-01-01

    Neglected tropical diseases (NTDs) are a group of tropical infectious diseases of poorest people. Of 17 NTDs managed by WHO, two, guinea worm disease (by 2015) and yaws (by 2020) are targeted for eradication, and four (blinding trachoma, human African trypanosomiasis, leprosy, and lymphatic filariasis) for elimination by 2020. The goals look promising but 11 others are still highly prevalent. Soil-transmitted helminths (STHs) are one NTD which prevail over the world including temperate zones. They had been highly prevalent in Korea but are mostly disappearing at present through systematic and sustainable control activity. The successful experience of STH control enables Korean experts to develop many programs of NTD control in developing countries. Several programs of both official development aid and non-governmental organizations are now targeting NTDs. Most NTDs are low in health priority compared to their health threats because they are chronic, insidious, and of low mortality. No one, including the victims, raised priority of NTD control with a loud voice in the endemic field of the diseases. After the millennium development goals declared disease control over the world, NTDs are becoming less neglected globally. Even with limited resources, beginning a sustainable national program is the key for the control and elimination of NTDs. No more neglect, especially no more self-neglect, can eliminate diseases and upgrade quality of life of the neglected people. PMID:26617444

  10. Topographic Rossby Waves Generated by Tropical Cyclones

    NASA Astrophysics Data System (ADS)

    Dukhovskoy, D. S.; Morey, S. L.

    2013-05-01

    Analytical and numerical studies suggest that given appropriate slope, the ocean responds to a tropical storm with low-frequency motions trapped over a continental slope, the Coastal Trapped Waves. The presented study is focused on Topographic Rossby Waves (TRW), sub-inertial oscillations propagating over a sloping bottom. Generation and propagation of TRW under barotropic (Continental Shelf Waves or Shelf Waves) and baroclinic (Bottom Trapped Waves) approximations are discussed. A real-case model study of a storm surge in Apalachee Bay, northeastern Gulf of Mexico during Hurricane Dennis (July, 2005) is presented to demonstrate the role of the shelf waves in coastal inundation. The presentation also discusses excitation of baroclinic bottom-intensified wave motions on the continental slope by a tropical cyclone. An idealized model experiment demonstrates that a continental shelf that (1) responds to a storm as a baroclinic ocean and (2) has a slope steep enough to dominate the planetary β-effect (but small enough to prevent internal Kelvin-type modes) can support baroclinic topographic waves.

  11. Stratified coastal ocean interactions with tropical cyclones

    NASA Astrophysics Data System (ADS)

    Glenn, S. M.; Miles, T. N.; Seroka, G. N.; Xu, Y.; Forney, R. K.; Yu, F.; Roarty, H.; Schofield, O.; Kohut, J.

    2016-03-01

    Hurricane-intensity forecast improvements currently lag the progress achieved for hurricane tracks. Integrated ocean observations and simulations during hurricane Irene (2011) reveal that the wind-forced two-layer circulation of the stratified coastal ocean, and resultant shear-induced mixing, led to significant and rapid ahead-of-eye-centre cooling (at least 6 °C and up to 11 °C) over a wide swath of the continental shelf. Atmospheric simulations establish this cooling as the missing contribution required to reproduce Irene's accelerated intensity reduction. Historical buoys from 1985 to 2015 show that ahead-of-eye-centre cooling occurred beneath all 11 tropical cyclones that traversed the Mid-Atlantic Bight continental shelf during stratified summer conditions. A Yellow Sea buoy similarly revealed significant and rapid ahead-of-eye-centre cooling during Typhoon Muifa (2011). These findings establish that including realistic coastal baroclinic processes in forecasts of storm intensity and impacts will be increasingly critical to mid-latitude population centres as sea levels rise and tropical cyclone maximum intensities migrate poleward.

  12. Tropical easterly jet located using TOMS data

    NASA Technical Reports Server (NTRS)

    Bolhofer, William C.

    1987-01-01

    The formative stages of the onset of the 1979 southwest monsoon was marked by a WNW-ESE oriented band of marine convection over the South Arabian Sea. This convection was first observed on June 10, 1979 using satellite cloud imagery. The marine convection appeared during a major acceleration of the upper troposphere easterly wind field. A composite vertical meridional cross-section of upper level winds for June 11, revealed the core of the Tropical Easterly Jet (TEJ) at 115 mb, 9.5 deg N. Time analysis of the upper level wind field over the Tropical Wind Observing Ship (TWOS) polygon show a lowering of both the pressure level of maximum wind and tropopause level with acceleration of the upper level easterlies. The tropopause was as much as 20 mb lower on the equatorial side of the TEJ. Streamline analysis of the maximum observed easterly winds over India did not reveal the horizontal position of the TEJ. Careful analysis of Total Ozone Mapping Spectrometer (TOMS) data for June 11, 1979 showed relatively high values of ozone south of India. It was observed that the latitudinal position of the TEJ on June 11, at approximately 70 deg E coincided with the northern edge of relatively high ozone values. Using this as a reference, the TEJ core was identified as far as NE Bay of Bengal (the limits of the available TOMS data).

  13. Tropical rat mites (Ornithonyssus bacoti) - serious ectoparasites.

    PubMed

    Beck, Wieland; Fölster-Holst, Regina

    2009-08-01

    In Germany there is limited information available about the distribution of the tropical rat mite (Ornithonyssus bacoti) in rodents. A few case reports show that this hematophagous mite species may also cause dermatitis in man. Having close body contact to small rodents is an important question for patients with pruritic dermatoses. The definitive diagnosis of this ectoparasitosis requires the detection of the parasite, which is more likely to be found in the environment of its host (in the cages, in the litter or in corners or cracks of the living area) than on the hosts' skin itself. A case of infestation with tropical rat mites in a family is reported here. Three mice that had been removed from the home two months before were the reservoir. The mites were detected in a room where the cage with the mice had been placed months ago. Treatment requires the eradication of the parasites on its hosts (by a veterinarian) and in the environment (by an exterminator) with adequate acaricides such as permethrin.

  14. Tropical forests: present status and future outlook.

    PubMed

    Myers, N

    1991-09-01

    Tropical forests still cover almost 8 million km squared of the humid tropics but they are being destroyed at ever-more rapid rates. In 1989, the area deforested amounted to 142,200 km squared, or nearly 90% more than in 1979. Thus, whereas the 1989 amounted total to 1.8% of the remaining biome, the proportion could well continue to rise for the foreseeable future, until there is little forest in just a few decades. Deforestati on patterns are far from even throughout the biome. In much of the Southeast and Southern Asia, East and West Africa, and Central America, there is likely to be little forest left by the year 2000 or shortly thereafter. But in the Zaire basin, western Brazilian Amazonia, and the Guyana highlands, sizeable expanses of forest could persist a good while longer. The main agent of deforestation in the 'shifted cultivator' or displaced peasant, who, responding to land hunger and general lack of rural development in traditional farming areas of countries concerned, feels there is no alternative but to adopt a slash-and-burn lifestyle in forestlands. This person is now accounting for at least 60% of deforestation, a rapidly expanding proportion. However, he receives far less policy attention than the commercial logger, the cattle rancher, and other agents of deforestation.

  15. Climate change and tropical marine agriculture.

    PubMed

    Crabbe, M James C

    2009-01-01

    The coral reef ecosystem forms part of a 'seascape' that includes land-based ecosystems such as mangroves and forests, and ideally should form a complete system for conservation and management. Aquaculture, including artisanal fishing for fish and invertebrates, shrimp farming, and seaweed farming, is a major part of the farming and gleaning practices of many tropical communities, particularly on small islands, and depends upon the integrity of the reefs. Climate change is making major impacts on these communities, not least through global warming and high CO(2) concentrations. Corals grow within very narrow limits of temperature, provide livelihoods for millions of people in tropical areas, and are under serious threat from a variety of environmental and climate extremes. Corals survive and grow through a symbiotic relationship with photosynthetic algae: zooxanthellae. Such systems apply highly co-operative regulation to minimize the fluctuation of metabolite concentration profiles in the face of transient perturbations. This review will discuss research on how climate influences reef ecosystems, and how science can lead to conservation actions, with benefits for the human populations reliant on the reefs for their survival.

  16. Investigation of Tropical Transport with UARS Data

    NASA Technical Reports Server (NTRS)

    Dunkerton, Timothy J.

    1999-01-01

    Measurements of trace constituents obtained by instruments aboard the Upper Atmosphere Research Satellite (UARS) have been used to study transport processes associated with the quasi-biennial oscillation, laterally propagating Rossby waves, and upward propagating Kelvin waves in the tropical and subtropical upper troposphere and stratosphere. Mean vertical motions, vertical diffusivities and in-mixing rates were inferred from observations of the 'tape recorder' signal in near-equatorial stratospheric water vapor. The effect of the quasi-biennial oscillation (QBO) on tracer distributions in the upper half of the stratosphere was seen in a spectacular 'staircase' pattern, predominantly in the winter hemisphere, revealing the latitudinally asymmetric nature of QBO transport due to induced mean meridional circulations and modulation of lateral mixing associated with planetary Rossby waves. The propagation of Rossby waves across the equator in the westerly phase of the QBO was seen in tracer fields and corroborating United Kingdom Meteorological Office (UKMO) analyses; a modeling study of the effect of these waves on typical QBO wind profiles was performed. Water vapor in the upper troposphere and lower stratosphere was found to exhibit signatures of the tropical intraseasonal oscillation (TIO) and faster Kelvin waves in the two regions, respectively.

  17. Climatic regimes of tropical convection and rainfall

    SciTech Connect

    Wang, Bin )

    1994-07-01

    Annual distribution and phase propagation of tropical convection are delineated using harmonic and amplitude-phase characteristics analysis of climatological pentad mean outgoing longwave radiation and monthly frequencies of highly reflective cloud. An annual eastward propagation of peak rainy season along the equator from the central Indian Ocean (60[degrees]E) to Arafura Sea (130[degrees]E) is revealed. This indicates a transition from the withdrawal of the Indian summer monsoon to the onset of the Australian summer monsoon. Significant bimodal variations are found around major summer monsoon regions. These variations originate from the interference of two adjacent regimes. The convergence zones over the eastern North Pacific, the South Pacific, and the southwest Indian Ocean are identified as a marine monsoon regime that is characterized by a unimodal variation with a concentrated summer rainfall associated with the development of surface westerlies equatorward of a monsoon trough. Conversely, the central North Pacific and North Atlantic convergence zones between persistent northeast and southeast trades are classified as trade-wind convergence zones; which differ from the marine monsoon regime by their persistent rainy season and characteristic bimodal variation with peak rainy seasons occurring in late spring and fall. The roles of the annual march of sea surface temperature in the phase propagation and formation of various climatic regimes of tropical convection are also discussed. 34 refs., 8 figs., 1 tab.

  18. Tropical Skin Diseases in Children: A Review- Part I.

    PubMed

    García-Romero, Maria Teresa; Lara-Corrales, Irene; Kovarik, Carrie L; Pope, Elena; Arenas, Roberto

    2016-05-01

    Because of travel and migration patterns, tropical skin diseases are now seen all around the world, not just in tropical or developing countries. Nutrition, housing, and environmental factors play an important role in these infectious diseases, so when they appear out of their normal environments, their classic presentation may vary. Tropical diseases can also present differently in childhood, making their recognition, diagnosis, and management a clinical challenge. Health care providers in developed countries need to be familiar with tropical skin diseases and be able to diagnose them in returning travelers or immigrants in order to optimize care. This article aims to review the epidemiologic, clinical, diagnostic, and therapeutic aspects of some of the most common tropical dermatologic conditions in children.

  19. Dynamics and species richness of tropical rain forests.

    PubMed Central

    Phillips, O L; Hall, P; Gentry, A H; Sawyer, S A; Vásquez, R

    1994-01-01

    We present a worldwide analysis of humid tropical forest dynamics and tree species richness. New tree mortality, recruitment, and species richness data include the most dynamic and diverse mature tropical forests known. Twenty-five sites show a strong tendency for the most species-rich forests to be dynamic and aseasonal. Mean annual tree mortality and recruitment-turnover-is the most predictive factor of species richness, implying that small-scale disturbance helps regulate tropical forest diversity. Turnover rates are also closely related to the amount of basal area turnover in mature tropical forests. Therefore the contribution of small-scale disturbance to maintaining tropical forest diversity may ultimately be driven by ecosystem productivity. PMID:11607468

  20. Technologies to sustain tropical forest resources, OTA-F-214

    SciTech Connect

    Not Available

    1984-01-01

    The destruction of tropical forests represents one of those subtle depletions of the earth's resources that humankind usually tends to recognize and bewail only after it is too late. Each year, 11.3 million hectares of tropical forests (an area roughly the size of Pennsylvania) are cleared and converted to other land uses or to unproductive land. Once farmed and then abandoned, the land has lost much of its inherent productivity. This report examines what technologies could be developed or adapted in order to reduce the need to waste tropical land and yet respond to the growing demand for forest products and services within the tropical nations. Changing technologies alone, however, the report points out, will not be enough to sustain the tropical forests because the underlying causes of the deforestation are institutional, social, and economic.

  1. Modellig the Foliage Seasonal Carbon Cycle in Tropical Forests

    NASA Astrophysics Data System (ADS)

    De Weirdt, M.; Verbeeck, H.; Maignan, F.; Peylin, P.; Ciais, P.; Moreau, I.; Hanert, E.; Defourny, P.; Steppe, K.

    2011-01-01

    Phenological modeling for tropical forests remains poorly developed and many global ecosystem models, like ORCHIDEE, assume that canopy dynamics of evergreen tropical forests show no seasonality. The current ORCHIDEE scheme fails to adequately model the seasonal variability of carbon fluxes observed in tropical evergreen forests. A better description of the underlying mechanisms that drive tropical forest canopy seasonal photosynthesis dynamics and phenology could possibly overcome this problem. To address this issue, seasonal variations in leaf phenology and photosynthesis dynamics for evergreen tropical forests were introduced and validated against in-situ carbon flux measurements. Both a seasonal photosynthetic capacity and a litterfall seasonality were introduced in ORCHIDEE and the resulting increased dry season photosynthesis and changed seasonal Net Ecosystem Exchange (NEE) patterns for flux tower sites in the Amazon were evaluated.

  2. How important and different are tropical rivers? - An overview

    NASA Astrophysics Data System (ADS)

    Syvitski, James P. M.; Cohen, Sagy; Kettner, Albert J.; Brakenridge, G. Robert

    2014-12-01

    Tropical river systems, wherein much of the drainage basin experiences tropical climate are strongly influenced by the annual and inter-annual variations of the Inter-tropical Convergence Zone (ITCZ) and its derivative monsoonal winds. Rivers draining rainforests and those subjected to tropical monsoons typically demonstrate high runoff, but with notable exceptions. High rainfall intensities from burst weather events are common in the tropics. The release of rain-forming aerosols also appears to uniquely increase regional rainfall, but its geomorphic manifestation is hard to detect. Compared to other more temperate river systems, climate-driven tropical rivers do not appear to transport a disproportionate amount of particulate load to the world's oceans, and their warmer, less viscous waters are less competent. Tropical biogeochemical environments do appear to influence the sedimentary environment. Multiple-year hydrographs reveal that seasonality is a dominant feature of most tropical rivers, but the rivers of Papua New Guinea are somewhat unique being less seasonally modulated. Modeled riverine suspended sediment flux through global catchments is used in conjunction with observational data for 35 tropical basins to highlight key basin scaling relationships. A 50 year, daily model simulation illuminates how precipitation, relief, lithology and drainage basin area affect sediment load, yield and concentration. Local sediment yield within the Amazon is highest near the Andes, but decreases towards the ocean as the river's discharge is diluted by water influxes from sediment-deprived rainforest tributaries. Bedload is strongly affected by the hydraulic gradient and discharge, and the interplay of these two parameters predicts foci of net bedload deposition or erosion. Rivers of the tropics have comparatively low inter-annual variation in sediment yield.

  3. Tropical Cyclone Signatures in Atmospheric Convective Available Potential Energy

    NASA Astrophysics Data System (ADS)

    Studholme, Joshua; Gulev, Sergey

    2016-04-01

    Tropical cyclones play an important role in the climate system providing transports of energy and water vapor, forcing the ocean, and also affecting mid-latitude circulation phenomena. Tropical cyclone tracks experience strong interannual variability and in addition, longer term trend-like changes in all ocean basins. Analysis of recent historical data reveal a poleward shift in the locations of tropical cyclone tracks in both the Northern and Southern Hemispheres (Kossin et al. 2014, Nature, 509, 349-352). The physical consequences of these alterations are largely unconstrained. For example, the increasing encroachment of tropical cyclone activity into the extra-tropical environment presents a novel and still poorly understood paradigm for tropical-extratropical interactions. In this respect, the role that the atmospheric convective available potential energy (CAPE) plays in the dynamics of tropical cyclones is highly interesting. The two characteristic global-scale spatial patterns in CAPE are identified using EOF analysis. The first pattern shows an abundance of CAPE in the centre of the Pacific and corresponds to the El Nino Southern Oscillation. The second one is capturing positive CAPE anomalies in the oceanic tropics and negative anomalies over equatorial Africa. Associated with these buoyancy patterns, alterations in tropical cyclone activity occur in all basins forming both zonal and meridional patterns. Atmospheric buoyancy is the trigger for deep convection, and subsequently cyclone genesis. This is the mechanism of impact upon location at the start of cyclone tracks. It is found to have less impact upon where cyclones subsequently move, whether or not they undergo extratropical transition and when and where they experience lysis. It is shown that CAPE plays a critical role in the general circulation in the tropics which in turn is the larger steering context for embedded systems within the Walker and Hadley cells. So this lack of `latter life' impact

  4. Lightning and 85-GHz MCSs in the Global Tropics

    NASA Technical Reports Server (NTRS)

    Toracinta, E. Richard; Zipser, E. J.

    1999-01-01

    Numerous observations of tropical convection show that tropical continental mesoscale convective systems (MCSs) are much more prolific lightning producers than their oceanic counterparts. Satellite-based climatologies using 85-GHz passive microwave ice-scattering signatures from the Special Sensor Microwave/Imager (SSM/I) indicate that MCSs of various size and intensity are found throughout the global tropics. In contrast, global lightning distributions show a strong land bias with an order of magnitude difference between land and ocean lightning. This is somewhat puzzling, since 85-GHz ice-scattering and the charge separation processes that lead to lightning are both thought to depend upon the existence of large graupel particles. The fact that low 85-GHz brightness temperatures are observed in tropical oceanic MCSs containing virtually no lightning leads to the postulate that tropical oceanic and tropical continental MCSs have fundamentally different hydrometeor profiles through the mixed phase region of the cloud (0 C <= T <= 20 C). Until recently, validation of this postulate has not been practicable on a global scale. Recent deployment of the Tropical Rainfall Measuring Mission (TRMM) satellite presents a unique opportunity for MCS studies. The multi-sensor instrument ensemble aboard TRMM, including a multi-channel microwave radiometer, the Lightning Imaging Sensor (LIS), and the first space-borne radar, facilitates high-resolution case studies of MCS structure throughout the global tropics. An important precursor, however, is to better understand the distribution of MCSs and lightning in the tropics. With that objective in mind, this research undertakes a systematic comparison of 85-GHz-defined MCSs and lightning over the global tropics for a full year, as an initial step toward quantifying differences between land and ocean convective systems.

  5. In field damage of high and low cyanogenic cassava due to a generalist insect herbivore Cyrtomenus bergi (Hemiptera: Cydnidae).

    PubMed

    Riis, Lisbeth; Bellotti, Anthony Charles; Castaño, Oscar

    2003-12-01

    The hypothesis that cyanogenic potential in cassava roots deters polyphagous insects in the field is relevant to current efforts to reduce or eliminate the cyanogenic potential in cassava. To test this hypothesis, experiments were conducted in the field under natural selection pressure of the polyphagous root feeder Cyrtomenus bergi Froeschner (Hemiptera: Cydnidae). A number of cassava varieties (33) as well as 13 cassava siblings and their parental clone, each representing a determined level of cyanogenic potential (CNP), were scored for damage caused by C. bergi and related to CNP and nonglycosidic cyanogens, measured as hydrogen cyanide. Additionally, 161 low-CNP varieties (< 50 ppm hydrogen cyanide, fresh weight) from the cassava germplasm core collection at Centro Internacional de Agricultura Tropical (CIAT) were screened for resistance/tolerance to C. bergi. Low root damage scores were registered at all levels of CNP. Nevertheless, CNP and yield (or root size) partly explained the damage in cassava siblings (r2 = 0.82) and different cassava varieties (r2 = 0.42), but only when mean values of damage scores were used. This relation was only significant in one of two crop cycles. A logistic model describes the underlying negative relation between CNP and damage. An exponential model describes the underlying negative relation between root size and damage. Damage, caused by C. bergi feeding, released nonglycosidic cyanogens, and an exponential model fits the underlying positive relation. Fifteen low-CNP clones were selected for potential resistance/tolerance against C. bergi.

  6. A DNA-Based Procedure for In Planta Detection of Fusarium oxysporum f. sp. phaseoli.

    PubMed

    Alves-Santos, Fernando M; Ramos, Brisa; García-Sánchez, M Asunción; Eslava, Arturo P; Díaz-Mínguez, José María

    2002-03-01

    ABSTRACT We have characterized strains of Fusarium oxysporum from common bean fields in Spain that were nonpathogenic on common bean, as well as F. oxysporum strains (F. oxysporum f. sp. phaseoli) pathogenic to common bean by random amplified polymorphic DNA (RAPD) analysis. We identified a RAPD marker (RAPD 4.12) specific for the highly virulent pathogenic strains of the seven races of F. oxysporum f. sp. phaseoli. Sequence analysis of RAPD 4.12 allowed the design of oligonucleotides that amplify a 609-bp sequence characterized amplified region (SCAR) marker (SCAR-B310A280). Under controlled environmental and greenhouse conditions, detection of the pathogen by polymerase chain reaction was 100% successful in root samples of infected but still symptomless plants and in stem samples of plants with disease severity of >/=4 in the Centro Internacional de Agricultura Tropical (CIAT; Cali, Colombia) scale. The diagnostic procedure can be completed in 5 h and allows the detection of all known races of the pathogen in plant samples at early stages of the disease with no visible symptoms.

  7. Mapping the spatial distribution of global anthropogenic mercury atmospheric emission inventories

    NASA Astrophysics Data System (ADS)

    Wilson, Simon J.; Steenhuisen, Frits; Pacyna, Jozef M.; Pacyna, Elisabeth G.

    This paper describes the procedures employed to spatially distribute global inventories of anthropogenic emissions of mercury to the atmosphere, prepared by Pacyna, E.G., Pacyna, J.M., Steenhuisen, F., Wilson, S. [2006. Global anthropogenic mercury emission inventory for 2000. Atmospheric Environment, this issue, doi:10.1016/j.atmosenv.2006.03.041], and briefly discusses the results of this work. A new spatially distributed global emission inventory for the (nominal) year 2000, and a revised version of the 1995 inventory are presented. Emissions estimates for total mercury and major species groups are distributed within latitude/longitude-based grids with a resolution of 1×1 and 0.5×0.5°. A key component in the spatial distribution procedure is the use of population distribution as a surrogate parameter to distribute emissions from sources that cannot be accurately geographically located. In this connection, new gridded population datasets were prepared, based on the CEISIN GPW3 datasets (CIESIN, 2004. Gridded Population of the World (GPW), Version 3. Center for International Earth Science Information Network (CIESIN), Columbia University and Centro Internacional de Agricultura Tropical (CIAT). GPW3 data are available at http://beta.sedac.ciesin.columbia.edu/gpw/index.jsp). The spatially distributed emissions inventories and population datasets prepared in the course of this work are available on the Internet at www.amap.no/Resources/HgEmissions/

  8. Modeling Tropical Precipitation in a Single Column.

    NASA Astrophysics Data System (ADS)

    Sobel, Adam H.; Bretherton, Christopher S.

    2000-12-01

    A modified formulation of the traditional single column model for representing a limited area near the equator is proposed. This formulation can also be considered a two-column model in the limit as the area represented by one of the columns becomes very large compared to the other. Only a single column is explicitly modeled, but its free tropospheric temperature, rather than its mean vertical velocity, is prescribed. This allows the precipitation and vertical velocity to be true prognostic variables, as in prior analytical theories of tropical precipitation. Two models developed by other authors are modified according to the proposed formulation. The first is the intermediate atmospheric model of J. D. Neelin and N. Zeng, but with the horizontal connections between columns broken, rendering it a set of disconnected column models. The second is the column model of N. O. Rennó, K. A. Emanuel, and P. H. Stone. In the first model, the set of disconnected column models is run with a fixed temperature that is uniform in the Tropics, and insolation, SST, and surface wind speed taken from a control run of the original model. The column models produce a climatological precipitation field that is grossly similar to that of the control run, despite that the circulation implied by the column models is not required to conserve mass. The addition of horizontal moisture advection by the wind from the control run substantially improves the simulation in dry regions. In the second model the sensitivity of the modeled steady-state precipitation and relative humidity to varying SST and wind speed is examined. The transition from shallow to deep convection is simulated in a `Lagrangian' calculation in which the column model is subjected to an SST that increases in time. In this simulation, the onset of deep convection is delayed to a higher SST than in the steady-state case, due to the effect of horizontal moisture advection (viewed in a Lagrangian reference frame). In both of the

  9. Tropical cyclone Pam field survey in Vanuatu

    NASA Astrophysics Data System (ADS)

    Fritz, Hermann M.; Pilarczyk, Jessica E.; Kosciuch, Thomas; Hong, Isabel; Rarai, Allan; Harrison, Morris J.; Jockley, Fred R.; Horton, Benjamin P.

    2016-04-01

    Severe tropical cyclone Pam (Cat. 5, SSHS) crossed the Vanuatu archipelago with sustained winds of 270 km/h on March 13 and 14, 2015 and made landfall on Erromango. Pam is the most intense tropical cyclone to make landfall on Vanuatu since the advent of satellite imagery based intensity estimates in the 1970s. Pam caused one of the worst natural disaster in Vanuatu's recorded history. Eleven fatalities were directly attributed to cyclone Pam and mostly due to lack of shelter from airborne debris. On March 6 Pam formed east of the Santa Cruz Islands causing coastal inundation on Tuvalu's Vaitupu Island located some 1100 km east of the cyclone center. Pam intensified while tracking southward along Vanuatu severely affecting the Shefa and Tafea Provinces. An international storm surge reconnaissance team was deployed to Vanuatu from June 3 to 17, 2015 to complement earlier local surveys. Cyclone Pam struck a remote island archipelago particularly vulnerable to the combined cyclonic multi-hazards encompassing extreme wind gusts, massive rainfall and coastal flooding due to a combination of storm surge and storm wave impacts. The team surveyed coastal villages on Epi, the Shepherd Islands (Tongoa and Mataso), Efate (including Lelepa), Erromango, and Tanna. The survey spanned 320 km parallel to the cyclone track between Epi and Tanna encompassing more than 45 sites including the hardest hit settlements. Coastal flooding profiles were surveyed from the shoreline to the limit of inundation. Maximum coastal flood elevations and overland flow depths were measured based on water marks on buildings, scars on trees, rafted debris and corroborated with eyewitness accounts. We surveyed 91 high water marks with characteristic coastal flood levels in the 3 to 7 m range and composed of storm surge with superimposed storm waves. Inundation distances were mostly limited to a few hundred meters but reached 800 m on Epi Island. Wrack lines containing pumice perfectly delineated the

  10. Structural Dynamics of Tropical Moist Forest Gaps

    PubMed Central

    Hunter, Maria O.; Keller, Michael; Morton, Douglas; Cook, Bruce; Lefsky, Michael; Ducey, Mark; Saleska, Scott; de Oliveira, Raimundo Cosme; Schietti, Juliana

    2015-01-01

    Gap phase dynamics are the dominant mode of forest turnover in tropical forests. However, gap processes are infrequently studied at the landscape scale. Airborne lidar data offer detailed information on three-dimensional forest structure, providing a means to characterize fine-scale (1 m) processes in tropical forests over large areas. Lidar-based estimates of forest structure (top down) differ from traditional field measurements (bottom up), and necessitate clear-cut definitions unencumbered by the wisdom of a field observer. We offer a new definition of a forest gap that is driven by forest dynamics and consistent with precise ranging measurements from airborne lidar data and tall, multi-layered tropical forest structure. We used 1000 ha of multi-temporal lidar data (2008, 2012) at two sites, the Tapajos National Forest and Ducke Reserve, to study gap dynamics in the Brazilian Amazon. Here, we identified dynamic gaps as contiguous areas of significant growth, that correspond to areas > 10 m2, with height <10 m. Applying the dynamic definition at both sites, we found over twice as much area in gap at Tapajos National Forest (4.8 %) as compared to Ducke Reserve (2.0 %). On average, gaps were smaller at Ducke Reserve and closed slightly more rapidly, with estimated height gains of 1.2 m y-1 versus 1.1 m y-1 at Tapajos. At the Tapajos site, height growth in gap centers was greater than the average height gain in gaps (1.3 m y-1 versus 1.1 m y-1). Rates of height growth between lidar acquisitions reflect the interplay between gap edge mortality, horizontal ingrowth and gap size at the two sites. We estimated that approximately 10 % of gap area closed via horizontal ingrowth at Ducke Reserve as opposed to 6 % at Tapajos National Forest. Height loss (interpreted as repeat damage and/or mortality) and horizontal ingrowth accounted for similar proportions of gap area at Ducke Reserve (13 % and 10 %, respectively). At Tapajos, height loss had a much stronger signal (23

  11. Overview of the Airborne Tropical TRopopause EX

    NASA Technical Reports Server (NTRS)

    Singh, Hanwant B.; Jensen, Eric J.; Pfister, Leonhard

    2014-01-01

    The NASA Airborne Tropical TRopopause EXperiment (ATTREX) is a series of airborne campaigns focused on understanding physical processes in the Tropical Tropopause Layer (TTL) and their role in atmospheric chemistry and climate. ATTREX is using the high-altitude, long-duration NASA Global Hawk Unmanned Air System to make in situ and remote-sensing measurements spanning the Pacific. A particular ATIREX emphasis is to better understand the dehydration of air as it passes through the cold tropical tropopause region. The ATTREX payload contains 12 in situ and remote sensing instruments that measure water vapor, clouds, multiple gaseous tracers (CO, CO2, CH4, NMHC, SF6, CFCs, N2O), reactive chemical compounds (O3, BrO, NO2), meteorological parameters, and radiative fluxes. ATTREX flight series have been conducted in the fall of 2011 from Armstrong Flight Research Center (AFRC) in California, in the winter of 2013 from AFRC, and in the winter/spring of 2014 from Guam. The first two f light series provided extensive sampling of the central and eastern Pacific, whereas the last flight series permitted sampling in the western Pacific. The sampling strategy has primarily involved repeated ascents and descents through the depth of the TTL (about 13-19 km). Over 100 TTL profiles were obtained on each flight series. The ATTREX dataset includes TTL water vapor measurements with unprecedented accuracy, ice crystal size distributions and habits. The cloud and water measurements provide unique information about TTL cloud formation, the persistence of supersaturation with respect to ice, and dehydration. The plethora of tracers measured on the Global Hawk flights are providing unique information about TTL transport pathways and time scales. The meteorological measurements are revealing dynamical phenomena controlling the TTL thermal structure, and the radiation measurements are providing information about heating rates associated with TTL clouds and water vapor. This presentation

  12. Structural Dynamics of Tropical Moist Forest Gaps.

    PubMed

    Hunter, Maria O; Keller, Michael; Morton, Douglas; Cook, Bruce; Lefsky, Michael; Ducey, Mark; Saleska, Scott; de Oliveira, Raimundo Cosme; Schietti, Juliana

    2015-01-01

    Gap phase dynamics are the dominant mode of forest turnover in tropical forests. However, gap processes are infrequently studied at the landscape scale. Airborne lidar data offer detailed information on three-dimensional forest structure, providing a means to characterize fine-scale (1 m) processes in tropical forests over large areas. Lidar-based estimates of forest structure (top down) differ from traditional field measurements (bottom up), and necessitate clear-cut definitions unencumbered by the wisdom of a field observer. We offer a new definition of a forest gap that is driven by forest dynamics and consistent with precise ranging measurements from airborne lidar data and tall, multi-layered tropical forest structure. We used 1000 ha of multi-temporal lidar data (2008, 2012) at two sites, the Tapajos National Forest and Ducke Reserve, to study gap dynamics in the Brazilian Amazon. Here, we identified dynamic gaps as contiguous areas of significant growth, that correspond to areas > 10 m2, with height <10 m. Applying the dynamic definition at both sites, we found over twice as much area in gap at Tapajos National Forest (4.8%) as compared to Ducke Reserve (2.0%). On average, gaps were smaller at Ducke Reserve and closed slightly more rapidly, with estimated height gains of 1.2 m y-1 versus 1.1 m y-1 at Tapajos. At the Tapajos site, height growth in gap centers was greater than the average height gain in gaps (1.3 m y-1 versus 1.1 m y-1). Rates of height growth between lidar acquisitions reflect the interplay between gap edge mortality, horizontal ingrowth and gap size at the two sites. We estimated that approximately 10% of gap area closed via horizontal ingrowth at Ducke Reserve as opposed to 6% at Tapajos National Forest. Height loss (interpreted as repeat damage and/or mortality) and horizontal ingrowth accounted for similar proportions of gap area at Ducke Reserve (13% and 10%, respectively). At Tapajos, height loss had a much stronger signal (23% versus 6

  13. Projecting global tropical cyclone economic damages with validation of tropical cyclone economic damage model

    NASA Astrophysics Data System (ADS)

    Iseri, Y.; Iwasaki, A.; Miyazaki, C.; Kanae, S.

    2014-12-01

    Tropical cyclones (TCs) sometimes cause serious damages to human society and thus possible changes of TC properties in the future have been concerned. In fact, the Fifth Assessment Report (AR5) by IPCC (Intergovernmental Panel on Climate Change) mentions likely increasing in intensity and rain rate of TCs. In addition, future change of socioeconomic condition (e.g. population growth) might worsen TC impacts in the future. Thereby, in this study, we developed regression models to estimate economic damages by TCs (hereafter TC damage model), and employed those models to project TC economic damages under several future climate and socioeconomic scenarios. We developed the TC damage models for each of 4 regions; western North Pacific, North American, North Indian, and Southern Hemisphere. The inputs for TC damage model are tropical cyclone central pressure, populations in the area exposed by tropical cyclone wind, and GDP (Gross Domestic Product) per capita. The TC damage models we firstly developed tended to overestimate very low damages and also underestimate very high damages. Thereby we modified structure of TC damage models to improve model performance, and then executed extensive validation of the model. The modified model presented better performance in estimating very low and high TC damages. After the modification and validation of the model, we determined the structure of TC damage models and projected TC economic damages. The result indicated increase in TC economic damage in global scale, while TC economic damage against world GDP would decrease in the future, which result is consistent with previous study.

  14. Tropical Rainfall Measuring Mission: Monitoring the Global Tropics for 3 Years and Beyond. 1.1

    NASA Technical Reports Server (NTRS)

    Shepherd, Marshall; Starr, David OC. (Technical Monitor)

    2001-01-01

    The Tropical Rainfall Measuring Mission (TRMM) was launched in November 1997 as a joint U.S.-Japanese mission to advance understanding of the global energy and water cycle by providing distributions of rainfall and latent heating over the global tropics. As a part of NASA's Earth System Enterprise, TRMM seeks to understand the mechanisms through which changes in tropical rainfall influence global circulation. Additionally, a goal is to improve the ability to model these processes in order to predict global circulations and rainfall variability at monthly and longer time scales. Such understanding has implications for assessing climate processes related to El Nino/La Nina and Global Warming. TRMM has also provided unexpected and exciting new knowledge and applications in areas related to hurricane monitoring, lightning, pollution, hydrology, and other areas. This CD-ROM includes a self-contained PowerPoint presentation that provides an overview of TRMM and significant science results; a set of data movies or animation; and listings of current TRMM-related publications in the literature.

  15. Agroforestry: a refuge for tropical biodiversity?

    PubMed

    Bhagwat, Shonil A; Willis, Katherine J; Birks, H John B; Whittaker, Robert J

    2008-05-01

    As rates of deforestation continue to rise in many parts of the tropics, the international conservation community is faced with the challenge of finding approaches which can reduce deforestation and provide rural livelihoods in addition to conserving biodiversity. Much of modern-day conservation is motivated by a desire to conserve 'pristine nature' in protected areas, while there is growing recognition of the long-term human involvement in forest dynamics and of the importance of conservation outside protected areas. Agroforestry -- intentional management of shade trees with agricultural crops -- has the potential for providing habitats outside formally protected land, connecting nature reserves and alleviating resource-use pressure on conservation areas. Here we examine the role of agroforestry systems in maintaining species diversity and conclude that these systems can play an important role in biodiversity conservation in human-dominated landscapes.

  16. Space options for tropical cyclone hazard mitigation

    NASA Astrophysics Data System (ADS)

    Dicaire, Isabelle; Nakamura, Ryoko; Arikawa, Yoshihisa; Okada, Kazuyuki; Itahashi, Takamasa; Summerer, Leopold

    2015-02-01

    This paper investigates potential space options for mitigating the impact of tropical cyclones on cities and civilians. Ground-based techniques combined with space-based remote sensing instrumentation are presented together with space-borne concepts employing space solar power technology. Two space-borne mitigation options are considered: atmospheric warming based on microwave irradiation and laser-induced cloud seeding based on laser power transfer. Finally technology roadmaps dedicated to the space-borne options are presented, including a detailed discussion on the technological viability and technology readiness level of our proposed systems. Based on these assessments, the space-borne cyclone mitigation options presented in this paper may be established in a quarter of a century.

  17. Tropical cyclone recurvature: An intrinsic property?

    NASA Astrophysics Data System (ADS)

    Chan, Kelvin T. F.; Chan, Johnny C. L.

    2016-08-01

    The typical track of a tropical cyclone (TC) in the Northern Hemisphere is an initial northwestward movement followed by an eventual turning toward the east. Such turning is referred to as recurvature and often explained by the change of the environmental flow that steers the TC. Here we show that even in the absence of background flow, a TC initiated at a high enough latitude can recurve itself. Differential horizontal advection of the planetary vorticity by the TC circulation at different vertical levels leads to the development of vertical wind shear, upper tropospheric anticyclone, and asymmetric distribution of convection. The flow associated with the upper tropospheric anticyclone on the equatorward side of the TC and the diabatic heating associated with the asymmetric convection combine to cause the TC to recurve. Such knowledge, an intrinsic recurvature property of the TC is important in forecasting the TC track when the environmental flow is weak.

  18. Solar Cycle Variability in Tropical Column Ozone

    NASA Astrophysics Data System (ADS)

    Yung, Y. L.; Liang, M.; Li, K.; Jiang, X.; Camp, C. D.

    2011-12-01

    Using an empirical orthogonal function (EOF) method [Camp et al., 2003], we analyzed the Merged Ozone Data (MOD) set from late 1978 to the present. The decadal variability of column ozone in the tropics follows that of the sun over three solar cycles. The peak-to-peak amplitude is about 10 DU (Dobson Units), consistent with the conclusion of Camp et al. [2003], who analyzed the MOD data up to and including 2000. Previous attempts to model the amplitude of the observed solar cycle in ozone were unsuccessful, as models tended to underestimate the solar cycle effect. Using the Whole Atmosphere Community Climate Model (WACCM) in combination with the latest satellite measurements of solar variability in the UV [McClintock et al., 2005; Harder et al., 2009], we correctly simulate the solar cycle signal in the total column ozone for the first time. The implications for solar forcing on middle atmosphere chemistry are discussed.

  19. Interhemispheric thermal gradient and tropical Pacific climate

    NASA Astrophysics Data System (ADS)

    Chiang, John C. H.; Fang, Yue; Chang, P.

    2008-07-01

    We explore the impact of interhemispheric thermal gradients forcing on the tropical Pacific ocean-atmosphere climate in an intermediate coupled model. The equatorial zonal sea surface temperature (SST) gradient strengthens with an increased northward interhemispheric thermal gradient, the increase arising from earlier onset and later retreat of the seasonal cold tongue, and intensification during the peak cold season. When the mean interhemispheric thermal gradient is reversed, the central equatorial Pacific SST annual cycle abruptly reverses in phase, with its cold season in Mar-May rather than Sep-Nov. While startling, this response is consistent with a prevailing hypothesis that ties the cold tongue SST annual cycle phase to the hemispheric mean asymmetry of the Intertropical Convergence Zone. El Niño-Southern Oscillation activity is also sensitive to the interhemispheric thermal gradient, with peak activity occurring when the mean gradient is small, reducing rapidly as the mean gradient increases in either direction.

  20. Methanol and the productivity of tropical crops

    SciTech Connect

    Ferguson, T.U.

    1995-12-31

    Studies are being conducted in Trinidad and Tobago, St. Lucia and St. Kitts/Nevis to determine the effect of aqueous solutions of methanol on the growth and yield of a wide range of vegetable, field and perennial crops. The paper presents a summary of results to data for ten of the crops studied. Six of these crops, lettuce, sweet pepper, tomato, mango and breadfruit, have shown significant increases in growth or yield with methanol application, while others such as pigeon pea, rice, banana and cocoa have shown more limited responses. There appears to be some potential for the use of methanol in tropical crop production but further studies are required before this apparent potential can be harnessed.

  1. AVHRR for monitoring global tropical deforestation

    NASA Technical Reports Server (NTRS)

    Malingreau, J. P.; Laporte, N.; Tucker, C. J.

    1989-01-01

    Advanced Very High Resolution Radiometer (AVHRR) data have been used to assess the dynamics of forest trnsformations in three parts of the tropical belt. A large portion of the Amazon Basin has been systematically covered by Local Area Coverage (LAC) data in the 1985-1987 period. The analysis of the vegetation index and thermal data led to the identification and measurement of large areas of active deforestation. The Kalimantan/Borneo forest fires were monitored and their impact was evaluated using the Global Area Coverage (GAC) 4 km resolution data. Finally, High Resolution Picture Transmission (HRPT) data have provided preliminary information on current activities taking place at the boundary between the savanna and the forest in the Southern part of West Africa. The AVHRR approach is found to be a highly valuable means for carrying out deforestation assessments in regional and global perspectives.

  2. Arthropod diversity in a tropical forest.

    PubMed

    Basset, Yves; Cizek, Lukas; Cuénoud, Philippe; Didham, Raphael K; Guilhaumon, François; Missa, Olivier; Novotny, Vojtech; Ødegaard, Frode; Roslin, Tomas; Schmidl, Jürgen; Tishechkin, Alexey K; Winchester, Neville N; Roubik, David W; Aberlenc, Henri-Pierre; Bail, Johannes; Barrios, Héctor; Bridle, Jon R; Castaño-Meneses, Gabriela; Corbara, Bruno; Curletti, Gianfranco; Duarte da Rocha, Wesley; De Bakker, Domir; Delabie, Jacques H C; Dejean, Alain; Fagan, Laura L; Floren, Andreas; Kitching, Roger L; Medianero, Enrique; Miller, Scott E; Gama de Oliveira, Evandro; Orivel, Jérôme; Pollet, Marc; Rapp, Mathieu; Ribeiro, Sérvio P; Roisin, Yves; Schmidt, Jesper B; Sørensen, Line; Leponce, Maurice

    2012-12-14

    Most eukaryotic organisms are arthropods. Yet, their diversity in rich terrestrial ecosystems is still unknown. Here we produce tangible estimates of the total species richness of arthropods in a tropical rainforest. Using a comprehensive range of structured protocols, we sampled the phylogenetic breadth of arthropod taxa from the soil to the forest canopy in the San Lorenzo forest, Panama. We collected 6144 arthropod species from 0.48 hectare and extrapolated total species richness to larger areas on the basis of competing models. The whole 6000-hectare forest reserve most likely sustains 25,000 arthropod species. Notably, just 1 hectare of rainforest yields >60% of the arthropod biodiversity held in the wider landscape. Models based on plant diversity fitted the accumulated species richness of both herbivore and nonherbivore taxa exceptionally well. This lends credence to global estimates of arthropod biodiversity developed from plant models.

  3. Priority setting and the 'neglected' tropical diseases.

    PubMed

    Canning, David

    2006-06-01

    In this paper David Canning argues that interventions against 'neglected' tropical diseases should be thought of as investments in human capital and form an integral part of global poverty reduction. He argues that overall burden of disease should not be the criterion for priority setting; if the goal is to maximize health benefits from a fixed health budget then cost-effective interventions should be prioritized. Whilst many people find objectionable the assignment of a monetary value to health, a cost-benefit approach, combining health and economic benefits, would allow the health sector to present arguments to policy makers, based on the rate of return on investment. Since many health interventions in low-income countries have exceptionally high rankings in terms of cost-benefit ratios, this should result in large flows from other sectors to the health sector.

  4. Tropical Cloud Properties and Radiative Heating Profiles

    DOE Data Explorer

    Mather, James

    2008-01-15

    We have generated a suite of products that includes merged soundings, cloud microphysics, and radiative fluxes and heating profiles. The cloud microphysics is strongly based on the ARM Microbase value added product (Miller et al., 2003). We have made a few changes to the microbase parameterizations to address issues we observed in our initial analysis of the tropical data. The merged sounding product is not directly related to the product developed by ARM but is similar in that it uses the microwave radiometer to scale the radiosonde column water vapor. The radiative fluxes also differ from the ARM BBHRP (Broadband Heating Rate Profile) product in terms of the radiative transfer model and the sampling interval.

  5. Major Australian tropical fruits biodiversity: bioactive compounds and their bioactivities.

    PubMed

    Pierson, Jean T; Dietzgen, Ralf G; Shaw, Paul N; Roberts-Thomson, Sarah J; Monteith, Gregory R; Gidley, Michael J

    2012-03-01

    The plant kingdom harbours many diverse bioactive molecules of pharmacological relevance. Temperate fruits and vegetables have been highly studied in this regard, but there have been fewer studies of fruits and vegetables from the tropics. As global consumers demand and are prepared to pay for new appealing and exotic foods, tropical fruits are now being more intensively investigated. Polyphenols and major classes of compounds like flavonoids or carotenoids are ubiquitously present in these fruits, as they are in the temperate ones, but particular classes of compounds are unique to tropical fruits and other plant parts. Bioactivity studies of compounds specific to tropical fruit plants may lead to new drug discoveries, while the synergistic action of the wide range of diverse compounds contained in plant extracts underlies nutritional and health properties of tropical fruits and vegetables. The evidence for in vitro and animal bioactivities is a strong indicator of the pharmacological promise shown in tropical fruit plant biodiversity. In this review, we will discuss both the occurrence of potential bioactive compounds isolated and identified from a selection of tropical fruit plants of importance in Australia, as well as recent studies of bioactivity associated with such fruits and other fruit plant parts.

  6. Reconciling Glacial Snow Lines With Tropical Sea Surface Temperatures

    NASA Astrophysics Data System (ADS)

    Lorenz, S. J.; Lohmann, G.

    Reconstructions of tropical snow lines during the last glacial maximum (LGM) 21,000 years ago are incompatible with the sea surface temperature (SST) reconstructions of the CLIMAP project, when assuming present day atmospheric lapse rates (e.g. Pe- teet and Rind 1985). Since proxy data for the vertical structure of the atmosphere during glacial times do not exist, numerical experiments with an atmospheric gen- eral circulation model for glacial and interglacial climates have been performed. Our model experiments reveal that slightly cooler tropical SSTs relative to the ones by CLIMAP (1981) are sufficient to simulate proper glacial freezing temperature levels. The depression of tropical snow lines in our LGM experiment can be attributed to two effects: Less moisture content provides an increased environmental lapse rate in the free atmosphere. This effect is strongest in the tropical middle troposphere where we observe an additional two degrees cooling. Secondly, the surface temperature near tropical glaciers is further cooled by a longer duration of snow cover. Our model result provides a consistent view of the last glacial maximum climate with much colder tem- peratures than today in the tropical mountains in concordance with moderate lowering of tropical SSTs.

  7. Neglected tropical diseases: diagnosis, clinical management, treatment and control.

    PubMed

    Utzinger, Jürg; Becker, Sören L; Knopp, Stefanie; Blum, Johannes; Neumayr, Andreas L; Keiser, Jennifer; Hatz, Christoph F

    2012-11-22

    Branded in 2005, "neglected tropical diseases" have gained traction in terms of advocacy, interest for research, enhanced funding and political will for their control and eventual elimination. Starting with an initial set of 13 neglected tropical diseases--seven helminth, three bacterial and three protozoal infections--the list considerably expanded to more than 40 diseases that now also includes viral, fungal and ectoparasitic infections. In this review, we provide a comprehensive overview of the neglected tropical diseases, their causative agents and the current geographical distribution, including their importance for the general practitioners seeing returning travellers and migrants in Switzerland. We characterise the most important of the neglected tropical diseases in terms of at-risk population, estimated number of infections, annual mortality rates and global burden, including current knowledge gaps. With an emphasis on neglected tropical diseases due to helminths, protozoa and ectoparasites, we review common diagnostic methods and current recommendations for treatment at the population level and the individual patient, thereby juxtaposing the situation in highly endemic countries on one side, with Switzerland on the other. We highlight the clinical presentation and management of the neglected tropical diseases in general and then elaborate on two examples, strongyloidiasis and leptospirosis. Our review provides a global perspective of neglected tropical diseases and we hope that it will prove useful for the general practitioner and clinician in Switzerland and elsewhere to enhance their suspicion index, differential diagnosis, clinical management and treatment, including referral to specialised clinics and laboratories when need be.

  8. The future of tropical species on a warmer planet.

    PubMed

    Wright, S Joseph; Muller-Landau, Helene C; Schipper, Jan

    2009-12-01

    Modern global temperature and land cover and projected future temperatures suggest that tropical forest species will be particularly sensitive to global warming. Given a moderate greenhouse gas emissions scenario, fully 75% of the tropical forests present in 2000 will experience mean annual temperatures in 2100 that are greater than the highest mean annual temperature that supports closed-canopy forest today. Temperature-sensitive species might extend their ranges to cool refuges, defined here as areas where temperatures projected for 2100 match 1960s temperatures in the modern range. Distances to such cool refuges are greatest for equatorial species and are particularly large for key tropical forest areas including the Amazon and Congo River Basins, West Africa, and the upper elevations of many tropical mountains. In sum, tropical species are likely to be particularly sensitive to global warming because they are adapted to limited geographic and seasonal variation in temperature, already lived at or near the highest temperatures on Earth before global warming began, and are often isolated from cool refuges. To illustrate these three points, we examined the distributions and habitat associations of all extant mammal species. The distance to the nearest cool refuge exceeded 1000 km for more than 20% of the tropical and less than 4% of the extratropical species with small ranges. The biological impact of global warming is likely to be as severe in the tropics as at temperate and boreal latitudes.

  9. Hydration of the upper troposphere by tropical cyclones

    NASA Astrophysics Data System (ADS)

    Ray, Eric A.; Rosenlof, Karen H.

    2007-06-01

    Tropical cyclones in the Atlantic and Pacific ocean basins are found to have a significant impact on the amount of water vapor in the tropical and subtropical upper troposphere. Measurements from AIRS on Aqua and MLS on Aura are used to reveal details of the water vapor and temperature structure of the upper troposphere in the vicinity of tropical cyclones that have been unavailable from previous satellite observations. These measurements show that the most intense tropical cyclones (categories 4 and 5) increase average water vapor mixing ratios between 300 and 150 hPa in a roughly 1500 km2 area around the cyclones by 10-50% over their lifetimes. Category 3 and weaker tropical cyclones hydrate the upper troposphere on average roughly half as effectively as the most intense cyclones. The most intense cyclones also increase average water vapor in the upper troposphere by 2-10% in the entire ocean basin in which they occur. This amount of hydration of the tropical upper troposphere suggests that tropical cyclones play a role in the water vapor budget, and associated climate feedbacks, in a region much larger than the cyclone vicinity.

  10. Lacunarity as a texture measure for a tropical forest landscape

    SciTech Connect

    Su, Haiping; Krummel, J.

    1996-01-01

    Fragmentation and loss of tropical forest cover alters terrestrial plant and animal population dynamics, reduces biodiversity and carbon storage capacity, and, as a global phenomenon could affect regional and global climate patterns. Lacunarity as a texture measure can offer a simple solution to characterize the texture of tropical forest landscape and determine spatial patterns associated with ecological processes. Lacunarity quantifies the deviation from translational invariance by describing the distribution of gaps within a binary image at multiple scales. As lacunarity increases, the spatial arrangement of tropical forest gaps will also increase. In this study, we used the Spatial Modeler in Imagine as a graphic programming tool to calculate lacunarity indices for a tropical forest landscape in Southern Mexico and Northern Guatemala. Lacunarity indices were derived from classified Landsat MSS images acquired in 1974 and 1984. Random-generated binary images were also used to derive lacunarity indices and compared with the lacunarity of forest patterns derived from the classified MSS images. Tropical forest area declined about 17%, with most of the forest areas converted into pasture/grassland for grazing. During this period, lacunarity increased about 25%. Results of this study suggest that tropical forest fragmentation could be quantified with lacunarity measures. The study also demonstrated that the Spatial Modeler can be useful as a programming tool to quantify spatial patterns of tropical forest landscape by using remotely sensed data.

  11. Air-sea interaction in the tropical Pacific Ocean

    NASA Technical Reports Server (NTRS)

    Allison, L. J.; Steranka, J.; Holub, R. J.; Hansen, J.; Godshall, F. A.; Prabhakara, C.

    1972-01-01

    Charts of 3-month sea surface temperature (SST) anomalies in the eastern tropical Pacific Ocean were produced for the period 1949 to 1970. The anomalies along the United States and South American west coasts and in the eastern tropical Pacific appeared to be oscillating in phase during this period. Similarly, the satellite-derived cloudiness for each of four quadrants of the Pacific Ocean (130 deg E to 100 deg W, 30 deg N to 25 deg S) appeared to be oscillating in phase. In addition, a global tropical cloudiness oscillation from 30 deg N to 30 deg S was noted from 1965 to 1970, by using monthly satellite television nephanalyses. The SST anomalies were found to have a good degree of correlation both positive and negative with the following monthly geophysical parameters: (1) satellite-derived cloudiness, (2) strength of the North and South Pacific semipermanent anticyclones, (3) tropical Pacific island rainfall, and (4) Darwin surface pressure. Several strong direct local and crossequatorial relationships were noted. In particular, the high degree of correlation between the tropical island rainfall and the SST anomalies (r = +0.93) permitted the derivation of SST's for the tropical Pacific back to 1905. The close occurrence of cold tropical SST and North Pacific 700-mb positive height anomalies with central United States drought conditions was noted.

  12. Primary forests are irreplaceable for sustaining tropical biodiversity.

    PubMed

    Gibson, Luke; Lee, Tien Ming; Koh, Lian Pin; Brook, Barry W; Gardner, Toby A; Barlow, Jos; Peres, Carlos A; Bradshaw, Corey J A; Laurance, William F; Lovejoy, Thomas E; Sodhi, Navjot S

    2011-09-14

    Human-driven land-use changes increasingly threaten biodiversity, particularly in tropical forests where both species diversity and human pressures on natural environments are high. The rapid conversion of tropical forests for agriculture, timber production and other uses has generated vast, human-dominated landscapes with potentially dire consequences for tropical biodiversity. Today, few truly undisturbed tropical forests exist, whereas those degraded by repeated logging and fires, as well as secondary and plantation forests, are rapidly expanding. Here we provide a global assessment of the impact of disturbance and land conversion on biodiversity in tropical forests using a meta-analysis of 138 studies. We analysed 2,220 pairwise comparisons of biodiversity values in primary forests (with little or no human disturbance) and disturbed forests. We found that biodiversity values were substantially lower in degraded forests, but that this varied considerably by geographic region, taxonomic group, ecological metric and disturbance type. Even after partly accounting for confounding colonization and succession effects due to the composition of surrounding habitats, isolation and time since disturbance, we find that most forms of forest degradation have an overwhelmingly detrimental effect on tropical biodiversity. Our results clearly indicate that when it comes to maintaining tropical biodiversity, there is no substitute for primary forests.

  13. Spectral Trends of Titan's Tropical Surface

    NASA Astrophysics Data System (ADS)

    Griffith, Caitlin Ann; Penteado, Paulo F.; Turner, Jake; Montiel, Nicholas; Schoenfeld, Ashley; Lopes, Rosaly M. C.; Soderblom, Laurence A.; Neish, Catherine; Radebaugh, Jani

    2016-10-01

    Titan's surface can be observed most clearly at 8 spectral regions that lie in between the strong methane bands in Titan's spectrum. Within these "windows", between 0.9 to 5 microns, the surface is nonetheless obscured by methane and haze, the latter of which is optically thick at lower wavelengths. Thus studies of Titan's surface must eliminate the effects of atmospheric extinction and extract the subtle spectral features that underlie the dominant spectral trends.To determine the subtle spectral features of Titan's tropical surface (30S--30N) we conducted a Principal Components Analysis (PCA) of the I/F at the 1.1, 1.3, 1.6 and 2.0 um wavelength windows, recorded by Cassini/VIMS. The PCA analysis identifies the spectral trend that defines the highest variance in the data (the principal component), as well as successively weaker orthogonal trends, without a priori assumptions about the surface composition, e.g. as needed in radiative transfer analyses.Our analysis derives the spectral features at the four wavelengths that describe Titan's tropical surface. We detect a large almost contiguous region that extends roughly 160 degrees in longitude and which exhibits absorption features at 1.6 and 2.0, as well as 2.8 um (characteristic of water ice). This vast and perhaps tectonic feature is, in part, associated with terrain that is hypothesized to be some of the oldest surfaces on Titan. In addition, the PCA analysis indicates at least 2 separate organic spectra signatures, potentially due to the separation of liquid and refractory sediments or to their chemically alteration over time. Here we discuss the PCA analysis and compare our derived compositional maps of Titan's surface with Radar maps of the topography and morphology, to entertain questions regarding the geology of Titan's surface the age of its atmosphere.

  14. The Environmental Legacy of Modern Tropical Deforestation.

    PubMed

    Rosa, Isabel M D; Smith, Matthew J; Wearn, Oliver R; Purves, Drew; Ewers, Robert M

    2016-08-22

    Tropical deforestation has caused a significant share of carbon emissions and species losses, but historical patterns have rarely been explicitly considered when estimating these impacts [1]. A deforestation event today leads to a time-delayed future release of carbon, from the eventual decay either of forest products or of slash left at the site [2]. Similarly, deforestation often does not result in the immediate loss of species, and communities may exhibit a process of "relaxation" to their new equilibrium over time [3]. We used a spatially explicit land cover change model [4] to reconstruct the annual rates and spatial patterns of tropical deforestation that occurred between 1950 and 2009 in the Amazon, in the Congo Basin, and across Southeast Asia. Using these patterns, we estimated the resulting gross vegetation carbon emissions [2, 5] and species losses over time [6]. Importantly, we accounted for the time lags inherent in both the release of carbon and the extinction of species. We show that even if deforestation had completely halted in 2010, time lags ensured there would still be a carbon emissions debt of at least 8.6 petagrams, equivalent to 5-10 years of global deforestation, and an extinction debt of more than 140 bird, mammal, and amphibian forest-specific species, which if paid, would increase the number of 20(th)-century extinctions in these groups by 120%. Given the magnitude of these debts, commitments to reduce emissions and biodiversity loss are unlikely to be realized without specific actions that directly address this damaging environmental legacy.

  15. Celestial Moderation of Tropical Seabird Behavior

    PubMed Central

    Pinet, Patrick; Jaeger, Audrey; Cordier, Emmanuel; Potin, Gaël; Le Corre, Matthieu

    2011-01-01

    Most animals, including birds, have cyclic life histories and numerous studies generally conducted on captive animals have shown that photoperiod is the main factor influencing this periodicity. Moon cycles can also affect periodic behavior of birds. Few studies have investigated the influence of these environmental cues in natural settings, and particularly in tropical areas where the change in photoperiod is slight and some bird species keep cyclic behaviors. Using miniaturized light sensors, we simultaneously investigated under natural conditions the influence of photoperiod and moon phases on the migration dates and at-sea activity of a tropical seabird species, the Barau's petrel, throughout its annual cycle. Firstly, we found that birds consistently started their pre- and post-breeding migrations at precise dates corresponding in both cases to a day-duration of 12.5 hours, suggesting a strong influence of the photoperiod in the regulation of migration behavior. We also found that mean population arrival dates to the colony changed from year to year and they were influenced by moon phases. Returns at their colonies occurred around the last full moon of the austral winter, suggesting that moon cycle is used by birds to synchronize their arrival. Secondly, variations of day-time activity were sinusoidal and correlated to seasonal changes of daylength. We thus hypothesize that the photoperiod could directly affect the behavior of the birds at sea. Night-time at-sea activity exhibited a clear cycle of 29.2 days, suggesting that nocturnal foraging was highly regulated by moon phase, particularly during the non-breeding season. To our knowledge, this is the first study to document a mixed regulation of the behavior of a wild bird by photoperiod and moon phases throughout its annual cycle. PMID:22110711

  16. Reviewing Dengue: Still a Neglected Tropical Disease?

    PubMed Central

    Horstick, Olaf; Tozan, Yesim; Wilder-Smith, Annelies

    2015-01-01

    Dengue is currently listed as a “neglected tropical disease” (NTD). But is dengue still an NTD or not? Classifying dengue as an NTD may carry advantages, but is it justified? This review considers the criteria for the definition of an NTD, the current diverse lists of NTDs by different stakeholders, and the commonalities and differences of dengue with other NTDs. We also review the current research gaps and research activities and the adequacy of funding for dengue research and development (R&D) (2003–2013). NTD definitions have been developed to a higher precision since the early 2000s, with the following main features: NTDs are characterised as a) poverty related, b) endemic to the tropics and subtropics, c) lacking public health attention, d) having poor research funding and shortcomings in R&D, e) usually associated with high morbidity but low mortality, and f) often having no specific treatment available. Dengue meets most of these criteria, but not all. Although dengue predominantly affects resource-limited countries, it does not necessarily only target the poor and marginalised in those countries. Dengue increasingly attracts public health attention, and in some affected countries it is now a high profile disease. Research funding for dengue has increased exponentially in the past two decades, in particular in the area of dengue vaccine development. However, despite advances in dengue research, dengue epidemics are increasing in frequency and magnitude, and dengue is expanding to new areas. Specific treatment and a highly effective vaccine remain elusive. Major research gaps exist in the area of integrated surveillance and vector control. Hence, although dengue differs from many of the NTDs, it still meets important criteria commonly used for NTDs. The current need for increased R&D spending, shared by dengue and other NTDs, is perhaps the key reason why dengue should continue to be considered an NTD. PMID:25928673

  17. Cloud Condensation Nuclei Measurements in Tropical Cyclones

    NASA Astrophysics Data System (ADS)

    Hudson, J. G.; Simpson, J.

    2002-05-01

    The first measurements of cloud condensation nuclei (CCN) within and around tropical cyclones were made with the Desert Research Institute (DRI) CCN spectrometer (Hudson 1989) from a NOAA P-3 Hurricane Hunter aircraft throughout the 2001 season. Two penetrations of the closed eye of Hurricane Erin off the northeast US coast on Sept. 10 showed concentrations consistently well in excess of 1000 per cubic cm at approximately 1.4% supersaturation. Simultaneous condensation nuclei (CN--total particle) concentrations were consistently well in excess of 2000 per cubic cm throughout these closed eye penetrations. These within eye measurements at 4 km altitude far exceeded CCN and CN measurements just outside of the storm at similar altitudes--300 and 600 per cubic cm respectively. These CCN and CN concentrations within this closed eye were far above concentrations in maritime air masses; they are characteristic of continental or polluted air masses. Although there was a possibility that Saharan dust may have gotten into this storm these sub tenth micrometer particles are much too small and much too numerous to be dust. Such high concentrations may have originated from European air pollution, which may have been transported by similar airflow patterns to those that carry Saharan dust across the Atlantic. These high concentrations may be a manifestation of descending air that brings higher concentrations that are often characteristic of the upper troposphere (Clarke and Kapustin 2002). Later in the month measurements in Humberto showed highly variable CCN and CN concentrations that ranged from less than 5 per cubic cm to more than 1000 per cubic cm over km scale distances within and around the open eye of this tropical storm/hurricane. These very low concentrations suggest strong cloud scavenging. Clarke, A.D. and V.N. Kapustin, J. Atmos. Sci., 59, 363-382, 2002. Hudson, J.G., J. Atmos. & Ocean. Tech., 6, 1055-1065, 1989.

  18. Netting bias in tropical bird studies

    USGS Publications Warehouse

    Coates-Estrada, R.; Dowell, B.A.; Fallon, J.E.; Robbins, C.S.; Wilson, Marcia H.; Sader, Steven A.

    1995-01-01

    Mist netting is the method most commonly used for gathering quantitative information on birds in the American tropics. Point count surveys or other methods often are used in conjunction with netting to reduce some of the many biases associated with netting, specially the failure of stationary nets within 2 m of the ground to sample birds of the tall canopy. We compare totals by both methods. Even close to the ground there are biases related to time of day and mesh size that have not been addressed in tropical studies. Some researchers operate nets all day, others only in the morning or in the morning and evening. Since 1986 we have netted birds and conducted point count surveys at more than 130 sites representing a broad spectrum of habitats in Mexico, Belize, and Guatemala. Using data only from those days when we could operate nets continuously from about dawn to dusk, we compare capture rates throughout the day to show the bias per part-day operations for certain families and species of birds and for the ratio of neotropical migrants to resident birds. More than half of 5000+ birds captured were caught after noon. Trochilidae and parulinae were captured primarily in the morning, Dendrocolaptidae in the middle of the day. Tyrannidae were more active than most birds in early afternoon, and Turdinae had morning and evening peaks. At each site we use a combination of 30-mm and 36-mm nets. The 30-mm mesh consistently captured more seedeaters, gnatcatchers, and small warblers, whereas the 36-mm mesh was more effective for birds of thrush size and larger.

  19. Cloud Condensation Nuclei Measurements in Tropical Cyclones

    NASA Technical Reports Server (NTRS)

    Hudson, J. G.; Simpson, J.

    2002-01-01

    The first measurements of cloud condensation nuclei (CCN) within and around tropical cyclones were made with the Desert Research Institute (DRI) CCN spectrometer (Hudson 1909) from a NOAA P-3 Hurricane Hunter aircraft throughout the 2001 season. Two penetrations of the closed eye of Hurricane Erin off the northeast US coast on Sept. 10 showed concentrations consistently well in excess of 1000 per cubic cm at approximately 1.4% supersaturation. Simultaneous condensation nuclei (CN--total particle) concentrations were consistently well in excess of 2000 per cubic cm throughout these closed eye penetrations. These within eye measurements at 4 km altitude for exceeded CCN and CN measurements just outside of the storm at similar altitudes--300 and 600 per cubic cm respectively. These CCN and CN concentrations within this closed eye were far above concentrations in maritime air masses; they are characteristic of continental or polluted air masses. Although there was a possibility that Saharan duct may have gotten into this storm these sub tenth micrometer particles are much too small and much too numerous to be dust. Such high concentrations may have originated from European air pollution, which may have been transported by similar airflow patterns to those that carry Saharan dust across the Atlantic. These high concentrations may be a manifestation of descending air that brings higher concentrations that are often characteristic of the upper troposphere (Clarke and Kapustin 2002). Later in the month measurements in Humberto showed highly variable CCN and CN concentrations that ranged from lots than 5 per cubic cm to more than 1000 per Cubic cm over km scale distances within and around the open eye of this tropical storm/hurricane. These very low concentrations suggest strong cloud scavenging.

  20. Celestial moderation of tropical seabird behavior.

    PubMed

    Pinet, Patrick; Jaeger, Audrey; Cordier, Emmanuel; Potin, Gaël; Le Corre, Matthieu

    2011-01-01

    Most animals, including birds, have cyclic life histories and numerous studies generally conducted on captive animals have shown that photoperiod is the main factor influencing this periodicity. Moon cycles can also affect periodic behavior of birds. Few studies have investigated the influence of these environmental cues in natural settings, and particularly in tropical areas where the change in photoperiod is slight and some bird species keep cyclic behaviors. Using miniaturized light sensors, we simultaneously investigated under natural conditions the influence of photoperiod and moon phases on the migration dates and at-sea activity of a tropical seabird species, the Barau's petrel, throughout its annual cycle. Firstly, we found that birds consistently started their pre- and post-breeding migrations at precise dates corresponding in both cases to a day-duration of 12.5 hours, suggesting a strong influence of the photoperiod in the regulation of migration behavior. We also found that mean population arrival dates to the colony changed from year to year and they were influenced by moon phases. Returns at their colonies occurred around the last full moon of the austral winter, suggesting that moon cycle is used by birds to synchronize their arrival. Secondly, variations of day-time activity were sinusoidal and correlated to seasonal changes of daylength. We thus hypothesize that the photoperiod could directly affect the behavior of the birds at sea. Night-time at-sea activity exhibited a clear cycle of 29.2 days, suggesting that nocturnal foraging was highly regulated by moon phase, particularly during the non-breeding season. To our knowledge, this is the first study to document a mixed regulation of the behavior of a wild bird by photoperiod and moon phases throughout its annual cycle.

  1. Pollinator recognition by a keystone tropical plant

    PubMed Central

    Betts, Matthew G.; Hadley, Adam S.; Kress, W. John

    2015-01-01

    Understanding the mechanisms enabling coevolution in complex mutualistic networks remains a central challenge in evolutionary biology. We show for the first time, to our knowledge, that a tropical plant species has the capacity to discriminate among floral visitors, investing in reproduction differentially across the pollinator community. After we standardized pollen quality in 223 aviary experiments, successful pollination of Heliconia tortuosa (measured as pollen tube abundance) occurred frequently when plants were visited by long-distance traplining hummingbird species with specialized bills (x¯ pollen tubes = 1.21 ± 0.12 SE) but was reduced 5.7 times when visited by straight-billed territorial birds (x¯ pollen tubes = 0.20 ± 0.074 SE) or insects. Our subsequent experiments revealed that plants use the nectar extraction capacity of tropical hummingbirds, a positive function of bill length, as a cue to turn on reproductively. Furthermore, we show that hummingbirds with long bills and high nectar extraction efficiency engaged in daily movements at broad spatial scales (∼1 km), but that territorial species moved only short distances (<100 m). Such pollinator recognition may therefore affect mate selection and maximize receipt of high-quality pollen from multiple parents. Although a diffuse pollinator network is implied, because all six species of hummingbirds carry pollen of H. tortuosa, only two species with specialized bills contribute meaningfully to its reproduction. We hypothesize that this pollinator filtering behavior constitutes a crucial mechanism facilitating coevolution in multispecies plant–pollinator networks. However, pollinator recognition also greatly reduces the number of realized pollinators, thereby rendering mutualistic networks more vulnerable to environmental change. PMID:25733902

  2. Pollinator recognition by a keystone tropical plant.

    PubMed

    Betts, Matthew G; Hadley, Adam S; Kress, W John

    2015-03-17

    Understanding the mechanisms enabling coevolution in complex mutualistic networks remains a central challenge in evolutionary biology. We show for the first time, to our knowledge, that a tropical plant species has the capacity to discriminate among floral visitors, investing in reproduction differentially across the pollinator community. After we standardized pollen quality in 223 aviary experiments, successful pollination of Heliconia tortuosa (measured as pollen tube abundance) occurred frequently when plants were visited by long-distance traplining hummingbird species with specialized bills (mean pollen tubes = 1.21 ± 0.12 SE) but was reduced 5.7 times when visited by straight-billed territorial birds (mean pollen tubes = 0.20 ± 0.074 SE) or insects. Our subsequent experiments revealed that plants use the nectar extraction capacity of tropical hummingbirds, a positive function of bill length, as a cue to turn on reproductively. Furthermore, we show that hummingbirds with long bills and high nectar extraction efficiency engaged in daily movements at broad spatial scales (∼1 km), but that territorial species moved only short distances (<100 m). Such pollinator recognition may therefore affect mate selection and maximize receipt of high-quality pollen from multiple parents. Although a diffuse pollinator network is implied, because all six species of hummingbirds carry pollen of H. tortuosa, only two species with specialized bills contribute meaningfully to its reproduction. We hypothesize that this pollinator filtering behavior constitutes a crucial mechanism facilitating coevolution in multispecies plant-pollinator networks. However, pollinator recognition also greatly reduces the number of realized pollinators, thereby rendering mutualistic networks more vulnerable to environmental change.

  3. Urgent need for warming experiments in tropical forests.

    PubMed

    Cavaleri, Molly A; Reed, Sasha C; Smith, W Kolby; Wood, Tana E

    2015-06-01

    Although tropical forests account for only a fraction of the planet's terrestrial surface, they exchange more carbon dioxide with the atmosphere than any other biome on Earth, and thus play a disproportionate role in the global climate. In the next 20 years, the tropics will experience unprecedented warming, yet there is exceedingly high uncertainty about their potential responses to this imminent climatic change. Here, we prioritize research approaches given both funding and logistical constraints in order to resolve major uncertainties about how tropical forests function and also to improve predictive capacity of earth system models. We investigate overall model uncertainty of tropical latitudes and explore the scientific benefits and inevitable trade-offs inherent in large-scale manipulative field experiments. With a Coupled Model Intercomparison Project Phase 5 analysis, we found that model variability in projected net ecosystem production was nearly 3 times greater in the tropics than for any other latitude. Through a review of the most current literature, we concluded that manipulative warming experiments are vital to accurately predict future tropical forest carbon balance, and we further recommend the establishment of a network of comparable studies spanning gradients of precipitation, edaphic qualities, plant types, and/or land use change. We provide arguments for long-term, single-factor warming experiments that incorporate warming of the most biogeochemically active ecosystem components (i.e. leaves, roots, soil microbes). Hypothesis testing of underlying mechanisms should be a priority, along with improving model parameterization and constraints. No single tropical forest is representative of all tropical forests; therefore logistical feasibility should be the most important consideration for locating large-scale manipulative experiments. Above all, we advocate for multi-faceted research programs, and we offer arguments for what we consider the most

  4. Urgent need for warming experiments in tropical forests

    USGS Publications Warehouse

    Calaveri, Molly A.; Reed, Sasha C.; Smith, W. Kolby; Wood, Tana E.

    2015-01-01

    Although tropical forests account for only a fraction of the planet's terrestrial surface, they exchange more carbon dioxide with the atmosphere than any other biome on Earth, and thus play a disproportionate role in the global climate. In the next 20 years, the tropics will experience unprecedented warming, yet there is exceedingly high uncertainty about their potential responses to this imminent climatic change. Here, we prioritize research approaches given both funding and logistical constraints in order to resolve major uncertainties about how tropical forests function and also to improve predictive capacity of earth system models. We investigate overall model uncertainty of tropical latitudes and explore the scientific benefits and inevitable trade-offs inherent in large-scale manipulative field experiments. With a Coupled Model Intercomparison Project Phase 5 analysis, we found that model variability in projected net ecosystem production was nearly 3 times greater in the tropics than for any other latitude. Through a review of the most current literature, we concluded that manipulative warming experiments are vital to accurately predict future tropical forest carbon balance, and we further recommend the establishment of a network of comparable studies spanning gradients of precipitation, edaphic qualities, plant types, and/or land use change. We provide arguments for long-term, single-factor warming experiments that incorporate warming of the most biogeochemically active ecosystem components (i.e. leaves, roots, soil microbes). Hypothesis testing of underlying mechanisms should be a priority, along with improving model parameterization and constraints. No single tropical forest is representative of all tropical forests; therefore logistical feasibility should be the most important consideration for locating large-scale manipulative experiments. Above all, we advocate for multi-faceted research programs, and we offer arguments for what we consider the most

  5. Study of the nutrient distribution in root tips of the tropical forage Brachiaria

    NASA Astrophysics Data System (ADS)

    Pineda, C. A.; Wenzl, P.; Mayer, J.; Mesjasz-Przybylowicz, J.; Przybylowicz, W. J.; Prozesky, V. M.

    1997-07-01

    A Brachiaria breeding project is being conducted at CIAT, Colombia to combine acid soil adaptation of B. decumbens with other favourable traits of Brachiaria species that are less adapted to acid soils. Micro-PIXE was applied to investigate nutrient uptake and distribution in root tips of different species grown in hydroponic culture under control and simulated acid soil stress conditions. Different sample measurement approaches were evaluated, including: (1) linear scans with single point measurements along the root axis; (2) mapping of whole root tips; and (3) mapping of root cross sections. Different tissue types could be distinguished on the base of differences in nutrient concentrations and/or Al stress. Al, if supplied under nutrient stress conditions, increased P accumulation in the central vascular tissue of the meristematic and elongation zone of B. decumbens and B. brizantha. Furthermore, a negative correlation was found between Al and Cl accumulation in the root cap of B. decumbens.

  6. Selected gastrointestinal pathologies in tropical sub-Saharan Africa.

    PubMed Central

    Balint, G. A.

    1998-01-01

    Doctors need to be well informed about differences in the presentation of certain diseases in tropical and temperate climates. In this article the characteristics of some gastrointestinal diseases, as they recur in sub-Saharan Africa, are briefly reviewed. Diseases of the stomach--including ulcertaion and cancer--are uncommon in Africa, although duodenal ulcer is common all over the tropics. In contrast, colorectal cancer is an extremely rare illness in sub-Saharan Africa, while hepatocellular carcinoma is much commoner than in Europe or North America and the very high incidence of this tumour in tropical countries is cause for concern. PMID:9648363

  7. Monsoon circulations and tropical heterogeneous chlorine chemistry in the stratosphere

    NASA Astrophysics Data System (ADS)

    Solomon, Susan; Kinnison, Doug; Garcia, Rolando R.; Bandoro, Justin; Mills, Michael; Wilka, Catherine; Neely, Ryan R.; Schmidt, Anja; Barnes, John E.; Vernier, Jean-Paul; Höpfner, Michael

    2016-12-01

    Model simulations presented in this paper suggest that transport processes associated with the summer monsoons bring increased abundances of hydrochloric acid into contact with liquid sulfate aerosols in the cold tropical lowermost stratosphere, leading to heterogeneous chemical activation of chlorine species. The calculations indicate that the spatial and seasonal distributions of chlorine monoxide and chlorine nitrate near the monsoon regions of the northern hemisphere tropical and subtropical lowermost stratosphere could provide indicators of heterogeneous chlorine processing. In the model, these processes impact the local ozone budget and decrease ozone abundances, implying a chemical contribution to longer-term northern tropical ozone profile changes at 16-19 km.

  8. Coastal flooding by tropical cyclones and sea-level rise.

    PubMed

    Woodruff, Jonathan D; Irish, Jennifer L; Camargo, Suzana J

    2013-12-05

    The future impacts of climate change on landfalling tropical cyclones are unclear. Regardless of this uncertainty, flooding by tropical cyclones will increase as a result of accelerated sea-level rise. Under similar rates of rapid sea-level rise during the early Holocene epoch most low-lying sedimentary coastlines were generally much less resilient to storm impacts. Society must learn to live with a rapidly evolving shoreline that is increasingly prone to flooding from tropical cyclones. These impacts can be mitigated partly with adaptive strategies, which include careful stewardship of sediments and reductions in human-induced land subsidence.

  9. Water hyacinth as indicator of heavy metal pollution the tropics

    SciTech Connect

    Gonzalez, H.; Otero, M. ); Lodenius, M. )

    1989-12-01

    The water hyacinth (Eichhornia crassipes) is a common aquatic plant in many tropical countries. Its ability absorb nutrients and other elements from the water has made it possible to use it for water purification purposes. Eichhornia, especially stems and leaves, have been successfully used as indicators of heavy metal pollution in tropical countries. The uptake of heavy metals in this plant is stronger in the roots than in the floating shoots. Metallothionein-like compounds have been found from roots of this species after cadmium exposure. The purpose of this investigation was to study the possibilities of using roots of water hyacinth as a biological indicator of metal pollution in tropical aquatic ecosystems.

  10. Eddies and Tropical Instability Waves in the eastern tropical Pacific: A review

    NASA Astrophysics Data System (ADS)

    Willett, Cynthia S.; Leben, Robert R.; Lavín, Miguel F.

    2006-05-01

    Mesoscale eddies and tropical instability waves in the eastern tropical Pacific, first revealed by satellite infrared imagery, play an important role in the dynamics and biology of the region, and in the transfer of mass, energy, heat, and biological constituents from the shelf to the deep ocean and across the equatorial currents. From boreal late autumn to early spring, four to 18 cyclonic or anticyclonic eddies are formed off the coastal region between southern Mexico and Panama. The anticyclonic gyres, which tend to be larger and last longer than the cyclonic ones, are the best studied: they typically are ∼180-500 km in diameter, depress the pycnocline from ∼60 to 145 m at the eddy center, have swirl speeds in excess of 1 m s -1, migrate west at velocities ranging from 11 to 19 cm s -1 (with a slight southward component), and maintain a height signature of up to 30 cm. The primary generating agents for these eddies are the strong, intermittent wind jets that blow across the isthmus of Tehuantepec in Mexico, the lake district in Nicaragua and Costa Rica, and the Panama canal. Other proposed eddy-generating mechanisms are the conservation of vorticity as the North Equatorial Counter Current (NECC) turns north on reaching America, and the instability of coastally trapped waves/currents. Tropical Instability Waves (TIWs) are perturbations in the SST fronts on either side of the equatorial cold tongue. They produce SST variations on the order of 1-2 °C, have periods of 20-40 days, wavelengths of 1000-2000 km, phase speeds of around 0.5 m s -1 and propagate westward both north and south of the Equator. The Tropical Instability Vortices (TIVs) are a train of westward-propagating anticyclonic eddies associated with the TIWs. They exhibit eddy currents exceeding 1.3 m s -1, a westward phase propagation speed between 30 and 40 km d -1, a signature above the pycnocline, and eastward energy propagation. Like the TIWs, they result from the latitudinal barotropically

  11. Current status of tropical fruit breeding and genetics for three tropical fruit species cultivated in Japan: pineapple, mango, and papaya

    PubMed Central

    Ogata, Tatsushi; Yamanaka, Shinsuke; Shoda, Moriyuki; Urasaki, Naoya; Yamamoto, Toshiya

    2016-01-01

    Tropical fruit crops are predominantly produced in tropical and subtropical developing countries, but some are now grown in southern Japan. Pineapple (Ananas comosus), mango (Mangifera indica) and papaya (Carica papaya) are major tropical fruits cultivated in Japan. Modern, well-organized breeding systems have not yet been developed for most tropical fruit species. Most parts of Japan are in the temperate climate zone, but some southern areas such as the Ryukyu Islands, which stretch from Kyushu to Taiwan, are at the northern limits for tropical fruit production without artificial heating. In this review, we describe the current status of tropical fruit breeding, genetics, genomics, and biotechnology of three main tropical fruits (pineapple, mango, and papaya) that are cultivated and consumed in Japan. More than ten new elite cultivars of pineapple have been released with improved fruit quality and suitability for consumption as fresh fruit. New challenges and perspectives for obtaining high fruit quality are discussed in the context of breeding programs for pineapple. PMID:27069392

  12. What was tropical about tropical neurasthenia? The utility of the diagnosis in the management of British East Africa.

    PubMed

    Crozier, Anna

    2009-10-01

    During the first quarter of the twentieth century, tropical neurasthenia was a popular diagnosis for a nervous condition experienced by Europeans in the topics. Tropical neurasthenia was not psychosis or madness, but was rather an ennui or loss of "edge" brought about by the strains of tropical life, especially the unfamiliar, hot climate. A catch-all for a wide range of symptoms, many missionaries, colonial staff, and settlers throughout Empire were repatriated because of it, although this article concentrates on Colonial Service employees working in British East Africa. While histories of tropical neurasthenia have usefully (and correctly) explained this diagnosis as an expression of the anxieties of the colonial regime, this article adds a new dimension to the historiography by arguing that tropical neurasthenia can only be properly understood as a hybrid form, dependent not only upon the peculiarities of the colonial situation, but also descended from British and American clinical understandings of neurasthenia. Moreover, once tropical neurasthenia is properly acknowledged as being typical of clinical understandings of the time, other reasons for its comparatively long endurance in the colonial situation emerge. This article shows that tropical neurasthenia remained a popular diagnosis in East Africa not only because (as historians have argued previously) it dovetailed with prevalent ideas of colonial acclimatization, but also because it was a practically useful tool in the management and regulation of colonial personnel.

  13. NASA's GPM Sees Towering Thunderstorms in Intensifying Tropical Storm Earl

    NASA Video Gallery

    The Global Precipitation Measurement mission, or GPM, core observatory satellite passed over intensifying tropical storm Earl in the Caribbean Sea northeast of Honduras on Aug. 2, 2016 at 11:56 p.m...

  14. NASA Sees Heavy Rain in Arabian Sea Tropical Cyclone

    NASA Video Gallery

    On June 29, GPM showed Tropical Cyclone 02A had a few powerful convective thunderstorms southwest of the center of circulation were dropping rain at the extreme rate of over 209 mm (8.2 inches) per...

  15. 19. View northwest of Tropic Chamber reciprocal compressors (typical), in ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    19. View northwest of Tropic Chamber reciprocal compressors (typical), in machine area. - Natick Research & Development Laboratories, Climatic Chambers Building, U.S. Army Natick Research, Development & Engineering Center (NRDEC), Natick, Middlesex County, MA

  16. 9. View to west of Tropic Dressing Room (typical). ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    9. View to west of Tropic Dressing Room (typical). - Natick Research & Development Laboratories, Climatic Chambers Building, U.S. Army Natick Research, Development & Engineering Center (NRDEC), Natick, Middlesex County, MA

  17. 18. View north of Tropic Chamber Worthington centrifugal compressor and ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    18. View north of Tropic Chamber Worthington centrifugal compressor and control panel, in machine area. - Natick Research & Development Laboratories, Climatic Chambers Building, U.S. Army Natick Research, Development & Engineering Center (NRDEC), Natick, Middlesex County, MA

  18. 14. View north of Tropic wind tunnel and frontal view ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    14. View north of Tropic wind tunnel and frontal view of main fan (typical). - Natick Research & Development Laboratories, Climatic Chambers Building, U.S. Army Natick Research, Development & Engineering Center (NRDEC), Natick, Middlesex County, MA

  19. 15. View northeast of main control panels, Arctic and Tropic ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    15. View northeast of main control panels, Arctic and Tropic Chambers, in machine area. - Natick Research & Development Laboratories, Climatic Chambers Building, U.S. Army Natick Research, Development & Engineering Center (NRDEC), Natick, Middlesex County, MA

  20. 21. PHOTOCOPY OF PHOTOGRAPH. view north of Tropic Chamber, ca. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    21. PHOTOCOPY OF PHOTOGRAPH. view north of Tropic Chamber, ca. 1955. (Source: NRDEC). - Natick Research & Development Laboratories, Climatic Chambers Building, U.S. Army Natick Research, Development & Engineering Center (NRDEC), Natick, Middlesex County, MA

  1. Tropical Storm Gordon Makes a U-Turn

    NASA Video Gallery

    An animation of satellite observations from August 14-17, 2012, shows the birth and strengthening of the Atlantic Ocean's Tropical Storm Gordon making a U-turn and heading back to the east. This vi...

  2. Seed Dispersal and Spatial Pattern in Tropical Trees

    PubMed Central

    Seidler, Tristram G; Plotkin, Joshua B

    2006-01-01

    Theories of tropical tree diversity emphasize dispersal limitation as a potential mechanism for separating species in space and reducing competitive exclusion. We compared the dispersal morphologies, fruit sizes, and spatial distributions of 561 tree species within a fully mapped, 50-hectare plot of primary tropical forest in peninsular Malaysia. We demonstrate here that the extent and scale of conspecific spatial aggregation is correlated with the mode of seed dispersal. This relationship holds for saplings as well as for mature trees. Phylogenetically independent contrasts confirm that the relationship between dispersal and spatial pattern is significant even after controlling for common ancestry among species. We found the same qualitative results for a 50-hectare tropical forest plot in Panama. Our results provide broad empirical evidence for the importance of dispersal mode in establishing the long-term community structure of tropical forests. PMID:17048988

  3. A GPM Satellite Flyover of Tropical Storm Darby

    NASA Video Gallery

    The animated flyby from NASA's GPM satellite shows Tropical Storm Darby in 3-D on July 23. GPM saw a line of intense storms in Darby, located southeast of the big island of Hawaii was dropping rain...

  4. Brazil's neglected tropical diseases: an overview and a report card.

    PubMed

    Hotez, Peter J; Fujiwara, Ricardo T

    2014-08-01

    Today, the nation of Brazil leads the Western Hemisphere in terms of the number of its citizens living with neglected tropical diseases (NTDs). These diseases continue to trap Brazil's "bottom 20 million" in extreme poverty.

  5. Satellite Movie Shows Three Tropical Cyclones in Eastern Pacific

    NASA Video Gallery

    This animation of NOAA's GOES-Wast satellite imagery from August 2 through 4 shows the movement of Tropical Depression Genevieve (left) southwest of Hawaii, Hurricane Iselle (center) in the Eastern...

  6. Heavy Rain Seen in Tropical Depression Ma-on

    NASA Video Gallery

    On Nov. 10, 2016, GPM's radar (Ku Band) found rain falling at a rate of over 198 millimeters (7.8 inches) per hour in an area east of the tropical depression's center. Storm tops of many convective...

  7. GPM Satellite Sees Tropical Depression 9 Dropping Heavy Rainfall

    NASA Video Gallery

    On Aug. 29 at 2:56 a.m. EDT GPM showed that precipitation was intense in convective storms in Tropical Depression 9 over the western side of Cuba. GPM revealed that some showers were coming down at...

  8. Satellite Movie Shows Andres Weaken to a Tropical Storm

    NASA Video Gallery

    This animation of imagery from NOAA's GOES-West satellite from June 1 to 3 shows Hurricane Andres eye disappear and weaken to a tropical storm in the Eastern Pacific Ocean, south of Baja California...

  9. A 3-D Look at Post-Tropical Cyclone Hermine

    NASA Video Gallery

    This 3-D flyby animation of GPM imagery shows Post-Tropical Storm Hermine on Sept. 6. Rain was falling at a rate of over 1.1 inches (27 mm) per hour between the Atlantic coast and Hermine's center ...

  10. Hypocrealean fungi from a tropical rainforest in Queensland, Australia

    Technology Transfer Automated Retrieval System (TEKTRAN)

    During a weeklong Mycoblitz in the Atherton Tablelands of Queensland, Australia, many hypocrealean fungi were collected. Preliminary identifications indicate that many of these specimens are part of the pantropical hypocrealean biota. Some of the common tropical species collected include: Bionectria...

  11. Tropical rainforest response to marine sky brightening climate engineering

    NASA Astrophysics Data System (ADS)

    Muri, Helene; Niemeier, Ulrike; Kristjánsson, Jón Egill

    2015-04-01

    Tropical forests represent a major atmospheric carbon dioxide sink. Here the gross primary productivity (GPP) response of tropical rainforests to climate engineering via marine sky brightening under a future scenario is investigated in three Earth system models. The model response is diverse, and in two of the three models, the tropical GPP shows a decrease from the marine sky brightening climate engineering. Partial correlation analysis indicates precipitation to be important in one of those models, while precipitation and temperature are limiting factors in the other. One model experiences a reversal of its Amazon dieback under marine sky brightening. There, the strongest partial correlation of GPP is to temperature and incoming solar radiation at the surface. Carbon fertilization provides a higher future tropical rainforest GPP overall, both with and without climate engineering. Salt damage to plants and soils could be an important aspect of marine sky brightening.

  12. GOES-East Animation of Tropical Storm Erika

    NASA Video Gallery

    This animation of GOES-East visible and infrared imagery shows the development and track of Tropical Storm Erika from Aug. 25 to Aug. 28, 2015 ending in eastern Caribbean Sea. Credit: NASA/NOAA GOE...

  13. Rainfall Totals from the Tropical Cyclones Passing Over Philippines

    NASA Video Gallery

    Rainfall totals from the TRMM satellite of all tropical cyclones that passed through the Philippines from January through November 11, 2013. Red indicated areas where rainfall totals were greater t...

  14. Satellite Sees Tropical Storm Chantal Move Over Hispaniola

    NASA Video Gallery

    This NOAA GOES-East satellite animation from July 6 to July 10 shows the development of Tropical Storm Chantal in the Atlantic Ocean and movement over Hispaniola by July 10. TRT 0:06 Credit: NASA/N...

  15. Soil science in the tropics - the next 75 years

    SciTech Connect

    Theng, B.K.G. )

    1991-01-01

    This paper does not describe the future course of soil science in the tropics. Rather, it is concerned with some soil-related issues that tropical countries will have to face, and resolve, in the short and medium term. The tropics chosen for discussion here are deforestation, the resultant degradation of the soil resource, and soil management for continuous crop production, with particular reference to the humid tropics. The development and implementation of sustainable farming systems in order to arrest, if not reverse, soil degradation must rest on the willing cooperation of the people involved. Soil conservation programs should not only be acceptable to, but also be compatible with the socio-economic aspirations and conditions of the local community.

  16. [Tropical dermatology training in the Bundeswehr: Deployment in Manaus, Brazil].

    PubMed

    Fischer, M

    2015-05-01

    Training in tropical dermatology at the Fundação de Medicina tropical (FMT-AM) in Manaus, Brazil, offers an ideal opportunity to become familiar with the broad spectrum of tropical skin-diseases which are endemic in the tropical rainforest of the Amazon region. Besides frequently observed cases of cutaneous leishmaniasis of the new world, mucocutaneous forms of leishmaniasis and all entities of the different deep mycoses of South America are also regularly diagnosed. Of special importance in the dermatological care of the population is the early diagnosis of all clinical forms of leprosy and the long-term care of HIV patients. Modern diagnostics, including histopathology and molecular biology analytical methods, enable patients at the FMT-AM to be diagnosed without having to solely rely on clinical presentation and epidemiological data.

  17. TRMM Sees Rainfall Totals from Tropical Cyclone Guito

    NASA Video Gallery

    This animation of rainfall gathered from February 11-19, 2014 by NASA's TRMM satellite revealed that Tropical Cyclone Guito produced as much as 16.9 inches/430 mm of rainfall in the center of the M...

  18. Energy Design Guidelines for High Performance Schools: Tropical Island Climates

    SciTech Connect

    2004-11-01

    Design guidelines outline high performance principles for the new or retrofit design of K-12 schools in tropical island climates. By incorporating energy improvements into construction or renovation plans, schools can reduce energy consumption and costs.

  19. Diagnostic budgets of analyzed and modelled tropical plumes

    NASA Technical Reports Server (NTRS)

    Mcguirk, James P.; Vest, Gerry W.

    1993-01-01

    Blackwell et al. successfully simulated tropical plumes in a global barotropic model valid at 200 mb. The plume evolved in response to strong equatorial convergence which simulated a surge in the Walker Circulation. The defining characteristics of simulated plumes are: a subtropical jet with southerlies emanating from the deep tropics; a tropical/mid-latitude trough to the west; a convergence/divergence dipole straddling the trough; and strong cross contour flow at the tropical base of the jet. Diagnostic budgets of vorticity, divergence, and kinetic energy are calculated to explain the evolution of the modelled plumes. Budgets describe the unforced (basic) state, forced plumes, forced cases with no plumes, and ECMWF analyzed plumes.

  20. Satellite Sees Hurricane Leslie and Tropical Storm Michael in Atlantic

    NASA Video Gallery

    A movie of satellite observations from Sept. 2-5, 2012, shows Leslie strengthen into a Hurricane on September 5 as it nears Bermuda, and tiny Tropical Storm Michael in the central Atlantic Ocean. T...

  1. NASA Sees Tropical Storm Malakas in 3-D

    NASA Video Gallery

    This animated 3-D flyby of Tropical Storm Malakas was created by radar data from the GPM core satellite. On Sept. 13 at 0111 UTC GPM's instruments showed that Malakas contained exceptionally heavy ...

  2. Agricultural expansion and its impacts on tropical nature.

    PubMed

    Laurance, William F; Sayer, Jeffrey; Cassman, Kenneth G

    2014-02-01

    The human population is projected to reach 11 billion this century, with the greatest increases in tropical developing nations. This growth, in concert with rising per-capita consumption, will require large increases in food and biofuel production. How will these megatrends affect tropical terrestrial and aquatic ecosystems and biodiversity? We foresee (i) major expansion and intensification of tropical agriculture, especially in Sub-Saharan Africa and South America; (ii) continuing rapid loss and alteration of tropical old-growth forests, woodlands, and semi-arid environments; (iii) a pivotal role for new roadways in determining the spatial extent of agriculture; and (iv) intensified conflicts between food production and nature conservation. Key priorities are to improve technologies and policies that promote more ecologically efficient food production while optimizing the allocation of lands to conservation and agriculture.

  3. 23. PHOTOCOPY OF PHOTOGRAPH. View west of Tropic Chamber refrigeration ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    23. PHOTOCOPY OF PHOTOGRAPH. View west of Tropic Chamber refrigeration equipment, ca. 1955. (Source: NRDEC). - Natick Research & Development Laboratories, Climatic Chambers Building, U.S. Army Natick Research, Development & Engineering Center (NRDEC), Natick, Middlesex County, MA

  4. 17. View northwest of Tropic Chamber refrigeration equipment, in machine ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    17. View northwest of Tropic Chamber refrigeration equipment, in machine area. - Natick Research & Development Laboratories, Climatic Chambers Building, U.S. Army Natick Research, Development & Engineering Center (NRDEC), Natick, Middlesex County, MA

  5. Consequences of defaunation for a tropical tree community.

    PubMed

    Harrison, Rhett D; Tan, Sylvester; Plotkin, Joshua B; Slik, Ferry; Detto, Matteo; Brenes, Tania; Itoh, Akira; Davies, Stuart J

    2013-05-01

    Hunting affects a considerably greater area of the tropical forest biome than deforestation and logging combined. Often even large remote protected areas are depleted of a substantial proportion of their vertebrate fauna. However, understanding of the long-term ecological consequences of defaunation in tropical forests remains poor. Using tree census data from a large-scale plot monitored over a 15-year period since the approximate onset of intense hunting, we provide a comprehensive assessment of the immediate consequences of defaunation for a tropical tree community. Our data strongly suggest that over-hunting has engendered pervasive changes in tree population spatial structure and dynamics, leading to a consistent decline in local tree diversity over time. However, we do not find any support for suggestions that over-hunting reduces above-ground biomass or biomass accumulation rate in this forest. To maintain critical ecosystem processes in tropical forests increased efforts are required to protect and restore wildlife populations.

  6. Satellite Movie Shows Development of Tropical Storm Julia

    NASA Video Gallery

    This animation of NOAA's GOES-East satellite imagery from Sept. 12 to Sept. 14 shows the development of Tropical Storm Julia over Florida and movement into Georgia. TRT 00:22 Credit: NASA/NOAA GOES...

  7. Tropical Cyclone Mahasen Rain Moving Into Bay Of Bengal

    NASA Video Gallery

    This animated TRMM Multisatellite Precipitation Analysis shows the rainfall that occurred with Tropical Cyclone Mahasen during the week of May 6 through 13, 2013 as it moved through the Bay of Beng...

  8. Satellite Shows Landfall and Movement of Tropical Storm Andrea

    NASA Video Gallery

    This NOAA GOES-East satellite animation shows the landfall and movement of Tropical Storm Andrea from June 5 to June 7. The video ends as Andrea's center was moving over South Carolina on its way u...

  9. A Tropical Ecology Field Program in Central America.

    ERIC Educational Resources Information Center

    Fisher, Ronald L., Jr.; McLaren, J. Philip

    1989-01-01

    Described is a field trip for high school and college students to the country of Belize to study tropical ecology. Discussed are planning and special considerations. Included are a sample schedule and a planning guide. (CW)

  10. Diagnosing the Ice Crystal Enhancement Factor in the Tropics

    NASA Technical Reports Server (NTRS)

    Zeng, Xiping; Tao, Wei-Kuo; Matsui, Toshihisa; Xie, Shaocheng; Lang, Stephen; Zhang, Minghua; Starr, David O'C; Li, Xiaowen; Simpson, Joanne

    2009-01-01

    Recent modeling studies have revealed that ice crystal number concentration is one of the dominant factors in the effect of clouds on radiation. Since the ice crystal enhancement factor and ice nuclei concentration determine the concentration, they are both important in quantifying the contribution of increased ice nuclei to global warming. In this study, long-term cloud-resolving model (CRM) simulations are compared with field observations to estimate the ice crystal enhancement factor in tropical and midlatitudinal clouds, respectively. It is found that the factor in tropical clouds is 10 3-104 times larger than that of mid-latitudinal ones, which makes physical sense because entrainment and detrainment in the Tropics are much stronger than in middle latitudes. The effect of entrainment/detrainment on the enhancement factor, especially in tropical clouds, suggests that cloud microphysical parameterizations should be coupled with subgrid turbulence parameterizations within CRMs to obtain a more accurate depiction of cloud-radiative forcing.

  11. GPM Satellite Flyby of Tropical Cyclone 03S

    NASA Video Gallery

    On January 25 at 6:51 p.m. EST (2351 UTC) the GPM satellite found rainfall rates in some of the bands of thunderstorms around the developing tropical cyclone were falling at a rate of almost 83 mm ...

  12. GPM Sees Heavy Rain in Tropical Cyclone Yvette

    NASA Video Gallery

    On Dec. 19, the GPM core satellite found Tropical Cyclone 02S was dropping rain at a rate of over 127 mm (5 inches) per hour in this area of intense convective showers where cloud tops reached alti...

  13. Saving Tropical Rain Forests through Teacher-Student Activism.

    ERIC Educational Resources Information Center

    Calhoun, Bruce

    1990-01-01

    Described are the formation, goals, and activities of a network of teachers and students designed to help raise consciousness about conservation topics. A two-week minicourse on tropical diversity, ecology, and society is outlined. (CW)

  14. GPM Satellite Sees Heavy Rainfall in Tropical Cyclone Carlos

    NASA Video Gallery

    The GPM core observatory satellite flew above tropical cyclone Carlos on February 7, 2017 at 1056 UTC and measured a few downpours in the bands west of the Carlos' center of circulation dropping ra...

  15. On the impact of the FGGE on tropical forecasts

    NASA Technical Reports Server (NTRS)

    Heckley, W. A.

    1985-01-01

    It has become evident from operational experience that a good forecast requires, in general, a good analysis. This is as true in the tropics as it is in the extratropics. One can find many examples of bad data being accepted by the analysis scheme and significantly degrading the subsequent forecast. Equally, a lack of data may result in a forecast completely missing the early development of, for example, a midlatitude cyclone or tropical depression. Also, single level data may be misinterpreted by an analysis scheme. These problems are compounded in the tropics by our relative ignorance of the dynamics, the necessarily crude descriptions of many important physical processes, and fundamental in analysis. The impact of the FGGE on tropical analysis/forecasting is reviewed.

  16. 46 CFR 42.30-20 - Seasonal Tropical Areas.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Hong Kong to the Port of Sual (Luzon Island), and the west coasts of the Islands of Luzon, Samar, and... area within the Great Barrier Reef included in the Tropical Zone, and by the east coast of...

  17. 46 CFR 42.30-20 - Seasonal Tropical Areas.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Hong Kong to the Port of Sual (Luzon Island), and the west coasts of the Islands of Luzon, Samar, and... area within the Great Barrier Reef included in the Tropical Zone, and by the east coast of...

  18. 46 CFR 42.30-20 - Seasonal Tropical Areas.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Hong Kong to the Port of Sual (Luzon Island), and the west coasts of the Islands of Luzon, Samar, and... area within the Great Barrier Reef included in the Tropical Zone, and by the east coast of...

  19. 46 CFR 42.30-20 - Seasonal Tropical Areas.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... Hong Kong to the Port of Sual (Luzon Island), and the west coasts of the Islands of Luzon, Samar, and... area within the Great Barrier Reef included in the Tropical Zone, and by the east coast of...

  20. 46 CFR 42.30-20 - Seasonal Tropical Areas.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... Hong Kong to the Port of Sual (Luzon Island), and the west coasts of the Islands of Luzon, Samar, and... area within the Great Barrier Reef included in the Tropical Zone, and by the east coast of...

  1. GOES-West animation of Tropical Storm Rick

    NASA Video Gallery

    This animation of visible and infrared imagery from NOAA's GOES-West satellite shows the weakening of Tropical Storm Rick into a remnant low pressure area from Nov. 21 to Nov. 23. Credit: NASA/NOAA...

  2. Satellite Tracks Tropical Storm Madeline and Hurricane Lester

    NASA Video Gallery

    This animation of NOAA's GOES-West satellite imagery from August 30 to September 2 shows Tropical Storm Madeline move past Hawaii and weaken to a depression and Hurricane Lester approaching the Haw...

  3. Distinct bacterial communities dominate tropical and temperate zone leaf litter.

    PubMed

    Kim, Mincheol; Kim, Woo-Sung; Tripathi, Binu M; Adams, Jonathan

    2014-05-01

    Little is known of the bacterial community of tropical rainforest leaf litter and how it might differ from temperate forest leaf litter and from the soils underneath. We sampled leaf litter in a similarly advanced stage of decay, and for comparison, we also sampled the surface layer of soil, at three tropical forest sites in Malaysia and four temperate forest sites in South Korea. Illumina sequencing targeting partial bacterial 16S ribosomal ribonucleic acid (rRNA) gene revealed that the bacterial community composition of both temperate and tropical litter is quite distinct from the soils underneath. Litter in both temperate and tropical forest was dominated by Proteobacteria and Actinobacteria, while soil is dominated by Acidobacteria and, to a lesser extent, Proteobacteria. However, bacterial communities of temperate and tropical litter clustered separately from one another on an ordination. The soil bacterial community structures were also distinctive to each climatic zone, suggesting that there must be a climate-specific biogeographical pattern in bacterial community composition. The differences were also found in the level of diversity. The temperate litter has a higher operational taxonomic unit (OTU) diversity than the tropical litter, paralleling the trend in soil diversity. Overall, it is striking that the difference in community composition between the leaf litter and the soil a few centimeters underneath is about the same as that between leaf litter in tropical and temperate climates, thousands of kilometers apart. However, one substantial difference was that the leaf litter of two tropical forest sites, Meranti and Forest Research Institute Malaysia (FRIM), was overwhelmingly dominated by the single genus Burkholderia, at 37 and 23 % of reads, respectively. The 454 sequencing result showed that most Burkholderia species in tropical leaf litter belong to nonpathogenic "plant beneficial" lineages. The differences from the temperate zone in the bacterial

  4. Urgent need for warming experiments in tropical forests

    NASA Astrophysics Data System (ADS)

    Cavaleri, Molly A.; Reed, Sasha C.; Kolby Smith, W.; Wood, Tana E.

    2015-04-01

    Tropical forests represent one of the planet's most active biogeochemical engines. Although only 15 % of the planet's terrestrial surface is comprised of tropical forests, they account for over 2/3 of live terrestrial plant biomass, nearly 1/3 of all soil carbon (C), and exchange more carbon dioxide (CO2) with the atmosphere than any other biome. In the coming decades, the tropics will experience unprecedented changes in temperature, rapid increases in atmospheric CO2 concentrations, and significant alterations in the timing and amount of rainfall. Given the disproportionate role tropical forests play in the global climate, combined with the high uncertainty surrounding their responses to change, funding agencies are increasingly interested in how these ecosystems will respond to future climatic conditions. Thus, it is imperative that the scientific community identify key research priorities to resolve major uncertainties about the functioning of tropical forests and to improve predictive capacity of earth system models. With these goals in mind, we ask (1) can we quantify the uncertainty in C balance response to climate change in the tropics? (2) why should we implement large-scale manipulation experiments in tropical forests? (3) how many environmental factors should be manipulated? (4) which environmental factor(s) to manipulate? and (5) at what spatial and temporal scales should these manipulations occur? We investigate overall model uncertainty of tropical latitudes with a Coupled Model Intercomparison Project Phase 5 (CMIP5) analysis and review current literature to discuss the scientific benefits and inevitable trade-offs inherent in large-scale manipulative field experiments. We discuss how to prioritize research approaches given both funding and logistical constraints in order to optimize the knowledge gained from the limited resources available for such research.

  5. Tropical Skin Diseases in Children: A Review-Part II.

    PubMed

    García-Romero, Maria Teresa; Lara-Corrales, Irene; Kovarik, Carrie L; Pope, Elena; Arenas, Roberto

    2016-05-01

    Tropical skin diseases are infectious conditions influenced by factors such as nutrition, housing, and the environment. Migration patterns have caused these conditions to be seen all around the world, not only in developing countries. Many of these diseases have a different presentation in childhood, which changes the diagnostic approach and management options. In this article, we review some of the most common tropical mycobacterial, protozoan, parasitic, and viral dermatologic conditions in children, including their epidemiologic, clinical, diagnostic, and therapeutic aspects.

  6. Incorporation of Tropical Cyclone Avoidance Into Automated Ship Scheduling

    DTIC Science & Technology

    2014-06-01

    TROPICAL CYCLONE AVOIDANCE INTO AUTOMATED SHIP SCHEDULING by Stephen W. Lantz June 2014 Thesis Advisor: Walter DeGrange Co-Advisor: Eva...COVERED Master’s Thesis 4. TITLE AND SUBTITLE INCORPORATION OF TROPICAL CYCLONE AVOIDANCE INTO AUTOMATED SHIP SCHEDULING 5. FUNDING NUMBERS 6... cyclones (TCs) frequently disrupt these plans, requiring diversions and inefficient steaming speeds. We evaluate the impact of adding anticipated TC

  7. Differences between nonprecipitating tropical and trade wind marine shallow cumuli

    SciTech Connect

    Ghate, Virendra P.; Miller, Mark A.; Zhu, Ping

    2015-11-13

    In this study, marine nonprecipitating cumulus topped boundary layers (CTBLs) observed in a tropical and in a trade wind region are contrasted based on their cloud macrophysical, dynamical, and radiative structures. Data from the Atmospheric Radiation Measurement (ARM) observational site previously operating at Manus Island, Papua New Guinea, and data collected during the deployment of ARM Mobile Facility at the island of Graciosa, in the Azores, were used in this study. The tropical marine CTBLs were deeper, had higher surface fluxes and boundary layer radiative cooling, but lower wind speeds compared to their trade wind counterparts. The radiative velocity scale was 50%-70% of the surface convective velocity scale at both locations, highlighting the prominent role played by radiation in maintaining turbulence in marine CTBLs. Despite greater thicknesses, the chord lengths of tropical cumuli were on average lower than those of trade wind cumuli, and as a result of lower cloud cover, the hourly averaged (cloudy and clear) liquid water paths of tropical cumuli were lower than the trade wind cumuli. At both locations ~70% of the cloudy profiles were updrafts, while the average amount of updrafts near cloud base stronger than 1 m s–1 was ~22% in tropical cumuli and ~12% in the trade wind cumuli. The mean in-cloud radar reflectivity within updrafts and mean updraft velocity was higher in tropical cumuli than the trade wind cumuli. Despite stronger vertical velocities and a higher number of strong updrafts, due to lower cloud fraction, the updraft mass flux was lower in the tropical cumuli compared to the trade wind cumuli. The observations suggest that the tropical and trade wind marine cumulus clouds differ significantly in their macrophysical and dynamical structures

  8. Differences between nonprecipitating tropical and trade wind marine shallow cumuli

    DOE PAGES

    Ghate, Virendra P.; Miller, Mark A.; Zhu, Ping

    2015-11-13

    In this study, marine nonprecipitating cumulus topped boundary layers (CTBLs) observed in a tropical and in a trade wind region are contrasted based on their cloud macrophysical, dynamical, and radiative structures. Data from the Atmospheric Radiation Measurement (ARM) observational site previously operating at Manus Island, Papua New Guinea, and data collected during the deployment of ARM Mobile Facility at the island of Graciosa, in the Azores, were used in this study. The tropical marine CTBLs were deeper, had higher surface fluxes and boundary layer radiative cooling, but lower wind speeds compared to their trade wind counterparts. The radiative velocity scalemore » was 50%-70% of the surface convective velocity scale at both locations, highlighting the prominent role played by radiation in maintaining turbulence in marine CTBLs. Despite greater thicknesses, the chord lengths of tropical cumuli were on average lower than those of trade wind cumuli, and as a result of lower cloud cover, the hourly averaged (cloudy and clear) liquid water paths of tropical cumuli were lower than the trade wind cumuli. At both locations ~70% of the cloudy profiles were updrafts, while the average amount of updrafts near cloud base stronger than 1 m s–1 was ~22% in tropical cumuli and ~12% in the trade wind cumuli. The mean in-cloud radar reflectivity within updrafts and mean updraft velocity was higher in tropical cumuli than the trade wind cumuli. Despite stronger vertical velocities and a higher number of strong updrafts, due to lower cloud fraction, the updraft mass flux was lower in the tropical cumuli compared to the trade wind cumuli. The observations suggest that the tropical and trade wind marine cumulus clouds differ significantly in their macrophysical and dynamical structures« less

  9. Medical geography and tropical diseases in Brazil, 1880-1914.

    PubMed

    Gachelin, G

    2005-12-01

    The description of clinical signs and the geographical distribution of the presently known tropical diseases have markedly varied with time. These changes are largely due to the migration of the diseases, to the increasing precision of the nosography and finally, the identification of autochthonous diseases and of their vectors. The sequence of events that led to the present distribution of tropical diseases in Brazil is deduced from XIXth century treatises of "Géographie médicale".

  10. The development of Tropical Rainfall Measuring Mission (TRMM)

    NASA Technical Reports Server (NTRS)

    Kozu, Toshiaki; Kojima, Masahiro; Oikawa, Koki; Okamoto, Ken'ichi; Keating, Thomas; Cline, Helmut P.

    1992-01-01

    The Tropical Rainfall Measuring Mission (TRMM) is a joint-program between the U.S. and Japan. The objective of this international cooperative program is to carry out the systematic study of tropical rainfall required for major strides in weather and climate research. In this paper, launch operation, mission operation and data processing as well as the system design and development status of the TRMM satellite are presented.

  11. Benzoquinones and Hydroquinones in Defensive Secretions of Tropical Millipedes

    NASA Astrophysics Data System (ADS)

    Deml, R.; Huth, A.

    The defensive secretions of two tropical species of millipedes (the spirostreptid Telodeinopus aoutii and a species of Harpagophoridae) contain a complex mixture of closely related benzoquinones and hydroquinones. The major compounds are toluquinone and 2-methoxy-3-methylbenzoquinone, accompanied by the minor components, 2,3-dimethoxybenzoquinone and toluhydroquinone. Because of the large size and the geographic separation of the test animals a common defensive strategy of tropical, large millipedes against predation by vertebrates is assumed.

  12. Tropical fishes dominate temperate reef fish communities within western Japan.

    PubMed

    Nakamura, Yohei; Feary, David A; Kanda, Masaru; Yamaoka, Kosaku

    2013-01-01

    Climate change is resulting in rapid poleward shifts in the geographical distribution of tropical and subtropical fish species. We can expect that such range shifts are likely to be limited by species-specific resource requirements, with temperate rocky reefs potentially lacking a range of settlement substrates or specific dietary components important in structuring the settlement and success of tropical and subtropical fish species. We examined the importance of resource use in structuring the distribution patterns of range shifting tropical and subtropical fishes, comparing this with resident temperate fish species within western Japan (Tosa Bay); the abundance, diversity, size class, functional structure and latitudinal range of reef fishes utilizing both coral reef and adjacent rocky reef habitat were quantified over a 2 year period (2008-2010). This region has undergone rapid poleward expansion of reef-building corals in response to increasing coastal water temperatures, and forms one of the global hotspots for rapid coastal changes. Despite the temperate latitude surveyed (33°N, 133°E) the fish assemblage was both numerically, and in terms of richness, dominated by tropical fishes. Such tropical faunal dominance was apparent within both coral, and rocky reef habitats. The size structure of the assemblage suggested that a relatively large number of tropical species are overwintering within both coral and rocky habitats, with a subset of these species being potentially reproductively active. The relatively high abundance and richness of tropical species with obligate associations with live coral resources (i.e., obligate corallivores) shows that this region holds the most well developed temperate-located tropical fish fauna globally. We argue that future tropicalisation of the fish fauna in western Japan, associated with increasing coral habitat development and reported increasing shifts in coastal water temperatures, may have considerable positive economic

  13. Materiel Testing in the Tropics (6th Ed)

    DTIC Science & Technology

    1979-04-01

    ceramics Test methodology Panama Canal Zone Textiles Plastics Tropic Test Center Protective coatings Tropical animals 20. (cont) of Materiel Testing in...Canal Zone . .. 1-3 D Materiel Testing in the Panama Canal Zone . . . . . . . ... . 1-5 E Canal Zone Environment--Brief Overview .. .. .... ...... 1-6...trapped there, and by the heavy biomass of the canopy itself. E. CANAL ZONE ENVIRONMENT--BRIEF OVERVIEW The Canal Zone (see frontispiece) bisects the

  14. Tropical Storm Alberto, Seen Through New 'Eyes'

    NASA Technical Reports Server (NTRS)

    2006-01-01

    [figure removed for brevity, see original site] Figure 1

    NASA's new CloudSat satellite captured its first tropical storm, Alberto, as it spun over the Gulf of Mexico the morning of June 12, 2006. This image comparison shows how CloudSat 'sees' such storms differently than conventional weather satellites. The CloudSat image (top of this page and bottom of figure 1) is compared with images obtained at nearly the same time from two National Oceanic and Atmospheric Administration National Weather Service tools that are mainstays for monitoring the development and movement of tropical cyclones: the NEXRAD storm detection radar, which maps out precipitation patterns for that portion of the storm that comes into its range, and the GOES-12 (Geostationary Operational Environmental Satellite) infrared imager, which is presented here to indicate the scale of the storm and the location where CloudSat overflies it. CloudSat sees the storm outside the range of NEXRAD and provides significantly greater vertical detail compared to the GOES satellite. NEXRAD, for example, can only see out to about 402 kilometers (250 nautical miles), and so could not see the portion of the storm that CloudSat was flying over at the time. GOES-12 only sees the very top of the clouds, and cannot provide any detail about what is being seen beneath the cloud tops.

    The CloudSat data show a storm that reaches about 16 kilometers (10 miles) in height and extends perhaps 1,000 kilometers (621 miles) in scale. The green line at the bottom of the CloudSat image is the radar echo of the Earth's surface. Where this line starts to disappear (change color) under the storm is where the rainfall is heaviest. Very heavy rainfall can be seen over about 400 kilometers (249 miles) of the satellite track. Cirrus clouds can also been seen out ahead of the storm (near letter A) -- this is also evident in the GOES-12 image. A smaller thunderstorm is visible in the CloudSat image under that cirrus cloud

  15. Sediment Movement Near a Tropical Wood Jam

    NASA Astrophysics Data System (ADS)

    Cadol, D.; Wohl, E.

    2008-12-01

    One mechanism by which wood interacts with sediment transport is the trapping of sediment behind jams. In tropical streams, higher discharge per unit of contributing area and higher microbial diversity relative to temperate zones are likely to cause in-stream wood to be more transient. This may reduce the residence time of jams, also reducing wood-induced sediment storage. To begin to evaluate this possibility, tracer clasts, scour chains, and wood pieces were surveyed four times from June 2007 to June 2008 at a wood jam in a stream in Costa Rica. At the study site the moderate gradient (3.2%) stream drains 1.6 km2 of preserved old-growth tropical wet forest of La Selva Biological Station. The mean grain size of the bed material is 205 mm, ranging from coarse sand to boulders, with discontinuous bedrock outcrops on both banks. Distance traveled by the tracer clasts was positively correlated with both maximum and average daily rainfall during the time between surveys. Between the first two surveys, a new accumulation of wood in the jam blocked the thalweg and redirected the majority of flow around the side of the jam. A 15-cm-thick wedge of sediment was deposited behind the blockage, and gravel bars adjacent to and immediately downstream of the jam were scoured by as much as 30 cm. The majority of the gravel sized tracer clasts placed upstream of the jam were not recovered and were presumably incorporated into the sediment wedge. Tracer clasts placed in the portion of the channel affected by the redirected flow were transported downstream as much as 47 m. Clasts larger than D55 (220 mm) were not transported in the course of the study. The jam and key pieces persisted for the entire study period, and the number of pieces in the jam stayed nearly constant. However, the structure was modified and only 46% of the original pieces were retained for the full year. The clast transport distance was positively correlated with wood turnover rate for the three inter

  16. Tropical Depression Debbie in the Atlantic

    NASA Technical Reports Server (NTRS)

    2006-01-01

    [figure removed for brevity, see original site] [figure removed for brevity, see original site] Microwave ImageVisible Light Image

    Infrared Image These images show Tropical Depression Debbie in the Atlantic, from the Atmospheric Infrared Sounder (AIRS) on NASA's Aqua satellite on August 22, 2006. This AIRS image shows the temperature of the cloud tops or the surface of the Earth in cloud-free regions. The lowest temperatures (in purple) are associated with high, cold cloud tops that make up the top of the storm. The infrared signal does not penetrate through clouds. Where there are no clouds the AIRS instrument reads the infrared signal from the surface of the Earth, revealing warmer temperatures (red). At the time the data were taken from which these images were made the eye had not yet opened but the storm is now well organized. The location of the future eye appears as a circle at 275 K brightness temperature in the microwave image just to the SE of the Azores.

    Microwave Image The microwave image is created from microwave radiation emitted by Earth's atmosphere and received by the instrument. It shows where the heaviest rainfall is taking place (in blue) in the storm. Blue areas outside of the storm where there are either some clouds or no clouds, indicate where the sea surface shines through.

    Vis/NIR Image Tropical Depression Debbie captured by the visible light/near-infrared sensor on the AIRS instrument.

    The Atmospheric Infrared Sounder Experiment, with its visible, infrared, and microwave detectors, provides a three-dimensional look at Earth's weather. Working in tandem, the three instruments can make simultaneous observations all the way down to the Earth's surface, even in the presence of heavy clouds. With more than 2,000 channels sensing different regions of the atmosphere, the system creates a global, 3-D map of atmospheric temperature and humidity and provides information on clouds, greenhouse gases, and many other atmospheric

  17. Tropical Cyclone Interactions Within Central American Gyres

    NASA Astrophysics Data System (ADS)

    Papin, P. P.; Bosart, L. F.; Torn, R. D.

    2014-12-01

    Central American gyres (CAGs) are broad (~1000 km diameter) low-level cyclonic circulations that organize over Central America during the tropical cyclone (TC) season. While CAGs have rarely been studied, prior work on similar circulations has been conducted on monsoon depressions (MDs) and monsoon gyres (MGs), which possess spatial scales of 1000 - 2500 km in the west Pacific basin. A key difference between MDs and MGs is related to the organization of vorticity around the low-level circulation. MDs possess a symmetrical vorticity pattern where vorticity accumulates near the circulation center over time, occasionally developing into a large TC. In contrast, MGs possess asymmetrical vorticity, organized in mesovorticies, which rotate cyclonically along the periphery of the MG circulation. Small tropical cyclones (TCs) occasionally develop from these mesovorticies. Interaction and development of TCs within CAGs are also common, as noted by a CAG identified during the 2010 PREDICT field project, which involved the interaction of TC Matthew and the development of TC Nicole within the larger CAG. This project is motivated by the lack of prior research on CAGs, as well as the complex scale interactions that occasionally occur between TCs and CAGs. This presentation focuses on the mutual interaction of vortices embedded in the larger-scale cyclonic flow comprising the CAG circulation. Case studies will be presented using a circulation framework to illustrate the relationship between different scale vorticity elements within the CAG. Some of these case studies resemble a MD-like evolution, where a large TC develops through the accumulation of symmetrical vorticity around the CAG (e.g. TC Opal 1995, TC Frances 1998). Other instances resemble a MG-like evolution, where smaller mesovorticies rotate around a common circulation center (e.g. TC Florence 1988). The circulation analysis framework aids in the diagnosis of interaction between different scale cyclonic vortices, and

  18. Nitrogen deposition in tropical forests from deforestation and savanna fires

    NASA Astrophysics Data System (ADS)

    Chen, Y.; Randerson, J. T.; van der Werf, G.; Morton, D. C.; Kasibhatla, P. S.

    2009-12-01

    Tropical forests account for nearly half of global net primary production (NPP) and may contribute substantially to contemporary and future land carbon (C) sinks. We used satellite-derived estimates of global fire emissions and a chemical transport model to estimate atmospheric nitrogen (N) fluxes from deforestation and savanna fires in tropical ecosystems. N emissions and deposition led to a substantial net transport of N equatorward, from savannas and areas undergoing deforestation to tropical forests. On average, N emissions from fires were equivalent to approximately 28% of biological N fixation (BNF) in savannas (4.8 kg N ha-1 yr-1) and 38% of BNF from ecosystems at the deforestation frontier (9.1 kg N ha-1 yr-1). N deposition occurred in interior tropical forests at a rate equivalent to 4% of their BNF (1.1 kg N ha-1 yr-1). This percentage was highest for African tropical forests in the Congo Basin (16%; 3.7 kg N ha-1 yr-1) owing to equatorward transport from northern and southern savannas. These results suggest that land use change, including deforestation fires, may be enhancing nutrient availability and carbon sequestration in nearby tropical forest ecosystems.

  19. Maximum covariance analysis to identify intraseasonal oscillations over tropical Brazil

    NASA Astrophysics Data System (ADS)

    Barreto, Naurinete J. C.; Mesquita, Michel d. S.; Mendes, David; Spyrides, Maria H. C.; Pedra, George U.; Lucio, Paulo S.

    2016-10-01

    A reliable prognosis of extreme precipitation events in the tropics is arguably challenging to obtain due to the interaction of meteorological systems at various time scales. A pivotal component of the global climate variability is the so-called intraseasonal oscillations, phenomena that occur between 20 and 100 days. The Madden-Julian Oscillation (MJO), which is directly related to the modulation of convective precipitation in the equatorial belt, is considered the primary oscillation in the tropical region. The aim of this study is to diagnose the connection between the MJO signal and the regional intraseasonal rainfall variability over tropical Brazil. This is achieved through the development of an index called Multivariate Intraseasonal Index for Tropical Brazil (MITB). This index is based on Maximum Covariance Analysis (MCA) applied to the filtered daily anomalies of rainfall data over tropical Brazil against a group of covariates consisting of: outgoing longwave radiation and the zonal component u of the wind at 850 and 200 hPa. The first two MCA modes, which were used to create the { MITB}_1 and { MITB}_2 indices, represent 65 and 16 % of the explained variance, respectively. The combined multivariate index was able to satisfactorily represent the pattern of intraseasonal variability over tropical Brazil, showing that there are periods of activation and inhibition of precipitation connected with the pattern of MJO propagation. The MITB index could potentially be used as a diagnostic tool for intraseasonal forecasting.

  20. The sensitivity of the tropical hydrological cycle to ENSO

    SciTech Connect

    Soden, B.J.

    2000-02-01

    It has been suggested that warmer temperatures associated with increasing greenhouse gas emissions will increase precipitation intensity and result in a more vigorous hydrologic cycle. Satellite observations of temperature, water vapor, precipitation and longwave radiation are used to characterize the variation of the tropical hydrologic and energy budgets associated with the El Nino-Southern Oscillation (ENSO). As the tropical oceans warm during an El Nino event, the precipitation intensity, water vapor mass, and temperature of the tropical atmosphere are observed to increase, reflecting a more vigorous hydrologic cycle. The enhanced latent heat release and resultant atmospheric warming lead to an increase in the emission of longwave radiation. Atmospheric global climate models, forced with observed sea surface temperatures (SSTs), accurately reproduce the observed tropospheric temperature, water vapor, and outgoing longwave radiation changes. However, the predicted variations in tropical-mean precipitation rate and surface longwave radiation are substantially smaller than observed. The comparison suggests that either (1) the sensitivity of the tropical hydrological cycle to ENSO-driven changes in SST is substantially underpredicted in existing climate models or (2) that current satellite observations are inadequate to accurately monitor ENSO-related changes in the tropical-mean precipitation. Either conclusion has important implications for current efforts to monitor and predict changes in the intensity of the hydrological cycle.

  1. Neurological aspects of neglected tropical diseases: an unrecognized burden.

    PubMed

    Jannin, Jean; Gabrielli, Albis Francesco

    2013-01-01

    Neglected tropical diseases are a group of mostly infectious diseases that thrive among poor populations in tropical countries. A significant proportion of the conditions affecting the neurological system in such countries can be attributed to neglected tropical diseases of helminth, protozoan, bacterial, or viral origin. The neurological burden of neglected tropical diseases has not been thoroughly investigated yet, but is expected to be significant; its full appreciation, estimation, and recognition present significant challenges, as shown by the case of the "silent epidemic" of epilepsy. While tropical infections involving the nervous system are today largely preventable or treatable, as vaccines or chemotherapeutic agents are available to kill or neutralize the responsible agents, associated morbidity - when established - cannot be cured. In resource-poor settings it is likely that many infections will not be treated and will therefore progress into their advanced and severe stages, thus being increasingly associated with irreversible morbidity; this is also the case for neurological morbidity, which often entails permanent disability. Public health should aim at reducing the burden of tropical neurological diseases through interventions addressing the infection, the associated morbidity, and the disability deriving from it.

  2. Community-acquired acute kidney injury in tropical countries.

    PubMed

    Jha, Vivekanand; Parameswaran, Sreejith

    2013-05-01

    Community-acquired acute kidney injury (AKI) in developing tropical countries is markedly different from AKI in developed countries with a temperate climate, which exemplifies the influence that environment can have on the epidemiology of human diseases. The aetiology and presentation of AKI reflect the ethnicity, socioeconomic factors, climatic and ecological characteristics in tropical countries. Tropical zones are characterized by high year-round temperatures and the absence of frost, which supports the propagation of infections that can cause AKI, including malaria, leptospirosis, HIV and diarrhoeal diseases. Other major causes of AKI in tropical countries are envenomation; ingestion of toxic herbs or chemicals; poisoning; and obstetric complications. These factors are associated with low levels of income, poor access to treatment, and social or cultural practices (such as the use of traditional herbal medicines and treatments) that contribute to poor outcomes of patients with AKI. Most causes of AKI in developing tropical countries are preventable, but strategies to improve the outcomes and reduce the burden of tropical AKI require both improvements in basic public health, achieved through effective interventions, and increased access to effective medical care (especially for patients with established AKI).

  3. Low Carbon Costs of Nitrogen Fixation in Tropical Dry Forests

    NASA Astrophysics Data System (ADS)

    Gei, M. G.; Powers, J. S.

    2015-12-01

    Legume tree species with the ability to fix nitrogen (N) are highly diverse and widespread across tropical forests but in particular in the dry tropics. Their ecological success in lower latitudes has been called a "paradox": soil N in the tropics is thought to be high, while acquiring N through fixation incurs high energetic costs. However, the long held assumptions that N fixation is limited by photosynthate and that N fixation penalizes plant productivity have rarely been tested, particularly in legume tree species. We show results from three different experiments where we grew eleven species of tropical dry forest legumes. We quantified plant biomass and N fixation using nodulation and the 15N natural isotope abundance (Ndfa or nitrogen derived from fixation). These data show little evidence for costs of N fixation in seedlings grown under different soil fertility, light regimes, and with different microbial communities. Seedling productivity did not incur major costs because of N fixation: indeed, the average slope between Ndfa and biomass was positive (range in slopes: -0.03 to 0.3). Moreover, foliar N, which varied among species, was tightly constrained and not correlated with Ndfa. This finding implies that legume species have a target N that does not change depending on N acquisition strategies. The process of N fixation in tropical legumes may be more carbon efficient than previously thought. This view is more consistent with the hyperabundance of members of this family in tropical ecosystems.

  4. Tropical variability and the validation of convective parameterizations

    SciTech Connect

    Slingo, J.; Hodges, K.; Sperber, K.

    1996-12-01

    The weather in the tropics is dominated by the effects of cumulus convection, be it the daily cycle of rain over the continents, tropical cyclones or the seasonal monsoon rains. In turn, the heating associated with cumulus convection is the dominant driving mechanism for tropical circulation. In the last two decades, observation of the tropics by satellites have revealed a rich tapestry of space and time scales in convective activity. These range from individual clouds, to cloud clusters associated with synoptic scale disturbances, through to super cloud clusters which display intraseasonal behavior. On the planetary scale, tropical convection shoes seasonal and interannual variability associated with, for example, monsoons and the effects of ENSO. One of the main purposed of this paper is to demonstrate the type of diagnostics which should be applied to GCMs when assessing the skill of the model and the validity of the convection scheme. In the final section, a technique for studying the behavior of tropical weather systems in a statistical manner will be described, and its application to ECMWF ReAnalyses (ERA) and to geostationary satellite imagery will be discussed.

  5. Measurements of trace gases above the tropical forests....

    NASA Astrophysics Data System (ADS)

    Nicolas-Perea, V.; Monks, P. S.

    2009-04-01

    Measurements of trace gases above the tropical forests; A comparison between ozone levels in the forest and the oil palm plantation areas using the BAe -146 aircraft. The atmospheric composition of Sabah region (Borneo) was sampled using the FAAM BAE-146 instrumented aircraft during July 2008 as part of the OP3 (Oxidant particle photochemical processes above a South East Asia tropical rain forest) project. Tropical forests play an important role in the carbon and energy balance of the Earth (which determine global climate) and are themselves vulnerable to climate change. The tropical biosphere is one of the main sources of reactive trace gas emissions into the global atmosphere, and understanding the role of ozone in these areas is of major importance given the rapid changes in land-use in the tropics. This poster presents preliminary ozone concentrations results collected using the FAAM BAE 146 instrumented aircraft over some of Malaysia most extended oil palm plantations; comparing these with the results recorded when flying over forest areas. Oil palm is becoming one of the most widespread tropical crops; in Malaysia 13% of the land area (4.3Mha) is now oil palm plantations (MPOCP, 2008) compared with 1% in 1974 (FAO, 2005). This poster is expected to show very significant ozone concentrations over the two different landscapes. The set-up of the instruments, the specific sampling sites, as well as the land cover areas will be described.

  6. Post-disaster medical rescue strategy in tropical regions

    PubMed Central

    Li, Xiang-hui; Hou, Shi-ke; Zheng, Jing-chen; Fan, Hao-jun; Song, Jian-qi

    2012-01-01

    BACKGROUND: Earthquakes, floods, droughts, storms, mudslides, landslides, and forest wild fires are serious threats to human lives and properties. The present study aimed to study the environmental characteristics and pathogenic traits, recapitulate experiences, and augment applications of medical reliefs in tropical regions. METHODS: Analysis was made on work and projects of emergency medical rescue, based on information and data collected from 3 emergency medical rescue missions of China International Search and Rescue Team to overseas earthquakes and tsunamis aftermaths in tropical disaster regions — Indonesia-Aceh, Indonesia-Yogyakarta, and Haiti-Port au Prince. RESULTS: Shock, infection and heat stroke were frequently encountered in addition to outbreaks of infectious diseases, skin diseases, and diarrhea during post-disaster emergency medical rescue in tropical regions. CONCLUSIONS: High temperature, high humidity, and proliferation of microorganisms and parasites are the characteristics of tropical climate that impose strict requirements on the preparation of rescue work including selective team members suitable for a particular rescue mission and the provisioning of medical equipment and life support materials. The overseas rescue mission itself needs a scientific, efficient, simple workflow for providing efficient emergency medical assistance. Since shock and infection are major tasks in post-disaster treatment of severely injured victims in tropical regions, the prevention and diagnosis of hyperthermia, insect-borne infectious diseases, tropic skin diseases, infectious diarrhea, and pest harms of disaster victims and rescue team staff should be emphasized during the rescue operations. PMID:25215034

  7. No evidence that elevated CO2 gives tropical lianas an advantage over tropical trees.

    PubMed

    Marvin, David C; Winter, Klaus; Burnham, Robyn J; Schnitzer, Stefan A

    2015-05-01

    Recent studies indicate that lianas are increasing in size and abundance relative to trees in neotropical forests. As a result, forest dynamics and carbon balance may be altered through liana-induced suppression of tree growth and increases in tree mortality. Increasing atmospheric CO2 is hypothesized to be responsible for the increase in neotropical lianas, yet no study has directly compared the relative response of tropical lianas and trees to elevated CO2 . We explicitly tested whether tropical lianas had a larger response to elevated CO2 than co-occurring tropical trees and whether seasonal drought alters the response of either growth form. In two experiments conducted in central Panama, one spanning both wet and dry seasons and one restricted to the dry season, we grew liana (n = 12) and tree (n = 10) species in open-top growth chambers maintained at ambient or twice-ambient CO2 levels. Seedlings of eight individuals (four lianas, four trees) were grown in the ground in each chamber for at least 3 months during each season. We found that both liana and tree seedlings had a significant and positive response to elevated CO2 (in biomass, leaf area, leaf mass per area, and photosynthesis), but that the relative response to elevated CO2 for all variables was not significantly greater for lianas than trees regardless of the season. The lack of differences in the relative response between growth forms does not support the hypothesis that elevated CO2 is responsible for increasing liana size and abundance across the neotropics.

  8. Climate, nitrogen limitation, and nitrate losses from tropical rainforests

    NASA Astrophysics Data System (ADS)

    Brookshire, J.; Gerber, S.; Menge, D.

    2010-12-01

    Researchers have long observed that rates of plant growth, litter fall, and decomposition are generally higher in tropical forests than temperate forests. On one hand, this broad geographic pattern has a seemingly simple and intuitive explanation: perennially warm temperatures and ample rainfall in tropical latitudes promote luxuriant vegetative growth and rapid litter decomposition relative to temperate latitudes. However, temperature and moisture also affect other ecosystem processes, which are known to affect plant growth and decomposition. For example, nutrients necessary for biomass growth vary widely in availability across soils and climates and thus have the potential to constrain rates of primary production. In particular, researchers have long observed that many tropical forests accumulate, recycle, and export large amounts of nitrogen (N) relative to temperate forests. Here, we focus on the observation that hydrologic nitrate losses from unpolluted, humid, old-growth tropical forests can be considerably higher than from analogous temperate forests. We ask whether high nitrate losses from tropical forests are consistent with an N-limited ecosystem with proportionally greater inorganic leaks due to larger and faster cycling detrital pools under a warm, wet climate. We evaluate this question in the context of a simple analytical framework of terrestrial N cycling and compare our predictions to data of nitrate-N in stream waters of mature temperate and tropical rainforests. Our model describes the temporal tendency of mineral N pools (predominantly nitrate) in soils. We evaluate N losses under the hypothesis of N limitation, while allowing for parameters sensitive to climate to vary for temperate vs. tropical forests. According to our analysis, the observed 17 fold higher NO3- losses from tropical than temperate forests is only consistent with N limitation if the N uptake rate constant is 4 fold lower in tropical than temperate forests. Given that plant

  9. Factors controlling tropospheric O3, OH, NO x and SO2 over the tropical Pacific during PEM-Tropics B

    NASA Astrophysics Data System (ADS)

    Wang, Yuhang; Liu, Shaw C.; Wine, Paul H.; Davis, Douglas D.; Sandholm, Scott T.; Atlas, Eillot L.; Avery, Melody A.; Blake, Donald R.; Blake, Nicola J.; Brune, William H.; Heikes, Brian G.; Sachse, Glen W.; Shetter, Richard E.; Singh, Hanwant B.; Talbot, Robert W.; Tan, David

    2001-12-01

    Observations over the tropical Pacific during the Pacific Exploratory Mission (PEM)-Tropics B experiment (March-April 1999) are analyzed. Concentrations of CO and long-lived nonmethane hydrocarbons in the region are significantly enhanced due to transport of pollutants from northern industrial continents. This pollutant import also enhances moderately O3 concentrations but not NOx concentrations. It therefore tends to depress OH concentrations over the tropical Pacific. These effects contrast to the large enhancements of O3 and NOx concentrations and the moderate increase of OH concentrations due to biomass burning outflow during the PEM-Tropics A experiment (September-October 1996). Observed CH3I concentrations, as in PEM-Tropics A, indicate that convective mass outflux in the middle and upper troposphere is largely independent of altitude over the tropical Pacific. Constraining a one-dimensional model with CH3I observations yields a 10-day timescale for convective turnover of the free troposphere, a factor of 2 faster than during PEM-Tropics A. Model simulated HO2, CH2O, H2O2, and CH3OOH concentrations are generally in agreement with observations. However, simulated OH concentrations are lower (˜25%) than observations above 6 km. Whereas models tend to overestimate previous field measurements, simulated HNO3 concentrations during PEM-Tropics B are too low (a factor of 2-4 below 6 km) compared to observations. Budget analyses indicate that chemical production of O3 accounts for only 50% of chemical loss; significant transport of O3 into the region appears to take place within the tropics. Convective transport Of CH3OOH enhances the production of HOx and O3 in the upper troposphere, but this effect is offset by HOx loss due to the scavenging of H2O2. Convective transport and scavenging of reactive nitrogen species imply a necessary source of 0.4-1 Tg yr-1 of NOx in the free troposphere (above 4 km) over the tropics. A large fraction of the source could be from

  10. Deterministic Chaos in Tropical Atmospheric Dynamics.

    NASA Astrophysics Data System (ADS)

    Waelbroeck, H.

    1995-07-01

    An 11-year dataset from the tropical weather station of Tlaxcala, Mexico, is examined. It is found that mutual information drops quickly with the delay, to a positive value that relaxes to zero with a timescale of 20 days. The mutual dependence of the observables is also examined and it is concluded that the dataset gives the equivalent of eight variables per day, known to a precision of 2%. It is determined that the effective dimension of the attractor is Deff 11.7 at the scale 3.5% < R/Rmax < 8%. Evidence is found that the effective dimension increases as R/Rmax 0, supporting a conjecture by Lorenz that the climate system may consist of a large number of weakly coupled subsystems, some of which have low-dimensional attractors. A local reconstruction of the dynamics in phase space is performed; the short-term predictability is modest and agrees with theoretical estimates. Useful skill in predictions of 10-day rainfall accumulation anomalies reflects the persistence of weather patterns, which follow the 20-day decay rate of the mutual information.

  11. Degradation of chlorpyrifos in tropical rice soils.

    PubMed

    Das, Subhasis; Adhya, Tapan K

    2015-04-01

    Chlorpyrifos [O,O-diethyl O-(3,5,6-trichloro-2-pyridinol) phosphorothioate] is used worldwide as an agricultural insecticide against a broad spectrum of insect pests of economically important crops including rice, and soil application to control termites. The insecticide mostly undergoes hydrolysis to diethyl thiophosphoric acid (DETP) and 3,5,6-trichloro-2-pyridinol (TCP), and negligible amounts of other intermediate products. In a laboratory-cum-greenhouse study, chlorpyrifos, applied at a rate of 10 mg kg(-1) soil to five tropical rice soils of wide physico-chemical variability, degraded with a half-life ranging from 27.07 to 3.82 days. TCP was the major metabolite under both non-flooded and flooded conditions. Chlorpyrifos degradation had significant negative relationship with electrical conductivity (EC), cation exchange capacity (CEC), clay and sand contents of the soils under non-flooded conditions. Results indicate that degradation of chlorpyrifos was accelerated with increase in its application frequency, across the representative rice soils. Management regimes including moisture content and presence or absence of rice plants also influenced the process. Biotic factors also play an important role in the degradation of chlorpyrifos as demonstrated by its convincing degradation in mineral salts medium inoculated with non-sterile soil suspension.

  12. Cholestyramine improves tropical-related diarrhea.

    PubMed

    Balagani, Rajesh; Wills, Brandon; Leikin, Jerrold B

    2006-01-01

    Patients exposed to the toxic dinoflagellate Pfiesteria develop an illness characterized by secretory diarrhea, conjunctival irritation, skin lesions, and varying degrees of neurologic manifestations. The anion-exchange resin, cholestyramine has been reported in one small case series to be an effective treatment of severe diarrhea associated with Pfiesteria intoxication. A 54-year-old man traveled to the Dominican Republic where he went swimming in what he describes as "dirty ocean water". Within an hour, he noted a generalized burning and itching of his skin. Later on, he noted pruritic vesicular skin lesions, intense frontal headache, and conjunctivitis. A few days later, he complained of abdominal cramping, nausea, and hourly episodes of watery, non-bloody diarrhea. Due to the constellation of symptoms, Pfiesteria intoxication was suspected. On arrival in the United States, he sought medical care for continued symptoms. Physical examination was remarkable for conjunctival injection, linear vesicular lesions (5 cm in length) over his right ankle and left orbit as well as erythema over foreskin of his penis. Mental status and memory were normal. Laboratory studies revealed an elevated serum creatinine, which eventually normalized, and stool studies were negative for leukocytes, blood, and enteric pathogens. Intense diarrhea persisted until he was started on cholestyramine (4 g PO tid). The diarrhea resolved within 2 hours of starting treatment. The headache was initially treated with narcotic agents but only resolved with IV diphenhydramine (25 mg q 4 h). Cholestyramine and diphenhydramine appear to be effective therapeutic agents for tropical-related diarrhea and headache, respectively.

  13. Viral infections in travellers from tropical Africa.

    PubMed

    Woodruff, A W; Bowen, E T; Platt, G S

    1978-04-15

    Examination of sera from 86 travellers to Britain from tropical Africa disclosed evidence of past infection with 10 identifiable viruses, of which the most important were O'nyong-nyong, dengue, chikungunya, and Ntaya. The findings indicate that infection with O'nyong-nyong may be acquired sporadically in Nigeria, Ghana, and Sierra Leone, where it has not previously been identified. Chikungunya infection had not been recorded in West Africa other than Nigeria and Senegal. Patients from Sierra Leone and contiguous Liberia had antibodies to this infection. An outbread of dengue fever in the Seychelles in early 1977 was confirmed. Ntaya virus, though known in Uganda, Cameroon, and Zaire, appears also to be transmitted in Kenya, Nigeria, and Zambia. Clinical studies indicated that chikungunya infection may present with alimentary features, possibly with jaundice. The clinical features of Ntaya infection may include kizarre neurological manifestations in addition to fever. The absence of Lassa antibodies among these travellers suggested that this infection is not a common hazard among such persons.

  14. Tropical cyclones in reanalysis data sets

    NASA Astrophysics Data System (ADS)

    Murakami, Hiroyuki

    2014-03-01

    This study evaluates and compares tropical cyclones (TCs) in state-of-the-art reanalysis data sets including the following: the Japanese 55-year Reanalysis (JRA-55), Japanese 25-year Reanalysis, European Centre for Medium-Range Weather Forecasts Reanalysis-40, Interim Reanalysis, National Centers for Environmental Prediction Climate Forecast System Reanalysis, and NASA's Modern Era Retrospective Analysis for Research and Application (MERRA). Most of the reanalyses reproduce a reasonable global spatial distribution of observed TCs and temporal interannual variation of total TC frequency. Of the six reanalysis data sets, JRA-55 appears to be the best in terms of the following: the highest skill for spatial and temporal distribution of TC frequency of occurrence, highest TC hitting rate, lower false alarm rate, reasonable TC structure in terms of the relationship between maximum surface wind speed and sea level pressure, and higher correlation coefficients for interannual variations of TC frequency. These results also suggest that the finest-resolution reanalysis data sets, like MERRA, are not always the best in terms of TC climatology.

  15. Observed strong currents under global tropical cyclones

    NASA Astrophysics Data System (ADS)

    Chang, Yu-Chia; Tseng, Ruo-Shan; Chu, Peter C.; Chen, Jau-Ming; Centurioni, Luca R.

    2016-07-01

    Global data from drifters of the Surface Velocity Program (Niiler, 2001) and tropical cyclones (TCs) from the Joint Typhoon Warning Center and National Hurricane Center were analyzed to demonstrate strong ocean currents and their characteristics under various storm intensities in the Northern Hemisphere (NH) and in the Southern Hemisphere (SH). Mean TC's translation speed (Uh) is faster in the NH (~ 4.7 m s- 1) than in the SH (~ 4.0 m s- 1), owing to the fact that TCs are more intense in the NH than in the SH. The rightward (leftward) bias of ocean mixed-layer (OML) velocity occurs in the NH (SH). As a result of this slower Uh and thus a smaller Froude number in the SH, the flow patterns in the SH under the same intensity levels of TCs are more symmetric relative to the TC center and the OML velocities are stronger. This study provides the first characterization of the near-surface OML velocity response to all recorded TCs in the SH from direct velocity measurements.

  16. A numerical investigation of tropical island thunderstorms

    SciTech Connect

    Golding, B.W. )

    1993-05-01

    A version of the United Kingdom Meteorological Office mesoscale weather prediction model is used to simulate cases of deep tropical convection from the Island Thunderstorm Experiment off the north coast of Australia. Selected cases contrast rather isolated storm development in a dry basic state, with widespread precipitation from a moist basic state. Excellent agreement is found between the simulations and the observed early shower development on both occasions. Initiation of convection occurs along the sea-breeze front, which is then reinforced by downdraft outflows. Merging of simulated cells occurs where the outflows meet, producing cells with cloud tops above 18 km and updraft speeds of 60 m s[sup [minus]1]. The later movement of the storms is less well represented, probably due to weakness in the storm-mean flow interaction. Comparison of the cases shows that differences in the timing of initiation and intensity of subsequent convection are well captured, and relate to differences in the initial sounding. Mean budgets of heat. moisture, and momentum are presented, and sensitivity of the simulations to resolution, island shape, and model microphysics is explored. 48 refs., 12 figs.

  17. Studying insect diversity in the tropics.

    PubMed Central

    Godfray, H C; Lewis, T; Memmott, J

    1999-01-01

    Understanding the extent and causes of insect diversity in the humid tropics is one of the major challenges in modern ecology. We review some of the current approaches to this problem, and discuss how future progress may be made. Recent calculations that there may be more than 30 million species of insect on earth have focused attention on the magnitude of this problem and stimulated several new lines of research (although the true figure is now widely thought to be between five and ten million species). We discuss work based on insecticidal logging surveys; studies of herbivore and parasitoid specificity; macroecological approaches; and the construction of food webs. It is argued that progress in estimating insect diversity and in understanding insect community dynamics will be enhanced by building local inventories of species diversity, and in descriptive and experimental studies of the trophic structure of communities. As an illustration of work aimed at the last goal, we discuss the construction and analysis of quantitative host-parasitoid food webs, drawing on our work on leaf miner communities in Central America. PMID:11605624

  18. Diurnal Variations of Clouds in Tropical Cyclones

    NASA Astrophysics Data System (ADS)

    Wu, Qiaoyan; Ruan, Zhenxin

    2016-04-01

    Using 14 years (2000-2013) of pixel-resolution infrared (IR) brightness temperature data and best track data, this study estimates the diurnal variations of convective systems in tropical cyclones (TCs) in the western North Pacific. The very cold cloud cover (IR brightness temperatures < 208 K) of TCs reaches a maximum areal extent in the early morning (0000-0300 LST) and then decreases after the sunrise. The decrease of very cold cloud cover is followed by an increase of cloud cover between 208 K and 240 K with a maximum areal extent in the afternoon (1500-1800 LST). TC IR cloud top temperatures < 240 K have minimum values in the morning (0300-0600 LST) , while TC IR cloud top temperatures > 240 K have mean minimum values in the afternoon (1500-1800 LST). The out-of-phase relation between different cloud conditions with IR cloud top temperatures < 240 K and IR cloud top temperatures > 240 K lead to radius-averaged IR temperature show two minima within a day. Different diurnal evolution under different cloud conditions suggests that TC convective systems are better described in terms of both areal extent and cloud-top temperature. The maximum cloud cover with IR cloud top temperatures colder than 208 K in the morning and the maximum cloud cover with IR cloud top temperatures between 208 K and 240 K in the afternoon suggest that two different mechanisms might be involved with the diurnal variations of these two types of TC cloud conditions.

  19. Oceanic origin of southeast tropical Atlantic biases

    NASA Astrophysics Data System (ADS)

    Xu, Zhao; Li, Mingkui; Patricola, Christina M.; Chang, Ping

    2014-12-01

    Most coupled general circulation models suffer from a prominent warm sea surface temperature bias in the southeast tropical Atlantic Ocean off the coast of Africa. The origin of the bias is not understood and remains highly controversial. Previous studies suggest that the origin of the bias stems from systematic errors of atmospheric models in simulating surface heat flux and coastal wind, or poorly simulated coastal upwelling. In this study, we show, using different reanalysis and observational data sets combined with a set of eddy-resolving regional ocean model simulations, that systematic errors in ocean models also make a significant contribution to the bias problem. In particular (1) the strong warm bias at the Angola-Benguela front that is maintained by the local wind and the convergence of Angola and Benguela Currents is caused by an overshooting of the Angola Current in ocean models and (2) the alongshore warm bias to the south of the front is caused by ocean model deficiencies in simulating the sharp thermocline along the Angola coast, which is linked to biases in the equatorial thermocline, and the complex circulation system within the Benguela upwelling zone.

  20. Phylogenetic structure in tropical hummingbird communities.

    PubMed

    Graham, Catherine H; Parra, Juan L; Rahbek, Carsten; McGuire, Jimmy A

    2009-11-17

    How biotic interactions, current and historical environment, and biogeographic barriers determine community structure is a fundamental question in ecology and evolution, especially in diverse tropical regions. To evaluate patterns of local and regional diversity, we quantified the phylogenetic composition of 189 hummingbird communities in Ecuador. We assessed how species and phylogenetic composition changed along environmental gradients and across biogeographic barriers. We show that humid, low-elevation communities are phylogenetically overdispersed (coexistence of distant relatives), a pattern that is consistent with the idea that competition influences the local composition of hummingbirds. At higher elevations communities are phylogenetically clustered (coexistence of close relatives), consistent with the expectation of environmental filtering, which may result from the challenge of sustaining an expensive means of locomotion at high elevations. We found that communities in the lowlands on opposite sides of the Andes tend to be phylogenetically similar despite their large differences in species composition, a pattern implicating the Andes as an important dispersal barrier. In contrast, along the steep environmental gradient between the lowlands and the Andes we found evidence that species turnover is comprised of relatively distantly related species. The integration of local and regional patterns of diversity across environmental gradients and biogeographic barriers provides insight into the potential underlying mechanisms that have shaped community composition and phylogenetic diversity in one of the most species-rich, complex regions of the world.