348 research outputs found
Predictable decadal forcing of the North Atlantic jet speed by sub-polar North Atlantic sea surface temperatures
No full textIt has been demonstrated that decadal variations in the North Atlantic Oscillation (NAO) can be predicted by current forecast models. While Atlantic Multidecadal Variability (AMV) in sea surface temperatures (SSTs) has been hypothesised as the source of this skill, the validity of this hypothesis and the pathways involved remain unclear. We show, using reanalysis and data from two forecast models, that the decadal predictability of the NAO can be entirely accounted for by the predictability of decadal variations in the speed of the North Atlantic eddy-driven jet, with no predictability of decadal variations in the jet latitude. The sub-polar North Atlantic (SPNA) is identified as the only obvious common source of an SST-based signal across the models and reanalysis, and the predictability of the jet speed is shown to be consistent with a forcing from the SPNA visible already within a single season. The pathway is argued to be tropospheric in nature, with the SPNA-associated heating extending up to the mid-troposphere, which alters the meridional temperature gradient around the climatological jet core. The relative roles of anthropogenic aerosol emissions and the Atlantic Meridional Overturning Circulation (AMOC) at generating predictable SPNA variability are also discussed. The analysis is extensively supported by the novel use of a set of seasonal hindcasts spanning the 20th century and forced with prescribed SSTs.</p
MJO-QBO Model Inter-comparison Data
No full textData in support of the paper "The Lack of a QBO-MJO Connection in Climate Models with a Nudged Stratosphere" by Zane K. Martin, Isla R. Simpson, Pu Lin, Clara Orbe, Qi Tang, Julie M. Caron, Chih-Chieh Chen, Hyemi Kim, L. Ruby Leung, Jadwiga H. Richter, and Shaocheng Xie, currently in preparation for submission.
Data is organized by model, then ensemble member, then the temporal data resolution.
Daily data are daily model OLR (olr/) and precipitation (precip/) in lat/lon/time format, over at least the tropical region spanning all longitudes and 20N to 20S. Daily data also include the Real-time Multivariate MJO index (RMM; RMM_index/) value from each model and ensemble members. OLR and precip files are provided on a 2.5 x 2.5 degree similar grid, rather than the models' native grid.
Monthly data are temperature (temp/, at all vertical levels and all longitudes, from at least 20N to 20S, and the 100 hPa temperature file, as described more in the paper) zonal wind (at all vertical levels, and the 50 hPa wind file; wind/), and TEM vertical velocity (wtem/)
Evaluación comparativa de la diversidad de flora silvestre entre la Isla Taquile y el cerro Chiani de la península de Chucuito en época lluviosa, Puno
No full textRealicé la investigación en la isla Taquile y el cerro Chiani de la península de Chucuito, entre los meses de noviembre 2010 a febrero 2011. Las hipótesis fueron 1) la riqueza específica y abundancia proporcional de especies de flora silvestre de la isla de Taquile será diferente, en relación al cerro Chiani, 2) el incremento de la altitud y la disminución de la temperatura, influirá en la disminución de la riqueza específica y abundancia proporcional de especies, en la isla de Taquile y cerro Chiani y 3) a mayor precipitación pluvial (mm), la abundancia proporcional de especies de flora silvestre variará en la isla Taquile y el cerro Chiani. Los objetivos fueron: 1) Comparación de la riqueza específica y abundancia proporcional de especies de flora silvestre, entre la isla Taquile y el cerro Chiani, 2) Evaluación de la riqueza específica y abundancia proporcional de especies de flora silvestre, en la isla Taquile y el cerro Chiani en relación a la altitud y temperatura ambiental y 3) Evaluación de la abundancia proporcional de especies de flora silvestre, en la isla Taquile y el cerro Chiani en relación a la precipitación pluvial. La metodología fue: Hice evaluaciones quincenales en ambas zonas de estudio, aplicando el método acumulativo y zigzag. Los índices que apliqué fueron el de Simpson y Shannon, calculados con el software Krebs. Apliqué pruebas no paramétricas de Mann Whitney y Kruskal Wallis y pruebas de correlación simple, utilizando el software INFOSTAT. Los resultados fueron: En la isla Taquile registré 94 especies, pertenecientes a 35 familias y en el cerro Chiani registré 93 especies pertenecientes a 38 familias. No encontré diferencia de la riqueza específica, índice de Simpson entre las dos zonas en estudio (P = 0,3417; P = 0,1120) respectivamente. Sin embargo, con el índice de Shannon hubo diferencia entre las dos zonas (P <0,0001). Analizando la diversidad durante los meses de evaluación, encontré diferencia estadística de la diversidad de especies según los índices de Simpson y Shannon para ambas zonas (P< 0,0001 para ambos casos). En la isla Taquile no encontré diferencia de la riqueza de especies a las diferentes altitudes evaluadas (P = 0,1504), pero si encontré diferencia de acuerdo con el índice de Simpson y Shannon (P = 0,0042 y P = 0,0305 respectivamente). El coeficiente de correlación entre el índice de Simpson y de Shannon con la temperatura fue 0,04 y 0,11 respectivamente. En el cerro Chiani si hubo diferencia de la riqueza de especies a las diferentes altitudes evaluadas en el cerro Chiani (P = 0,0661), pero no encontré diferencia de la diversidad de especies según el índice de Simpson y Shannon (P = 0,4845 y P = 0,4406 respectivamente). Los índices de correlación entre el índice de Simpson y Shannon con la temperatura fueron 0,24 y 0,33 respectivamente. En la isla de Taquile, el coeficiente de correlación entre la diversidad de especies según el índice de dominancia de Simpson y Shannon con la precipitación pluvial fue r = 0,47 y r = 0,56 respectivamente. En el cerro Chiani el coeficiente de correlación encontrada entre el índice de Simpson y Shannon con la precipitación fue r = 0,53 y r = 0,57 respectivamenteTesi
La auto(r)ficción bífida en Isla partida de Daniela Tarazona
No full textThis article explores the bifid author fiction developed by Daniela Tarazona in Isla partida. Employing Sabine Schlickers’ concept of author fiction, it traces the series of splits that the authorial voice undergoes in order to account for the complications of the writing exercise. At least three splits are proposed: that of Daniela Tarazona as a narrator-writer, as a character in a (meta)novel, and as a she who is in reality Eunice Odio, the Costa Rican poet who lived in Mexico in the sixties. It is concluded that the bifid author fiction allows the author to develop a social critique of her familiar and political context, and at the same time, a professional introspection and reflection. As Sabine Schlickers suggests, author fiction draws on the vulnerability of the writer to expose aspects of their daily life that will be reevaluated or reconsidered by them.El presente artículo explora la auto(r)ficción bífida que desarrolla Daniela Tarazona en Isla partida. A partir del concepto de auto(r)ficción de Sabine Schlickers se traza la serie de desdoblamientos que sufre la voz autoral para dar cuenta de las complicaciones del ejercicio escritural. Se proponen al menos tres desdoblamientos: el de Daniela Tarazona como narradora-escritora, como personaje de una (meta)novela y como un ella que en realidad es Eunice Odio, la poeta costarricense que vivió en México en los sesenta. Se concluye que la auto(r)ficción bífida le permite a la autora desarrollar una crítica social de su contexto familiar y político, y a su vez, una introspección y reflexión profesional. Como sugiere Sabine Schlickers, la auto(r)ficción recurre a la vulnerabilidad del escritor para exponer aspectos de su vida cotidiana que serán reevaluados o reconsiderados por él
Western boundary currents and climate change
No full textA recent paper in Journal of Geophysical Research-Oceans connects recent changes in atmospheric circulation to poleward movement and intensification of western boundary currents. Causes and characteristics of past and future trends in surface wind stress and western boundary currents are discussed here
A minimal model to diagnose the contribution of the stratosphere to tropospheric forecast skill
No full textFunding: Simon H. Lee is supported by NERC via the SCENARIO Doctoral Training Partnership (NE/L002566/1). Isla R Simpson was supported by the National Center for Atmospheric Research, which is a major facility sponsored by the National Science Foundation under the Cooperative Agreement 1852977.Many recent studies have confirmed that variability in the stratosphere is a significant source of surface sub-seasonal prediction skill during Northern Hemisphere winter. It may be beneficial, therefore, to think about times in which there might be windows-of-opportunity for skillful sub-seasonal predictions based on the initial or predicted state of the stratosphere. In this study, we propose a simple, minimal model that can be used to understand the impact of the stratosphere on tropospheric predictability. Our model purposefully excludes state dependent predictability in either the stratosphere or troposphere or in the coupling between the two. Model parameters are set up to broadly represent current sub-seasonal prediction systems by comparison with four dynamical models from the Sub-Seasonal to Seasonal Prediction Project database. The model can reproduce the increases in correlation skill in sub-sets of forecasts for weak and strong lower stratospheric polar vortex states over neutral states despite the lack of dependence of coupling or predictability on the stratospheric state. We demonstrate why different forecast skill diagnostics can give a very different impression of the relative skill in the three sub-sets. Forecasts with large stratospheric signals and low amounts of noise are demonstrated to also be windows-of-opportunity for skillful tropospheric forecasts, but we show that these windows can be obscured by the presence of unrelated tropospheric signals.Peer reviewe
Climate change predicted to lengthen transatlantic travel times
No full textAmong the many consequences of rising atmospheric greenhouse gas concentrations, is a change to the medium through which planes fly. An emerging area of research is the impact that these changes may have on the airline industry, with studies addressing aspects ranging from the impact of rising temperatures on aeroplane weight restrictions (Coffel and Horton 2015 Wea. Climate Soc. http://dx.doi.org/10.1175/wcas-d-14-00026.1 7 http://dx.doi.org/10.1175/wcas-d-14-00026.1 ) to the impact of changing wind shears on the occurrence of clear air turbulence (Williams and Joshi 2014 Nat. Clim. Change http://dx.doi.org/10.1038/nclimate1866 3 http://dx.doi.org/10.1038/nclimate1866 ). Now, a recent study by Paul Williams (2016 Environ. Res. Lett. http://dx.doi.org/10.1088/1748-9326/11/2/024008 11 http://dx.doi.org/10.1088/1748-9326/11/2/024008 ), assesses the impact that changing winds may have on the duration of transatlantic flights
The Unprecedented Late-Summer 2023 Heatwave in Southeastern South America: Attribution and future projection of similar events
No full textInternational audienc
A grant proposal to study the benefits of utilizing a sensory diet approach to assist in on task behavior for students with Autism Spectrum Disorders
No full textIncludes bibliographical references
Teleconnections of the Quasi-Biennial Oscillation in a multi-model ensemble of QBO-resolving models
No full textThe Quasi-biennial Oscillation (QBO) dominates the interannual variability of the tropical stratosphere and influences other regions of the atmosphere. The high predictability of the QBO implies that its teleconnections could lead to increased skill of seasonal and decadal forecasts provided the relevant mechanisms are accurately represented in models. Here modelling and sampling uncertainties of QBO teleconnections are examined using a multi-model ensemble of QBO-resolving atmospheric general circulation models that have carried out a set of coordinated experiments as part of the Stratosphere-troposphere Processes And their Role in Climate (SPARC) QBO initiative (QBOi). During Northern Hemisphere winter, the stratospheric polar vortex in most of these models strengthens when the QBO near 50 hPa is westerly and weakens when it is easterly, consistent with, but weaker than, the observed response. These weak responses are likely due to model errors, such as systematically weak QBO amplitudes near 50 hPa, affecting the teleconnection. The teleconnection to the North Atlantic Oscillation is less well captured overall, but of similar strength to the observed signal in the few models that do show it. The models do not show clear evidence of a QBO teleconnection to the Northern Hemisphere Pacific-sector subtropical jet.We acknowledge the UK's Centre for Environmental Data Analysis (CEDA) for hosting the QBOi data archive. This work was supported by the National Center for Atmospheric Research, which is a major facility sponsored by the National Science Foundation under Cooperative Agreement no. 1852977. Portions of this study were supported by the Regional and Global Model Analysis (RGMA) component of the Earth and Environmental System Modeling Program of the U.S. Department of Energy's Office of Biological & Environmental Research (BER) via National Science Foundation IA 1844590. NB was supported by the Met Office Hadley Centre Programme funded by BEIS and Defra. SO and LG were supported by the National Centre for Atmospheric Science and the Natural Environment Research Council (NE/P006779/1, NE/N018001/1). FL and SO were supported by the JPI-Climate/Belmont Forum 423 project GOTHAM (ANR-15-JCLI-0004-01, NERC NE/P006779/1). CC and FS were supported by the Copernicus Climate Change Service, funded by the EU and implemented by ECMWF. HN was supported by the Environment Research and Technology Development Fund (S-12) of the Environmental Restoration and Conservation Agency of Japan and by Grant-in-Aid (JP18K03748, JP20H05171) for Science Research (KAKENHI) from the Ministry of Education, Culture, Sports, Science, and Technology of Japan. For the EMAC simulations, PB, TK, and SV acknowledge support by the state of Baden-Württemberg through bwHPC. YK was supported by the Japan Society for Promotion of Science (JSPS) KAKENHI (grant nos. JP15KK0178, JP17K18816, JP18H01286 and 19H05702) and by the Environment Research and Technology Development Fund (JPMEERF20192004) of the Environmental Restoration and Conservation Agency of Japan. YK and KH were supported by the Japan Agency for Marine-Earth Science and Technology (JAMSTEC) through its sponsorship of research at the International Pacific Research Center. SW and YK were partly supported by the “Integrated Research Program for Advancing Climate Models (TOUGOU program)” from the Ministry of Education, Culture, Sports, Science and Technology (MEXT), Japan. The Earth Simulator was used for MIROC-ESM and MIROC-AGCM-LL simulations. We acknowledge the scientific guidance of the World Climate Research Programme (WCRP) for helping motivate this work, coordinated under the framework of the Stratosphere-troposphere Processes And their Role in Climate (SPARC) QBO initiative (QBOi) led by JA, NB, KH and SO.Peer Reviewed"Article signat per 29 autors/es: James A. Anstey, Isla R. Simpson, Jadwiga H. Richter, Hiroaki Naoe, Masakazu Taguchi, Federico Serva, Lesley J. Gray, Neal Butchart, Kevin Hamilton, Scott Osprey, Omar Bellprat, Peter Braesicke, Andrew C. Bushell, Chiara Cagnazzo, Chih-Chieh Chen, Hye-Yeong Chun, Rolando R. Garcia, Laura Holt, Yoshio Kawatani, Tobias Kerzenmacher, Young-Ha Kim, Francois Lott, Charles McLandress, John Scinocca, Timothy N. Stockdale, Stefan Versick, Shingo Watanabe, Kohei Yoshida, Seiji Yukimoto"Postprint (published version
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