Surface-Atmosphere Moisture Interactions in the Frozen Ground Regions of Eurasia

Climate models simulate an intensifying Arctic hydrologic cycle in response to climatic warming, however the role of surface-atmosphere interactions from degrading frozen ground is unclear in these projections. Using Modern-Era Retrospective Analysis for Research and Applications (MERRA) data in high-latitude Eurasia, we examine long-term variability in surface-atmosphere coupling as represented by the statistical relationship between surface evaporative fraction (EF) and afternoon precipitation. Changes in EF, precipitation, and their statistical association are then related to underlying permafrost type and snow cover. Results indicate significant positive trends in July EF in the Central Siberian Plateau, corresponding to significant increases in afternoon precipitation. The positive trends are only significant over continuous permafrost, with non-significant or negative EF and precipitation trends over isolated, sporadic, and discontinuous permafrost areas. Concurrently, increasing EF and subsequent precipitation are found to coincide with significant trends in May and June snowmelt, which potentially provides the moisture source for the observed enhanced latent heating and moisture recycling in the region. As climate change causes continuous permafrost to transition to discontinuous, discontinuous to sporadic, sporadic to isolated, and isolated permafrost disappears, this will also alter patterns of atmospheric convection, moisture recycling, and hence the hydrologic cycle in high-latitude land areas

Changes in the 1963–2013 shallow ground thermal regime in Russian permafrost regions

Spatial variability and temporal trends of the shallow ground thermal regime and permafrost active-layer thickness (ALT) were estimated over 1963–2013 using daily soil temperature data available from stations of the Russian Hydrometeorological Service. Correlation analysis was used to evaluate the role of changing climatic conditions on the ground thermal regime. ALT data collected by the Circumpolar Active Layer Monitoring program in Russia were used to expand the geography of ALT observations over 1999–2013, and to identify ‘hot spots’ of soil temperature and ALT change. Results indicate that a substantially higher rate of change in the thermal regime of permafrost-affected soils prevailed during 1999–2013, relative to the last fifty years. Results indicate that the thermal regime of the upper permafrost in western Russia is strongly associated with air temperature, with much weaker relationships in central and eastern Russia. The thermal regime of permafrost-affected soils shows stronger dependence on climatic conditions over the last fifteen years relative to the historical 50-year period. Geostatistical analysis revealed that the cities of Norilsk and Susuman are hot spots of permafrost degradation. Of six settlements selected for detailed analysis in various parts of the permafrost regions, all but one (Chukotka), show substantial changes in the shallow ground thermal regime. Northern locations in the continuous permafrost region show thickening of the active layer, while those farther south experienced development of residual thaw layers above the permafrost and decreases in the duration of the freezing period

Response of seasonal soil freeze depth to climate change across China

Abstract. The response of seasonal soil freeze depth to climate change has repercussions for the surface energy and water balance, ecosystems, the carbon cycle, and soil nutrient exchange. Despite its importance, the response of soil freeze depth to climate change is largely unknown. This study employs the Stefan solution and observations from 845 meteorological stations to investigate the response of variations in soil freeze depth to climate change across China. Observations include daily air temperatures, daily soil temperatures at various depths, mean monthly gridded air temperatures, and the normalized difference vegetation index. Results show that soil freeze depth decreased significantly at a rate of −0.18 ± 0.03 cm yr−1, resulting in a net decrease of 8.05 ± 1.5 cm over 1967–2012 across China. On the regional scale, soil freeze depth decreases varied between 0.0 and 0.4 cm yr−1 in most parts of China during 1950–2009. By investigating potential climatic and environmental driving factors of soil freeze depth variability, we find that mean annual air temperature and ground surface temperature, air thawing index, ground surface thawing index, and vegetation growth are all negatively associated with soil freeze depth. Changes in snow depth are not correlated with soil freeze depth. Air and ground surface freezing indices are positively correlated with soil freeze depth. Comparing these potential driving factors of soil freeze depth, we find that freezing index and vegetation growth are more strongly correlated with soil freeze depth, while snow depth is not significant. We conclude that air temperature increases are responsible for the decrease in seasonal freeze depth. These results are important for understanding the soil freeze–thaw dynamics and the impacts of soil freeze depth on ecosystem and hydrological process. </jats:p

Mulheres escritoras e representação do feminino no « Romance de 30 » no Brasil

Les années 30 représentent un moment fondamental dans le processus culturel et identitaire du Brésil, où la fonction sociale de la littérature, notamment du roman, et le rôle de l’écrivain en tant que ‘conscience vivante’ du pays sont reconnus et problématisés. Cependant, dans la majorité des histoires, des anthologies et des manuels littéraires, aucun nom de femme ne figure parmi les auteurs canoniques de la période, à l’exception de celui de Rachel de Queiroz. L’analyse des sources de l’époque montre que, au contraire, auteures comme Lúcia Benedetti, Jenny Pimentel de Borba, Làsinha Luís Carlos de Caldas Brito, Maria José Dupré, Ondina Ferreira, Emi Bulhões Carvalho Fonseca, Ignez Mariz, Carolina Nabuco, Lúcia Miguel Pereira, Dinah Silveira de Queiroz, Tetrá de Teffé et bien d’autres sont publiées, lues et appréciées par la critique et le public. A partir d’une étude du contexte historique et littéraire, ainsi que de la réception et des aspects éditoriaux, les mécanismes qui ont permis leur effacement de la mémoire sont démontés et expliquée leur non intégration à la tradition littéraire brésilienne. La lecture des romans de ces auteures permet d’approfondir le discours sur la participation des femmes au moment littéraire et social des années 30 et 40 par une analyse des représentations. Les personnages qui peuplent ces ouvrages, et notamment les personnages féminins, sont un objet idéal pour analyser les phénomènes identitaires qui caractérisent ce moment historique avec ses contradictions.The 1930’s represent a fundamental period in the development of Brazil’s culture and identity, as a time during which the social function of literature, specifically the novel, and the role of the author as the “living conscience” of the country are found and problematicized. However, in the majority of stories, anthologies, and literary manuals, not one female author’s name is found among the canonic authors of the period, with the exception of Rachel de Queiroz. The analysis of sources from the era demonstrate that, on the contrary, female authors such as Lúcia Benedetti, Jenny Pimentel de Borba, Làsinha Luís Carlos de Caldas Brito, Maria José Dupré, Ondina Ferreira, Emi Bulhões Carvalho Fonseca, Ignez Mariz, Carolina Nabuco, Lúcia Miguel Pereira, Dinah Silveira de Queiroz, Tetrá de Teffé and many others were published, read, and appreciated by the critic and the public. Following the examination of the historical and literary context of these writings, as well as their reception and editorial aspects, the mechanisms which allowed for their deletion from memory are dismantled, explaining the lack of integration of these writings in the Brazilian literary tradition. Reading and analyzing the representations of these female authors’ novels allows for the expansion of the discourse on the participation of women in the literary and social era of the 1930’s and 1940’s. The characters, notably the female ones, which populate these works are an ideal subject for the analysis of phenomena of identity which characterize this historical time period, along with their contradictions.Os anos 30 representam um momento fundamental no processo cultural e identitário do Brasil, onde a função social da literatura, especialmente do romance, e o papel do escritor como « consciência viva » do país são reconhecidos e problematizados. Contudo, na maioria das histórias, antologias e manuais literários, nenhum nome feminino figura entre os autores canônicos do período, com a exceção de Rachel de Queiroz. A análise das fontes da época mostra que, pelo contrário, autoras como Lúcia Benedetti, Jenny Pimentel de Borba, Làsinha Luís Carlos de Caldas Brito, Maria José Dupré, Ondina Ferreira, Emi Bulhões Carvalho da Fonseca, Ignez Mariz, Carolina Nabuco, Lucia Miguel Pereira, Dinah Silveira de Queiroz, Tetrá de Teffé e tantas outras foram publicadas, lidas e apreciadas pela crítica e pelo público. A partir de um estudo do contexto histórico e literário, bem como da recepção e dos aspectos editoriais, os mecanismos que permitiram o desaparecimento de tais autoras da memória são desmontados, explicando sua falta de integração à tradição literária brasileira. A leitura dos romances destas autoras permite o aprofundamento do discurso sobre a participação das mulheres no contexto literário e social dos anos 30 e 40 através de uma análise das representações. As personagens que povoam estas obras, especialmente as personagens femininas, são um objeto ideal para analisar os fenômenos identitários que caracterizam este momento histórico e suas contradições

Summary of Behavioral Change Point Analysis (BCPA) of 9 collared elephants totaling 16 tracking years from 2003 to 2006 when BCPA indicated a significant change in the mean, variance, or autocorrelation of persistence velocity.

<p>Solid black dot is the dry-wet Transition Date (TD). Time on the horizontal axis increases to the right, i.e., movement changes occur after the TD and decreases to the left, i.e., movement changes occur before the TD; the horizontal axis, as shown in the key, is in increments of one week. Vertical arrow shows the direction of the parameter change: up  =  parameter increase; down  =  parameter decrease. Tagged elephants are identified by a three-letter code followed by a number: E (eastern) or W (western); K (Kunene) or O (Omusati); and F (female) or M (male).</p

Daily total area rainfall is shown over the 400×400 km Study Region (a) for each of the five years (2002 to 2006) based on 0.25°x0.25° spatial resolution and determined from a hybrid climatology of surface raingage and satellite-based estimates of rainfall.

<p>The extreme rainfall of 6360 cm over the Study Region (a) on 21 February 2002 is only partially shown.</p

Western Namibia, showing the Hoarusib and Hoanib catchment areas of the western Kunene, and the Uniab and Huab catchment areas of the eastern Kunene together with the location of the Omusati region.

<p>Isolines (mm) of mean annual rainfall are superimposed <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0108736#pone.0108736-Leggett1" target="_blank">[6]</a>.</p