The impact of climatic and non-climatic factors on land surface temperature in southwestern Romania     

Cristina?Florina?Ro?caEmail author  Gabriela?Victoria?Harpa  Adina-Eliza?Croitoru  Ioana?Herbel  Alexandru?Mircea?Imbroane  Doina?Cristina?Burada 《Theoretical and Applied Climatology》2017,130(3-4):775-790

Land surface temperature is one of the most important parameters related to global warming. It depends mainly on soil type, discontinuous vegetation cover, or lack of precipitation. The main purpose of this paper is to investigate the relationship between high LST, synoptic conditions and air masses trajectories, vegetation cover, and soil type in one of the driest region in Romania. In order to calculate the land surface temperature and normalized difference vegetation index, five satellite images of LANDSAT missions 5 and 7, covering a period of 26 years (1986–2011), were selected, all of them collected in the month of June. The areas with low vegetation density were derived from normalized difference vegetation index, while soil types have been extracted from Corine Land Cover database. HYSPLIT application was employed to identify the air masses origin based on their backward trajectories for each of the five study cases. Pearson, logarithmic, and quadratic correlations were used to detect the relationships between land surface temperature and observed ground temperatures, as well as between land surface temperature and normalized difference vegetation index. The most important findings are: strong correlation between land surface temperature derived from satellite images and maximum ground temperature recorded in a weather station located in the area, as well as between areas with land surface temperature equal to or higher than 40.0 °C and those with lack of vegetation; the sandy soils are the most prone to high land surface temperature and lack of vegetation, followed by the chernozems and brown soils; extremely severe drought events may occur in the region.  相似文献   

Amplitude domain analysis for the 30 August 1986 Vrancea intermediate earthquake     

Luminiţa Ardeleanu  Victoria Oancea 《Natural Hazards》1990,3(3):305-314

The amplitude domain analysis applied to the major Vrancea (Romania) earthquake of 30 August 1986 leads to the determination of some parameters characterizing the amplitude and the time duration of the signal.Digital three-component acceleration data, obtained at 10 Romanian seismic stations with epicentral distances between 40 and 200 km, are used. The results are compared with those obtained by Schenk for strong Californian earthquakes.Paper presented in the 21st General Assembly of the European Seismological Commission, Sofia, 1988.  相似文献   

Results of U–Pb LA–ICP–MS dating of detrital zircons from Ediacaran–Early Cambrian deposits of the eastern part of the Baltic monoclise     

A. S. Ivleva  V. N. Podkovyrov  V. B. Ershova  O. A. Anfinson  A. K. Khudoley  P. V. Fedorov  A. V. Maslov  D. Yu. Zdobin 《Doklady Earth Sciences》2016,468(2):593-597

Here we present the results of U–Pb LA–ICP–MS dating of detrital zircons from the Ediacaran–Early Cambrian deposits of the eastern part of the Baltic monoclise (Leningrad Region). The obtained age spectra of the detrital zircons suggest that, in the Ediacaran–Early Cambrian, the main clastic material source to the northwest of the Russian Platform was the Baltic Shield. Then in the Early Cambrian along with the Baltic Shield provenance, a clastic source from the Timanian margin of Baltica (northeast in modern coordinates) contributed to the deposits. The obtained data either somewhat set limits of the Timanian orogen formation as older than the previously suggested Middle Cambrian (about 510 Ma), based on the “absence of a Proto–Uralian–Timanian provenance signal” in the Sablino Formation rocks in the south Ladoga, or suggest another rearrangement of detritus transportation paths at the end of Stage 3 (Atdabanian).  相似文献   

Late Holocene Environmental Reconstructions from Lake Solai,Kenya     

Michelle Goman  Gail M. Ashley  R. Bernhart Owen  Victoria C. Hover  Dev K. Maharjan 《The Professional geographer》2017,69(3):438-454

Playa lake systems tend to be overlooked archives of paleoenvironmental change due to the likelihood of a short and intermittent record of deposition. Groundwater-fed wetlands associated with these climate-sensitive playas, however, preserve changes in hydrologic budget and are thus valuable archives for semiarid regions. This study examines the paleoecological record of a groundwater-fed wetland from Lake Solai, Kenya. Biological proxies are used to reconstruct paleoenvironmental change and climate impacts over the past millennium. Dry conditions persisted between CE 1115 and 1490, followed by wetter conditions during the Little Ice Age. Near surface sediments indicate increasing anthropogenic impact through pastoralism.  相似文献   

Stochastic Analysis Method of Sea Environment Simulated by Numerical Models     

刘德辅  焦桂英  张明霞  温书勤 《中国海洋工程》2003,17(2)

1 .IntroductionNumericalmodelsmostwidelyusedforseaenvironmentandsedimenttransportfocusonsolvingseriesofdifferentialequations .Theinputandoutputofanumericalmodelareconsideredasdecisivefactors .Butinrealitythecausesofnaturaleventssuchasmeteorological,astronomical,oceanograph ic ,geomorphologicandgeophysicalfactorsarerandom .Therearemanyuncertaintiesinvolvedininputfactorsinnumericalmodels .Correspondinglytheoutputsofnumericalmodelsarealsorandom .There fore ,theoutputparametersofnumericalmodelsca…  相似文献   

The phytoplankton bloom response to wind events and upwelled nutrients during the CoOP WEST study     

Frances P. Wilkerson  Adria M. Lassiter  Richard C. Dugdale  Albert Marchi  Victoria E. Hogue 《Deep Sea Research Part II: Topical Studies in Oceanography》2006,53(25-26):3023

In the coastal waters off northern California, seasonal wind-driven upwelling supplies abundant nutrients to be processed by phytoplankton productivity. As part of the Coastal Ocean Processes: Wind Events and Shelf Transport (CoOP WEST) study, nutrients, CO₂, size-fractionated chlorophyll, and phytoplankton community structure were measured in the upwelling region off Bodega Bay, CA, during May–June 2000, 2001 and 2002. The ability of this ecosystem to assimilate nitrate (NO₃) and silicic acid/silicate (Si(OH)₄) and accumulate particulate material (i.e. phytoplankton) was realized in all 3 years, following short events of upwelling-favorable winds, followed by periods of relaxed winds. This was observed as phytoplankton blooms, dominated by chlorophyll in cells greater than 5 μm in diameter, that reduced the ambient nutrients to zero. These communities were located over the near-shore shelf (<100 m depth) and were dominated by diatoms. An optimal window of 3–7 days of relaxed winds, following an upwelling pulse, was required for chlorophyll accumulation. The large-celled phytoplankton that result are likely important players in coastal new production and carbon cycling.  相似文献   

Plants versus streams: Their groundwater-mediated competition at “El Morro,” a developing catchment in the dry plains of Argentina     

Esteban G. Jobbágy  Santiago Lorenzo  Nicolás Buono  Ricardo Páez  Yésica Diaz  Victoria Marchesini  Marcelo D. Nosetto 《水文研究》2021,35(5):e14188

Our understanding of how groundwater mediates evapotranspiration/streamflow partitioning is still fragmented and catchment studies under changing vegetation conditions can provide a useful frame for integration. We explored this partition in a flat sedimentary dry catchment in central Argentina in which the replacement of native vegetation with rainfed crops was accompanied by the abrupt formation of groundwater-fed streams by subsurface erosion (i.e., sapping) episodes. Historical records indicated widespread water table rises (~0.3 m y⁻¹ on average). Groundwater level and stream baseflow fluctuated seasonally with minima in the warm rainy season, indicating that evaporative discharge rather than rainfall shapes saturated flows. Diurnal groundwater level fluctuations showed that plant uptake was widespread where water tables are shallow (<3 m) but restricted to deep-rooted Prosopis forests where they are deep (7–10 m). MODIS and LANDSAT NDVI revealed a long-term greening for native vegetation, new wetlands included, but not for croplands, suggesting more limited evapotranspiration-groundwater level regulation under agriculture. Close to the deepest (20 m) and most active incisions, groundwater level and greenness declined and stream baseflow showed no seasonal fluctuations, hinting decoupling from evapotranspiration. Intense ecological and geomorphological transformations in this catchment exposed the interplay of five mechanisms governing evapotranspiration/streamflow partition including (a) unsaturated uptake and both (b) riparian and (c) distributed uptake from the saturated zone by plants, as well as (d) deepening incisions and (e) sediment deposits over riparian zones by streams. Acknowledging the complex interplay of these mechanisms with groundwater is crucial to predict and manage future hydrological changes in the dry plains of South America.  相似文献   

Public support for carbon dioxide removal strategies: the role of tampering with nature perceptions     

Wolske  Kimberly S.  Raimi  Kaitlin T.  Campbell-Arvai  Victoria  Hart  P. Sol 《Climatic change》2019,152(3-4):345-361

Climatic Change - Carbon dioxide removal (CDR) describes a suite of controversial approaches to mitigating climate change that involve removing existing carbon dioxide from the atmosphere. Through...  相似文献   

Decentring poverty studies: Middle class alliances and the social construction of poverty   总被引：1，自引：0，他引：1  

Victoria Lawson  with Middle Class Poverty Politics Research Group 《Singapore journal of tropical geography》2012,33(1):1-19

Editors' Note: The following is the tenth in the Singapore Journal of Tropical Geography Lecture Series. It is based on the plenary presentation of 13 April at the AAG held in Seattle in 2011. In this essay I explore relational poverty analysis to take seriously the spatially varied intersections of political‐economic, social ordering and cultural‐political processes in shaping understandings of poverty. My work as part of the Middle Class Poverty Politics Research Group employs a relational comparative methodology to theorize where, when and under what circumstances those framed as ‘middle class’ act in opposition to or in solidarity with those named as ‘poor’. Our approach focuses on the exploitative effects of capital accumulation, processes of unequal sociospatial categorization and political and discursive systems that limit or exclude the poor. Our research focuses on places experiencing capitalist crisis because intense periods of restructuring highlight material and discursive struggles over poverty. We conclude by identifying a research agenda focused on the ways in which poverty politics are constituted by the nonpoor through place and in the articulation of places with processes of political economy, governance and cultural politics.  相似文献   

Tracing glacier wastage in the Northern Tien Shan (Kyrgyzstan/Central Asia) over the last 40 years   总被引：2，自引：1，他引：1  

Peter Niederer  Viktor Bilenko  Natasha Ershova  Hans Hurni  Sergeji Yerokhin  Daniel Maselli 《Climatic change》2008,86(1-2):227-234

The status and dynamics of glaciers are crucial for agriculture in semiarid parts of Central Asia, since river flow is characterized by major runoff in spring and summer, supplied by glacier- and snowmelt. Ideally, this coincides with the critical period of water demand for irrigation. The present study shows a clear trend in glacier retreat between 1963 and 2000 in the Sokoluk watershed, a catchment of the Northern Tien Shan mountain range in Kyrgyzstan. The overall area loss of 28% observed for the period 1963–2000, and a clear acceleration of wastage since the 1980s, correlate with the results of previous studies in other regions of the Tien Shan as well as the Alps. In particular, glaciers smaller than 0.5 km² have exhibited this phenomenon most starkly. While they registered a medium decrease of only 9.1% for 1963–1986, they lost 41.5% of their surface area between 1986 and 2000. Furthermore, a general increase in the minimum glacier elevation of 78 m has been observed over the last three decades. This corresponds to about one-third of the entire retreat of the minimum glacier elevation in the Northern Tien Shan since the Little Ice Age maximum.  相似文献