نتایج جستجو برای: شاخص pdsi

تعداد نتایج: 74708  

2015
Tianyi Zhang Hesong Wang

We identified the spatiotemporal patterns of the Normalized Difference Vegetation Index (NDVI) for the years 1982-2008 in the desert areas of Northwest China and quantified the impacts of climate and non-climate factors on NDVI changes. The results indicate that although the mean NDVI has improved in 24.7% of the study region; 16.3% among the region has been stagnating in recent years and only ...

2013
Ellis Q. Margolis Thomas W. Swetnam

Understanding relationships between variability in historical fire occurrence and ocean–atmosphere oscillations provides opportunities for fire forecasting and projecting changes in fire regimes under climate change scenarios.We analysed tree-ring reconstructed regional climate teleconnections and fire–climate relationships in upper elevation forests (.2700m) from 16 sites in eight mountain ran...

2012
Xiangtao Xu Shilong Piao Xuhui Wang Anping Chen Philippe Ciais Ranga B Myneni

Extreme climatic events like droughts, floods, heat waves and ice storms impact ecosystems as well as human societies. There is wide concern about how terrestrial ecosystems respond to extreme climatic events in the context of global warming. In this study, we used satellite-derived vegetation greenness data (Normalized Difference Vegetation Index; NDVI), in situ weather station data (temperatu...

2010
SERGIO M. VICENTE-SERRANO SANTIAGO BEGUERÍA JUAN I. LÓPEZ-MORENO

The authors propose a new climatic drought index: the standardized precipitation evapotranspiration index (SPEI). The SPEI is based on precipitation and temperature data, and it has the advantage of combining multiscalar character with the capacity to include the effects of temperature variability on drought assessment. The procedure to calculate the index is detailed and involves a climatic wa...

2018
Carlos H. R. Lima Amir AghaKouchak

Abstract Most Amazonia drought studies have focused on rainfall deficits and their impact on river discharges, while the analysis of other important driver variables, such as temperature and soil moisture, has attracted less attention. Here we try to better understand the spatiotemporal dynamics of Amazonia droughts and associated climate teleconnections as characterized by the Palmer Drought S...

2017
SEUNG H. BAEK JASON E. SMERDON SLOAN COATS A. PARK WILLIAMS BENJAMIN I. COOK EDWARD R. COOK RICHARD SEAGER

The tree-ring-based North American Drought Atlas (NADA), Monsoon Asia Drought Atlas (MADA), and Old World Drought Atlas (OWDA) collectively yield a near-hemispheric gridded reconstruction of hydroclimate variability over the last millennium. To test the robustness of the large-scale representation of hydroclimate variability across the drought atlases, the joint expression of seasonal climate v...

2016
Harrison Hong Frank Weikai Li Jiangmin Xu

We investigate whether stock markets efficiently price risks brought on or exacerbated by climate change. We focus on drought, the most damaging natural disaster for crops and food-company cash flows. We show that prolonged drought in a country, measured by the Palmer Drought Severity Index (PDSI) from climate studies, forecasts both poor stock returns and profitability ratios for food companie...

2011
BENJAMIN I. COOK RICHARD SEAGER RON L. MILLER JOSEPH A. MASON

Tree-ring-based reconstructions of the Palmer drought severity index (PDSI) indicate that, during the Medieval Climate Anomaly (MCA), the central plains of North America experienced recurrent periods of drought spanning decades or longer. These megadroughts had exceptional persistence compared to more recent events, but the causes remain uncertain. The authors conducted a suite of general circu...

2007
Brandon M. Collins Philip N. Omi

Recent studies have linked the Atlantic Mdtidecadal Oscillation (AMO) and the Pacific Decadal Oscillation (PDO) with drought occurrence in the interior United States. This study evaluates the influence of AM0 and PDO phases on interannual relationships between climate and wildfire-burned area during the 20th century. Palmer's Drought Severity Index (PDSI) is strongly related to burned area at b...

Journal: :Environmental entomology 2008
Elizabeth G Hebertson Michael J Jenkins

This study investigated relationships between climate and historic spruce beetle, Dendroctonus rufipennis Kirby (Coleoptera: Curculionidae), outbreaks in northern and southeastern Utah and western Colorado between 1905 and 1996. A chronology of outbreak years was constructed from historic records, research papers, newspapers, and other sources of information. Historic climate data for the regio...

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