Record-breaking climate anomalies lead to severe drought and environmental disruption in western Patagonia in 2016

2018 ◽  
Vol 74 (3) ◽  
pp. 217-229 ◽  
Author(s):  
RD Garreaud
2020 ◽  
Vol 375 (1810) ◽  
pp. 20190507 ◽  
Author(s):  
A. Bastos ◽  
Z. Fu ◽  
P. Ciais ◽  
P. Friedlingstein ◽  
S. Sitch ◽  
...  

In Europe, three widespread extreme summer drought and heat (DH) events have occurred in 2003, 2010 and 2018. These events were comparable in magnitude but varied in their geographical distribution and biomes affected. In this study, we perform a comparative analysis of the impact of the DH events on ecosystem CO 2 fluxes over Europe based on an ensemble of 11 dynamic global vegetation models (DGVMs), and the observation-based FLUXCOM product. We find that all DH events were associated with decreases in net ecosystem productivity (NEP), but the gross summer flux anomalies differ between DGVMs and FLUXCOM. At the annual scale, FLUXCOM and DGVMs indicate close to neutral or above-average land CO 2 uptake in DH2003 and DH2018, due to increased productivity in spring and reduced respiration in autumn and winter compensating for less photosynthetic uptake in summer. Most DGVMs estimate lower gross primary production (GPP) sensitivity to soil moisture during extreme summers than FLUXCOM. Finally, we show that the different impacts of the DH events at continental-scale GPP are in part related to differences in vegetation composition of the regions affected and to regional compensating or offsetting effects from climate anomalies beyond the DH centres. This article is part of the theme issue ‘Impacts of the 2018 severe drought and heatwave in Europe: from site to continental scale’.


2019 ◽  
Vol 11 (20) ◽  
pp. 5767 ◽  
Author(s):  
Jin ◽  
Zhang ◽  
Wang ◽  
Zhang ◽  
Bao ◽  
...  

Continuous climate warming in the last few decades has led to global climate anomalies, resulting in frequent drought events in arid/semiarid regions with fragile and sensitive ecological environment. The Mongolian Plateau (MP) is located at the mid-latitude arid/semiarid climate region, which is deemed as the most sensitive region in response to global climate change. In order to understand the spatiotemporal characteristics of droughts in Mongolian Plateau under changing climate, we divided the study area into three climatic regions via Köppen climate classification. Then, the seasonal and annual drought trends were analyzed by standardized precipitation evaporation index (SPEI), which is a function of monthly mean temperatures, highest temperatures, lowest temperatures and precipitations, collected from the 184 meteorological stations from 1980 to 2015. Mann–Kendall (MK) test was employed to detect if there is an abrupt change of annual drought, while the empirical orthogonal function method (EOF) was adopted to investigate the spatiotemporal characteristics of droughts across the Mongolian Plateau. Results from MK test illustrated that the SPEI-12 exhibited statistically significant downward trends (a < 0.05) for all three climatic regions of the Mongolian Plateau.EOF spatial analysis indicated that Region III experienced the most severe drought from 1980 to 2015. During the 35 years period, an abrupt change of drought was detected in 1999. Before year 1999, the climate was relatively humid. However, the entire region became more arid after year 1999, reflected by remarkably increased frequency and intensity of drought. SPEI-3 revealed the trend of drought at seasonal scale. We found that drought became more severe in spring, summer, and fall seasons for the entire MP. However, winter became more humid. Different climate regions exhibited quite different drought seasonality: Region I experienced a severe arid trend in summer and fall. For Region II and III, summer became more arid. All three regions became more humid in winter season, especially for Region I, with the Sen’s slope of 0.0241/a.


2010 ◽  
Vol 27 (2) ◽  
pp. 182-187 ◽  
Author(s):  
Quan-liang CHEN ◽  
Wei HUA ◽  
Guang-ming XIONG ◽  
Hui XU ◽  
Xiao-ran LIU
Keyword(s):  

2012 ◽  
Vol 7 (4) ◽  
Author(s):  
N. Rowan ◽  
E. Hecox ◽  
S. Morea

The last decade has brought many changes to Colorado's water supply outlook. Despite the recent economic recession, the state has experienced significant population growth, and Colorado's population is expected to nearly double within the next 40 years. Other pressures on Colorado's water supply include severe drought, a desire to meet multiple needs (i.e., municipal, environmental, recreational) with existing resources, and impacts to agriculture due to water shortages, urbanization, and transfers to new users. To address these challenges, the Colorado Water Conservation Board (CWCB) has undertaken a visioning process to explore solutions to these future water supply challenges. As part of this process, CWCB has led the state in identifying demand and supply strategies to meet the state's future water needs while considering agriculture and the environment. These strategies have been combined into varying portfolios that include methods such as conservation, local water projects, new Colorado River development, and agricultural transfers. This paper details the development and evaluation of these portfolios and describes stakeholder's efforts to balance meeting Colorado's water needs in the future.


1982 ◽  
Vol 14 (4-5) ◽  
pp. 43-58 ◽  
Author(s):  
M Rizet ◽  
J Mouchet

This study was conducted in order to understand the taste and odour problems that occurred in the Seine and the Marne rivers during the severe drought of 1976. Samples were taken every 15 days from several locations in the rivers themselves and from storage reservoirs upstream from Paris. Algae and actinomycetes were identified and counted. Metabolite concentrations were measured. These data were correlated with threshold odor numbers and bacteriological water quality parameters.


Trees ◽  
2021 ◽  
Author(s):  
Anastasia Christopoulou ◽  
Nikolaos M. Fyllas ◽  
Barbara Gmińska-Nowak ◽  
Yasemin Özarslan ◽  
Margarita Arianoutsou ◽  
...  

Abstract Key message Long Bosnian pine chronologies from different mountains are shaped by different climatic parameters and can help identify past drought events and reconstruct landscape histories. Abstract We developed a 735-year-long Pinus heldreichii chronology from the southern distribution limit of the species, expanding the available database of long Bosnian pine chronologies. Tree-ring growth was mainly positively correlated with growing degree days (GDD: r1950–2018 = 0.476) while higher temperatures during both winter and growing season also enhanced growth (TWT: r1950–2018 = 0.361 and TGS: 0.289, respectively). Annual precipitation, during both calendar and water years, had a negative but weaker impact on annual tree growth. The newly developed chronology correlates well with chronologies developed from the neighboring mountains. The years with ring width index (RWI) lower than the average were found to correspond to cool years with dry summers. Still, the newly developed chronology was able to capture severe drought events, such as those in 1660, 1687, and 1725. Several old living trees had internal scars presumably caused by fires. Therefore, old mature trees could be used for fire history reconstruction in addition to climate reconstruction. Although the presence of lightning scars indicates an important natural agent of fire ignition, human activities associated with animal grazing could also be an underlying reason for fires in the region.


Atmosphere ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 294
Author(s):  
Norel Rimbu ◽  
Monica Ionita ◽  
Gerrit Lohmann

The variability of stable oxygen isotope ratios (δ18O) from Greenland ice cores is commonly linked to changes in local climate and associated teleconnection patterns. In this respect, in this study we investigate ice core δ18O variability from a synoptic scale perspective to assess the potential of such records as proxies for extreme climate variability and associated weather patterns. We show that positive (negative) δ18O anomalies in three southern and central Greenland ice cores are associated with relatively high (low) Rossby Wave Breaking (RWB) activity in the North Atlantic region. Both cyclonic and anticyclonic RWB patterns associated with high δ18O show filaments of strong moisture transport from the Atlantic Ocean towards Greenland. During such events, warm and wet conditions are recorded over southern, western and central part of Greenland. In the same time the cyclonic and anticyclonic RWB patterns show enhanced southward advection of cold polar air masses on their eastern side, leading to extreme cold conditions over Europe. The association between high δ18O winters in Greenland ice cores and extremely cold winters over Europe is partly explained by the modulation of the RWB frequency by the tropical Atlantic sea surface temperature forcing, as shown in recent modeling studies. We argue that δ18O from Greenland ice cores can be used as a proxy for RWB activity in the Atlantic European region and associated extreme weather and climate anomalies.


Forests ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 332
Author(s):  
Min Li ◽  
Haoyun Wang ◽  
Xizhou Zhao ◽  
Zhongke Lu ◽  
Xueguang Sun ◽  
...  

Masson pine is an important afforestation species in southern China, where seasonal drought is common. The present study focused on the effects of Suillus placidus, an ectomycorrhizal fungus, inoculation on the growth and physiological and biochemical performance of masson pine seedlings under four different watering treatments (well-watered, mild drought, moderate drought, and severe drought) to evaluate the symbiotic relationship between S. placidus and masson pine seedlings. Ectomycorrhizal-inoculated (ECM) and non-inoculated (NM) seedlings were grown in pots and maintained for 60 days using the weighing method. Results showed that seedlings’ growth, dry weight, RWC, chlorophyll content, PSII efficiency, and photosynthesis decreased as drought stress intensified in both ECM and NM plants. This suggests that drought stress significantly limits the growth and photosynthetic performance of masson pine seedlings. Nevertheless, increased An/gs and proline contents in both NM and ECM prevented oxidative damage caused by drought stress. In addition, increased peroxidase (POD) activity is an essential defense mechanism of ECM seedling under drought stress. Compared with NM, ECM seedlings showed faster growth, higher RWC, and photosynthetic performance, and lower lipid peroxidation in cell membranes under drought stress, as indicated by higher POD activity and lower proline and malondialdehyde (MDA). Our experiment found that S. placidus inoculation can enhance the drought resistance of masson pine seedlings by increasing antioxidant enzyme activity, water use efficiency, and proline content, thereby enhancing growth under water-deficiency conditions. S. placidus can be used to cultivate high-quality seedlings and improve their survival in regions that experience seasonal droughts.


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