scholarly journals Impact of Climate Change on Stratospheric Sudden Warmings as Simulated by the Canadian Middle Atmosphere Model

2009 ◽  
Vol 22 (20) ◽  
pp. 5449-5463 ◽  
Author(s):  
Charles McLandress ◽  
Theodore G. Shepherd
Keyword(s):  
Climate Change ◽  
Middle Atmosphere ◽  
Reanalysis Data ◽  
A Value ◽  
Significant Difference ◽  
Stratospheric Sudden Warmings ◽  
The Future ◽  
Transient Climate Change ◽  
Atmosphere Model ◽  
Absolute Criterion

Abstract The dynamics of Northern Hemisphere major midwinter stratospheric sudden warmings (SSWs) are examined using transient climate change simulations from the Canadian Middle Atmosphere Model (CMAM). The simulated SSWs show good overall agreement with reanalysis data in terms of composite structure, statistics, and frequency. Using observed or model sea surface temperatures (SSTs) is found to make no significant difference to the SSWs, indicating that the use of model SSTs in the simulations extending into the future is not an issue. When SSWs are defined by the standard (wind based) definition, an absolute criterion, their frequency is found to increase by ∼60% by the end of this century, in conjunction with a ∼25% decrease in their temperature amplitude. However, when a relative criterion based on the northern annular mode index is used to define the SSWs, no future increase in frequency is found. The latter is consistent with the fact that the variance of 100-hPa daily heat flux anomalies is unaffected by climate change. The future increase in frequency of SSWs using the standard method is a result of the weakened climatological mean winds resulting from climate change, which make it easier for the SSW criterion to be met. A comparison of winters with and without SSWs reveals that the weakening of the climatological westerlies is not a result of SSWs. The Brewer–Dobson circulation is found to be stronger by ∼10% during winters with SSWs, which is a value that does not change significantly in the future.

scholarly journals Past and future conditions for polar stratospheric cloud formation simulated by the Canadian Middle Atmosphere Model

2008 ◽  
Vol 8 (4) ◽  
pp. 16555-16583
Author(s):  
P. Hitchcock ◽  
T. G. Shepherd ◽  
C. McLandress
Keyword(s):  
Climate Change ◽  
Low Temperature ◽  
Ozone Depletion ◽  
Lower Stratosphere ◽  
Middle Atmosphere ◽  
The Arctic ◽  
Temperature Extremes ◽  
The Future ◽  
Atmosphere Model ◽  
The Antarctic

Abstract. Observations of the Arctic winter lower stratosphere over the past four decades suggest that the thermodynamic conditions required for the formation of polar stratospheric clouds (PSCs) have become increasingly widespread in the Northern Hemisphere. The trend is apparent only in the coldest winters during which the Arctic stratosphere is minimally disturbed by upwelling wave activity from the troposphere. The mechanism responsible for this increase remains unclear. In an effort to evaluate possible mechanisms, we analyze here the polar stratospheric temperatures in an ensemble of three 150-year integrations of the Canadian Middle Atmosphere Model (CMAM), an interactive chemistry-climate model which simulates ozone depletion and recovery, as well as climate change. We find that in the Antarctic winter lower stratosphere, the low temperature extremes required for PSC formation increase in the model as ozone is depleted, but remain steady through the twenty-first century as the warming from ozone recovery roughly balances the cooling from climate change. Thus, ozone depletion itself plays a major role in the Antarctic response. The model trend in low temperature extremes in the Arctic through the latter half of the twentieth century is weaker and less statistically robust than the observed trend. It is not projected to continue into the future. Ozone depletion in the Arctic is weaker in the CMAM than in observations, which may account for the weak past trend in low temperature extremes. In the future, radiative cooling in the Arctic winter due to climate change is more than compensated by an increase in dynamically driven downwelling over the pole.

scholarly journals Past and future conditions for polar stratospheric cloud formation simulated by the Canadian Middle Atmosphere Model

2009 ◽  
Vol 9 (2) ◽  
pp. 483-495 ◽  
Author(s):  
P. Hitchcock ◽  
T. G. Shepherd ◽  
C. McLandress
Keyword(s):  
Climate Change ◽  
Low Temperature ◽  
Ozone Depletion ◽  
Lower Stratosphere ◽  
Middle Atmosphere ◽  
The Arctic ◽  
Temperature Extremes ◽  
Polar Stratospheric Cloud ◽  
Atmosphere Model ◽  
The Antarctic

Abstract. We analyze here the polar stratospheric temperatures in an ensemble of three 150-year integrations of the Canadian Middle Atmosphere Model (CMAM), an interactive chemistry-climate model which simulates ozone depletion and recovery, as well as climate change. A key motivation is to understand possible mechanisms for the observed trend in the extent of conditions favourable for polar stratospheric cloud (PSC) formation in the Arctic winter lower stratosphere. We find that in the Antarctic winter lower stratosphere, the low temperature extremes required for PSC formation increase in the model as ozone is depleted, but remain steady through the twenty-first century as the warming from ozone recovery roughly balances the cooling from climate change. Thus, ozone depletion itself plays a major role in the Antarctic trends in low temperature extremes. The model trend in low temperature extremes in the Arctic through the latter half of the twentieth century is weaker and less statistically robust than the observed trend. It is not projected to continue into the future. Ozone depletion in the Arctic is weaker in the CMAM than in observations, which may account for the weak past trend in low temperature extremes. In the future, radiative cooling in the Arctic winter due to climate change is more than compensated by an increase in dynamically driven downwelling over the pole.

What we can learn from the parallels between the COVID-19 and the future climate change crises

2020 ◽  
Author(s):  
Rubén D. Manzanedo ◽  
Peter Manning
Keyword(s):  
Climate Change ◽  
Global Economy ◽  
Global Climate ◽  
Future Climate Change ◽  
Substantial Portion ◽  
Preventative Measures ◽  
The Future ◽  
Behavioral Norm ◽  
Climate Crisis ◽  
Global Population

The ongoing COVID-19 outbreak pandemic is now a global crisis. It has caused 1.6+ million confirmed cases and 100 000+ deaths at the time of writing and triggered unprecedented preventative measures that have put a substantial portion of the global population under confinement, imposed isolation, and established ‘social distancing’ as a new global behavioral norm. The COVID-19 crisis has affected all aspects of everyday life and work, while also threatening the health of the global economy. This crisis offers also an unprecedented view of what the global climate crisis may look like. In fact, some of the parallels between the COVID-19 crisis and what we expect from the looming global climate emergency are remarkable. Reflecting upon the most challenging aspects of today’s crisis and how they compare with those expected from the climate change emergency may help us better prepare for the future.

Love, Inc.

2019 ◽  
Author(s):  
Laurie Essig
Keyword(s):  
Climate Change ◽  
Global Climate Change ◽  
Structural Changes ◽  
Global Climate ◽  
Dating Apps ◽  
Sense Of Security ◽  
True Love ◽  
The Future ◽  
False Sense ◽  
Global Movements

In Love, Inc., Laurie Essig argues that love is not all we need. As the future became less secure—with global climate change and the transfer of wealth to the few—Americans became more romantic. Romance is not just what lovers do but also what lovers learn through ideology. As an ideology, romance allowed us to privatize our futures, to imagine ourselves as safe and secure tomorrow if only we could find our "one true love" today. But the fairy dust of romance blinded us to what we really need: global movements and structural changes. By traveling through dating apps and spectacular engagements, white weddings and Disney honeymoons, Essig shows us how romance was sold to us and why we bought it. Love, Inc. seduced so many of us into a false sense of security, but it also, paradoxically, gives us hope in hopeless times. This book explores the struggle between our inner cynics and our inner romantic.

PENGARUH PENDIDIKAN KESEHATAN REPRODUKSI PADA PEER GROUP (TEMAN SEBAYA) TERHADAP PENGETAHUAN DAN PERSEPSI REMAJA TENTANG PENDEWASAAN USIA PERKAWINAN DI SMA NEGERI 1 KECAMATAN NAMORAMBE KAB. DELI SERDANG 2018

2020 ◽  
Vol 1 (2) ◽  
pp. 56-66
Author(s):  
Irma Linda
Keyword(s):  
Standard Deviation ◽  
Health Education ◽  
Reproductive Health ◽  
Peer Group ◽  
Peer Groups ◽  
A Value ◽  
Significant Difference ◽  
Reproductive Health Education ◽  
The Mean ◽  
Adolescent Perceptions

Background: Early marriages are at high risk of marital failure, poor family quality, young pregnancies at risk of maternal death, and the risk of being mentally ill to foster marriage and be responsible parents. Objective: To determine the effect of reproductive health education on peer groups (peers) on the knowledge and perceptions of adolescents about marriage age maturity. Method: This research uses the Quasi experimental method with One group pre and post test design, conducted from May to September 2018. The statistical analysis used in this study is a paired T test with a confidence level of 95% (α = 0, 05). Results: There is an average difference in the mean value of adolescent knowledge between the first and second measurements is 0.50 with a standard deviation of 1.922. The mean difference in mean scores of adolescent perceptions between the first and second measurements was 4.42 with a standard deviation of 9.611. Conclusion: There is a significant difference between adolescent knowledge on the pretest and posttest measurements with a value of P = 0.002, and there is a significant difference between adolescent perceptions on the pretest and posttest measurements with a value of p = 0.001. Increasing the number of facilities and facilities related to reproductive health education by peer groups (peers) in adolescents is carried out on an ongoing basis at school, in collaboration with local health workers as prevention of risky pregnancy.

Planning for the Future in the Face of Climate Change

2015 ◽  
Vol 2015 (2) ◽  
pp. 1-10
Author(s):  
Christopher Crockett ◽  
Paul Kohl ◽  
Julia Rockwell ◽  
Teresa DiGenova
Keyword(s):  
Climate Change ◽  
The Future ◽  
The Face

Standardisation of von Willebrand Factor in Therapeutic Concentrates: Calibration of the 1st International Standard for von Willebrand Factor Concentrate (00/514)

2002 ◽  
Vol 88 (09) ◽  
pp. 380-386 ◽  
Author(s):  
Dawn Sands ◽  
Andrew Chang ◽  
Claudine Mazurier ◽  
Anthony Hubbard
Keyword(s):  
Von Willebrand Factor ◽  
International Study ◽  
Expert Committee ◽  
International Standard ◽  
A Value ◽  
Significant Difference ◽  
Factor Concentrate ◽  
Von Willebrand ◽  
Willebrand Factor ◽  
Good Agreement

SummaryAn international study involving 26 laboratories assayed two candidate von Willebrand Factor (VWF) concentrates (B and C) for VWF:Antigen (VWF:Ag), VWF:Ristocetin Cofactor (VWF:RCo) and VWF:Collagen binding (VWF:CB) relative to the 4th International Standard Factor VIII/VWF Plasma (4th IS Plasma) (97/586). Estimates of VWF:Ag showed good agreement between different methods, for both candidates, and the overall combined means were 11.01 IU/ml with inter-laboratory variability (GCV) of 10.9% for candidate B and 14.01 IU/ml (GCV 11.8%) for candidate C. Estimates of VWF:RCo showed no significant difference between methods for both candidates and gave overall means of 9.38 IU/ml (GCV 23.7%) for candidate B and 10.19 IU/ml (GCV 24.4%) for candidate C. Prior to the calibration of the candidates for VWF:CB it was necessary to calibrate the 4th IS Plasma relative to local frozen normal plasma pools; there was good agreement between different collagen reagents and an overall mean of 0.83 IU per ampoule (GCV 11.8%) was assigned. In contrast, estimates of VWF:CB in both candidates showed large differences between collagen reagents with inter-laboratory GCV’s of 40%. Candidate B (00/514) was established as the 1st International Standard von Willebrand Factor Concentrate by the WHO Expert Committee on Biological Standardisation in November 2001 with assigned values for VWF:Ag (11.0 IU/ampoule) and VWF:RCo (9.4 IU/ampoule). Large inter-laboratory variability of estimates precluded the assignment of a value for VWF:CB.

scholarly journals The Impact of Human Pressure and Climate Change on the Habitat Availability and Protection of Cypripedium (Orchidaceae) in Northeast China

Plants ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 84
Author(s):  
Huanchu Liu ◽  
Hans Jacquemyn ◽  
Xingyuan He ◽  
Wei Chen ◽  
Yanqing Huang ◽  
...  
Keyword(s):  
Climate Change ◽  
Northeast China ◽  
Habitat Destruction ◽  
Changbai Mountains ◽  
Suitable Habitat ◽  
Human Pressure ◽  
Terrestrial Orchids ◽  
The Future ◽  
Suitable Habitats ◽  
The Impact

Human pressure on the environment and climate change are two important factors contributing to species decline and overall loss of biodiversity. Orchids may be particularly vulnerable to human-induced losses of habitat and the pervasive impact of global climate change. In this study, we simulated the extent of the suitable habitat of three species of the terrestrial orchid genus Cypripedium in northeast China and assessed the impact of human pressure and climate change on the future distribution of these species. Cypripedium represents a genus of long-lived terrestrial orchids that contains several species with great ornamental value. Severe habitat destruction and overcollection have led to major population declines in recent decades. Our results showed that at present the most suitable habitats of the three species can be found in Da Xing’an Ling, Xiao Xing’an Ling and in the Changbai Mountains. Human activity was predicted to have the largest impact on species distributions in the Changbai Mountains. In addition, climate change was predicted to lead to a shift in distribution towards higher elevations and to an increased fragmentation of suitable habitats of the three investigated Cypripedium species in the study area. These results will be valuable for decision makers to identify areas that are likely to maintain viable Cypripedium populations in the future and to develop conservation strategies to protect the remaining populations of these enigmatic orchid species.

scholarly journals Impacts of Climate Change Interacting Abiotic Factors on Growth, aflD and aflR Gene Expression and Aflatoxin B1 Production by Aspergillus flavus Strains In Vitro and on Pistachio Nuts

Toxins ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 385
Author(s):  
Alaa Baazeem ◽  
Alicia Rodriguez ◽  
Angel Medina ◽  
Naresh Magan
Keyword(s):  
Climate Change ◽  
Gene Expression ◽  
Water Stress ◽  
Aspergillus Flavus ◽  
Aflatoxin B1 ◽  
Abiotic Factors ◽  
Pistachio Nuts ◽  
Significant Difference ◽  
Spoilage Fungi

Pistachio nuts are an important economic tree nut crop which is used directly or processed for many food-related activities. They can become colonized by mycotoxigenic spoilage fungi, especially Aspergillus flavus, mainly resulting in contamination with aflatoxins (AFs), especially aflatoxin B1 (AFB1). The prevailing climate in which these crops are grown changes as temperature and atmospheric CO2 levels increase, and episodes of extreme wet/dry cycles occur due to human industrial activity. The objectives of this study were to evaluate the effect of interacting Climate Change (CC)-related abiotic factors of temperature (35 vs. 37 °C), CO2 (400 vs. 1000 ppm), and water stress (0.98–0.93 water activity, aw) on (a) growth (b) aflD and aflR biosynthetic gene expression and (c) AFB1 production by two strains A. flavus (AB3, AB10) in vitro on milled pistachio-based media and when colonizing layers of shelled raw pistachio nuts. The A. flavus strains were resilient in terms of growth on pistachio-based media and the colonisation of pistachio nuts with no significant difference when exposed to the interacting three-way climate-related abiotic factors. However, in vitro studies showed that AFB1 production was significantly stimulated (p < 0.05), especially when exposed to 1000 ppm CO2 at 0.98–0.95 aw and 35 °C, and sometimes in the 37 °C treatment group at 0.98 aw. The relative expression of the structural aflD gene involved in AFB1 biosynthesis was decreased or only slightly increased, relative to the control conditions at elevated CO, regardless of the aw level examined. For the regulatory aflR gene expression, there was a significant (p < 0.05) increase in 1000 ppm CO2 and 37 °C for both strains, especially at 0.95 aw. The in situ colonization of pistachio nuts resulted in a significant (p < 0.05) stimulation of AFB1 production at 35 °C and 1000 ppm CO2 for both strains, especially at 0.98 aw. At 37 °C, AFB1 production was either decreased, in strain AB3, or remained similar, as in strain AB10, when exposed to 1000 ppm CO2. This suggests that CC factors may have a differential effect, depending on the interacting conditions of temperature, exposure to CO2 and the level of water stress on AFB1 production.

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