Diurnal timing of warmer air under climate change affects magnitude, timing and duration of stream temperature change

2012 ◽  
Vol 27 (16) ◽  
pp. 2367-2378 ◽  
Author(s):  
Mousa Diabat ◽  
Roy Haggerty ◽  
Steven M. Wondzell
Keyword(s):  
Climate Change ◽  
Temperature Change ◽  
Stream Temperature

scholarly journals Past temperature reconstructions from deep ice cores: relevance for future climate change

2006 ◽  
Vol 2 (2) ◽  
pp. 145-165 ◽  
Author(s):  
V. Masson-Delmotte ◽  
G. Dreyfus ◽  
P. Braconnot ◽  
S. Johnsen ◽  
J. Jouzel ◽  
...  
Keyword(s):  
Climate Change ◽  
Temperature Change ◽  
Climate Models ◽  
Ice Core ◽  
Ice Cores ◽  
Future Climate ◽  
Future Climate Change ◽  
Interglacial Period ◽  
Temperature Reconstructions

Abstract. Ice cores provide unique archives of past climate and environmental changes based only on physical processes. Quantitative temperature reconstructions are essential for the comparison between ice core records and climate models. We give an overview of the methods that have been developed to reconstruct past local temperatures from deep ice cores and highlight several points that are relevant for future climate change. We first analyse the long term fluctuations of temperature as depicted in the long Antarctic record from EPICA Dome C. The long term imprint of obliquity changes in the EPICA Dome C record is highlighted and compared to simulations conducted with the ECBILT-CLIO intermediate complexity climate model. We discuss the comparison between the current interglacial period and the long interglacial corresponding to marine isotopic stage 11, ~400 kyr BP. Previous studies had focused on the role of precession and the thresholds required to induce glacial inceptions. We suggest that, due to the low eccentricity configuration of MIS 11 and the Holocene, the effect of precession on the incoming solar radiation is damped and that changes in obliquity must be taken into account. The EPICA Dome C alignment of terminations I and VI published in 2004 corresponds to a phasing of the obliquity signals. A conjunction of low obliquity and minimum northern hemisphere summer insolation is not found in the next tens of thousand years, supporting the idea of an unusually long interglacial ahead. As a second point relevant for future climate change, we discuss the magnitude and rate of change of past temperatures reconstructed from Greenland (NorthGRIP) and Antarctic (Dome C) ice cores. Past episodes of temperatures above the present-day values by up to 5°C are recorded at both locations during the penultimate interglacial period. The rate of polar warming simulated by coupled climate models forced by a CO2 increase of 1% per year is compared to ice-core-based temperature reconstructions. In Antarctica, the CO2-induced warming lies clearly beyond the natural rhythm of temperature fluctuations. In Greenland, the CO2-induced warming is as fast or faster than the most rapid temperature shifts of the last ice age. The magnitude of polar temperature change in response to a quadrupling of atmospheric CO2 is comparable to the magnitude of the polar temperature change from the Last Glacial Maximum to present-day. When forced by prescribed changes in ice sheet reconstructions and CO2 changes, climate models systematically underestimate the glacial-interglacial polar temperature change.

scholarly journals Future Temperature Extremes Will Be More Harmful: A New Critical Factor for Improved Forecasts

2019 ◽  
Vol 16 (20) ◽  
pp. 4015 ◽  
Author(s):  
Costas A. Varotsos ◽  
Yuri A. Mazei
Keyword(s):  
Climate Change ◽  
Temperature Change ◽  
Heat Waves ◽  
Extreme Temperature ◽  
Well Being ◽  
Early Warning Systems ◽  
Extreme Weather Events ◽  
Anthropogenic Activity ◽  
Extreme Temperature Events ◽  
The Past

There is increasing evidence that extreme weather events such as frequent and intense cold spells and heat waves cause unprecedented deaths and diseases in both developed and developing countries. Thus, they require extensive and immediate research to limit the risks involved. Average temperatures in Europe in June–July 2019 were the hottest ever measured and attributed to climate change. The problem, however, of a thorough study of natural climate change is the lack of experimental data from the long past, where anthropogenic activity was then very limited. Today, this problem can be successfully resolved using, inter alia, biological indicators that have provided reliable environmental information for thousands of years in the past. The present study used high-resolution quantitative reconstruction data derived from biological records of Lake Silvaplana sediments covering the period 1181–1945. The purpose of this study was to determine whether a slight temperature change in the past could trigger current or future intense temperature change or changes. Modern analytical tools were used for this purpose, which eventually showed that temperature fluctuations were persistent. That is, they exhibit long memory with scaling behavior, which means that an increase (decrease) in temperature in the past was always followed by another increase (decrease) in the future with multiple amplitudes. Therefore, the increase in the frequency, intensity, and duration of extreme temperature events due to climate change will be more pronounced than expected. This will affect human well-being and mortality more than that estimated in today’s modeling scenarios. The scaling property detected here can be used for more accurate monthly to decadal forecasting of extreme temperature events. Thus, it is possible to develop improved early warning systems that will reduce the public health risk at local, national, and international levels.

Seasonal temperature variations influence tapetum mitosis patterns associated with reproductive fitness

Genome ◽  
2014 ◽  
Vol 57 (9) ◽  
pp. 517-521 ◽  
Author(s):  
Umesh C. Lavania ◽  
Surochita Basu ◽  
Jyotsana Singh Kushwaha ◽  
Seshu Lavania
Keyword(s):  
Climate Change ◽  
Temperature Change ◽  
Reproductive Fitness ◽  
Seasonal Temperature ◽  
Seed Fertility ◽  
Mild Winter ◽  
Differential Behavior ◽  
Sporogenous Tissue ◽  
Differential Behaviour ◽  
Environmentally Sensitive

Environmental stress in plants impacts many biological processes, including male gametogenesis, and affects several cytological mechanisms that are strongly interrelated. To understand the likely impact of rising temperature on reproductive fitness in the climate change regime, a study of tapetal mitosis and its accompanying meiosis over seasons was made to elucidate the influence of temperature change on the cytological events occurring during microsporogenesis. For this we used two species of an environmentally sensitive plant system, i.e., genus Cymbopogon Sprengel (Poaceae), namely Cymbopogon nardus (L.) Rendle var. confertiflorus (Steud.) Bor (2n = 20) and Cymbopogon jwaruncusha (Jones) Schult. (2n = 20). Both species flower profusely during extreme summer (48 °C) and mild winter (15 °C) but support low and high seed fertility, respectively, in the two seasons. We have shown that tapetal mitotic patterns over seasons entail differential behavior for tapetal mitosis. During the process of tapetum development there are episodes of endomitosis that form either (i) an endopolyploid genomically imbalanced uninucleate and multinucleate tapetum, and (or) (ii) an acytokinetic multinucleate genomically balanced tapetum, with the progression of meiosis in the accompanying sporogenous tissue. The relative frequency of occurrence of the two types of tapetum mitosis patterns is significantly different in the two seasons, and it is found to be correlated with the temperature conditions. Whereas, the former (genomically imbalanced tapetum) are prevalent during the hot summer, the latter (genomically balanced tapetum) are frequent under optimal conditions. Such a differential behaviour in tapetal mitosis vis-à-vis temperature change is also correspondingly accompanied by substantial disturbances or regularity in meiotic anaphase disjunction. Both species show similar patterns. The study underpins that tapetal mitotic behaviour per se could be a reasonable indicator to elucidate the effect of climate change on reproductive fitness.

scholarly journals Climate-induced population displacements in a 4 ° C+ world

2011 ◽  
Vol 369 (1934) ◽  
pp. 182-195 ◽  
Author(s):  
François Gemenne
Keyword(s):  
Climate Change ◽  
Temperature Change ◽  
Temperature Rise ◽  
Sub Saharan Africa ◽  
Population Movements ◽  
Temperature Changes ◽  
Policy Responses ◽  
Sub Saharan

Massive population displacements are now regularly presented as one of the most dramatic possible consequences of climate change. Current forecasts and projections show that regions that would be affected by such population movements are low-lying islands, coastal and deltaic regions, as well as sub-Saharan Africa. Such estimates, however, are usually based on a 2 ° C temperature rise. In the event of a 4 ° C+ warming, not only is it likely that climate-induced population movements will be more considerable, but also their patterns could be significantly different, as people might react differently to temperature changes that would represent a threat to their very survival. This paper puts forward the hypothesis that a greater temperature change would affect not only the magnitude of the associated population movements, but also—and above all—the characteristics of these movements, and therefore the policy responses that can address them. The paper outlines the policy evolutions that climate-induced displacements in a 4 ° C+ world would require.

scholarly journals A Global Approach to Assess the Potential Impact of Climate Change on Stream Water Temperatures and Related In-Stream First-Order Decay Rates

2012 ◽  
Vol 13 (3) ◽  
pp. 1052-1065 ◽  
Author(s):  
Manuel Punzet ◽  
Frank Voß ◽  
Anja Voß ◽  
Ellen Kynast ◽  
Ilona Bärlund
Keyword(s):  
Climate Change ◽  
Water Quality ◽  
Regression Model ◽  
Stream Water ◽  
Stream Temperature ◽  
Decay Rates ◽  
Regression Equation ◽  
Impact Of Climate Change ◽  
Global Regression ◽  
Warm Temperate

Abstract Stream water temperature is an important factor used in water quality modeling. To estimate monthly stream temperature on a global scale, a simple nonlinear regression model was developed. It was applied to stream temperatures recorded over a 36-yr period (1965–2001) at 1659 globally distributed gauging stations. Representative monthly air temperatures were obtained from the nearest grid cell included in the new global meteorological forcing dataset—the Water and Global Change (WATCH) Forcing Data. The regression model reproduced monthly stream temperatures with an efficiency of fit of 0.87. In addition, the regression model was applied for different climate zones (polar, snow, warm temperate arid, and equatorial climates) based on the Köppen–Geiger climate classification. For snow, warm temperate, and arid climates the efficiency of fit was larger than 0.82 including more than 1504 stations (90% of all records used). Analyses of heat-storage effects (seasonal hysteresis) did not show noticeable differences between the warming/cooling and global regression curves, respectively. The maximum difference between both limbs of the hysteresis curves was 1.6°C and thus neglected in the further analysis of the study. For validation purposes time series of stream temperatures for five individual river basins were computed applying the global regression equation. The accuracy of the global regression equation could be confirmed. About 77% of the predicted values differed by 3°C or less from measured stream temperatures. To examine the impact of climate change on stream water temperatures, gridded global monthly stream temperatures for the climate normal period (1961–90) were calculated as well as stream temperatures for the A2 and B1 climate change emission scenarios for the 2050s (2041–70). On average, there will be an increase of 1°–4°C in monthly stream temperature under the two climate scenarios. It was also found that in the months December, January, and February a noticeable warming predominantly occurs along the equatorial zone, while during the months June, July, and August large-scale or large increases can be observed in the northern and southern temperate zones. Consequently, projections of decay rates show a similar seasonal and spatial pattern as the corresponding stream temperatures. A regional increase up to ~25% could be observed. Thus, to ensure sufficient water quality for human purposes, but also for freshwater ecosystems, sustainable management strategies are required.

scholarly journals Cumulative carbon as a policy framework for achieving climate stabilization

2012 ◽  
Vol 370 (1974) ◽  
pp. 4365-4379 ◽  
Author(s):  
H. Damon Matthews ◽  
Susan Solomon ◽  
Raymond Pierrehumbert
Keyword(s):  
Climate Change ◽  
Greenhouse Gas ◽  
Temperature Change ◽  
Carbon Emissions ◽  
Climate Impacts ◽  
Global Temperature ◽  
Policy Framework ◽  
Climate Mitigation ◽  
Rate Of Increase ◽  
Global Temperature Change

The primary objective of the United Nations Framework Convention on Climate Change is to stabilize greenhouse gas concentrations at a level that will avoid dangerous climate impacts. However, greenhouse gas concentration stabilization is an awkward framework within which to assess dangerous climate change on account of the significant lag between a given concentration level and the eventual equilibrium temperature change. By contrast, recent research has shown that global temperature change can be well described by a given cumulative carbon emissions budget. Here, we propose that cumulative carbon emissions represent an alternative framework that is applicable both as a tool for climate mitigation as well as for the assessment of potential climate impacts. We show first that both atmospheric CO 2 concentration at a given year and the associated temperature change are generally associated with a unique cumulative carbon emissions budget that is largely independent of the emissions scenario. The rate of global temperature change can therefore be related to first order to the rate of increase of cumulative carbon emissions. However, transient warming over the next century will also be strongly affected by emissions of shorter lived forcing agents such as aerosols and methane. Non-CO 2 emissions therefore contribute to uncertainty in the cumulative carbon budget associated with near-term temperature targets, and may suggest the need for a mitigation approach that considers separately short- and long-lived gas emissions. By contrast, long-term temperature change remains primarily associated with total cumulative carbon emissions owing to the much longer atmospheric residence time of CO 2 relative to other major climate forcing agents.

scholarly journals ANALISIS KORELASI RADIATIVE FORCING METANA (CH4) DENGAN PERUBAHAN TEMPERATUR DI KOTOTABANG TAHUN 2004 � 2009

Jurnal Dampak ◽  
2013 ◽  
Vol 10 (1) ◽  
pp. 29
Author(s):  
Dwi Pujiastuti
Keyword(s):  
Climate Change ◽  
Surface Temperature ◽  
Temperature Change ◽  
Positive Feedback ◽  
Radiative Forcing ◽  
Measured Temperature ◽  
Weather Station ◽  
Automatic Weather Station ◽  
Average Temperature ◽  
Calculation Results

ABSTRAK Telah dilakukan perhitungan radiative forcing gas Metana (CH4) menggunakan konsentrasi (CH4) dari tahun 2004 2009 di Kototabang dengan menggunakan metode Intergovernmental on Panel Climate Change (IPCC). Hasil perhitungan kemudian dikorelasikan dengan selisih temperatur yang merupakan data bulanan temperatur permukaan Kototabang dikurangi dengan temperatur rata-rata selama 6 tahun pengukuran. Temperatur permukaan diukur dengan menggunakan instrumen Automatic Weather station (AWS) yang ada di stasiun GAW Kototabang. Dari hasil analisi diperoleh nilai radiatve forcing mengalami peningkatan dari 0,24338 Wm-2pada tahun 2004 menjadi 0,246221 Wm-2 pada tahun 2009. Hal ini menunjukkan lebih banyak energi radiasi matahari yang diserap daripada yang diemisikan (Positive feedback). Tetapi hasil korelasi radiative forcing CH4 dengan selisih temperatur memiliki koefisien determinasi yang rendah yaitu 0,0047. Hal ini karena perubahan temperatur di Kototabang yang tercatat di AWS bukan hanya dipengaruhi oleh nilai konsentrasi metana saja tapi juga oleh aerosol, awan, dan gas rumah kaca lainnya. Hal juga ini menunjukkan bahwa konsentrasi gas metana tidak signifikan mempengaruhi perubahan temperatur di Kototabang. Kata kunci: Kototabang, metana, radiative forcing, temperaturABSTRACTRadiative forcing of methane (CH4) gas has been calculated based on its concentration in Kototabang from 2004 to 2009, by using Intergovernmental on Panel Climate Change (IPCC) method. The calculation results were further correlated to the temperature differences, i.e., monthly surface temperature subtracted by the average temperature data at Kototabang during the six year of measurement. The surface temperature was measured by using Automatic Weather Station (AWS) installed at the Global Atmospheric Watch (GAW) Kototabang. Based on the analysis, there was an increment of the radiative forcing from 0.24338Wm-2 in 2004 to 0.246221Wm-2 in 2009. This showed the solar energy was more absorbed than emitted (positive feedback). However, the result of correlation analysis between CH4 radiative forcing and the temperature difference shows a low determinant coefficient, i.e., 0.0047. This is due to the measured temperature change in Kototabang is not only affected by methane concentrations but also influenced by aerosol, clouds and other green house gases. This also shows that methane gas concentration did not significantly influence the temperature change in Kototabang.Keywords: Kototabang, methane, radiative forcing, temperature

scholarly journals Fluid Dynamics Simulation and Temperature Gradient Validation along a Greenhouse Temperature Gradient

2020 ◽  
Author(s):  
Sung Kyeom Kim ◽  
Hee Ju Lee ◽  
Seung Hwan Wi ◽  
Seong-Won Lee ◽  
ILHWAN Seo
Keyword(s):  
Climate Change ◽  
Fluid Dynamics ◽  
Temperature Gradient ◽  
Temperature Change ◽  
Temperature Difference ◽  
Physiological Response ◽  
Crop Production ◽  
Extreme Weather ◽  
Temperature Gradients ◽  
Response To Temperature

Abstract Background: Climate change is increasing the vulnerability of horticultural crop cultivation and production. It is urgent to study such extreme weather phenomena (heatwave, drought, etc.), and in particular, to evaluate crop productivity according to temperature change. For this purpose, the crop physiological response to temperature change in simulated weather conditions was studied. However, there is a limitation in artificial light wavelength, which requires experiments to be carried out in protected facilities or open fields. In this study, we simulated temperature differences with computational fluid dynamics (CFD) in tunnel-type greenhouses. They can create temperature gradients and improve the accuracy of CFD with vertically and horizontally measured temperature profiles. The growth and physiological response of Kimchi cabbage were examined and validated using a temperature gradient within a semi-closed plastic tunnel.Results: Correlation coefficients of measured heights were: 1.120, 0.597, and 0.459. Root mean square error was below 0.1025, which means the CFD simulation values were highly accurate. The error analysis showed that it was possible to accurately predict temperature gradients change within a semi-closed tunnel-type greenhouse using CFD techniques. CFD results showed an average error of 0.597°C compared to field monitoring results. The maximum temperature difference of GTG was 5.7°C, suggesting a well-controlled set point (6°C difference between outside conditions and inside conditions of GTG). In a cloudy day, the gradient temperature of GTG was well maintained by the set differential temperature (dT), which suggests that the set dT was not precisely and accurately performed in GTG of a sunny day. There was a significant difference in the growth, net photosynthetic rate, transpiration rate, and Ci concentration along with temperature differences in GTG. Conclusions: CFD can simulate temperature gradient distribution in a tunnel-type greenhouse and predict the temperature difference for equipment with different specifications. These facilities can be used in climate change-related studies, such as assessment of crop production area optimization, crop physiological response to temperature, vulnerability assessment of crop production under increasing temperatures, or extreme weather.

scholarly journals A Review of Ocean Dynamics in the North Atlantic: Achievements and Challenges

Climate ◽  
2020 ◽  
Vol 8 (4) ◽  
pp. 49
Author(s):  
Knut Lehre Seip
Keyword(s):  
Climate Change ◽  
Temperature Change ◽  
North Atlantic ◽  
Ocean Dynamics ◽  
Local Climate ◽  
The North ◽  
Local Climate Change ◽  
Global Temperature Change ◽  
The North Atlantic ◽  
Over Time

I address 12 issues related to the study of ocean dynamics and its impact on global temperature change, regional and local climate change, and on the North Atlantic ecosystem. I outline the present achievements and challenges that lie ahead. I start with observations and methods to extend the observations of ocean oscillations over time and end with challenges to find connections between ocean dynamics in the North Atlantic and dynamics in other parts of the globe.

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