Relevance of decadal variations in surface radiative fluxes for climate change

2013 ◽  
Author(s):  
Martin Wild
Keyword(s):  
Climate Change ◽  
Radiative Fluxes ◽  
Decadal Variations

Capacity of climate models to capture multi-decadal hydrological variations over France

2020 ◽  
Author(s):  
Julien Boé ◽  
Rémy Bonnet
Keyword(s):  
Climate Change ◽  
Climate Models ◽  
Global Climate ◽  
Global Climate Models ◽  
Climate Change Signal ◽  
River Flows ◽  
Climate Reconstructions ◽  
Decadal Variations ◽  
Instrumental Period

<p>In France, large multi-decadal variations in river flows have occurred over the instrumental period. These multi-decadal variations, likely of internal origin, could be a major source of uncertainties in the evolution of river flows during the 21st century, and especially during the coming decades, when the climate change signal is weaker. Depending on their phase, these variations might indeed strongly temporarily amplify or weaken (and even possibly reverse) the signal of climate change. From an adaptation perspective, it is crucial that hydrological projections correctly capture the amplitude of these multi-decadal variations, so that the associated uncertainties can be correctly estimated. The realism of hydrological projections in this context lies to a large extent in the realism of climate models, used at the first stage of the vast majority of the studies of the impacts of climate change.</p><p>The brevity of the instrumental record makes it difficult to characterize robustly multi-decadal hydro-climate variations, and the lack of observations for important hydrological variables makes it difficult to understand the mechanisms at play. The evaluation of climate models in this context is therefore also particularly challenging. </p><p>In this presentation, I will describe our work to better characterize hydrological variations over France in terms of amplitude and mechanisms, thanks to joint use of newly developed hydrological reconstructions beginning in the mid-nineteenth century, long observations from data-rescue efforts and paleo-climate reconstructions. Based on this work, I will then describe the results of the evaluation of multi-decadal hydrological variations in current global climate models, in terms of amplitude and associated mechanisms, taking into account the very large sampling uncertainties associated with the characterization of multi-decadal variations on relatively short periods. </p>

Climate change trends in some of the rubber growing regions of North-East India

2015 ◽  
Vol 43 (3) ◽  
Author(s):  
Shammi Raj
Keyword(s):  
Climate Change ◽  
Relative Humidity ◽  
Change Analysis ◽  
North East India ◽  
Climate Change Effects ◽  
North East ◽  
Sunshine Hours ◽  
Decadal Variations ◽  
Future Policy ◽  
Limited Moisture

<div><table cellspacing="0" cellpadding="0" align="center"><tbody><tr><td align="left" valign="top"><p>Climate change   analysis has been conducted using daily surface meteorological datasets in   respect of nine parameters from five rubber growing locations in the East and   North-East India. Monthly, seasonal and annual variability in meteorological   parameters showed decreasing trends in relative humidity, sunshine hours and   pan evaporation rates coupled with increasing temperature extremes. Rise in   mean temperature was seen to be highest (0.34 0C per decade) for Dhenkanal   which experiences dry sub-humid type of climate. The data on relative humidity   and temperature also revealed the fact that warm surface temperatures, along   with limited moisture availability, may lead to lower relative humidity in   the future, since all the stations are away from the moist coastal belts.   Decreasing trends in sunshine hours were mainly observed during winter and   post monsoon seasons with decreasing number of days even with the optimum   required daily sunshine hours. The fact that there were no significant   changes in the amount of rainfall or the number of rainy days was in   conformity with several earlier reports in the northeast. Mean monthly   decadal variations have also been tested with earlier and recent sets. With   long term trends in most of the weather parameters, being lesser when   compared to that of the traditional rubber growing regions in India, it is   imperative that for rubber cultivation to thrive in this non-traditional   belt, future policy inputs will have to be based depending on the magnitude   of climate change effects.</p></td></tr></tbody></table></div>

Ecosystem-based adaptation in marine ecosystems of tropical Oceania in response to climate change.

2011 ◽  
Vol 17 (3) ◽  
pp. 241 ◽  
Author(s):  
H S Grantham ◽  
E McLeod ◽  
A Brooks ◽  
S D Jupiter ◽  
J Hardcastle ◽  
...  
Keyword(s):  
Climate Change ◽  
Social Systems ◽  
Climate Change Impacts ◽  
Co2 Concentration ◽  
Adaptation Strategies ◽  
Annual Rainfall ◽  
Climate Projections ◽  
Great Opportunity ◽  
Sea Levels ◽  
Decadal Variations

Tropical Oceania, including Melanesia, Polynesia, Micronesia and northern Australia, is one of the most biodiverse regions of the world. Climate change impacts have already occurred in the region and will become one of the greatest threats to biodiversity and people. Climate projections indicate that sea levels will rise in many places but not uniformly. Islands will warm and annual rainfall will increase and exhibit strong decadal variations. Increases in global atmospheric CO2 concentration are causing ocean acidification, compromising the ability of organisms such as corals to maintain their calcium carbonate skeletons. We discuss these climate threats and their implications for the biodiversity of several ecosystems (coral reefs, seagrass and mangroves) in the region. We highlight current adaptation approaches designed to address these threats, including efforts to integrate ecosystem and community-based approaches. Finally, we identify guiding principles for developing effective ecosystem-based adaptation strategies. Despite broad differences in governance and social systems within the region, particularly between Australia and the rest of the Pacific, threats and planning objectives are similar. Ensuring community awareness and participation are essential everywhere. The science underpinning ecosystem-based adaptation strategies is in its infancy but there is great opportunity for communicating approaches and lessons learnt between developing and developed nations in tropical Oceania.

scholarly journals Análise Descritiva da Precipitação, Temperatura, Umidade e Tendências Climáticas no Recife - Pe

2020 ◽  
Vol 13 (07) ◽  
pp. 3234
Author(s):  
Roni Valter De Souza Guedes ◽  
Thiago Luiz Do Vale Silva
Keyword(s):  
Climate Change ◽  
Relative Humidity ◽  
Minimum Temperature ◽  
Rainy Season ◽  
Descriptive Analysis ◽  
Extreme Rainfall ◽  
Maximum Temperature ◽  
Climate Trends ◽  
Local Climate ◽  
Decadal Variations

Os efeitos das mudanças climáticas sobre as principais variáveis atmosféricas locais é o objeto deste estudo, a partir de dados de 1961 a 2019 para a localidade do Recife-PE. A metodologia engloba uma análise exploratória e descritiva com distribuição de frequencia por faixas de intensidades pluviométricas e identificação de tendências em escalas temporais diversificadas em meses, quadras, estações, anos e décadas das variaveis precipitação, temperaturas e umidade do ar. Verificou-se redução das precipitações em algumas faixas intermediárias e aumento dos dias sem chuva, chuvas leves e chuvas intensas, com tendência anual da precipitação de diminuição ao longo das décadas. Observou-se também tendências de aumento das temperaturas máximas, mínimas e diminuição das umidades, com taxas diferenciadas entre os meses secos e chuvosos, com maiores variações nas estações de transição e indicativo de verões mais quentes e secos. A conclusão é que o clima do Recife está mudando alguns padrões climatológicos, com tendência de chuvas extremas durante a quadra chuvosa e provável aumento de ondas de calor fora do periodo chuvoso.  Descriptive Analysis of Precipitation, Temperature, Humidity and Climate Trends in Recife - PE A B S T R A C TThis study aims to describe and evaluate the changes and trends of meteorological variables in Recife - PE during the period from 1961 to 2019 and verify indications of climatic changes over the Region. The methodology includes an exploratory and descriptive analysis with frequency distribution by ranges of rainfall intensity and identifying trends in temporal scales of precipitation, temperatures, and air humidity. The results pointed a precipitation reduction in ranges between 10 to 70 mm, an increase in the number of days without rain, in rains below 10 mm, and rains with intensity above 100 mm, however, with a trend in the annual accumulated rainfall reduction in recent decades. There was an evident trend towards increasing maximum and minimum temperatures and decreasing relative humidity in the air, with different rates between the dry and rainy months, with emphasis on more significant variations in the transition seasons and indicative of hotter and drier summers, divergent behavior of the minimum temperature, stabilizing during the rainy season, and reduction in the last decade. Thus, the rate of increasing maximum temperature is more than 0.23ºC/decade, while the minimum temperature is rising 0.13ºC/decade, and the relative humidity is decreasing at a rate of 0.53%/decade. The local climate change at Recife registered different behaviors on seasonal scales and diversity in climatological patterns, with an increase in the concentration of extreme rainfall in the rainy season, a decrease in rainfall in the driest periods. Also, an increase in the probability of the occurrence of heatwaves.Keywords: Climate change, intensity frequencies, seasonal and decadal variations

scholarly journals A New Method Based on a Multilayer Perceptron Network to Determine In-Orbit Satellite Attitude for Spacecrafts without Active ADCS Like UVSQ-SAT

2021 ◽  
Vol 13 (6) ◽  
pp. 1185
Author(s):  
Adrien Finance ◽  
Mustapha Meftah ◽  
Christophe Dufour ◽  
Thomas Boutéraon ◽  
Slimane Bekki ◽  
...  
Keyword(s):  
Climate Change ◽  
Deep Learning ◽  
Learning System ◽  
New Method ◽  
Radiation Budget ◽  
The Sun ◽  
Radiative Fluxes ◽  
Satellite Attitude ◽  
The Earth ◽  
Radiation Measurements

Climate change is largely determined by the radiation budget imbalance at the Top Of the Atmosphere (TOA), which is generated by the increasing concentrations of greenhouse gases (GHGs). As a result, the Earth Energy Imbalance (EEI) is considered as an Essential Climate Variable (ECV) that has to be monitored continuously from space. However, accurate TOA radiation measurements remain very challenging. Ideally, EEI monitoring should be performed with a constellation of satellites in order to resolve as much as possible spatio-temporal fluctuations in EEI which contain important information on the underlying mechanisms driving climate change. The monitoring of EEI and its components (incoming solar, reflected solar, and terrestrial infrared fluxes) is the main objective of the UVSQ-SAT pathfinder nanosatellite, the first of its kind in the construction of a future constellation. UVSQ-SAT does not have an active determination system of its orientation with respect to the Sun and the Earth (i.e., the so-called attitude), a prerequisite in the calculation of EEI from the satellite radiation measurements. We present a new effective method to determine the UVSQ-SAT’s in-orbit attitude using its housekeeping and scientific sensors measurements and a well-established deep learning algorithm. One of the goals is to estimate the satellite attitude with a sufficient accuracy for retrieving the radiative fluxes (incoming solar, reflected solar, terrestrial infrared) on each face of the satellite with an uncertainty of less than ±5 Wm−2 (1σ). This new method can be extended to any other satellites with no active attitude determination or control system. To test the accuracy of the method, a ground-based calibration experiment with different attitudes is performed using the Sun as the radiative flux reference. Based on the deep learning estimation of the satellite ground-based attitude, the uncertainty on the solar flux retrieval is about ±16 Wm−2 (1σ). The quality of the retrieval is mainly limited by test conditions and the number of data samples used in training the deep learning system during the ground-based calibration. The expected increase in the number of training data samples will drastically decrease the uncertainty in the retrieved radiative fluxes. A very similar algorithm will be implemented and used in-orbit for UVSQ-SAT.

Averting robo-bees: why free-flying robotic bees are a bad idea

2019 ◽  
Vol 3 (6) ◽  
pp. 723-729
Author(s):  
Roslyn Gleadow ◽  
Jim Hanan ◽  
Alan Dorin
Keyword(s):  
Climate Change ◽  
Computer Simulation ◽  
Food Security ◽  
European Countries ◽  
Plant Interactions ◽  
Plant Insect Interactions ◽  
Native Habitat ◽  
Insect Pollinators ◽  
Insect Interactions

Food security and the sustainability of native ecosystems depends on plant-insect interactions in countless ways. Recently reported rapid and immense declines in insect numbers due to climate change, the use of pesticides and herbicides, the introduction of agricultural monocultures, and the destruction of insect native habitat, are all potential contributors to this grave situation. Some researchers are working towards a future where natural insect pollinators might be replaced with free-flying robotic bees, an ecologically problematic proposal. We argue instead that creating environments that are friendly to bees and exploring the use of other species for pollination and bio-control, particularly in non-European countries, are more ecologically sound approaches. The computer simulation of insect-plant interactions is a far more measured application of technology that may assist in managing, or averting, ‘Insect Armageddon' from both practical and ethical viewpoints.

Modelling ecosystem adaptation and dangerous rates of global warming

2019 ◽  
Vol 3 (2) ◽  
pp. 221-231 ◽  
Author(s):  
Rebecca Millington ◽  
Peter M. Cox ◽  
Jonathan R. Moore ◽  
Gabriel Yvon-Durocher
Keyword(s):  
Climate Change ◽  
Global Warming ◽  
Diffusion Rate ◽  
Individual Species ◽  
Genetic Evolution ◽  
Rates Of Change ◽  
Rapid Climate Change ◽  
Warming Climate ◽  
Intraspecies Competition ◽  
High Trait

Abstract We are in a period of relatively rapid climate change. This poses challenges for individual species and threatens the ecosystem services that humanity relies upon. Temperature is a key stressor. In a warming climate, individual organisms may be able to shift their thermal optima through phenotypic plasticity. However, such plasticity is unlikely to be sufficient over the coming centuries. Resilience to warming will also depend on how fast the distribution of traits that define a species can adapt through other methods, in particular through redistribution of the abundance of variants within the population and through genetic evolution. In this paper, we use a simple theoretical ‘trait diffusion’ model to explore how the resilience of a given species to climate change depends on the initial trait diversity (biodiversity), the trait diffusion rate (mutation rate), and the lifetime of the organism. We estimate theoretical dangerous rates of continuous global warming that would exceed the ability of a species to adapt through trait diffusion, and therefore lead to a collapse in the overall productivity of the species. As the rate of adaptation through intraspecies competition and genetic evolution decreases with species lifetime, we find critical rates of change that also depend fundamentally on lifetime. Dangerous rates of warming vary from 1°C per lifetime (at low trait diffusion rate) to 8°C per lifetime (at high trait diffusion rate). We conclude that rapid climate change is liable to favour short-lived organisms (e.g. microbes) rather than longer-lived organisms (e.g. trees).

Climate change and breeding success: decline of the capercaillie in Scotland

2001 ◽  
Vol 70 (1) ◽  
pp. 47-61 ◽  
Author(s):  
Robert Moss ◽  
James Oswald ◽  
David Baines
Keyword(s):  
Climate Change ◽  
Breeding Success
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