Effects of using air temperature as a proxy for potential evapotranspiration in climate change scenarios of Great Lakes basin hydrology

2011 ◽  
Vol 37 (4) ◽  
pp. 744-752 ◽  
Author(s):  
Brent M. Lofgren ◽  
Timothy S. Hunter ◽  
Jessica Wilbarger
Keyword(s):  
Climate Change ◽  
Great Lakes ◽  
Air Temperature ◽  
Potential Evapotranspiration ◽  
Climate Change Scenarios ◽  
Great Lakes Basin ◽  
Basin Hydrology

scholarly journals Historical Spatiotemporal Trends in Snowfall Extremes over the Canadian Domain of the Great Lakes Basin

2018 ◽  
Vol 2018 ◽  
pp. 1-20 ◽  
Author(s):  
Janine A. Baijnath-Rodino ◽  
Claude R. Duguay
Keyword(s):  
Climate Change ◽  
Great Lakes ◽  
Air Temperature ◽  
National Laboratory ◽  
Wind Gust ◽  
Great Lakes Basin ◽  
Adaptation Studies ◽  
Oak Ridge ◽  
Spatiotemporal Trends ◽  
Minimum Air Temperature

The Laurentian Great Lakes Basin (GLB) is prone to snowfall events developed from extratropical cyclones or lake-effect processes. Monitoring extreme snowfall trends in response to climate change is essential for sustainability and adaptation studies because climate change could significantly influence variability in precipitation during the 21st century. Many studies investigating snowfall within the GLB have focused on specific case study events with apparent under examinations of regional extreme snowfall trends. The current research explores the historical extremes in snowfall by assessing the intensity, frequency, and duration of snowfall within Ontario’s GLB. Spatiotemporal snowfall and precipitation trends are computed for the 1980 to 2015 period using Daymet (Version 3) monthly gridded interpolated datasets from the Oak Ridge National Laboratory. Results show that extreme snowfall intensity, frequency, and duration have significantly decreased, at the 90% confidence level, more so for the Canadian leeward shores of Lake Superior than that of Lake Huron, for the months of December and January. To help discern the spatiotemporal trends is snowfall extremes, several trend analyses for lake-induced predictor variables were analysed for two cities, Wawa and Wiarton, along the snowbelts of Lakes Superior and Huron, respectively. These variables include monthly maximum and minimum air temperature, maximum wind gust velocity, lake surface temperature, and maximum annual ice cover concentration. Resultant significant increase in December’s maximum and minimum air temperature for the city of Wawa may be a potential reason for the decreased extreme snowfall trends.

scholarly journals Physically Plausible Methods for Projecting Changes in Great Lakes Water Levels under Climate Change Scenarios

2016 ◽  
Vol 17 (8) ◽  
pp. 2209-2223 ◽  
Author(s):  
Brent M. Lofgren ◽  
Jonathan Rouhana
Keyword(s):  
Climate Change ◽  
Great Lakes ◽  
Air Temperature ◽  
Land Surface ◽  
Statistical Significance ◽  
Climate Impact ◽  
Water Levels ◽  
Climate Change Scenarios ◽  
Conservation Of Energy ◽  
Near Surface

Abstract A method for projecting the water levels of the Laurentian Great Lakes under scenarios of human-caused climate change, used almost to the exclusion of other methods in the past, relies very heavily on the large basin runoff model (LBRM) as a component for determining the water budget for the lake system. This model uses near-surface air temperature as a primary predictor of evapotranspiration (ET); as in previous published work, it is shown here that the model’s very high sensitivity to temperature causes it to overestimate ET in a way that is greatly at variance with the fundamental principle of conservation of energy at the land surface. The traditional formulation is characterized here as being equivalent to having several suns in the virtual sky created by LBRM. More physically based methods show, relative to the traditional method, often astoundingly less potential ET and less ET, more runoff from the land and net basin supply for the lake basins, and higher lake water levels in the future. Using various methods of estimating the statistical significance, it is found that, at minimum, these discrepancies in results are significant at the 99.998% level. The lesson for the larger climate impact community is to use caution about whether an impact is forced directly by air temperature itself or is significantly forced by season or latitude independently of temperature. The results here apply only to the water levels of the Great Lakes and the hydrology of its basin and do not affect larger questions of climate change.

scholarly journals Historical and future temporal trends in the summer Urban Heat Island of Athens (Greece) 

2021 ◽  
Author(s):  
Tim van der Schriek ◽  
Konstantinos V. Varotsos ◽  
Dimitra Founda ◽  
Christos Giannakopoulos
Keyword(s):  
Climate Change ◽  
Air Pollution ◽  
Air Temperature ◽  
Temporal Trends ◽  
Temperature Data ◽  
Climate Change Scenarios ◽  
Heat Island ◽  
Hot Days ◽  
The Future ◽  
Urban Heat

<p>Historical changes, spanning 1971–2016, in the Athens Urban Heat Island (UHI) over summer were assessed by contrasting two air temperature records from established meteorological stations in urban and rural settings. When contrasting two 20-year historical periods (1976–1995 and 1996–2015), there is a significant difference in summer UHI regimes. The stronger UHI-intensity of the second period (1996–2015) is likely linked to increased pollution and heat input. Observations suggest that the Athens summer UHI characteristics even fluctuate on multi-annual basis. Specifically, the reduction in air pollution during the Greek Economic Recession (2008-2016) probable subtly changed the UHI regime, through lowering the frequencies of extremely hot days (T<sub>max</sub> > 37 °C) and nights (T<sub>min</sub> > 26 °C).</p><p>Subsequently, we examined the future temporal trends of two different UHIs in Athens (Greece) under three climate change scenarios. A five-member regional climate model (RCM) sub-ensemble from EURO-CORDEX with a horizontal resolution of 0.11° (~12 × 12 km) simulated air temperature data, spanning the period 1976–2100, for the two station sites. Three future emissions scenarios (RCP2.6, RCP4.5 and RCP8.5) were implanted in the simulations after 2005. The observed daily maximum and minimum air temperature data (T<sub>max</sub> and T<sub>min</sub>) from two historical UHI regimes (1976–1995 and 1996–2015, respectively) were used, separately, to bias-adjust the model simulations thus creating two sets of results.</p><p>This novel approach allowed us to assess future temperature developments in Athens under two different UHI intensity regimes. We found that the future frequency of days with T<sub>max</sub> > 37 °C in Athens was only different from rural background values under the intense UHI regime. There is a large increase in the future frequency of nights with T<sub>min</sub> > 26 °C in Athens under all UHI regimes and climate scenarios; these events remain comparatively rare at the rural site.</p><p>This study shows a large urban amplification of the frequency of extremely hot days and nights which is likely forced by increasing air pollution and heat input. Consequently, local mitigation policies aimed at decreasing urban atmospheric pollution are expected to be also effective in reducing urban temperatures during extreme heat events in Athens under all future climate change scenarios. Such policies therefore have multiple benefits, including: reducing electricity (energy) needs, improving living quality and decreasing heat- and pollution related illnesses/deaths.</p><p> </p>

scholarly journals Impactos das mudanças climáticas na demanda hídrica e duração do ciclo do sorgo forrageiro e feijão-caupi no estado de Pernambuco

2015 ◽  
Vol 8 ◽  
pp. 542
Author(s):  
José Edson Florentino de Morais ◽  
Thieres George Freire da Silva ◽  
Marcela Lúcia Barbosa ◽  
Wellington Jairo da Silva Diniz ◽  
Carlos André Alves de Souza ◽  
...  
Keyword(s):  
Climate Change ◽  
Relative Humidity ◽  
Air Temperature ◽  
Water Demand ◽  
Stomatal Resistance ◽  
The State ◽  
Extreme Weather Events ◽  
Climate Change Scenarios ◽  
Area Index ◽  
Forage Sorghum

O aumento na ocorrência de eventos climáticos extremos nas últimas décadas é uma forte evidência das mudanças climáticas. Em regiões Semiáridas, onde a pressão de desertificação tem se intensificado, são esperadas diminuição da disponibilidade de água e maior ocorrência de períodos seca, e, consequentemente, efeitos na resposta fisiológica das plantas. Assim, objetivou-se analisar os impactos dos cenários de mudanças climáticas sobre a duração do ciclo fenológico e a demanda de água do sorgo forrageiro e do feijão-caupi cultivados no Estado de Pernambuco. Foram utilizados os valores mensais da normal climatológica brilho solar, temperatura do ar, umidade relativa do ar e velocidade do vento de dez municípios. Considerou-se um aumento de 1,8°C (Cenário B2) e 4,0°C (Cenário A1F1) na temperatura do ar e um decréscimo de 5,0% dos valores absolutos de umidade relativa do ar, além do aumento de 22% na resistência estomática e de 4% no índice de área foliar. Com base nessas informações foram gerados três cenários: situação atual e projeções futuras para B2 e A1F1. Os resultados revelaram uma redução média de 11% (B2) e 20% (A1F1), e de 10% (B2) e 17% (A1F1) na duração do ciclo, e de 4% (B2) e 8% (A1F1), e 2% (B2) e 5% (A1F1) na demanda de água acumulada para o sorgo forrageiro e feijão-caupi, respectivamente. Conclui-se que a magnitude das reduções da duração do ciclo e a demanda de água simulada para as culturas do sorgo forrageiro e do feijão-caupi variaram espaço-temporalmente no Estado de Pernambuco com os cenários de mudanças climáticas.ABSTRACT The increase in the occurrence of extreme weather events in recent decades is a strong evidence of climate change. In semiarid regions, where the pressure of desertification has intensified, are expected to decrease in the availability of water and higher occurrence of drought periods, and, consequently, effects on physiological response of plants. Thus, the objective of analyzing the impacts of climate change scenarios on the duration of phenological cycle and water demand of forage sorghum and cowpea, grown in the State of Pernambuco. Monthly values were used normal climatological solar brightness, air temperature, relative humidity and wind speed of ten municipalities. It was considered an increase of 1.8° C (B2 Scenario) and 4.0° C (A1F1 Scenario) on air temperature and a decrease of 5.0% of the absolute values of relative humidity, in addition to the 22% increase in stomatal resistance and 4% in leaf area index. Based on this information were generated three scenarios: current situation and future projections for B2, A1F1. The results revealed an average reduction of 11% (B2) and 20% (A1F1), and 10% (B2) and 17% (A1F1) for the duration of the cycle, and 4% (B2) and 8% (A1F1), and 2% (B2) and 5% (A1F1) in accumulated water demand for forage sorghum and cowpea, respectively. It is concluded that the magnitude of the reductions in the duration of the cycle and the simulated water demand for crops of forage sorghum and cowpea ranged space-temporarily in the State of Pernambuco with climate change scenarios.

scholarly journals Monitoring canopy and air temperature of dominant vegetation in tropical semi-arid using bioclimatic model

2016 ◽  
Vol 1 (1) ◽  
pp. 1-12
Author(s):  
Josiclêda Domiciano Galvíncio ◽  
Rejane Magalhães de Mendonça Pimentel
Keyword(s):  
Climate Change ◽  
Air Temperature ◽  
Dominant Species ◽  
Canopy Temperature ◽  
Leaf Temperature ◽  
Climate Change Scenarios ◽  
Arid Environments ◽  
Intergovernmental Panel ◽  
Dry Land ◽  
Bioclimatic Model

Typical vegetation of arid environments consists of few dominant species highly threatened by climate change. Jurema preta (Mimosa tenuiflora (Willd.) Poiret) is one of these successful species that now is dominant in extensive semiarid areas in the world. The development of a simple bioclimatic model using climate change scenarios based on optimistic and pessimistic predictions of the Intergovernmental Panel on Climate Change (IPCC) shown as a simple tool to predict possible responses of dominant species under dry land conditions and low functional biodiversity. The simple bioclimatic model proved satisfactory in creating climate change scenarios and impacts on the canopy temperature of Jurema preta in semiarid Brazil. The bioclimatic model was efficient to obtain spatially relevant estimations of air temperature from determinations of the surface temperature using satellite images. The model determined that the average difference of 5oC between the air temperature and the leaf temperature for Jurema preta, and an increase of 3oC in air temperature, promote an increase of 2oC in leaf temperature. It leads to disturbances in vital physiological mechanisms in the leaf, mainly the photosynthesis and efficient use of water.

scholarly journals EFFECT OF CLIMATE CHANGE ON POTENTIAL EVAPOTRANSPIRATION IN THE UPPER BEAS BASIN OF THE WESTERN INDIAN HIMALAYA

2019 ◽  
Vol XLII-3/W6 ◽  
pp. 51-57
Author(s):  
S. Rani ◽  
S. Sreekesh ◽  
P. Krishnan
Keyword(s):  
Climate Change ◽  
Agricultural Research ◽  
Potential Evapotranspiration ◽  
Swat Model ◽  
Indian Agricultural Research Institute ◽  
Future Climate Change ◽  
Climate Change Scenarios ◽  
Discharge Data ◽  
Indian Himalaya ◽  
Near Future

<p><strong>Abstract.</strong> Appraisal of potential evapotranspiration (PET) is needed for estimating the agricultural water requirement and understanding hydrological processes in an arena. Therefore, aim of the paper was to estimate the PET in the upper Beas basin, situated in the Western Indian Himalaya, under future climate change scenarios (by mid-21st century). Climate data (1969&amp;ndash;2010) of Manali, Bhuntar and Katrain were obtained from India Meteorological Department (IMD) and the Indian Agricultural Research Institute (IARI). Landsat data were used for mapping land use/land cover (LULC) conditions of the basin through decision tree technique. Elevation detail of the catchment area is derived from the Cartosat-1 digital elevation model (DEM). Simulations of PET were done by the Soil and Water Assessment Tool (SWAT) model. The model was calibrated using the average monthly discharge data from Thalout station. The study found fluctuations in PET under different climate change scenarios. It is likely to increase in near future owing to the rise in temperature. The higher water demand can be met from the excess snowmelt water reaching the lower basin area during the cropping seasons. This study will be helpful to understand water availability conditions in the upper Beas basin in the near future.</p>

scholarly journals Assessment of impact of climate change on water resources: a long term analysis of the Great Lakes of North America

2008 ◽  
Vol 12 (1) ◽  
pp. 239-255 ◽  
Author(s):  
E. McBean ◽  
H. Motiee
Keyword(s):  
Climate Change ◽  
Global Warming ◽  
Water Resources ◽  
North America ◽  
Great Lakes ◽  
Great Lakes Basin ◽  
Historical Trends ◽  
Global Circulation Models ◽  
The Impact

Abstract. In the threshold of the appearance of global warming from theory to reality, extensive research has focused on predicting the impact of potential climate change on water resources using results from Global Circulation Models (GCMs). This research carries this further by statistical analyses of long term meteorological and hydrological data. Seventy years of historical trends in precipitation, temperature, and streamflows in the Great Lakes of North America are developed using long term regression analyses and Mann-Kendall statistics. The results generated by the two statistical procedures are in agreement and demonstrate that many of these variables are experiencing statistically significant increases over a seven-decade period. The trend lines of streamflows in the three rivers of St. Clair, Niagara and St. Lawrence, and precipitation levels over four of the five Great Lakes, show statistically significant increases in flows and precipitation. Further, precipitation rates as predicted using fitted regression lines are compared with scenarios from GCMs and demonstrate similar forecast predictions for Lake Superior. Trend projections from historical data are higher than GCM predictions for Lakes Michigan/Huron. Significant variability in predictions, as developed from alternative GCMs, is noted. Given the general agreement as derived from very different procedures, predictions extrapolated from historical trends and from GCMs, there is evidence that hydrologic changes particularly for the precipitation in the Great Lakes Basin may be demonstrating influences arising from global warming and climate change.

scholarly journals Predicting the Suitable Geographical Distribution of Sinadoxa Corydalifolia under Different Climate Change Scenarios in the Three-River Region Using the MaxEnt Model

Plants ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 1015
Author(s):  
Xiaotao Huang ◽  
Li Ma ◽  
Chunbo Chen ◽  
Huakun Zhou ◽  
Buqing Yao ◽  
...  
Keyword(s):  
Climate Change ◽  
Air Temperature ◽  
Habitat Destruction ◽  
Distribution Model ◽  
Distribution Area ◽  
Climate Change Scenarios ◽  
Maxent Model ◽  
Co2 Concentrations ◽  
River Region ◽  
Temperature Seasonality

Sinadoxa corydalifolia is a perennial grass with considerable academic value as a rare species owing to habitat destruction and a narrow distribution. However, its distribution remains unclear. In this study, we predicted the distribution of Sinadoxa corydalifolia in the three-river region (the source of the Yangtze River, Yellow River, and Lancang River) under the context of climate change using the maximum entropy (MaxEnt) model. Under the current climate scenario, the suitable distribution mainly occurred in Yushu County and Nangqian County. The suitable distribution area of Sinadoxa corydalifolia covered 3107 km2, accounting for 0.57% of the three-river region. The mean diurnal air temperature range (Bio2), temperature seasonality (Bio4), and mean air temperature of the driest quarter (Bio9) contributed the most to the distribution model for Sinadoxa corydalifolia, with a cumulative contribution of 81.4%. The highest suitability occurred when air temperature seasonality (Bio4) ranged from 6500 to 6900. The highest suitable mean air temperature of the driest quarter ranged from −5 to 0 °C. The highest suitable mean diurnal temperature (Bio2) ranged from 8.9 to 9.7 °C. In future (2041–2060) scenarios, the suitable distribution areas of Sinadoxa corydalifolia from high to low are as follows: representative concentration pathway (RCP)26 (6171 km2) > RCP45 (6017 km2) > RCP80 (4238 km2) > RCP60 (2505 km2). In future (2061–2080) scenarios, the suitable distribution areas of Sinadoxa corydalifolia from high to low are as follows: RCP26 (18,299 km2) > RCP60 (11,977 km2) > RCP45 (10,354 km2) > RCP80 (7539 km2). In general, the suitable distribution will increase in the future. The distribution area of Sinadoxa corydalifolia will generally be larger under low CO2 concentrations than under high CO2 concentrations. This study will facilitate the development of appropriate conservation measures for Sinadoxa corydalifolia in the three-river region.

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