scholarly journals Glacier changes and climate trends derived from multiple sources in the data scarce Cordillera Vilcanota region, Southern Peruvian Andes

2012 ◽  
Vol 6 (1) ◽  
pp. 387-426 ◽  
Author(s):  
N. Salzmann ◽  
C. Huggel ◽  
M. Rohrer ◽  
W. Silverio ◽  
B. G. Mark ◽  
...  
Keyword(s):  
Air Temperature ◽  
Specific Humidity ◽  
Spatial And Temporal Variability ◽  
Climate Data ◽  
Climate Trends ◽  
Multiple Sources ◽  
Mountain Areas ◽  
Peruvian Andes ◽  
The Past ◽  
Alpine Regions

Abstract. The role of glaciers as temporal water reservoirs is particularly pronounced in the (outer) tropics because of the very distinct wet-dry seasons. Rapid glacier retreat caused by climatic changes is thus a major concern and decision makers demand urgently for regional/local glacier evolution trends, ice mass estimates and runoff assessments. However, in remote mountain areas, spatial and temporal data coverage is typically very scarce and this is further complicated by a high spatial and temporal variability in regions with complex topography. Here, we present an approach on how to deal with these constraints. For the Cordillera Vilcanota (Southern Peruvian Andes), which is the second largest glacierised Cordillera in Peru (after the Cordillera Blanca) and also comprises the Quelccaya Ice Cap, we assimilate a comprehensive multi-decadal collection of available glacier and climate data from multiple sources (satellite images, meteorological station data and climate Reanalysis), and analyze them for respective changes in glacier area and volume and related trends in air temperature, precipitation and specific humidity. In general, the climate data show a moderate (compared to other alpine regions) increase in air temperature, weak and not significant trends for precipitation sums, and an increase in specific humidity at the 500 hPa level. The latter is consistent with observed increase in water vapour at the tropopause level during the past decades. It is likely that the increase in specific humidity played a major role in the observed massive ice loss of the Cordillera Vilcanota over the past decades.

scholarly journals Glacier changes and climate trends derived from multiple sources in the data scarce Cordillera Vilcanota region, southern Peruvian Andes

2013 ◽  
Vol 7 (1) ◽  
pp. 103-118 ◽  
Author(s):  
N. Salzmann ◽  
C. Huggel ◽  
M. Rohrer ◽  
W. Silverio ◽  
B. G. Mark ◽  
...  
Keyword(s):  
Air Temperature ◽  
Specific Humidity ◽  
Spatial And Temporal Variability ◽  
Moderate Increase ◽  
Climate Data ◽  
Climate Trends ◽  
Multiple Sources ◽  
Mountain Areas ◽  
Peruvian Andes ◽  
Glacier Changes

Abstract. The role of glaciers as temporal water reservoirs is particularly pronounced in the (outer) tropics because of the very distinct wet/dry seasons. Rapid glacier retreat caused by climatic changes is thus a major concern, and decision makers demand urgently for regional/local glacier evolution trends, ice mass estimates and runoff assessments. However, in remote mountain areas, spatial and temporal data coverage is typically very scarce and this is further complicated by a high spatial and temporal variability in regions with complex topography. Here, we present an approach on how to deal with these constraints. For the Cordillera Vilcanota (southern Peruvian Andes), which is the second largest glacierized cordillera in Peru (after the Cordillera Blanca) and also comprises the Quelccaya Ice Cap, we assimilate a comprehensive multi-decadal collection of available glacier and climate data from multiple sources (satellite images, meteorological station data and climate reanalysis), and analyze them for respective changes in glacier area and volume and related trends in air temperature, precipitation and in a more general manner for specific humidity. While we found only marginal glacier changes between 1962 and 1985, there has been a massive ice loss since 1985 (about 30% of area and about 45% of volume). These high numbers corroborate studies from other glacierized cordilleras in Peru. The climate data show overall a moderate increase in air temperature, mostly weak and not significant trends for precipitation sums and probably cannot in full explain the observed substantial ice loss. Therefore, the likely increase of specific humidity in the upper troposphere, where the glaciers are located, is further discussed and we conclude that it played a major role in the observed massive ice loss of the Cordillera Vilcanota over the past decades.

scholarly journals Climate and basin drivers of seasonal river water temperature dynamics

2017 ◽  
Vol 21 (6) ◽  
pp. 3231-3247 ◽  
Author(s):  
Cédric L. R. Laizé ◽  
Cristian Bruna Meredith ◽  
Michael J. Dunbar ◽  
David M. Hannah
Keyword(s):  
Water Temperature ◽  
Air Temperature ◽  
Temporal Variability ◽  
Stream Water ◽  
Stream Temperature ◽  
Short Wave ◽  
Specific Humidity ◽  
Wave Radiation ◽  
Spatial And Temporal Variability ◽  
Wide Range

Abstract. Stream water temperature is a key control of many river processes (e.g. ecology, biogeochemistry, hydraulics) and services (e.g. power plant cooling, recreational use). Consequently, the effect of climate change and variability on stream temperature is a major scientific and practical concern. This paper aims (1) to improve the understanding of large-scale spatial and temporal variability in climate–water temperature associations, and (2) to assess explicitly the influence of basin properties as modifiers of these relationships. A dataset was assembled including six distinct modelled climatic variables (air temperature, downward short-wave and long-wave radiation, wind speed, specific humidity, and precipitation) and observed stream temperatures for the period 1984–2007 at 35 sites located on 21 rivers within 16 basins (Great Britain geographical extent); the study focuses on broad spatio-temporal patterns, and hence was based on 3-month-averaged data (i.e. seasonal). A wide range of basin properties was derived. Five models were fitted (all seasons, winter, spring, summer, and autumn). Both site and national spatial scales were investigated at once by using multi-level modelling with linear multiple regressions. Model selection used multi-model inference, which provides more robust models, based on sets of good models, rather than a single best model. Broad climate–water temperature associations common to all sites were obtained from the analysis of the fixed coefficients, while site-specific responses, i.e. random coefficients, were assessed against basin properties with analysis of variance (ANOVA). All six climate predictors investigated play a role as a control of water temperature. Air temperature and short-wave radiation are important for all models/seasons, while the other predictors are important for some models/seasons only. The form and strength of the climate–stream temperature association vary depending on season and on water temperature. The dominating climate drivers and physical processes may change across seasons and across the stream temperature range. The role of basin permeability, size, and elevation as modifiers of the climate–water temperature associations was confirmed; permeability has the primary influence, followed by size and elevation. Smaller, upland, and/or impermeable basins are the most influenced by atmospheric heat exchanges, while larger, lowland and permeable basins are the least influenced. The study showed the importance of accounting properly for the spatial and temporal variability of climate–stream temperature associations and their modification by basin properties.

scholarly journals Forced and Internal Components of Winter Air Temperature Trends over North America during the past 50 Years: Mechanisms and Implications*

2016 ◽  
Vol 29 (6) ◽  
pp. 2237-2258 ◽  
Author(s):  
Clara Deser ◽  
Laurent Terray ◽  
Adam S. Phillips
Keyword(s):  
North America ◽  
Atmospheric Circulation ◽  
Air Temperature ◽  
Radiative Forcing ◽  
The United States ◽  
Forced Response ◽  
Climate Change Signal ◽  
Climate Trends ◽  
Modeling Framework ◽  
The Past

Abstract This study elucidates the physical mechanisms underlying internal and forced components of winter surface air temperature (SAT) trends over North America during the past 50 years (1963–2012) using a combined observational and modeling framework. The modeling framework consists of 30 simulations with the Community Earth System Model (CESM) at 1° latitude–longitude resolution, each of which is subject to an identical scenario of historical radiative forcing but starts from a slightly different atmospheric state. Hence, any spread within the ensemble results from unpredictable internal variability superimposed upon the forced climate change signal. Constructed atmospheric circulation analogs are used to estimate the dynamical contribution to forced and internal components of SAT trends: thermodynamic contributions are obtained as a residual. Internal circulation trends are estimated to account for approximately one-third of the observed wintertime warming trend over North America and more than half locally over parts of Canada and the United States. Removing the effects of internal atmospheric circulation variability narrows the spread of SAT trends within the CESM ensemble and brings the observed trends closer to the model’s radiatively forced response. In addition, removing internal dynamics approximately doubles the signal-to-noise ratio of the simulated SAT trends and substantially advances the “time of emergence” of the forced component of SAT anomalies. The methodological framework proposed here provides a general template for improving physical understanding and interpretation of observed and simulated climate trends worldwide and may help to reconcile the diversity of SAT trends across the models from phase 5 of the Coupled Model Intercomparison Project (CMIP5).

scholarly journals Climate trends in a specific Mediterranean viticultural area between 1950 and 2006

OENO One ◽  
2008 ◽  
Vol 42 (3) ◽  
pp. 113 ◽  
Author(s):  
Frédéric Laget ◽  
Jean-Luc Tondut ◽  
Alain Deloire ◽  
Mary T. Kelly
Keyword(s):  
Climate Change ◽  
Potential Evapotranspiration ◽  
Time Frame ◽  
Total Solar Radiation ◽  
Climate Data ◽  
Climatic Parameters ◽  
Climate Trends ◽  
The Past ◽  
Harvest Dates ◽  
The Mean

<p style="text-align: justify;"><strong>Aims</strong>: An analysis of climate data between 1950 and 2006 in the Hérault department, situated in the Mediterranean of France is presented.</p><p style="text-align: justify;"><strong>Methods and results</strong>: Data presented include the evolution of mean annual and seasonal temperatures, the Huglin index, total solar radiation, night freshness index, the distribution and efficiency of rainfall and potential evapotranspiration (pET). Results showed an increase in mean annual temperatures of +1.3 °C between 1980 and 2006 and an increase in the mean pET which was 900 mm / year since 1999. Also, harvest dates advanced by up to three weeks and sugar concentrations at harvest increased by up to 1.5 % potential alcohol.</p><p style="text-align: justify;"><strong>Conclusion</strong>: The indicators show that in this area certain climatic parameters have evolved over the period studied. Changes are observable in some of the parameters (notably temperature) for the last 30 years whereas others have evolved only in the past few years (e.g. pET). Therefore it is necessary to be circumspect in drawing conclusions on climate change in the area, particularly as regards the possible consequences for viticulture. However, at the plot level, it is clear that irrigation of the vines is becoming increasingly necessary in this region.</p><p style="text-align: justify;"><strong>Significance and impact of study</strong>: Climate is a major factor in vine cultivation and in the understanding of viticultural terroirs and wine typicality. The climate trends observed over a 50-year period are discussed in the viticultural context of a Mediterranean region. However, the interaction between climate change and technical progress in viticulture and oenology complicate the analysis over the time frame under consideration.</p>

scholarly journals Climate and basin drivers of seasonal river water temperature dynamics

2016 ◽  
Author(s):  
C. L. R. Laizé ◽  
C. Bruna Meredith ◽  
M. Dunbar ◽  
D. M. Hannah
Keyword(s):  
Water Temperature ◽  
Air Temperature ◽  
Temporal Variability ◽  
Stream Water ◽  
Spatial Scales ◽  
Stream Temperature ◽  
Random Coefficients ◽  
Specific Humidity ◽  
Spatial And Temporal Variability ◽  
Wide Range

Abstract. Stream water temperature is a key control of many river processes (e.g. ecology, biogeochemistry, hydraulics) and services (e.g. power plant cooling, recreational use). Consequently, the effect of climate change and variability on stream temperature is a major scientific and practical concern. This paper aimed (1) to improve the understanding of large-scale spatial and temporal variability in climate–water temperature associations, and (2) to assess explicitly the influence of basin properties as modifiers of these relationships. A dataset was assembled including six distinct modelled climatic variables (air temperature, downward shortwave and longwave radiation, wind speed, specific humidity, and precipitation) and observed stream temperatures for the period 1984–2007 at 35 sites located on 21 rivers within 16 basins (Great Britain geographical extent); the study focused on broad spatio-temporal patterns hence was based on three-month averaged data (i.e. seasonal). A wide range of basin properties was derived. Five models were fitted (all seasons, winter, spring, summer, and autumn). Both site and national spatial scales were investigated at once by using multi-level modelling with linear multiple regressions. Model selection used Multi-Model Inference, which provides more robust models, based on sets of good models, rather than a single best model. Broad climate-water temperature associations common to all sites were obtained from the analysis of the fixed coefficients, while site-specific responses, i.e. random coefficients, were assessed against basin properties with ANOVA. All six climate predictors investigated play a role as a control of water temperature. Air temperature and shortwave radiation are important for all models/seasons, while the other predictors are important for some models/seasons only. The form and strength of the climate-stream temperature association vary depending on season and on water temperature. The dominating climate drivers and physical processes may change across seasons, and across the stream temperature range. The role of basin permeability, size, and elevation as modifiers of the climate-water temperature associations was confirmed; permeability has the primary influence, followed by size and elevation. Smaller, upland, and/or impermeable basins are the most influenced by atmospheric heat exchanges, while larger, lowland and permeable basins are least influenced. The study showed the importance of accounting properly for the spatial and temporal variability of climate-stream temperature associations and their modification by basin properties.

scholarly journals Evaluating CMIP5 models using AIRS tropospheric air temperature and specific humidity climatology

2013 ◽  
Vol 118 (1) ◽  
pp. 114-134 ◽  
Author(s):  
Baijun Tian ◽  
Eric J. Fetzer ◽  
Brian H. Kahn ◽  
Joao Teixeira ◽  
Evan Manning ◽  
...  
Keyword(s):  
Air Temperature ◽  
Specific Humidity ◽  
Cmip5 Models

scholarly journals Outdoor PM2.5, Ambient Air Temperature, and Asthma Symptoms in the Past 14 Days among Adults with Active Asthma

10.1289/ehp92 ◽  
2016 ◽  
Vol 124 (12) ◽  
pp. 1882-1890 ◽  
Author(s):  
Maria C. Mirabelli ◽  
Ambarish Vaidyanathan ◽  
W. Dana Flanders ◽  
Xiaoting Qin ◽  
Paul Garbe
Keyword(s):  
Air Temperature ◽  
Ambient Air ◽  
The Past ◽  
Asthma Symptoms ◽  
Ambient Air Temperature

scholarly journals Extreme Warming in the Kara Sea and Barents Sea during the Winter Period 2000–16

2017 ◽  
Vol 30 (22) ◽  
pp. 8913-8927 ◽  
Author(s):  
Svenja H. E. Kohnemann ◽  
Günther Heinemann ◽  
David H. Bromwich ◽  
Oliver Gutjahr
Keyword(s):  
Sea Ice ◽  
Air Temperature ◽  
Barents Sea ◽  
Kara Sea ◽  
The Arctic ◽  
Winter Period ◽  
Limited Area ◽  
Spatial And Temporal Variability ◽  
Large Variability ◽  
Air Temperatures

The regional climate model COSMO in Climate Limited-Area Mode (COSMO-CLM or CCLM) is used with a high resolution of 15 km for the entire Arctic for all winters 2002/03–2014/15. The simulations show a high spatial and temporal variability of the recent 2-m air temperature increase in the Arctic. The maximum warming occurs north of Novaya Zemlya in the Kara Sea and Barents Sea between March 2003 and 2012 and is responsible for up to a 20°C increase. Land-based observations confirm the increase but do not cover the maximum regions that are located over the ocean and sea ice. Also, the 30-km version of the Arctic System Reanalysis (ASR) is used to verify the CCLM for the overlapping time period 2002/03–2011/12. The differences between CCLM and ASR 2-m air temperatures vary slightly within 1°C for the ocean and sea ice area. Thus, ASR captures the extreme warming as well. The monthly 2-m air temperatures of observations and ERA-Interim data show a large variability for the winters 1979–2016. Nevertheless, the air temperature rise since the beginning of the twenty-first century is up to 8 times higher than in the decades before. The sea ice decrease is identified as the likely reason for the warming. The vertical temperature profiles show that the warming has a maximum near the surface, but a 0.5°C yr−1 increase is found up to 2 km. CCLM, ASR, and also the coarser resolved ERA-Interim data show that February and March are the months with the highest 2-m air temperature increases, averaged over the ocean and sea ice area north of 70°N; for CCLM the warming amounts to an average of almost 5°C for 2002/03–2011/12.

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