scholarly journals Contrails, Natural Clouds, and Diurnal Temperature Range

2008 ◽  
Vol 21 (19) ◽  
pp. 5061-5075 ◽  
Author(s):  
Simone Dietmüller ◽  
Michael Ponater ◽  
Robert Sausen ◽  
Klaus-Peter Hoinka ◽  
Susanne Pechtl
Keyword(s):  
United States ◽  
Radiative Forcing ◽  
Diurnal Temperature Range ◽  
Climate Model ◽  
Global Climate Model ◽  
The United States ◽  
Diurnal Temperature ◽  
Temperature Range ◽  
Radiative Impact

Abstract The direct impact of aircraft condensation trails (contrails) on surface temperature in regions of high aircraft density has been a matter of recent debate in climate research. Based on data analysis for the 3-day aviation grounding period over the United States, following the terrorists’ attack of 11 September 2001, a strong effect of contrails reducing the surface diurnal temperature range (DTR) has been suggested. Simulations with the global climate model ECHAM4 (including a contrail parameterization) and long-term time series of observation-based data are used for an independent cross check with longer data records, which allow statistically more reliable conclusions. The climate model underestimates the overall magnitude of the DTR compared to 40-yr ECMWF Re-Analysis (ERA-40) data and station data, but it captures most features of the DTR global distribution and the correlation between DTR and either cloud amount or cloud forcing. The diurnal cycle of contrail radiative impact is also qualitatively consistent with expectations, both at the surface and at the top of the atmosphere. Nevertheless, there is no DTR response to contrails in a simulation that inhibits a global radiative forcing considerably exceeding the upper limit of contrail radiative impact according to current assessments. Long-term trends of DTR, the level of natural DTR variability, and the specific effect of high clouds on DTR are also analyzed. In both ECHAM4 and ERA-40 data, the correlation of cloud coverage or cloud radiative forcing with the DTR is mainly apparent for low clouds. None of the results herein indicates a significant impact of contrails on reducing the DTR. Hence, it is concluded that the respective hypothesis as derived from the 3-day aviation-free period over the United States lacks the required statistical backing.

scholarly journals U.S. Diurnal Temperature Range Variability and Regional Causal Mechanisms, 1901–2002

2012 ◽  
Vol 25 (20) ◽  
pp. 7216-7231 ◽  
Author(s):  
Ryan G. Lauritsen ◽  
Jeffrey C. Rogers
Keyword(s):  
United States ◽  
Soil Moisture ◽  
Diurnal Temperature Range ◽  
Cloud Cover ◽  
The United States ◽  
Maximum Temperature ◽  
Climatic Research Unit ◽  
Diurnal Temperature ◽  
Temperature Range ◽  
Cover Soil

Abstract Long-term (1901–2002) diurnal temperature range (DTR) data are evaluated to examine their spatial and temporal variability across the United States; the early century origin of the DTR declines; and the relative regional contributions to DTR variability among cloud cover, precipitation, soil moisture, and atmosphere/ocean teleconnections. Rotated principal component analysis (RPCA) of the Climatic Research Unit (CRU) Time Series (TS) 2.1 dataset identifies five regions of unique spatial U.S. DTR variability. RPCA creates regional orthogonal indices of cloud cover, soil moisture, precipitation, and the teleconnections used subsequently in stepwise multiple linear regression to examine their regional impact on DTR, maximum temperature (Tmax), and minimum temperature (Tmin). The southwestern United States has the smallest DTR and cloud cover trends as both Tmax and Tmin increase over the century. The Tmin increases are the primary influence on DTR trend in other regions, except in the south-central United States, where downward Tmax trend largely affects its DTR decline. The Tmax and DTR tend to both exhibit simultaneous decadal variations during unusually wet and dry periods in response to cloud cover, soil moisture, and precipitation variability. The widely reported post-1950 DTR decline began regionally at various times ranging from around 1910 to the 1950s. Cloud cover alone accounts for up to 63.2% of regional annual DTR variability, with cloud cover trends driving DTR in northern states. Cloud cover, soil moisture, precipitation, and atmospheric/oceanic teleconnection indices account for up to 80.0% of regional variance over 1901–2002 (75.4% in detrended data), although the latter only account for small portions of this variability.

scholarly journals How aerosols and greenhouse gases influence the diurnal temperature range

2020 ◽  
Author(s):  
Camilla W. Stjern ◽  
Bjørn H. Samset ◽  
Olivier Boucher ◽  
Trond Iversen ◽  
Jean-François Lamarque ◽  
...  
Keyword(s):  
Global Warming ◽  
Greenhouse Gases ◽  
Greenhouse Gas ◽  
Diurnal Temperature Range ◽  
Climate Model ◽  
Global Climate ◽  
Global Climate Model ◽  
Diurnal Temperature ◽  
Temperature Range ◽  
The Future

Abstract. The diurnal temperature range (DTR), or difference between the maximum and minimum temperature within one day, is one of many climate parameters that affects health, agriculture and society. Understanding how DTR evolves under global warming is therefore crucial. Since physically different drivers of climate change, such as greenhouse gases and aerosols, have distinct influences on global and regional climate, predicting the future evolution of DTR requires knowledge of the effects of individual climate forcers, as well as of the future emissions mix, in particular in high emission regions. Using global climate model simulations from the Precipitation Driver and Response Model Intercomparison Project (PDRMIP), we investigate how idealized changes in the atmospheric levels of a greenhouse gas (CO2) and aerosols (black carbon and sulfate) influence DTR, globally and in selected regions. We find broad geographical patterns of annual mean change that are similar between climate drivers, pointing to a generalized response to global warming which is not defined by the individual forcing agents. Seasonal and regional differences, however, are substantial, which highlights the potential importance of local background conditions and feedbacks. While differences in DTR responses among drivers are minor in Europe and North America, there are distinctly different DTR responses to aerosols and greenhouse gas perturbations over India and China, where present aerosol emissions are particularly high. BC induces substantial reductions in DTR, which we attribute to strong modelled BC-induced cloud responses in these regions.

scholarly journals How aerosols and greenhouse gases influence the diurnal temperature range

2020 ◽  
Vol 20 (21) ◽  
pp. 13467-13480
Author(s):  
Camilla W. Stjern ◽  
Bjørn H. Samset ◽  
Olivier Boucher ◽  
Trond Iversen ◽  
Jean-François Lamarque ◽  
...  
Keyword(s):  
Global Warming ◽  
Greenhouse Gases ◽  
Greenhouse Gas ◽  
Diurnal Temperature Range ◽  
Climate Model ◽  
Global Climate ◽  
Global Climate Model ◽  
Diurnal Temperature ◽  
Temperature Range ◽  
The Future

Abstract. The diurnal temperature range (DTR) (or difference between the maximum and minimum temperature within a day) is one of many climate parameters that affects health, agriculture and society. Understanding how DTR evolves under global warming is therefore crucial. Physically different drivers of climate change, such as greenhouse gases and aerosols, have distinct influences on global and regional climate. Therefore, predicting the future evolution of DTR requires knowledge of the effects of individual climate forcers, as well as of the future emissions mix, in particular in high-emission regions. Using global climate model simulations from the Precipitation Driver and Response Model Intercomparison Project (PDRMIP), we investigate how idealized changes in the atmospheric levels of a greenhouse gas (CO2) and aerosols (black carbon and sulfate) influence DTR (globally and in selected regions). We find broad geographical patterns of annual mean change that are similar between climate drivers, pointing to a generalized response to global warming which is not defined by the individual forcing agents. Seasonal and regional differences, however, are substantial, which highlights the potential importance of local background conditions and feedbacks. While differences in DTR responses among drivers are minor in Europe and North America, there are distinctly different DTR responses to aerosols and greenhouse gas perturbations over India and China, where present aerosol emissions are particularly high. BC induces substantial reductions in DTR, which we attribute to strong modeled BC-induced cloud responses in these regions.

scholarly journals The long-term trend in the diurnal temperature range over Asia and its natural and anthropogenic causes

2016 ◽  
Vol 121 (7) ◽  
pp. 3519-3533 ◽  
Author(s):  
Lin Liu ◽  
Zhanqing Li ◽  
Xin Yang ◽  
Hainan Gong ◽  
Chao Li ◽  
...  
Keyword(s):  
Diurnal Temperature Range ◽  
Term Trend ◽  
Diurnal Temperature ◽  
Temperature Range ◽  
Long Term Trend

scholarly journals Variability and trend of diurnal temperature range in China and their relationship to total cloud cover and sunshine duration

2013 ◽  
Vol 31 (5) ◽  
pp. 795-804 ◽  
Author(s):  
X. Xia
Keyword(s):  
Diurnal Temperature Range ◽  
Cloud Cover ◽  
Sunshine Duration ◽  
Radiative Effect ◽  
Total Cloud Cover ◽  
Diurnal Temperature ◽  
Temperature Range ◽  
Clear Sky ◽  
Sky Conditions

Abstract. This study aims to investigate the effect of total cloud cover (TCC) and sunshine duration (SSD) in the variation of diurnal temperature range (DTR) in China during 1954–2009. As expected, the inter-annual variation of DTR was mainly determined by TCC. Analysis of trends of 30-year moving windows of DTR and TCC time series showed that TCC changes could account for that of DTR in some cases. However, TCC decreased during 1954–2009, which did not support DTR reduction across China. DTRs under sky conditions such as clear, cloudy and overcast showed nearly the same decreasing rate that completely accounted for the overall DTR reduction. Nevertheless, correlation between SSD and DTR was weak and not significant under clear sky conditions in which aerosol direct radiative effect should be dominant. Furthermore, 30–60% of DTR reduction was associated with DTR decrease under overcast conditions in south China. This implies that aerosol direct radiative effect appears not to be one of the main factors determining long-term changes in DTR in China.

scholarly journals Trends in Downward Solar Radiation at the Surface over North America from Climate Model Projections and Implications for Solar Energy

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Gerardo Andres Saenz ◽  
Huei-Ping Huang
Keyword(s):  
United States ◽  
North America ◽  
Solar Radiation ◽  
Solar Energy ◽  
Climate Model ◽  
Global Climate Model ◽  
The United States ◽  
Model Simulations ◽  
Climate Model Simulations ◽  
The Impact

The projected changes in the downward solar radiation at the surface over North America for late 21st century are deduced from global climate model simulations with greenhouse-gas (GHG) forcing. A robust trend is found in winter over the United States, which exhibits a simple pattern of a decrease of sunlight over Northern USA. and an increase of sunlight over Southern USA. This structure was identified in both the seasonal mean and the mean climatology at different times of the day. It is broadly consistent with the known poleward shift of storm tracks in winter in climate model simulations with GHG forcing. The centennial trend of the downward shortwave radiation at the surface in Northern USA. is on the order of 10% of the climatological value for the January monthly mean, and slightly over 10% at the time when it is midday in the United States. This indicates a nonnegligible influence of the GHG forcing on solar energy in the long term. Nevertheless, when dividing the 10% by a century, in the near term, the impact of the GHG forcing is relatively minor such that the estimate of solar power potential using present-day climatology will remain useful in the coming decades.

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