پديد آورندگان :
اميدوار، كمال نويسنده دانشگاه يزد omidvar, kamal , ابراهيمي، رضا نويسنده دانشگاه صنعتي خواجه نصيرالدين طوسي. دانشكده مهندسي هوافضا- Ebrahimi, E. , عليزاده، تيمور نويسنده ,
چكيده لاتين :
Introduction
One of the main problems in the use of atmospheric general circulation models (GCM) for
regional assessments is their low spatial resolution that is required to be downscaling by using
statistical or dynamical patterns. Therefore, in this study, it is necessary to consider the effects
of different ways on the investigated system. The best mean to consider and investigate the
effects of greenhouse gases on the atmosphere at regional scale is the use of hybrid models of
AOGCM, as one of the indices of climate degree days that its changes play an important role in
environmental issues such as energy consumption for heating and cooling in future. Given the
fact that Iran has diversity in elevation and climatic conditions and the most important factor in
the cooling needs is along with changes in altitude and atmospheric moisture, the climate
change is caused by the effects of global warming.
Physical Geography Research Quarterly, Vol. 48, No. 3
, Autumn
201
6
4
A new method for mapping the monthly cooling degree days, Iran
Kamal Omidvar
Professor of Climatology, University of Yazd, Iran
Reza Ebrahimi
?
Ph.D. Candidate of Climatology, University of Yazd, Iran
Teymour Alizade
Ph.D. Candidate in Climatology, University of Tehran, Iran
Received:
21 November 2015 Accepted:
16 March 2016
Extended Abstract
Introduction
One of the main problems in the use of atmospheric general circulation models (GCM) for
regional assessments is their low spatial resolution that is required to be downscaling by using
statistical or dynamical patterns. Therefore, in this study, it is necessary to consider the effects
of different ways on the investigated system. The best mean to consider and investigate the
effects of greenhouse gases on the atmosphere at regional scale is the use of hybrid models of
AOGCM, as one of the indices of climate degree days that its changes play an important role in
environmental issues such as energy consumption for heating and cooling in future. Given the
fact that Iran has diversity in elevation and climatic conditions and the most important factor in
the cooling needs is along with changes in altitude and atmospheric moisture, the climate
change is caused by the effects of global warming.
Materials and Methods
In this study, EH5OM database was used to detect the effects of global warming on cooling
degree days. This is like the data of general circulation of the atmosphere and ocean models.
This has been formed by data of atmospheric and ocean models. The data are implemented from
1960 to 2100, which are the general circulation of the atmosphere data. An international panel
of climate change has been implemented by A1B scenario. EH5OM hybrid model is one of the
most successful CMIP3 models in simulating climate, in comparison with the models of the
twentieth century. EH5OM is one of the hybrid models of atmosphere-ocean ECHAM5 i
s
related to atmospheric models and MPI-OM is related to ocean model. ECHAM has spectral
dynamic core; the data of this scenario have been implemented from 1950 to 2100; the data of
this scenario, from 2015 to 2050, were used in this study. Given that this research has regional
(Iran) dimension, the data in the fourth climatic regional models (RegCM4) are downscaled that are best suited for little scaling and regional processes (Roshan et al., 2012; Randall, 2007).
Downscaling model of output data are with dimensions of 0.27×0.27 longitude and latitude.
This covers about the dimensions of 30×30 km in area of Iran.
After the simulation, the average of daily temperature for a period of 36 years (2015-2050)
was derived by the model in a matrix with 2140×13140 arrays. In the matrix the rows represent
the days of a year and the columns are the numbers of cells
Results and Discussion
Table 1 shows EH5OM model scenarios under the conditions of greenhouse gases (carbon
dioxide and sulfur atmosphere) as published by the Max Planck Institute. These scenarios were
simulated for the period from 2000 to 2100. In fact, in this study we sought to identify change
parameters of cooling degree days, according to the scenario of this model. As it is shown in
Figure 1, in most of the scenarios greenhouse gas emission has taken an upward turn from the
twentieth century and most of them are included in group A scenarios.
Conclusion
In this research, after calculating the threshold of comfort in each station of the country and its
compatibility with the surrounding cells, cooling degree days and its changes were calculated.
The results of this research show warmer months of March, April and especially May and June
in the coming decades in the country compared with other months of the year. In fact, according
to the estimate of this scenario and the use of fossil fuels, the biggest challenge in the months of
spring is warmer weather and increased demand for energy consumption. This can be a sign of
early consumption of energy for cooling in the country in the coming decades.
Keywords: Arak, linear and non-linear regression, Statistical Downscaling Model (SDSM),
trend detection..
After the simulation, the average of daily temperature for a period of 36 years (2015-2050)
was derived by the model in a matrix with 2140×13140 arrays. In the matrix the rows represent
the days of a year and the columns are the numbers of cells.
These results were performed with the results of analysis; the process of cooling degree days
in the previous period, by Masoodian et al. (1393), showed that most of the upward range of
cooling needs can be seen in the summer. But it is in agreement with the results of Roshan et al.
(2012) who expressed warming regions of Iran in the first half of the year, in the upcoming
period, especially in South Bar. This suggests that hot areas of the country will become warmer
in spring. With the onset of summer, the number of the regions possessed the trend will be
reduced.
Conclusion
In this research, after calculating the threshold of comfort in each station of the country and its
compatibility with the surrounding cells, cooling degree days and its changes were calculated.
The results of this research show warmer months of March, April and especially May and June
in the coming decades in the country compared with other months of the year. In fact, according
to the estimate of this scenario and the use of fossil fuels, the biggest challenge in the months of
spring is warmer weather and increased demand for energy consumption. This can be a sign of
early consumption of energy for cooling in the country in the coming decades.
