جستجوی مقالات مرتبط با کلیدواژه « olr » در نشریات گروه « جغرافیا »

Since the planet Earth acts like a black body like the planet, and always in a quasi-conditioned state, as much energy as it receives from the sun, it loses energy through long-wave radiation from the earth. The solar radiation absorbed on the ground is converted to heat; however, due to the reflection of the earth, the earth is not hot and hot. The energy reflection process by the earth is called earth reflection or long infrared wavelength, which is indicated by watts per square meter (w / m2). The low OLR values are related to the cloud at high latitudes, so that high values of the long-wave radiation of the Earth's output mean smooth skies and low values of the clouds. This indicator is also used to estimate rainfall in the tropical region. OLR calculations and estimates are a key component of the MJO, MNO, Negative and Positive Phases (ENSO), North Atlantic Oscillation (NAO), and also to study the assessment of weather indicators.

In the present study, in order to calculate the long-wave IR radiation, the OLR data from 1975-2015 were daily from NCEP / NCAR databases of the National Oceanic and Oceanographic Organization of the United States with a spatial resolution of 2.5 * 2.5 degrees longitude and 4-hour time resolution (hours, 00:00, 06:00, 12:00 and 18:00) were extracted and analyzed. In order to calculate the long-wave radiation of Iran, in the region of Iran's Earth's atmosphere (from 25 to 40 degrees north and from 42.5 to 65 degrees east), using Grads and MiniTab programming facilities, weighted earth integral Watts per square meter. First, the general characteristics of the long wave were studied. In this study, linear regression (VIA) regression methods were used to analyze the trend. In this procedure, the amount of variability of the long wave of earthquake is estimated over time. In the present study, in order to better understand the data and make a more accurate decision about the level of statistical confidence, the method of analysis of the Moran model was used; also, the Moran Model and GeoDa software were used to calculate and map the corresponding graphs. In order to calculate the Moran index or index, first the z and P-value points are calculated, and in the next step, the index is evaluated and significant.

The results of this study showed that the mean long wave length of Iran is 263/3 W / m2. The highest mean longitude of the Earth's longitude is due to latitudes below 30 degrees north, especially in the southern and southeastern parts of the country. Nevertheless, it was observed that more than half of the country's average surface longitude was greater than the average. The lowest mean radiation of the long wave of earth exits was seen as a belt from the northeast to the northwest of the country, but its minimum core is in the northwest and northeast. The lowest daily spatial variation coefficient of Iran's high-tide wave is seen in the southeast and southern coast of the country and in parts of the central and eastern parts of the country. Therefore, the geographic latitudes are higher than the mean long wave of the earth and the coefficient of spatial variation increases. Spatial Distribution The temporal and spatial variations of the temporal and spatial variations of the long wave of Iran's annual output in most areas of Iran have been increasing. The most extreme slope is the increasing trend (on average, between 0.8121 and 0.696296 watts per square meter) in the southern part of the southern belt of the Persian Gulf and the Oman Sea. In order to better understand the result of the temporal and spatial changes of the long-wave IR radiation to 4 periods of 10 years (1975-2015), during the first period, the total area of the country had an insignificant increase trend . Of course, in the second period, in contrast to the first period, most of the country's area had a decreasing trend, so that the areas that had a growing trend in the first period had a decreasing trend in the second period. Also, in the third period, again, in the second period, the majority of the country's area was incrementally and statistically insignificant. Of course, in the fourth period, the long-wave radiation of the Earth's surface throughout the southeastern region of Iran has been increasing and statistically insignificant, which includes 14.3% of the country's total area; but in general, during the fourth period, 96% of the country's area has a decreasing trend, of which 50.32% is statistically significant, and 43.53% are statistically non-significant. This suggests that in all four 10-year periods, I have had a photographic process at the outlet of the tidal wave in Iran. The results of the spatial distribution of the local Moran index showed that the long wave of Iranian outbound radiation in the south-east, south, and in the east and west of the region, consisted of a high cluster pattern with 47/60 percent of the country's land area. The cluster pattern regions of the north are drawn from the northeast to the northwest and include the northeastern, north and northwest regions of the country as well as the northern heights of the Zagros Mountains of the country. The spatial self-correlation model has a similar positive correlation with the pattern of spatial autocorrelation, with the difference that the spatial spatial dependence pattern of the second period is decreasing, while the positive spatial self-dependency model from the third period to the next It will slow down. Nevertheless, it can be said that throughout the course of the model, the spatial self-sufficiency pattern negatively affects the recent periods of decline and also the positive spatial self-correlation pattern with 0.75 percent ascendance.

The purpose of this study is to analysis monthly OLR of the Iranian surface. For this purpose, the ground OLR data was extracted and analyzed from the ncep/ncar database during the statistical period of 1354-1398. In order to extract the have been used in the Gards software and GIS. Findings showed that by examining the spatial index of Gi statistic, the hot spots of Iran's OLR are 99% and 95% in August, July, June, September and October. Hot spots correspond to areas of the tropics and to latitudes below 30 degrees north; Also, the maximum cold spots are at the level of 99%, 95% in February, December, January, March, April, and the maximum cold spots OLR from the northeast to the northwest. It includes the northeastern, northern and northwestern regions of the country, as well as the northern highlands of the Zagros Mountains.