JOURNAL OF CLIMATE RESEARCH
Year:2016 | Volume:6 | Issue:23-24|Papers Count:10

Introduction As a dominant oscillation in tropical stratosphere, the Quasi-Biennial Oscillation (QBO) is believed to have significant effect on the extratropical troposphere. This study examines the extratropical effects of QBO from an energy viewpoint.

Introduction Iran is located in the world's arid and semi-arid regions so it has always been facing severe water resources restrictions. Evapotranspiration data can be used to calculate regional water and energy balance, soil water status; hence, it provides key information for water resource management. With long-term ET data, the effects of changes in climate, land use, and ecosystems disturbances on regional water resources and land surface energy change can be quantified. In addition, Evapotranspiration (ET) as a main component of the hydrological cycle is a significant parameter in hydrology, meteorology and particularly in water management and irrigation scheduling.

Introduction Thunderstorm is mesoscale and in some cases microscale and Most of the numerical weather forecast models encounter problem predicting them. Lack of access toupper atmospheric data in many parts of the earth's atmosphere makes the numerical forecast models one of the most important tools in determining such indices (Lopez et al, 2009). in another one by simulation of two violent storms through convective parameterization scheme model of WRF-NMM, it was manifested that the cumulus scheme Grell-Devenyi has a better function than the other schemes in calculating instability indices TTI, LI, KI and CAPE, and there is also a proper correspondence between the spatial and temporal patterns of precipitation with the observations (Prosenjit et al, 2008).

Introduction The History shows that human life from the beginning has always been exposed to natural hazards. Drought is one of the most important risks in Middle East. This Climate risks different to other disasters such as floods and earthquakes, and differences is in the impact of a slow, quiet and creep (chronic) this event over a long period. It is impossible to determine the exact start and end time, and the range is expanding it. Rainfall is the most important parameter in a drought so that the overall decrease in precipitation of long-term than normal is called drought.Iran is located in the region that many of the droughts have occurred in this area, as in the classical texts of prayers for rain and drought relief can be seen. Drought effects of drought is reducing water flow, as a study period of 1987 to 2007, Moderate to severe drought period (1996-2007) in Gonabad is Drying 51 Aqueduct, Rate reduction of 48% in the aqueduct and 41% of the wells and 31 percent of the region's springs and drop the Underground water tanks 2 meters and 10 cm (Behnyafr et al, 2011). In this study, using long term data (50 year) from the stations of Iran identify the behavior and the spatial distribution and homogeneous regions of long term drought.

Introduction: Cloud seeding is one of the most known aspects of weather modification in most regions of world, that according to the World Meteorological Organization among all weather modification applications, most of operational projects were focused on the increase in rain. Determination of the area under effect of seeding materials, known as the target area during measuring its efficiency is one of the most challenges in applying the cloud seeding method. In the current method of determining the target area, in measuring the cloud seeding project in Iran, the seeding materials from shooting place is transferred in GIS environment for two hours using wind speed and direction output of WRF mode in wind direction. Considering the complexities and lack of present sureness in determination methods of target area, in this paper it was attempted to provide a new method in order to determine the target area using the martial distribution model.

Introduction Climate is in under influenced with some different complex phenomena. One of important parameters is Precipitation that has change from a year to other year. Teleconnection Patterns and Indices are remote controller of precipitation amount variation in Iran and the entire world. So in this paper on of main goal is relationship between teleconnection and precipitation trends in main meteorological station of IRAN that have long term data base.

Introduction: The inertia-gravity waves (IGWs) are ageostrophic oscillations resulting from buoyancy and Coriolis effects whose frequencies lie between the inertial and buoyancy frequencies. These waves transfer energy and momentum in the horizontal and vertical directions, effect many atmospheric phenomena and cause perturbation in fields of pressure, temperature and wind. The IGWs are known to have several sources including low-level front (Snyder, 1993) and the upper-level jet-front system.

Introduction Atmospheric aerosols are very important in the Earth climate system due to their role in climate of the Earth, scatter sunlight and serve as cloud condensation nuclei (CCN). However, there are still many unanswered questions about how the composition of the aerosol varies and how this composition affects the climate system. While aerosols contain a mix of organic and inorganic material, a sub-fraction of the organic material in atmospheric aerosols is surface active agent (surfactant).

Introduction Rainfall is one of the most important elements of climate impact, especially when it occurs in a large area encompassing a few days is surely much greater impact on the natural environment and human will Factors, including the rise of precipitation, humidity, condensation Vhsth be caused by the general circulation of air. Precipitation climate is a complex phenomenon resulting from the interaction the purpose of this study synoptic causes precipitation heavy sweeping Vnadr in central Iran, in the range of (20 to 24) Farvardin 1386 help index instability using atmospheric models of both surface and upper level atmosphere is.