Meteorology and Climatology
On the most fundamental level, the Earth's climate is controlled by the radiation balance between the incoming solar radiation and the outgoing terrestrial radiation. However it is the internal redistribution of this energy, mainly in the atmosphere, that leads to a wealth of weather phenomena that occur over a wide range of spatial and temporal scales. Weather usually refers to the short term, daily variations of the atmosphere whereas the long term average is referred to as climate. Since the atmosphere is the most prominent component of the climate system, it is easy to understand why studies of global change originated over four decades ago as climate change investigations. Furthermore, the Earth is often referred to as the water planet since water is found mainly at or near the surface and in the atmosphere and therefore is a very prominent planetary feature when viewed from space. Water as a substance appears in the solid, liquid, and gaseous phases with all three playing important roles in the climate system. Water vapor, the gaseous phase, appears in the atmosphere and can account for up to 4% of the mass. It is the main absorber of infrared radiation and therefore is a major contributor to the greenhouse effect. Clouds and ice are the major factors that determine the albedo of the Earth and therefore are mostly responsible for the reflection of approximately 30% of the incoming solar radiation. Similarly evaporation from the surface, clouds and precipitation are important components of the hydrologic cycle through which water mass and energy in the form of latent heat are transported and redistributed around the globe.
From a dynamical perspective the atmosphere consists of a thin layer fluid heat from below and located on a rapidly spinning sphere. Thus the combined effects of thermal stratification and the Earth's rotation play central roles in shaping the circulation on a wide range of spatial and temporal scales. Our investigations have three major goals: (1) describing the physical and dynamical structure of the atmosphere and it variability on various scales; (2) understanding the basic physical processes that control this structure and its variability; and (3) development of mathematical methods for simulating and predicting the system. Considering the geographical location of Israel, our research focuses mainly on the Mediterranean region in general and on Israel in particular. The latter emphasizes local effects such as topography, land-sea contrasts, and urbanization. Some examples of our recent and ongoing research include:
- Dynamical seasonal forecasting for the Mediterranean region using a regional couple atmosphere-ocean model
- The role of air-sea interaction in the development of hurricane-like, severe storms over the Mediterranean Sea
- The use of a coupled modeling system for air quality prediction related to the planning of transportation infrastructure
- Precipitation formation processes in clouds using remote sensing
- Factors affecting land surface temperature in topo-climate, sea breeze, and synoptic scale systems