Spatial and temporal variability of soil moisture in relation with topographic and meteorological factors in south of Ardabil Province, Iran.

This research has been tried to evaluate the spatial and temporal variability of surface soil moisture (SM) in a semi-arid and cold region of Ardabil Province in Iran with an area of about 10,000 km. The used SM data is the SMAP Enhanced L2 Radiometer Half-Orbit 9 km Soil Moisture, provided by NASA. The study area was subdivided into 120 locations consisting 10 × 12 grids, matching with the pixels of the SMAP images.

Air quality classification and its temporal trend in Tehran, Iran, 2002-2012.

Airborne particulate matter with a diameter of 2.5 microns or less (PM2.5), as well as slightly bigger particles (PM10), arrive from the westerly direction and collect in the city centre of Tehran, the capital of Iran.