Lake Urmia in northwestern corner of Iran was once the second largest hypersaline lake of the world, covering on average an area of 5200 km 2 . However, the lake has been shrinking rapidly over the last 20 years, primarily due to anthropogenic influences, while climate change has had also a detectable influence. Climate change and anthropohenic impacts on the rapid shrinkage of Lake Urmia are investigated using long-term surface meteorological records of weather stations, while the number of constructed dams and expansion of irrigated areas in the Urmia Basin are also examined. Over the past few decades, a warming trend of the order 0.18 ∘ C decade −1 has been identified, while precipitation has been decreasing by approximately 9 mm decade −1 over the basin. As a consequence of such significant warming, evaporation from the lake has been increasing by the rate of 6.2 mm decade −1 . The increased air temperature and evaporation, along with the decreased precipitation indicate that Lake Urmia has been experiencing meteorological drought conditions. The main anthropogenic influence, on the other hand, has been overwhelming diversion of water sources for irrigation, which led to the socioeconomic drought of the region because demand for water has exceeded the supply. The meteorological drought, combined by the socioeconomic drought, have contributed to the significant shrinkage of Lake Urmia, started from the mid 1990s water level peak, although the latter has had the most significant contribution. As a consequence, the water level of Lake Urmia has been rapidly declining since 1995, with 6.1 m decline for the period 1995-2009. Its surface area has been also changing by the rate of −188.3 km 2 yr −1 , reaching from 5503 km 2 in 1998 to 2323 km 2 in 2011. Under the induced meteorological and, more importantly, socioeconomic drought conditions, substantial improvements in water management practices are required to preserve or partially restore the lake.

Using surface meteorological records of a 20-year period from 1991 to 2010, temporal variations in the frequency and concentration of transported dust events over Iran are investigated. Five regions of frequent dust events are identified. In the order of importance, these areas are the Khuzestan Plain, the coastal plain of the Persian Gulf, west of Iran, Tabas and Sistan. The first three areas create a belt of high frequency of dust events along the western foothills of the Zagros Mountains. The Khuzestan Plain is the area with the highest frequency of dust events, over which dust laden air is almost permanently present in summer, while the coastal plain of the Persian Gulf is the second most affected area. These two areas, along with west of Iran, are mostly influenced by transported dust from sources outside of Iran, while Tabas and Sistan are mostly influenced by arid lands in the interior of Iran. In contrast, the southern coastal strip of the Caspian Sea is the area with the least frequent dust episodes. Throughout Iran, the frequency of dust events strengthens in spring, peaks in summer and significantly weakens in autumn and winter, with the least observed frequency in winter. Significant monthly variations of the frequency of dust events were also identified, with the most and least frequencies in July and December, respectively. In terms of long-term frequency of dust events, our observational analyses show an overall rising trend of the frequency of Iran's dust events in recent years, predominantly attributed to increasingly frequent dust outbreaks in Iraq due to human intervention.

An extreme heavy snowfall event occurred over the southwest coast of the Caspian Sea over the period 31 January–5 February 2014 and caused huge economic losses to both the government and the people of Iran. This phenomenon has been analysed using in‐situ data and AVHRR satellite data, as well as NCEP/NCAR and GFSANL reanalysis data. The results indicate that a cold‐air outbreak from Scandinavia to the Caspian Sea provided an appropriate synoptic pattern for the passage of cold air over the warm lake. In addition, the existence of an omega blocking system at medium levels (~500hPa) over Europe resulted in the persistence of this synoptic system. Furthermore, favourable conditions such as thermal instability, long fetch and low directional wind shear caused this lake‐effect snow (LES). Finally, the Alborz Mountains and the form of the southwest coast of the Caspian Sea were also found to have a particular role in the formation of LES in this region.

Southwest Asia including the Middle East is one of the most prone regions to dust storm events. In recent years, there was an increase in the occurrence of these environmental and meteorological phenomena. Remote sensing could serve as an applicable method to detect and also characterise these events. In this study, two dust enhancement algorithms were used to investigate the behaviour of dust events using satellite data, compare with numerical model output and other satellite products and finally validate with in-situ measurements. The results show that the use of thermal infrared algorithm enhances dust more accurately. The aerosol optical depth from MODIS and output of a Dust Regional Atmospheric Model (DREAM8b) are applied for comparing the results. Ground-based observations of synoptic stations and sun photometers are used for validating the satellite products. To find the transport direction and the locations of the dust sources and the synoptic situations during these events, model outputs (HYSPLIT and NCEP/NCAR) are presented. Comparing the results with synoptic maps and the model outputs showed that using enhancement algorithms is a more reliable way than any other MODIS products or model outputs to enhance the dust.