Scientists discover Middle East dust cools Red Sea

Satellite imaging of earth’s atmospheric dust (pictured). Scientists have found that the amount of dust over the Red Sea is greater than over the land, with the largest radiative cooling effect of the sea in the world.
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Updated 03 March 2020

Scientists discover Middle East dust cools Red Sea

Researchers at the King Abdullah University of Science and Technology (KAUST) have discovered dust from the Middle East has a positive cooling effect over the land and the Red Sea.
“Saudi Arabia is in the so-called dust belt, emitting about a third of the world’s dust emissions,” said Professor Georgiy Stenchikov, director of the Earth Science and Engineering Program in physical sciences and engineering at KAUST. “Dust affects the entire world and it is the most abundant aerosol on Earth.”
Based on satellite data, scientists have found that the amount of dust over the Red Sea is greater than over the land, with the largest radiative cooling effect of the sea in the world.
“Dust cools the surface but warms the atmosphere, which is how it changes the circulation,” Stenchikov highlighted. “The Sahara dust shifts the rain belt in the summer to the north, increasing the circulation in the Sahel, for instance, so droughts would be more severe if there were no dust.”
Climate change is caused by the increasing concentration of greenhouse gases, which increase the Earth’s temperature. At the same time, the atmosphere is full of aerosols, which could either be natural or anthropological, that absorb and reflect solar radiation.
“Dust is a very complex aerosol,” Stenchikov saidd. “Not only does it reflect solar radiation, it also absorbs solar and infrared radiation and affects the atmospheric circulation, so it produces an extremely strong and complex effect overall on the circulation and the climate.”
“The concentration of dust in this center is very high,” he added. “The radiative effect is very high so the effect on the climate is also very strong — it affects the climate over land, the Red Sea and nearby waters. Dust deposition also provides nutrients to the sea.”

Dust is also a major climate driver, and its radiative effects are especially pronounced and relevant in the Middle East and over the Red Sea. Dust aerosols reduce the extreme surface air temperatures over the land and protect the coral reefs in the Red Sea.

Dr. Sergey Osipov, Max Planck Institute for Chemistry in Germany

In their paper published in the Journal of Geographical Research, the researchers showed that the climatological dust radiative forcing over the southern Red Sea is the largest in the world and, for the first time, studied the role of its effects in the region.
According to Dr. Sergey Osipov, from the atmospheric chemistry department at the Max Planck Institute for Chemistry in Germany, primary author of the study, it is essential to study mineral dust aerosols because of the broad spectrum of effects that span from our daily routines to climate change.
“In terms of the environmental hazards, dust contributes to ambient air pollution, which was recently recognized as a major health risk that reduces life expectancy,” Dr. Osipov said.
“Dust is also a major climate driver, and its radiative effects are especially pronounced and relevant in the Middle East and over the Red Sea. Dust aerosols reduce the extreme surface air temperatures over the land and protect the coral reefs in the
Red Sea.”


Signify expands UV-C disinfection portfolio to meet demand

Updated 12 July 2020

Signify expands UV-C disinfection portfolio to meet demand

Signify, a global professional and consumer lighting brand, is increasing its UV-C lighting production capacity and expanding its UV-C product portfolio. The company is leveraging more than 35 years of expertise in UV-C lighting to address the growing global need for the disinfection of air, surfaces and objects. 

“By increasing capacity and broadening the UV-C portfolio, Signify is helping keep people safe in a world that’s adjusting to a new normal,” the company said.

Its UV-C lighting is well-proven and trusted as an effective disinfectant. This was recently validated in a laboratory test by Boston University, showing that Signify’s UV-C light sources inactivate the virus that causes COVID-19 in a matter of seconds. This is crucial as it comes at a time when organizations are seeking ways to continue operations and provide service in a safe environment.

Signify’s new UV-C product range includes luminaires and chambers for a wide variety of professional applications. “We have introduced 12 families of UV-C lighting fixtures specifically designed to disinfect air, surfaces and objects. These products target different customer segments ranging from offices, schools, gyms, retail stores, warehouses, as well as on public transport,” said Harsh Chitale, leader of Signify’s Digital Solutions division. 

Part of the range are UV-C fixtures that are ideal for the deep disinfection of surfaces in offices, schools and restrooms. They are equipped with sensors and controls to ensure that they only operate when people and animals are not present. Other products include mobile, freestanding UV-C luminaires that can be wheeled into a hotel room or used to disinfect surfaces on public transport such as buses and trains. 

For the disinfection of objects, Signify launched a range of safe and quick-to-use UV-C disinfection chambers. These chambers are used in offices and municipal buildings to disinfect visitor tags, phones, bags, laptops and wallets in a matter of seconds. In stores they are ideal for disinfecting returned items, glasses or clothes tried on in a changing room. 

UV-C fixtures can also be used inside surface disinfection tunnels. In North America, a large retailer is piloting a UV-C tunnel for disinfecting shopping trolleys. In India, a hotel plans to use a Signify UV-C tunnel for disinfecting guests’ bags at check-in. 

To complement its portfolio, Signify recently acquired the assets of Germicidal Lamps & Applications (GLA), a small, Netherlands-based company with extensive expertise in UV-C disinfection solutions. The deal includes GLA’s upper-room UV-C air disinfection portfolio as well as deep application knowledge. 

“The assets and know-how acquired from GLA will help us to accelerate the development of our roadmap of UV-C based upper-room air disinfection systems. We plan to make these products available across the world soon,” said Paul Peeters, leader of Signify’s Digital Solutions Europe.

The upper-room air disinfection luminaires can be used with people in the room, as they are installed at a height which, in combination with shielding and optics, prevents exposure to the UV-C light source. Air in the upper part of the room is constantly disinfected using UV-C irradiation and natural convection of airflow in the room. This makes these perfect for use in schools, offices, gyms, retail outlets and other high-contact areas.