A night-time view of western Europe captured by crew members aboard the International Space Station. London is visible in the centre of the image, photographed from more than 250 miles above.
Smog was particularly bad in cities like Beijing, which declared a five-day pollution “red alert”. The Chinese capital reached dangerous levels of more than 400 micrograms per cubic metre. In Shijiazhuang, the capital of Hebei province, airborne pollutants surpassed World Health Organisation (WHO) guidelines by 100 times on 19 December.
From space, the smog appears grey in this view of north-eastern China. Heavy smog shrouds parts of the country, while the brightest, whiter areas are likely clouds or fog.
While smog regularly occurs in China, the extent of this event stands out and is comparable to a record-breaking air pollution event in January 2013, when ground-based sensors at the US embassy in Beijing reported PM2.5 measurements of 291 micrograms per cubic metre of air.
Low winter temperatures often cause dense, smog-laden air to be trapped low in the atmosphere. According to Andrew Sayer, an atmospheric scientist working for Universities Space Research Association at Nasa’s Goddard Space Flight Center, there are some indications that such incidents have been happening more frequently in the past few decades, though the reason for the increase has yet to be determined. “People are trying to figure out whether it’s due to changing air patterns,” he said, “or whether there’s more stuff in the air that stagnates.”
Expansion at the port of Rotterdam has changed the shape of the coastline of the Netherlands while increasing the cargo capacity at Europe’s largest port. This pair of Landsat images spanning 15 years shows the development of the Maasvlakte 2 project. The port provides accessibility for the transportation of cargo from Rotterdam to the rest of Europe. Land building at Maasvlakte 2 began in 2008. About 230m cubic metres of sand were dredged from the North Sea to create about 5,000 acres of new land. In addition, 7m metric tonnes of stone were used to construct new seawalls.
Commercial cargo operations at the new Maasvlakte 2 facility began in December 2014. Its terminals currently can hold 2.7m individual 20-foot shipping containers. There is more space for terminals to be built on the new land once demand increases, which would increase the port’s cargo handling capacity further. The expansion of land resulted in some loss of permanently flooded sandbanks that affected the availability of food for some protected bird species, such as the common scoter, the sandwich tern, and the common tern. However, this loss was compensated for by establishing a protected seabed area south of the Maasvlakte 2 in the Voordelta. Also, three bird-resting areas in the seabed were established where boat traffic is restricted. Landsat can help monitor this coast to ensure the positive impact of these protected areas as compensation for the land expansion.
In the upper-central section of the image an open-pit copper mine, appears white. This type of mining is often practised when deposits of minerals or rocks are found near the surface. To the west of this mine are two other open-pit mines filled with water. South of these water-filled mines are two circular structures reminiscent of clamshells. These are large solar power plants.
In the mid-1980s, Saudi Arabia embarked on an ambitious agricultural plan to grow crops in its desert areas using ancient fossil water deep beneath the sand. Centre-pivot irrigation systems were installed in the barren Wadi As-Sirhan basin in the north-west of the country. The water, once used to grow fruit, vegetables and wheat, was buried deep underground for thousands of years.
These Landsat images show the remarkable transformation of desert sand in 1986 into green, circular fields – some as large as 1km across – by 2016.
The drawback with centre-pivot irrigation lies in the fact that water in these aquifers is not recharged. Rainfall here only averages 100mm to 200mm per year, making groundwater in the area a non-renewable resource. Hydrologists predict it will only be feasible to pump the groundwater for another 50 years, so domestic wheat production will be phased out. Local farmers are being encouraged to engage in alternative sustainable agricultural activities, such as greenhouse farming using advance drip irrigation techniques to produce fruits and vegetables.
The retirement community concept proved wildly successful when Sun City was unveiled in 1960 with just five model homes, a recreation centre, one golf course, and one shopping centre. The opening weekend drew more than 100,000 people and inspired a cover story in Time. Decades later, the age-restricted community has seven pools, eight golf courses, and some 40,000 residents. Sun City proved so successful that several more retirement communities were built just to the west. A few of them include golf courses with distinctive layouts reminiscent of flowers when viewed from above.
A storm on 18 December brought not only snow, but bouts of thunder and lightning. While snow in Hawaii is not unusual (it can even fall in summer), thundersnow is less common.
The storm was reportedly associated with a Kona low. This low-pressure system brought a change in wind direction – winds that typically blow out of the northeast shifted to blow from the southwest. The winds from the leeward or “Kona” side drew moisture from the warm, tropical Pacific that ultimately fell as snow over the high elevations.