A bank of clouds covers East Java to the west, with a bright sun overhead casting shadows from the clouds along the ocean surface. Sunglint, an optical effect caused by the reflection of sunlight off the water surface directly back at the satellite sensor, exposes the waves created by the movement of currents in the ocean water. Internal waves are generated when the interface between layers is disturbed, such as when tidal flow passes over rough ocean floors, ridges, or other obstacles. The Lombok Strait, a relatively narrow passageway between Bali (west) and Lombok (east), allows flow of water from the Pacific Ocean into the Indian Ocean. The bottom of the strait is complex and rough, consisting of two main channels, one shallow and one deep. Because of the variation in water movement due to the complexity of the channels and ocean interface, the tides in the strait have a complex rhythm but tend to combine about every 14 days to create an exceptionally strong tidal flow. It is the combination of rough topography, strong tidal currents, and stratified water from the ocean exchange that makes the Lombok Strait famous for the generation of intensive internal waves.

Decline in Arctic sea ice. Credits: Nasa’s Scientific Visualisation Studio

The area covered by Arctic sea ice that is at least four years old has decreased from 718,000 sq miles (1,860,000 sq km) in September 1984 to 42,000 sq miles (110,000 sq km) in September 2016. Ice that has built up over the years tends to be thicker and less vulnerable to melting away than newer ice. The age of the ice is indicated by shades ranging from blue-grey for the youngest ice, to white for the oldest.

The Gibson Desert extends over more than 58,000 sq miles and sports gravel terrains covered by desert grasses, as well as red sandy plains and dune fields. A drought in the 1980s forced the indigenous Pintupi people to the central-eastern area of the desert, where they made contact with the rest of Australian society. To the left, the strange shapes in varying shades of blue are the remnants of areas purposefully burned by the Pintupi people to encourage plant growth or drive game animals into the open. Many of the Pintupi people moved to settlements when the British military began testing missiles in the region in the 1950s. The areas burned by the Pintupi people became overgrown, becoming even more susceptible to fires caused by people or lightning, which then burn out of control, leaving behind large burn scars. In the lower-right corner of the image is the Connolly Basin impact crater, believed to have been formed about 60m years ago. The rim, about 6 miles across, rises 25–30 metres above the crater’s basin.

The shape of this storm over the Mediterranean resembles something you would more often see spinning over the Pacific or Atlantic. The Noaa reported that the system appeared to be a T-number 1.0 storm on the Dvorak current intensity chart and was generating sustained winds of 29 mph, equivalent to a tropical depression on the Saffir-Simpson wind scale. The storm was strong enough to generate large waves that affected some areas of land. News reports noted that crews removed 177 tonnes of debris from the east coast of Malta. Cloud patterns in satellite imagery usually show cyclonic circulation before a storm reaches tropical storm intensity. Some of these storms over the Mediterranean have had characteristics similar to hurricanes, earning them the name “Medicanes”.

Two large green islands – Sardinia to the south, and Corsica to the north – sit in the blue waters of the Mediterranean. The snow-covered Alps run from west to east, extending about 750 miles. Eight countries share this mountainous terrain, including Monaco, France, Switzerland, Liechtenstein, Austria, Germany, Slovenia and, to the south, Italy. Fog and haze hang in Italy’s Po river valley south of the Alps. The valley contains the highest population density in Italy and produces large amounts of pollutants from vehicles, factories, coal-fired power plants, agricultural fires and other human activities. In autumn and winter, temperature inversions often trap both fog and pollutants near the surface of this valley.

To the north, parkland separates the subdivisions of San Diego county, California, from the manmade US-Mexico border. To the south, the gridded residential streets of Tijuana’s Libertad and Zona Norte neighbourhoods abut the common boundary.

The temperatures of the Great Lakes in North America are the warmest they’ve been since at least 2010 for this late in November, according to data from NOAA CoastWatch’s Great Lakes environmental research laboratory. The surface temperatures in November 2016 are several degrees warmer than those of this time two years ago. The warm lake waters and cold winter winds are the perfect combination for lake-effect snow, which NOAA defines as “snow showers that are created when cold, dry air passes over a large warmer lake, such as one of the Great Lakes, and picks up moisture and heat”. Just how much snow particular areas of the Great Lakes region will receive depends on which direction the winds blow.

The Republic of Maldives is located in the Indian Ocean, south-west of India. It comprises 26 atolls and 1,192 coral islands, with an average ground elevation of 1.5 metres. Tourism and fishing account for more than half of the country’s GDP. Kulhudhuffushi, in the upper-right corner, is the capital of Haa Dhaalu Atoll administrative division in the north of the Maldives.

Muddy brown sediment poured from the Irrawaddy Delta at the end of a long and extremely wet monsoon season in 2016. The rainy season in Myanmar begins in mid-May and typically ends in mid-November. According to ReliefWeb, floods brought by monsoon rains began pounding parts of Myanmar in late July, displacing at least 377,000 people from their homes as the waters gradually moved south towards the Irrawaddy Delta. By mid-October, the worst of the rains had passed and the floodwaters were receding; however, the waterways along the delta continued to pour sediment into the Gulf of Martaban (east) and the Andaman Sea. Such sediment is not unusual – it has been estimated that the Irrawaddy river is likely the third-largest contributor of sediment load in the world. The delta of the Irrawaddy river begins about 58 miles above the port city of Hinthada and spreads about 180 miles south to the Andaman Sea. The region is heavily populated and is also intensively cropped for rice. Much of the delta lies only about 3 metres above sea level, while the ocean floor is very shallow (less than 5.5 metres deep). The soil consists of fine silt, which has been carried down the muddy river channels and deposited while the water speed slows as it approaches the Andaman Sea.

In the Tafilalt oasis in south-east Morocco, dozens of thin lines run across the desert from the Anti-Atlas mountains towards the town of El Jorf. These are qanats (khettaras in Moroccan) – ancient underground water channels designed to transport water down slopes without active pumping.

Most wells involve digging a vertical shaft down until it reaches the water table, and then hauling or pumping the water up to the surface. Qanats consist of gently inclined horizontal tunnels dug into sloping terrain. When the horizontal tunnel hits the water table, gravity causes water to flow downhill in the channel toward outlets at the base of the slope.

While the channels that convey the water lie below the surface, the access shafts used for construction and maintenance are visible above ground. The access shafts are often dug near or through large earthen mounds made of material excavated during construction of the vertical shafts and channels.

From above, these earthen mounds form long chains that appear as relatively continuous lines. Cultivated land (green) – much of it covered with date palms – surrounds the town of El Jorf.

The qanats in this area date back to the 14th century and have provided water for towns and villages for several centuries. Widespread uses of diesel pumps and vertical wells began to lower the water table in the 1970s, causing some of the qanats in this region to go dry. Today, about half of the 69 qanats in Tafilalt still supply water. One recent analysis concluded the depth of the groundwater table had dropped 50% over the past 40 years, and the amount of date palm grown in the Tafilalt oasis had declined by 50%.

One of the most spectacular features of the planet: the dunes of the Namib sand sea. Looking inland near sunset, the highest linear dunes show smaller ones riding along their crests. Linear dunes are generally aligned parallel to the formative wind – in this case, strong winds from the south. Southerly winds explain the parallel north-aligned linear dunes to the left. But this simple pattern is disrupted near the Tsondab valley. The valley acts as a funnel for winds from the east. These less frequent but strong winter winds are channelled down the valley and usually carry large amounts of sand, similar to the Santa Ana winds in California. These strong easterly winds significantly deflect all the linear dunes near the valley so that they point downwind (image centre). Further inland (right), the north-pointing and west-pointing patterns appear superimposed, making a rectangular pattern.

The Namib Desert is very old – dating from the time when the cold, desert-forming Benguela Ocean current started to flow about 37m years ago – and wind and dune patterns have shifted over time. The Tsondab river is a well-known Namib Desert river because it is blocked by linear dunes 60 miles from the Atlantic. Research has shown that during wetter times, it did actually reach the ocean. The name Tsondab means “that which is running is suddenly stopped” in the local Khoisan language. Along the edge of the dune-free Tsondab river valley, we can see star dunes, which are smaller and display multiple arms (top left).

The Bahama Islands are one of the most recognisable places on Earth for astronauts and one of their favourite areas to photograph. The eyes are naturally drawn to the large areas of shallow seas, known as banks, that appear in light blue. The edge of the Little Bahama bank in the northern Bahamas is marked by the straight line of a coral reef. White breaking waves appear on the seaward edge of the reef, and the sea floor rapidly deepens north of this line (darker blue on the lower right).

This long-lens view shows all kinds of detail in the shallow water. The brightest swirls are shelly sands moulded into sweeping shapes. The largest sand feature (a U-shape in the centre of the image) lies opposite the widest break in the coral reef – where the tidal flow is strongest. A gap in the line of breakers shows the opening. The small island known as Strangers Cay is 2.25 miles long. Other black shapes are the shadows of clouds. Regular patterns of swells appear in the deeper water (lower right). The quieter, shallow water in the centre of the image – protected from the open sea by the reef – was streaked by a brisk north-east wind on the day this photo was taken.

The Bernardo O’Higgins national park in southern Chile includes much of the southern Patagonian ice field – the world’s second largest contiguous ice field beyond the poles – part of which is shown here. Classified as an expanse of ice covering less than 19,000 sq miles, ice fields are formed by a large accumulation of snow which turns into ice with years of compression and freezing. Shaped by the underlying topography, glaciers often form at the edges of an ice field, draining the ice off. The southern Patagonian ice field is the larger of two remnant parts of the Patagonian ice sheet, which covered all of southern Chile during the last glacial period about 12,000 years ago.

One of the main attractions in this area is the Brüggen glacier – also known as Pío XI glacier – visible in the lower-left corner of the image. This is the longest glacier in the southern hemisphere outside Antarctica, and has been advancing, first reaching the western shore in the 1960s, and then advancing north and south. Just above this glacier, we can see how the waters of Lake Greve appear lighter in this false-colour image compared to other water bodies. This is due to the presence of suspended fine sediment in the water produced by the abrasion of glaciers rubbing against rock, called “glacier milk”. The active, ice-covered Lautaro volcano can be seen in the lower-central part of the image.

Great Lakes, North America Credits: Thematic Mapper/Landsat 5/Nasa and Oli/Landsat 8/Nasa

The Great Salt Lake is the largest water body in the US after the Great Lakes. It is a terminal basin, which means the water that pours into the lake from rivers and streams has no outlet other than evaporation. This allows salts and minerals to concentrate in the lake such that it is three to five times saltier than the ocean. And yet this briny lake is a haven for more than 250 species of migratory birds who feast on the brine shrimp and flies that thrive there.

But now the millions of birds and shrimp are faced with a problem. For more than 150 years, humans have been taking more water out of the Salt Lake watershed than is flowing into it. They are now diverting about 40% of the river water (which would normally fill the lake) and using it for farming, industry, and human consumption. In October 2016, the Great Salt Lake reached its lowest recorded level: 1277.5 metres, averaged between the lake’s north and south arms. The volume of water in the Great Salt Lake has shrunk by 48% and the lake level has fallen 3.4 metres since 1847.

These two Landsat satellite images show recent changes in the Farmington Bay basin of the Great Salt Lake, captured on 11 September 2011 and 20 September 2016. According to scientists’ estimates, more than three-quarters of the lake bed is now exposed in Farmington Bay. Salt Lake City (lower-right) and its northern suburbs stretch around the east side of the lake.

The state has been promoting water conservation for urban and suburban areas, but this is only about 8% of water use. The hardest work lies in convincing farmers to do more with less, as approximately 63% of the water usage goes to agriculture.

The loss of water in the Great Salt Lake has led to more and larger dust storms in the area, while making it harder for companies to get the water they need for extracting salt and other minerals, a key piece of the local economy. Marinas and other water recreation operations are also struggling with the moving shoreline.