Earth's atmosphere is never still. Somewhere, at any given moment a storm is ripping across the surface of our planet. Maybe it will pass through in the middle of the night, waking only the dog, or maybe it will close the airport, flood the subway, and-or usher in a year of famine—perhaps a civil war. Our ability to track weather may (sometimes) give us some advance warning, but the weather itself is inevitable. It is the state of the atmosphere and we all experience it.
Weather prediction involves a lot of probabilities (and no certainties) and informed guesses, but weather observation gets better every year. In part we can thank NASA's Terra and Aqua satellites, both of which are equipped with MODIS (Moderate Resolution Imaging Spectroradiometer) instruments. These instruments (and others) happen to keep my inbox pretty full through any given week, but I'm not sure every single typhoon snapshot from orbit warrants its own post. So, let's try this: a weekly round-up.
I'll start by digesting images from NASA, which primarily includes typhoons, hurricanes, tropical storms, and dust storms, but maybe eventually less global events will fit. In any case, these are the storms of the first week of September, 2015. Hurricanes, tropical storms, dust storms, typhoons.
Sundanese Dust Storm
Image acquired: August 13, 2015
Source: NASA, Aqua (MODIS)
The wall of dust here billowing from southwest to northeast originated in northern Sudan and can be seen heading toward Egypt and the Red Sea.
"Strong, sometimes violent, dust storms are common in Sudan," the MODIS Land Rapid Response Team explains. "Known as haboobs, they are often the result of the initial downdraft of an approaching thunderstorm, which lifts large amounts of sand and clay from the arid land and drives it in large, rolling sheets across the landscape. The great quantities of sand blown by a haboob can drop visibility to near zero."
Image acquired: August 31, 2015
Source: NASA, Terra (MODIS)
Since the end of August, the Atlantic storm development process has been in overdrive. Off the western coast of Africa, sea surface temperatures have been simmering at around 85 degrees Fahrenheit—perfect fuel for a budding hurricane. Fred went from tropical depression to tropical storm to full-on hurricane in the span of a single day. It was the first hurricane to strike the Cape Verde islands, located northwest of the African continent, in over 100 years. Fortunately, Fred didn't make direct landfall, nor did it result in any loss of life. Damage was, however, extensive.
"By September 1, Fred had begun to weaken substantially, and lingered at tropical storm status through the day," the MODIS team reports. "The National Hurricane Center (NHC) reported that Fred will be moving in to an area of increase southwesterly shear and a less conducive thermodynamic environment. That movement should cause the tropical cyclone to gradually weaken through the next several days."
Tropical Storm Erika
Data acquired: August 27, 2015
Source: NASA, Aqua (MODIS)
Erika was born on August 21 between the western coast of Africa and the Cape Verde islands as a wave of low pressure. Over the next several days it tracked across the mid-Atlantic while gradually intensifying into a Tropical Storm. By the time it hit the Caribbean on the 27th, a strong westerly wind shear had neutralized it considerably, but hardly completely. It eventually dissipated east of Cuba.
"By August 31, the remnants of Erika were causing rain and flooding in the southern United States," the MODIS group notes. "Meanwhile, the island of Dominica had declared disaster status due to damage caused by tropical-storm-force winds and flooding. At least twenty people were reported killed, and as many as another 50 people were missing."
Hurricanes Kilo, Ignacio, and Jimena
Dates acquired: August 29 - 30
Source: NASA, Suomi-NPP satellite (VIIRS)
August was the first month in recorded history in which three category 4 hurricanes simultaneously crossed the eastern and central Pacific Ocean. The top image is a composite of data collected during three nighttime passes with a full-moon providing the needed illumination.
"Hurricane Kilo had maximum sustained winds of 215 kilometers (135 miles) per hour, according to an advisory issued by the Central Pacific Hurricane Center," NASA's Earth Observatory explains. "The storm moved toward the north-northwest, and posed no hazards to land. Meanwhile, Hurricane Ignacio had similar sustained wind speeds that measured 220 kilometers (140 miles) per hour; this storm, however, was closer to the Big Island's mainland and had the potential to produce damaging and life-threatening surf. Huricane Jimena, the easternmost of the three storms, carried maximum sustained winds of about 210 kilometers (130 miles) per hour, according to an advisory issued by the National Hurricane Center."
The second image is a also a composite, but this time collected during daylight hours. It represents the storms as of about 12 hours later than the first image.
Date acquired: August 2005, August 2015
Sources: NASA, Landsat 5/Landsat 8
A pair of false-color images show the dramatic transformation of Louisiana wetlands following the 2005 landfall of Hurricane Katrina. On the left is one week before the storm, while the right shows the same area imaged this past August. Normal vegetation is shown in green, while damaged vegetation appears brown. Obviously, the blue stuff is water.
"The wetlands surrounding Delacroix, a fishing town to the southeast of New Orleans, were some of the hardest hit by the hurricane," NASA's Earth Observatory explains. "Pounding surf, driving winds, and a potent storm surge transformed the marshes by picking apart mats of dead grass, stirring up and disbursing soft underlying sediments, scouring several new channels, and depositing leftover sediment and debris in new areas."