By Steff Gaulter
It sounds like the title of a really bad horror film: The Warm Blob. When I first heard about it, I imagined it to be green and slimy, looking like something out of a Ghostbusters movie. Sadly, however, that was just my slightly over active imagination, because you can’t actually see it.
The warm blob is simply the name which has been given to a region of water off the west coast of North America. As its name suggests, the water is warmer than usual. Why it formed remains a mystery, but it’s important as it could be having an effect on the weather in certain parts of the world.
It’s already known that our vast oceans have a huge impact on the atmosphere. The cold current which wells up off the coast of Peru is one of the reasons why Lima is the driest capital city in the world, expecting only 13mm of rain in the entire year. Meanwhile, it’s the warm current, known as the Gulf Stream, that ensures that the UK has a far milder climate than Canada, despite being on a similar latitude.
Our oceans are constantly churning, and even a slight change in their temperature can have a dramatic change in the weather all around the globe. You may have heard of El Nino which regularly forms in the Pacific Ocean; this is the slight warming of the surface water. It’s a natural phenomenon which happens every three to five years, and lasts for about eighteen months. The change is usually less than 1.5C, which sounds fairly insignificant, but it has a dramatic affect on the weather around the world.
During an El Nino event there is often more rain than usual along the coast of Peru, but far less than average in Indonesia. Even further afield, the weather can be dramatically different from usual: eastern Australia and South Africa often experience a drought, while the southern states of the USA are often hit by flooding.
El Nino is the warming of the Pacific Ocean, but there is also a cooling of the waters as well, known as La Nina. The Pacific oscillates between its warm and cool phases, and in doing so forces a change in the weather in many parts of the globe. However, whilst La Nina and El Nino may be the most famous ocean temperature changes, they are not the only ones. Other oceans have their own temperature patterns, and whereas the Indian Ocean Dipole and the Atlantic Multidecadal Oscillation may not have such catchy names, they still have an important affect on the global weather.
The blob isn’t thought to be part of any regular ocean change that is known about at present. It’s not thought to be linked to El Nino, because El Nino effects the waters near the equator, whereas the warm blob is much further north. It was first noticed last year, when a patch of water off the west coast of the US didn’t cool off as quickly as usual in the winter. Throughout the colder months of the year it retained its warmth and now, eighteen months later, it has extended approximately 1,600 km (1,000 miles) along the coastline, from Mexico all the way to Alaska. The water is between one and four Celsius (two to seven Fahrenheit) warmer than the surrounding ocean water, and the big question is, what affect is it having on the weather?
The blob already appears to be having an affect on marine life. Warm water generally contains less nutrients, so this warm patch of water is disrupting the food supply of many marine animals that would normally reside in the coastal waters. There are reports the temperature change has driven many fish out of their usual hunting grounds.
An important element to discover is whether the blob is having an affect on the amount of precipitation that falls in California. In 2013, California received less rain than in any year since its formation as a state in 1850, and the drought shows no sign of breaking any time soon. In fact, recent sediment studies have shown that over the last 3,000 years there has been a cycle of droughts across the region, and the regular rain seen over the last century may be something of an anomaly.
However, it’s not necessarily the lack of rain that is causing the most concern in the state. Much of California’s water supply comes from snow melt in the mountains, but in recent winters the snow has been in short supply. Without the snow there is a serious shortage of water, and this could be due to the blob.
The majority of the weather systems which bring snow to the Californian mountains come from the west, across the Pacific. With the water in the blob being warmer than usual, the air passing over it will also be warmed. This could potentially influence the amount of snow that falls in the mountains, instead transforming it to rain. This wouldn’t only trigger a drought in California, but also in Oregon and Washington as well.
Exactly how this area of warmer water has formed, or how long it will stay, is currently a mystery, but it’s a mystery that may need to be solved as it could have very important consequences to the residents of
California. HOTTER THAN USUAL: The summer in Qatar this year is forecasted to be hotter than usual due to El Nino. Photo by Najeer Feroke
