Aside from the Thornthwaite Climate Classification system which was reported upon a couple months ago (go here to read that article), the classification system that came before Thornthwaite’s time is the Koppen Climate Classification. The classification was first published by Russian climatologist Vladimir Koppen in 1884. Although it was published in 1884, it wasn’t completed until 1936 after several modifications by Koppen. To add several more modifications, climatologist Rudolf Geiger introduced several other changes that were needed. The two climatologists and their work is what gives this classification system the name of Koppen-Geiger climate classification. But, for the sake of title and to give credit to the creator, it is commonly known as the Koppen climate classification.
Koppen’s aim was to devise formulas that would define climatic boundaries in a way that would correspond to vegetation zones, known as biomes, which were being mapped out during his time. The system divides climates into five main climate groups, with each group being divided based on seasonal precipitation and temperature patterns. These groups are represented by capital letters A, B, C, D and E. All of which, except for B, are defined by temperature criteria. Type B looks more at the amount of precipitation or dryness rather than temperature. The climate designations are as follows: tropical, A; dry/arid, B; temperate, C; continental, D; and polar, E.”
Along with the capital letters to represent the type of climate, Koppen wanted more specific factors to truly identify the climate of a given area. With this in mind, he designated numerous other letters to represent the other features that a climate could have:
As shown in the table above, the lower case letters represent the kind of climate an area possesses. The overall differentiation is based upon temperature with precipitation dividing the classification further. Koppen wanted to show how climates are split up based upon vegetation and the precipitation they receive. He created just that, but with more concentration on temperature and precipitation. This differs from the Thornthwaite Classification System by relying upon the temperature and precipitation of the area. Thornthwaite, who grew up as a farmer and was educated in botany, expanded his system to the characteristics of the area; such as the vegetation type. Thornthwaite measured the precipitation and evaporation of the climate to classify it. To learn more about the Thornthwaite system refer to the link which was provided earlier in this article.
The Koppen classification system was the first of its kind that measured both temperature and precipitation and how they both effect the climate of a given area. Koppen’s system is still heavily used to this day and helps climatologists, along with other scientists, determine how to classify the climate of region.
To learn more about other interesting stories related to global climate issues, be sure to click on the following link: www.globalweatherclimatecenter.com/climate
©2019 Weather Forecaster Alec Kownacki
Los Angeles as seen from Griffith Park on January 10th, 2019, just days before an Atmospheric River moved into the region. Source: Gerardo Diaz Jr.
After spending a few days soaking in the Southern California sun, I was about ready to head back up to my home in the Midwest. That being said, my last morning in LA was anything but sunny. The sky was grey and traffic was backed up for miles on several of the freeways as rain slowly moved its way into the normally picturesque blue skies of the famed Golden Coast. Indeed, these conditions had only just begun to roll into the region after months of historic wildfires that left many parts of the State in ruins, including well-known towns such as Malibu. And while the region is renowned for having near-perfect weather all year round, these sudden and often abrupt rain events are an integral piece to the region’s climate.
Grey skies over the Santa Monica Pier. Source: Gerardo Diaz Jr.
Atmospheric Rivers, or ARs, are the transport of moisture from the tropics into higher latitudes. In the case of California, moisture tends to be transported over from the warm tropical waters of the West Pacific. As the moisture is carried over a landmass, the continental air mass will become saturated, resulting in the release of moisture in the form of precipitation. This process is so frequent and comes at such a varying degree of intensities on the West Coast that it is colloquially referred to as the Pineapple Express. Overall, ARs bring both benefits and challenges to the State, all while playing an important role in supplying and maintaining the entire region’s water sources.
Cloudy skies overlooking downtown Santa Monica on the morning of January 14th, 2019, as more and more moisture was advected onto shore. Source: Gerardo Diaz Jr.
In terms of their benefits, ARs are responsible for providing much of the annual precipitation for places like Southern California, along with the vast majority of the snow pack for higher elevations all along the entire stretch of the West Coast. The improvement of snowpack following a severe drought is critical for ski resorts all along the State. The lack of snow over much of the Sierra Range was a major cause for concern for resorts all across the State, especially in North and Central California. Thankfully, much of the region as of the time that this article was released has experienced a rejuvenation in its snow pack thanks entirely to the most recent AR. In fact, according to NWS Sacramento, many parts of the Sierra and outlying towns hare now at or even above average precipitation levels for the first time in months. As such, ARs can significantly help in alleviating drought conditions and can bring an immediate and sudden end to wildfire seasons, as has been the case over the last couple of years in California. The most recent and devastating fires across the State were essentially washed away by the introduction of moisture into the region via ARs.
The average amount of water that has fallen over parts of Central and Northern California this season. Source: National Weather Service, Sacramento.
With that all being said and done, moderate to strong ARs can have dramatic and extreme impacts to unsuspecting residents, especially if they occur immediately following a prolonged dry-spell. In fact, during this most recent rain spell alone, LA has seen over half of the rain it typically experiences in a single year, placing it in a much better situation than where the region was during the end of last year in terms of drought conditions but in a much more serious risk for flash flooding and landslides. Indeed, an immediate and large introduction of moisture to such a concentrated region just weeks after it experienced severe fire damage is a recipe for new challenges, including mudslides, and landslides, if said areas are introduced to large amounts of precipitation. This was exactly what occurred on January 17th, 2019, as reports of cars being either washed away or struck directly by mud and debris were reported all across the Pacific Coast Highway in Southern California. Simply put, the dried and burnt up mountains and hills in the region simply could not absorb the large quantities of precipitation that fell in the region during such a short amount of time. It also should be noted that Northern California is just as susceptible to extreme moisture introduction following heavy drought and fire weather conditions.
Damage along the Pacific Coast Highway due to a heavy rain-induced mudslide. Source: Courtesy Caltrans(@CaltransDist7).
It is an understatement to say that this atmospheric process is an important part of the climate system of the region. Without ARs, the state of California, and indeed the entire West Coast of the United States, would experience a much more arid climate and subsequently would struggle to maintain its current population. Nevertheless, when strong ARs bring large quantities of moisture are advected into the region in a short amount of time, the consequences can be extreme, especially in those areas that experience drought conditions immediately before the moisture advection. As such, understanding ARs is important for both meteorologists who forecast them and for those who live along the West Coast and experience their effects first-hand.
To learn more about other global climate topics, be sure to click here!
© 2018 Meteorologist Gerardo Diaz Jr.
Image credit: NBC News
Increasing ocean temperatures are one of the best indicators of how Earth’s climate is changing. This is because the oceans absorb excess heat in our planet’s system before the atmosphere does. While ocean heat storage is somewhat beneficial in the sense that it keeps heat out of the atmosphere, there are numerous consequences associated with warming oceans. Unfortunately, a recent study has shown that ocean temperature increase is accelerating – confirming predictions previously made by climate models. This accelerated warming spells danger for ocean ecosystems and for people as well.
Many species of ocean plants and animals can only live within specific temperature ranges. As ocean temperatures change, species that can move will migrate to places with more appropriate temperatures. Species that cannot move will perish. We currently see this happening in Australia’s Great Barrier Reef, which lost roughly half of its coral between 2016-2018. This loss can be attributed to elevated water temperatures in the Australian area of the Pacific Ocean.
These changes in aquatic ecosystems affect economies worldwide. First, many people around the world depend on fishing and selling their catches. Changes in fish/shellfish species in an area mean changes to how – or even whether – these people are able to make a livelihood. Other economies depend on ecotourism, which is when people visit a destination for experiences like scuba diving or snorkeling. As ecosystems that lend themselves to such activities disappear, tourism in these areas will collapse, bringing local economies with them.
Warming oceans also provide fuel for devastating hurricanes. These storms form where water is warm, and use the energy provided by warm water to grow in size and strength. Warmer ocean temperatures mean there is more energy available for hurricanes to grow. The more energy in a hurricane, the more rainfall it produces, and the higher winds it carries. Wind and rain cause the devastating impacts of hurricanes, from flooding to downed trees and power lines. It is likely that with warmer oceans, we will see more catastrophic hurricanes like Harvey, Irma, Maria, and Florence that have hit the United States in the past two years.
The best course of action in response to this information is to increase the amount of electrical power generated by renewable sources like wind and solar energy. However, technologies like fish farming and aquaculture may serve as a good adaptation to changing oceans and ensure that people who make their living by fishing can continue to earn money; and economies that rely heavily on this industry can continue to function.
©2018 Meteorologist Margaret Orr
For more about the Great Barrier Reef: https://www.forbes.com/sites/trevornace/2018/04/19/half-of-the-great-barrier-reef-coral-has-died-since-2016/#3954b37e5f9f
Barrier islands are important and dynamic geographic features that are essential to both humans and natural ecosystems. Recently, they have been struggling to remain intact. In the past, barrier islands have stayed above water by having their sands shifted towards the mainland by ocean waves, where the elevation is higher. When people build on these islands, it blocks the natural flow of sand that keeps the island alive. On top of this, climate change has increased the rate of sea level rise, making it harder for the islands to compensate with their shifting sands, putting barrier islands at even greater risk. So, the barrier islands are in trouble, but why are they so important?
The answer is simple: the utility offered by these islands is irreplaceable. Just a few benefits that barrier islands provide are sanctuaries for shellfish, fish, and birds, wetlands that filter pollutants, food, and protection against storm surge. Additionally, if humans develop on these islands, there is a financial benefit that comes from tourism and fishing. Unfortunately, as mentioned earlier, while human development on barrier islands creates financial benefits, it detracts from ecological benefits. That is why it is critical to consider the environmental impacts of building on barrier islands in order to strike a balance between financial income and environmental preservation.
With the rise in the intensity and frequency of hurricanes and tropical storms over the past decades, it has become even more important to consider the preservation of barrier islands because of their role as a buffer against storms and erosion. When a major storm strikes the mainland, it can experience storm surge, which is a rise in sea level that results from the strong winds of the storm constantly pushing ocean water towards the mainland. If an area experiences storm surge, damaging floods can cause severe damage to life and property. Barrier islands can shield against the brunt of the winds and waves from the storm and shift in response to wave energy to stay alive to protect against other storms.
Of course, barrier islands can’t protect against all the energy from storms that are approaching the mainland, so coastal cities should always have infrastructure that can withstand flooding. However, having a first line of defense against dangerous hurricanes is unfailingly useful and preserving these islands is crucial for our coastal cities in the face of a changing climate.
To learn more about other global climate topics, be sure to click here!
© 2018 Weather Forecaster Cole Bristow