Before finalizing the official classification, double check to see if any other cloud varieties, features, or accessories can be applied. Cumulus clouds only have one variety, radiatus (sometimes known as cloud streets), which doesn’t apply in this case. Cumulus clouds also have five associated supplementary features: arcus, fluctus, praecipitatio, tuba, and virga. In observing this cloud, it has none of these, so there isn’t a need to apply a feature to its classification. Cumulus clouds also have three associated accessory clouds: pannus, pileus, and velum. We’ve already decided it has a pileus accessory, but pannus and velum accessories don’t apply.
Cloud Identification Guide: Cloudspotting 101
Clouds are the equivalent of an ever-evolving painting in the sky. They have the ability to make for sunrises magnificent and sunsets spectacular. We’re surrounded by clouds almost every day of our lives. Doesn’t it seems like cloud identification should be something that comes naturally to us?
So why isn’t it? Maybe it’s because cloud names and terms are all in latin, and latin names scare us. Maybe it’s because we think we need a Ph.D in Atmospheric Sciences or Meteorology (not true!). Whatever the reason is, this site has been created to do one thing: help you easily identify and classify all different types of clouds.
The information below was created as a comprehensive guide to cloud identification and classification. Consider this page an instruction manual to the rest of the site. Let’s get started! ⛅️
TABLE OF CONTENTS
- Cloud Identification 101: An Intro to Cloud Types
- The 5 Latin Terms of Cloud Types
- Two Approaches to Identifying Cloud Types
- Cloud Identification 201: Species, Varieties, & Beyond
- Two Cloud Classification Walkthrough Examples
- How to Get Started in Cloudspotting
Cloud Identification 101: An Intro to Cloud Types
Below is an introduction and an infographic of each of the ten cloud types, or cloud generas. Each cloud name is comprised of one or two latin terms and are generally found organized by their level, or altitude.
The Three High Level Clouds
Cirrus (Ci) – High-altitude, thin, and wispy cloud streaks made of ice crystals
Cirrocumulus (Cc) – Small, flakey, and white high-altitude cumulus patches
Cirrostratus (Cs) – Thin, transparent, high-altitude layer capable of producing a halo
The Three Middle Level Clouds
Altocumulus (Ac) – Middle-altitude cumulus clouds arranged in groups or rolls
Altostratus (As) – Featureless, gray layer cloud capable of masking the sun
Nimbostratus (Ns) – Dark and featureless layer cloud responsible for rain and snow
The Four Low Level Clouds
Cumulonimbus (Cb) – Dark-based storm cloud capable of impressive vertical growth
Cumulus (Cu) – Low-altitude, fluffy heaps of clouds with cotton-like appearance
Stratus (St) – Gray, featureless low-altitude cloud capable of ground contact
Stratocumulus (Sc) – Thicker, dark gray, and somewhat conjoined heaps of clouds
In the next section, we’ll discuss the origins of these cloud types, their latin names and how they got their names, and how it pertains to the craft of cloud identification.
The 5 Latin Terms of Cloud Types
The ten different types of clouds are comprised of only five latin terms: cirro-, cumulo-, strato-, nimbo-, and alto-. These five terms are the building blocks of cloud types. The better you understand these terms and how to apply them, the easier cloud identification becomes.
Cirro- is translated from latin meaning ‘curl’.
There are three clouds that include the term ‘cirro’: cirrus, cirrocumulus, and cirrostratus. While this term is translated as ‘curl’, that doesn’t mean these three clouds are curly (though cirrus clouds can be, which makes it an appropriate name). The more important takeaway from this term is that the three clouds that include the term ‘cirro’ are found in the highest layer of the troposphere, which is the lowest layer of the Earth’s atmosphere found closest to the ground. That means these clouds can be found between approximately 16,000 and 50,000 feet, or 5 and 15 kilometers.
Cumulo- is translated from latin meaning ‘heap’.
There are five clouds that include the term ‘cumulo’: cumulus, stratocumulus, cumulonimbus, altocumulus, and cirrocumulus. Heap can also be described as piled or puffy. That means these five clouds have at least some puffy and heap-like characteristics to them.
Strato- is translated from latin meaning ‘layer’.
There are five clouds that include the term ‘strato’: stratus, stratocumulus, nimbostratus, altostratus, and cirrostratus. A layer cloud can be described as a cloud blanket that has much less definition relative to a heap cloud. The five clouds that listed here are generally featureless clouds relative to other clouds.
Nimbo- is translated from latin meaning ‘rain’.
There are only two clouds that include the term ‘nimbo’: cumulonimbus and nimbostratus. They are the only clouds that are regular rain producers.
Alto- is translated from latin meaning ‘high’.
There are only two clouds with the term ‘alto’: altocumulus and altostratus. The translation can be a bit deceiving because these clouds aren’t the clouds found in the highest part of the troposphere. Altocumulus simply means they’re still cumulus clouds, but they’re found higher than regular cumulus clouds. Similarly, altostratus means they’re still stratus clouds but found higher than stratus clouds. These clouds can be found between approximately 7,000 and 23,000 feet, or 2 and 7 kilometers.
Clouds and How They Form
At some point in your life, you have likely looked up at the sky and saw clouds that resembled an animal, object, or even a letter. Maybe you have seen a clear sky in the morning, and by the afternoon, the sky was filled with clouds. There are many unique types of clouds, but they are all formed out of the same materials. The main ingredients needed to make a cloud are water and dust, but you can also find pollen and salt particles in clouds.
The first step in cloud formation is accumulation of water vapor and dust particles in the atmosphere. The next step is the mass of particles and vapor cool down in temperature enough for ice crystals, or cloud droplets, to form. The temperature cools through the rising of the air. Now you have clouds! Sometimes the ice crystals separate in the clouds into positive and negative charges when there is turbulent wind. The negative charges become attracted to the positive charges that are naturally in the ground, and this causes lightning to form.
There are many different types of clouds, and many common types are shown in the photo below. Luke Howard, a chemist and meteorologist defined four main types of clouds, and all subtypes fall under these categories:
- Cumulus–these clouds are heaped or look like they are in a pile
- Stratus–these clouds form in sheets or layers
- Cirrus–these clouds are curly or thread-like
- Nimbus–these clouds are dark, gray, and produce rain
Specific types of clouds are found at different altitudes in the atmosphere. Low clouds are found at around 7,000 feet, medium clouds are found between 7,000 feet and 17,000 feet, and high clouds are found between 17,000 and 35,000 feet. The photo below shows the different locations of low, middle, and high clouds.
There are also some special clouds that are not part of the other groupings, such as contrails and orographic clouds. Contrails are formed from the water vapor released from jet plane engines. Orographic clouds are formed by the movement of air over mountains or sea breezes. They can also be formed when two masses of air flow meet at one point in the sky.
Next time you are outside, take a minute to look up at the sky and see what cloud types you can identify and where in the atmosphere they might be located!
Rules for EPC modeling
The beginning and the end of every event-driven process chain is always illustrated by an EPC event. An event is defined by the conditions that must be met to start and end the process. Multiple functions can follow each event or multiple events can follow each function, but there must be rules in between. In an EPC, such rules are called ‘OR’, ‘AND’, or ‘XOR’ and are represented as graphical connectors. The following table shows how you can use the various elements of an event-driven process chain:
Figure 2: Connection rules for Event-driven process chain
Event-driven process chains are often used at the lowest level of the process hierarchy. ARIS Basic not only offers the possibility of representing business processes by means of the event-driven process chain, but also provides the BPMN diagram for illustrating technical workflows and flow charts.
History of Event-driven process chains (EPC)
The EPC notation offers many ways for modeling processes, analyzing them, and identifying improvement potentials. Event-driven process chains are used in many industries and are supported by different tools. For example, the ERP provider SAP uses EPC diagrams to document processes of their SAP R/3 solution. EPCs were invented back in 1992 by Prof. Scheer and colleagues at the University of Saarland. Since then, they have seen an industry wide adoption.
The following example shows an EPC model. You can use the video tutorials provided to find an easy way into the world of ARIS.
Figure 3: How to model eEPC using EPC and ARIS
Let’s start modeling EPCs!
From here you can start to learn modeling an event-driven process chain (EPC) with ARIS Basic. The required steps are: Get your free ARIS, check some video tutorials, start modeling, share your models and discuss them with other users, and if you haven’t joined the ARIS Community yet do it now 😉
To get your free cheat sheet copy click on the picture to enlarge it and download the pdf document.
