science

SNOTEL

SNOTEL is a science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand SNOTEL rather than just read about it. In short: SNOTEL is an automated system of snowpack and related climate sensors operated by the Natural Resources Conservation Service (NRCS) of the United States Department of Agriculture in the Western United States. There are over 900 SNOTEL (or snow telemetry) sites in 11 states, including Alaska.

Key takeaways

SNOTEL belongs to science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect SNOTEL to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of SNOTEL from memory before moving on to harder problems.

Reference excerpt

SNOTEL is an automated system of snowpack and related climate sensors operated by the Natural Resources Conservation Service (NRCS) of the United States Department of Agriculture in the Western United States. There are over 900 SNOTEL (or snow telemetry) sites in 11 states, including Alaska. The sites are generally located in remote high-mountain watersheds where access is often difficult or restricted. Access for maintenance by the NRCS includes various modes from hiking and skiing to helicopters. All SNOTEL sites measure snow water content, accumulated precipitation, and air temperature. Some sites also measure snow depth, soil moisture and temperature, wind speed, solar radiation, humidity, and atmospheric pressure. These data are used to forecast yearly water supplies, predict floods, and for general climate research.

History Installation of SNOTEL began in the mid-1960s. Its use in climate forecasting was not originally envisioned, but it has become the standard climate data for western U.S. locations which are elevated sufficiently to have at least a seasonal snowpack. Ongoing algorithm upgrades correct and backfill missing data, while improvements in communications improve the overall quality of data collection.

Meteor burst technology (phased out)

SNOTEL used to use meteor burst communications technology to collect and communicate data in near-real-time. VHF radio signals are reflected at a steep angle off the ever-present band of ionized meteors existing from about 50 to 75 miles (80 to 120 km) above the earth. Sites are designed to operate unattended and without maintenance for a year. They are battery powered with solar cell recharge. The condition of each site is monitored daily when it reports on 8 operational functions. Serious problems or deteriorating performance trigger a response from the NRCS electronics technicians located in six data collection offices. A central computer at the NRCS's National Water and Climate Center (NWCC) in Portland, Oregon controls system operations and receives the data collected by the SNOTEL network. Meteor burst has been phased out of all SNOTEL sites. Today, SNOTEL sites use GOES, iridium, and cell networks to telemeter data.

System capabilities

Basic SNOTEL sites have a pressure sensing snow pillow, storage precipitation gauge, and air temperature sensor. However, they can accommodate 64 channels of data and will accept analog and parallel or serial digital sensors. On-site microprocessors provide functions such as computing daily maximum, minimum, and average temperature information. Generally, sensor data are recorded every 15 minutes and reported out in a daily poll of all sites. Special polls are conducted more frequently in response to specific needs. The new generation of remote sites, master stations, and central computer facilities allows for hourly interrogation of remote sites. The system has the ability to vary the configuration of a remote site by transmitting the appropriate commands telling the remote site what sensors to turn on or what parameters to send. A variety of calculations can be made on any sensor channel. For example, the user can select maximum, minimum, average, standard deviation, or circular averaging. Each sensor can be accessed independently at a specific interval. For example, wind speed may be sensed every minute during the day to arrive at an average, while the snow pillow may be accessed every 15 minutes for the accumulated total. System performance has increased over the years, mainly due to a better understanding of meteor burst communication characteristics and improved equipment. While a 95 percent response to a system-wide poll is the standard, over 99 percent is common.

Data storage, management and accessibility All data are received by the SNOTEL central computer, which in turn is linked to the Centralized Forecasting System (CFS) in the NWCC where data can be accessed. Once on the CFS the data is kept in a relational database, where various analysis and graphics programs are available. Current and historical data and analyses are available by dialing into the CFS, by disk or tape media, paper copy, and on the Internet.

References

External links

Official SNOTEL site Meteor Communications Corporation What You Don’t Know About Snow: The USDA’s SNOTEL Network is Playing a Critical Role in Protecting Water Resources in the Western United States

Illustrations

Worked examples

Example 1 — a first encounter with SNOTEL

Start with the simplest possible case. Write down what SNOTEL claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to SNOTEL before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about SNOTEL ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of SNOTEL

In research: SNOTEL appears in science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses SNOTEL in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: SNOTEL is common in secondary-school and first-year university syllabi. It links to neighbouring topics Meteorological stations, Snow, United States Department of Agriculture, so understanding it makes those chapters shorter.
In everyday life: Look for SNOTEL outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study SNOTEL in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what SNOTEL means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain SNOTEL out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is SNOTEL in simple terms?

Why does SNOTEL matter?

Because it connects several science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study SNOTEL?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on SNOTEL.