# Presentation: 580680

## Precipitation Protocols

## Goals for the Training Session

- Provide an inquiry context for the data collection and science content
- Provide accurate science content
- Review procedures for data collection
- Review data entry and analysis
- Discuss classroom implementation ideas
- Collect feedback from participants

- Photo taken by Carlye Calvin
- © University Corporation for Atmospheric Research

**Notes:**
These are the goals for the Precipitation Protocols training session.
Photo shows rain drops in Boulder, Colorado.  Photo taken by Carlye Calvin at the University Corporation for Atmospheric Research.

## Inquiry Context

- What is the seasonal variation in precipitation in different parts of the world?
- Does precipitation pH vary from storm to storm? Why?
- How do the amount and timing of precipitation relate to budburst and other phenology measurements?

- © National Center for Atmospheric Research

**Notes:**
Further Investigation Questions:
-When and how fast does the snow melt and make its water available to the environment?
-What is the pH of precipitation and how does it vary?
-Does precipitation pH vary from storm to storm? Why?
-How do the amount and timing of precipitation relate to budburst and other phenology measurements?

Photo shows a thunderstorm shaft below a cumulonimbus cloud (Boulder, Colorado).  Copyright National Center for Atmospheric Research.

## Local Inquiry Example

**Notes:**
Students can generate local inquiry questions to create a context for data collection to answer the question. Local inquiry topics can be connected or scaled to provide a local to global perspective on environmental research.
Please generate a local example that teachers and students can relate to.
Examples:
-Is this year particularly wet or dry for your location?
-What would happen if you got only half the normal amount of precipitation in a given year? How would the effects vary depending on when within the year there was less precipitation?
-When does your area get precipitation and why? (Time of day? Time of year?)
-Is the amount of precipitation you get at your school the same or different from the amount measured at the five nearest GLOBE schools? What causes these differences or similarities?
-Where do snow storms and rain storms come from before reaching your area?
-How do the amount and timing of precipitation in your area relate to land cover?
-How does the pH of precipitation relate to soil pH and the pH of nearby water bodies?
-If you have access to weather radar, what does rain look like on radar? (on television or the Web)

## Provide a denser network of observations than is available using only official weather stations
Provide finer resolution data crucial for investigating localized variations
Augment data needed for regional forecasts and climate records

- Provide finer resolution data crucial for investigating localized variations
- Augment data needed for regional forecasts and climate records

- © National Center for Atmospheric Research

**Why do GLOBE scientists research precipitation?**

**Notes:**
Student-collected measurements in the Precipitation Protocols are helpful to scientists in the following ways.
To provide a denser network of observations than is available using only official weather stations
To provide finer resolution data crucial for investigating localized variations (e.g., to answer questions like, is rainfall greater downwind from cities?)
To augment data needed for regional forecasts and climate records in areas of the world where there are few official weather stations

Photo shows a ground blizzard. Copyright National Center for Atmospheric Research

## Science Content: The Hydrologic Cycle

**Notes:**
Water continually circulates between Earth’s surface and atmosphere in what is called the hydrologic cycle. The hydrologic, or water, cycle is one of the basic processes in nature. Responding to heat from the sun and other influences, water from oceans, rivers, lakes, soils and vegetation evaporates into the air and becomes water vapor. Water vapor rises into the atmosphere, cools, and turns into liquid water or ice to become clouds. When water droplets or ice crystals get large enough, they fall back to the surface as rain or snow. Once on the ground water filters into the soil and is either absorbed by plants or percolates downward to groundwater reservoirs. If water does not filter into the soil, it runs off into streams and rivers and eventually into oceans, while some of it evaporates.

Water participates in many important chemical reactions and is a good solvent. Completely pure water rarely occurs in nature because it carries impurities as it travels through the hydrologic cycle. Rain and snow capture aerosols from the air. Acidic water slowly dissolves rocks, placing dissolved solids in water.

This diagram is found in the Hydrology Investigation of the Teacher’s Guide.

## Science Content: Rainfall Depth

**Notes:**
It is assumed that the same depth of rain that falls into the rain gauge fell over the area surrounding the gauge.

We are measuring rain DEPTH and not the volume of water that has fallen.  Thus, our unit of measurement is mm.

## Instruments: The Rain Gauge

- The units are mm, but it looks like cm. Why?

- The cross-sectional of measuring tube is 1/10 the cross-sectional area of the outer tube.

- So, 10 mm of rain falling into the outer tube _looks_ like it fills the measuring tube 10 cm high.

**Measurement is 10 mm!**

**Notes:**
This is a common question asked about the units on the rain gauge.

**The reason why this rain gauge is used: The funnel limits the amount of evaporation that occurs before the measurement is taken and the inner tube makes it easier to see the small/fine measurements.

Since the area of the top of the funnel (and the area of the top of the rain gauge) is ten times as big as the area of the top of the tube, ten times as much rain can fall into the funnel. Thus, the water in the tube is ten times as deep as it would be if it fell in the gauge without the funnel and tube in it.  

Why not demonstrate this by pouring the water out of the tube and into the larger gage and measuring its depth?

## The Measurements

- Liquid:
- Amount of rain
- pH of rain
- Solid:
- Amount of new snow
- Total depth of snow pack
- pH of new snow and snow pack
- Water equivalent of new snow and snow pack

- © National Center for Atmospheric Research

- © National Center for Atmospheric Research

**Notes:**
Precipitation refers to all forms of liquid or solid water that fall from the atmosphere and reach Earth’s surface.  
Liquid precipitation includes rainfall and drizzle.
Solid precipitation includes snow, ice pellets and hail.

Top right photo shows rain falling below a cumulonimbus cloud (Denver, Colorado).  Copyright National Center for Atmospheric Research.
Bottom right photo shows a tulip in spring show. Copyright National Center for Atmospheric Research.

## Collecting Data: Field/Lab Guides & Data Sheets

**Field/Lab Guides:**
**Liquid:**
- Rainfall Protocol Field Guide
**Solid:**
- Solid Precipitation Protocol Field Guide
- Solid Precipitation Protocol Lab Guide
- And _**one**_ of the following:
- Precipitation pH Using pH Paper and Large Salt Crystals Lab Guide
- Precipitation pH Using pH Paper and “Table” Salt Lab Guide
- Precipitation pH Using pH Meter and Large Salt Crystals Lab Guide
- Precipitation pH Using pH Meter and “Table” Salt Lab Guide
**Data Sheets: **
- And _**one**_ of the following:
- Integrated 1-Day Data Sheet
- Integrated 7-Day Data Sheet

**Notes:**
Field/Lab  Guides: All Field Guides are located in the Atmosphere section of the Teacher’s Guide.  The respective chapter and pages numbers are included below:
Liquid:
Rainfall Protocol Field Guide (Precipitation Protocol - 8)
Solid:
Solid Precipitation Protocol Field Guide (Precipitation Protocol – 9,10)
Solid Precipitation Protocol Lab Guide (Precipitation Protocol - 11)
And one of the following:
Precipitation pH Using pH Paper and Large Salt Crystals Lab Guide (Precipitation Protocol - 12)
Precipitation pH Using pH Paper and “Table” Salt Lab Guide (Precipitation Protocol - 13)
Precipitation pH Using pH Meter and Large Salt Crystals Lab Guide (Precipitation Protocol - 14)
Precipitation pH Using pH Meter and “Table” Salt Lab Guide (Precipitation Protocol - 15)
Data sheets: The data sheets are located in the Appendix of the Atmosphere section of the print Teacher’s Guide or they can be downloaded from the Teacher’s Guide link on the GLOBE Web site at any time.
-Integrated 1-Day Data Sheet (Appendix – 7,8)
-Integrated 7-Day Data Sheet (Appendix – 9,10,11)

## Collecting Data: ProtocolMeasuring Rainfall Amount

- Collecting Data: ProtocolMeasuring Rainfall Amount

- Read bottom of the meniscus
- Estimate to the nearest  0.1 mm
- 0 = None, T= Trace, M=Missing

**Notes:**
1) When reading the rain gauge:
	Be sure your eyes are level with the rain gauge
	Read the level at the bottom of the meniscus
2) Remember to report
	estimate to the nearest 0.1 mm
	no rainfall = 0.0 mm
	less than 0.5mm = T (Trace amount)
	if you spill any water before measuring = M (Missing) (If you have only spilled a little, record the amount not spilled as metadata.)	
3) Pour water into sampling jar and cover it for the pH measurement.
4) If there is rain in the overflow tube, follow steps in Field Guide.
5) Record number of days rain has accumulated in the gauge.
6) Dry the rain gauge and remount it on its post.

Photo shows a GLOBE Trainer reading a rain gauge in Fort Collins, Colorado (May 2004).

## Collecting Data: ProtocolSolid Precipitation 

- Total snowfall depth
- Use measuring stick in three different locations
- Total new snow depth
- Use measuring stick in three different locations on snow board

- Snowpack pH
- Snowpack rain equivalent
- New snow pH
- New snow rain equivalent

- Take four snow samples for:

**Notes:**
Total snowfall:
-Insert measuring stick vertically into snow until it rests on the ground.
-Read and record the depth.
-Repeat this measurement in at least two other locations.
-Record all three measurements as total snowfall.

Depth of new snow:
-If there is new snow, insert a measuring stick vertically until it rests on the snow board.
-Read and record the depth.
-Repeat this measurement in at least two more places on the snow board.
-Report all three measurements as depth of new snow.
-Clear off board 
Remember T = Trace, M=Missing (if snow board has been disturbed.)
Record number of days since last reading of snow on snow board.

Photo shows a student in Hungary taking snow depth.

## Collecting Data: ProtocolSolid Precipitation Samples

- Collect snow in a clean container
- Avoid picking up soil or leaves
- Avoid snow that has been in contact with the snow board or the ground
- Cover sample and allow snow to melt indoors
- Collect at least 30 mL of melted snow

**Notes:**
For each sample:
Using straight-sided container (such as overflow tube from rain gauge), and holding it straight up and down over the snow (either the snow board or the snowpack), push the container until it almost touches the ground or snow board.
Slide something flat and clean under the container just above the ground and turn the container right side up.
Save this sample in a clean container and mark appropriately.

## Collecting Data: ProtocolMeasuring Precipitation pH

- At the same time as the measuring rainfall amount or snow depth
- At least 2 mm of rainfall or 30 mL of melted snow must be collected
- Use pH paper or pH meter
- Always add salt
- Follow directions in appropriate Precipitation pH Lab Guide

**Notes:**
You can measure precipitation (liquid and melted solid) pH using pH paper or a pH meter.

Special considerations must be made because most precipitation has low conductivity and both pH paper and pH meters do not perform well for low conductivity samples. Adding salt crystals to the rain or melted snow will increase the conductivity to an appropriate level. You can use either large salt crystals (0.5 mm to 2.0 mm in diameter) or finely ground “table” salt (with crystals less than 0.5 mm in diameter).   Follow the guidelines in the appropriate Lab Guide to determine the correct amount of salt to use (Precipitation Protocols-12-15).

Specific instructions are written in the Precipitation pH Lab guides (depending on which type of pH measuring device and salt you are using).  Safety glasses and rubber gloves should be worn for safety.

**At this point give the participants the field guides and data collection sheets, go outside, and let them practice the measurements. 

## Enter Data on the GLOBE Web Site

- Step 1: Confirm that the atmospheric 	  	    study site definition is completed
- Step 2: Select “Integrated 1-Day or 7-Day” 	    from the atmosphere data entry menu
- Step 3: Enter date/UT time/select site
- Step 4: Enter rainfall, snowfall & pH data
- Step 5: Confirm data entries on verification 	    page

**Notes:**
**At this point, direct the participants to the GLOBE training data entry site and have them enter the data from their data collection sheets. Note: You will need to have a site definition already established or complete the Instrument Construction, Site Selection, and Set-Up training and define an atmosphere study site prior to entering the Precipitation data.
STEP 1: Be sure that you have completed an atmospheric study site definition.
STEP 2: Select one of the two data entry pages from the choices listed in the menu to enter precipitation data.
STEP 3: A valid date and UT time must match the site selected in order to enter the data.
STEP 4: Enter the data collected from the data sheet.
STEP 5: Confirm that the data entries are correct on the verification page.
You may click the enter more data button or return to the data entry home page or the main GLOBE home page when finished.

Email data entry is also available.  Directions can be found on the GLOBE Web site under Data Entry.

## Looking at the Data

**Notes:**
This graph is comparing the student-collected data from two GLOBE schools. One in Croatia and another in New Zealand. 
A teacher might ask students, “How does precipitation compare in Croatia and New Zealand?”
Comparison of this data should also include variables such as ocean influence, elevation, or land forms that may affect the local climate.
Students may compare their precipitation data with other locations to look at climate patterns over time, describe seasonal changes at a location, or project about how fresh water use might be affected by the differences in precipitation. Students may also speculate why the data collection from Croatia appears to end in late 2004.

Refer to the “Looking at Data” section of this protocol in the Teacher’s Guide for a data analysis activity.

## Classroom Implementation

- Inquiry
- Curriculum/Standards Alignment
- Assessment
- Classroom Management

**Notes:**
Have participants break into groups and discuss one or more of the above bullet items, as time allows.

Classroom Management Tips:
-- Measure rain inside for practice.
-- Pour the water out of the tube and measure the depth in the rain gauge to make the point that the numbers 
     on the inner tube of the gauge are in mm rather than cm.
-- Students can take turns doing measurements.
-- On a rainy day, compare your rainfall total to the amount reported in the newspaper, television, or Web.

## Getting Started

- The GLOBE Web site has information
- _[http://www.globe.gov](http://www.globe.gov/)_
- GLOBE Help Desk or your Country Coordinator can support you as you get started.
- Get your students involved doing real science!