Whether you live near the coast or inland, the ocean influences your climate and your weather. From storms to droughts, from summer heat to winter cold, the atmosphere and the ocean are inter-related. Taking the Pulse of the Ocean explores this inter-relationship through the eyes of ocean observing systems, an array of instruments deployed in the oceans which communicate to us the pulse of the coastal and global waters.
posted by Art at 10:07 AM
|
1 comments
posted by Art at 8:35 AM
|
1 comments
Dynamic Coastal Water and the Food Web
posted by Art at 9:57 AM
|
0 comments
Science Overview
Topic: Motion in the Coastal Ocean: Freshwater, Winds, and Tides
While the deep waters of the open ocean move under the influence of the global heat engine, the shallow waters of the estuary and continental shelf respond quickly to local and regional winds, to freshwater discharge from rivers, and to the interaction of the tide with the complex shape of the bottom topography. The circulation of the estuary depends, in particular, on the mixing of fresh and salt water, mixing from turbulent motion created by the tide and the winds. Some of the key circulations in the estuary and on the continental shelf can be simulated with simple laboratory experiments. The real estuary and shelf can be observed with instruments and sonars placed on buoys or on the ocean bottom. Coastal Ocean Observing Systems, such as the Chesapeake Bay Observing System (CBOS) are now building arrays of such sensors and relaying data and information back to users via the Internet in real time.
Discrete vs. continuous data comparison
Objective: Students will be able to explain the difference between discrete vs. continuous data.
Background
How we collect and use information is changing. Ocean scientist used to go out on ships and take data points at specific locations and extrapolate to a larger scale, both in time and space. Meteorologists would study day-old weather maps to predict storms such as hurricanes or tornados. Today, scientist have the added benefit of information that's no more than a few seconds old (e.g. real-time) and is telecast via satellite to computers and posted on the Internet.
On the Internet, real-time doesn’t always mean data available the moment they are collected. Rather, real-time data are updated on a regular basis and frequently changes. For example, weather satellite images updated every hour are still referred to as "real-time data.” At first, the distinction among real-time data, near real-time data and archived data may not be clear. However, as you continue to explore these resources, this difference will be become easier to understand.
The purpose of this activity is to help you explain to your students the difference between discrete (snapshots) and continuous and real time data.
Materials
Computers with Internet access.
Projector (optional)
Student hand-outs
Procedure
1. Access the COOL Classroom Web site at
http://www.coolclassroom.org/cool_projects/lessons/miniunits/lesson1.html
2. Take a look at the series of photographs and attempt to determine what has happened based on the information available to you.
3. Have students complete student worksheet
4. Discuss results with the class.
Worksheet: Discrete and Continuous Data
1. Write a description (frame by frame) of what you think the girl in the pictures is doing:
2. Watch the video clip and write a description of what the girl actually did:
3. Does the story you deduced from the still photographs match what happened in the video?
4. Which method gave you more information about what she was doing?(circle one)
A. Photographs
B. Video
Scientists attempt to interpret events and processes that occur in the ocean based on the data available to them. The more data that can be collected to fill in the unknown gaps, the more accurately scientists can interpret the hidden world of the ocean.
Vertical water movement field trip
Objective: Participants will investigate first hand the vertical mixing of waters in an estuary.
Background
Estuaries and oceans are natures examples of how different water densities separate. When scientists conduct vertical profiles through a water column, they can determine if there is mixing of top water and bottom water through analysis of temperature, salinity and oxygen readings through the vertical gradient. Whether or not the water column is mixed or not has strong implications for organisms living in this environment. For example, the main source of oxygen to bottom water is from mixing with surface water, which is in direct contact with the air. If there is no mixing, oxygen is depleted from the bottom water and organisms will either move or die.
The first purpose of this investigation is to determine if estuarine water is mixed or stratified through vertical measurements of temperature, salinity and oxygen. The second purpose is to compare one time field data with those data from observing systems and assess the advantages and disadvantages of the two methods of data collection.
Materials:
Boat
YSI instrument
Data sheet
Internet connection
Procedure:
Select a station in the Choptank River with a depth of at least 15 meters and record latitude and longitude. Observe weather conditions and record on data sheet.
Observing salinity and Temperature:
Lower the CTD instrument and record temperature, salinity every 2 meters.
Observing oxygen:
At the same time and location lower the YSI instrument and record temperature, salinity and oxygen every 2 meters.
Questions:
1. Was the water column mixed or stratified?
2. Explain your answer.
Vertical water movement field tripData Sheet for Vertical Mixing Field Trip
Station:___________________________
Latitude:__________________________ Longititude: _______________________
Weather: _________________________ _________________________________
Group: ___________________________ Date: ____________________________
Depth Time Temp (C) Do (mg/l) Salinity (psu)
Comparison of vertical mixing using field data vs. observing system data.
A. Now let’s investigate vertical mixing using data from the Chesapeake Bay Observing System (CBOS).
1. Back at your computer, go to the CBOS website: www.cbos.org
2. Click on the observing buoy (s) that are reporting salinity and temperature data from both the surface and the bottom of the water column.
3. Record your observations for the following”
Current surface salinity ___________________________________________
Current surface temperature ______________________________________
Current bottom salinity __________________________________________
Current bottom temperature _____________________________________
4. What other information can you obtain from the observing system?
B. Let’s compare our results from the field trip to real time data available from Observing Systems.
1. Which method of data acquisition provided a more comprehensive view of vertical mixing/stratification at the time of sampling?
2. Which method provided a better long term analysis of mixing/stratification over time?
Assessment
Which method would you use if:
1. You wanted to know if the water in the estuary was stratified at a certain depth?
2. You wanted to predict if there was going to be a turn-over event in the river?
3. You wanted to see if there might be a fish kill caused by low oxygen bottom waters.
Virtual Classroom Field Trip
Objective: Students will compare and contrast the applications of discrete vs. continuous data in relation to vertical mixing in an estuary and the ocean.
Background:
We have been using the terms "discrete" and "continuous" to describe data. Mathematics is said to be the language of scientists, so let’s take a closer look at what these terms really mean from a mathematicians viewpoint and how they relate to observing systems.
Mathematicians define discrete data as information based on counts. Only a finite number of values are possible, and the values cannot be subdivided meaningfully.
A good example of discrete data would be the number of glasses damaged in a shipment delivered to a store.
Another example: Population data. It's discrete because you are generally counting people and putting them into various categories like gender, race or age. So what about the '2.4 kids' statistic for average households? This illustrates the point that some data can not be broken down into smaller units and maintain meaning. (Resource: http://www.isixsigma.com/dictionary/Discrete_Data-226.htm)
So what is continuous data? Mathematicians say that continuous data is information that can be measured on a continuum or scale. Continuous data can have almost any numeric value and can be meaningfully subdivided into finer and finer increments, depending upon the precision of the measurement system.
Examples of continuous data are money, temperature, time, volume and size.
Simply stated…we will use the terms continuous and discrete more loosely to describe HOW we are using observing data. Discrete will refer to data consisting of unconnected distinct sampling efforts or “one time” sampling at a point in time. Continuous will refer to uninterrupted sampling over time. (resource: http://www.isixsigma.com/dictionary/Continuous_Data-96.htm)
You and your students can draw more examples of discrete vs. continuous data from the NOAA Web site: http://precip.fsl.noaa.gov/hourly_precip.html, which compares continuous and discrete weather data.
Here we will take a look at the advantages and disadvantages of both types of measurements using the vertical mixing as an example.
Materials:
Computers with Web access
Student Worksheet
Procedure:
Have the students obtain data from the following sources and then answer questions on the worksheet:
§ Water quality data from field trip
§ Ocean Observing Data from Chesapeake Bay Observing System: http://www.cbos.org/
§ Coastal Ocean, Gulf of Maine: http://www.gomoos.org/oceanconditions/
Worksheet: Virtual Field Trip
1). What “things" (characteristics or parameters) are common to all data sets?
2). Which site has the greatest “number of things” being measured? Observing sites or the field data?
3). Can you think of at least one advantage and one disadvantage of the observing sites continuous data collection?
Advantage
Disadvantage
3). Can you think of at least one advantage and one disadvantage of the discrete data collection from the field?
Advantage
Disadvantage
Let’s take it a step further…
Compare temperature, salinity and current speed for surface and bottom sensors at this moment in time at each of the observing sites below.
CBOS GOMOOSIsles of Shoals
Salinity
Temperature
Current speed
Questions to Consider…
1). Have these values changed over the past 24 hours? How?
2). Look closely at GoMOOS and CBOS data. Can you see differences? Describe those differences:
Salinity:__________________________________________________
Temperature:______________________________________________
Current speed:_____________________________________________
2). Can you think of reasons for similarities or differences?
Assessing water movement using drifters:
Horizontal movement or not?
posted by Art at 1:42 PM
|
0 comments
Aquaculture and Restoration Ecology Laboratory at Horn Point Laboratory, Cambridge, MD
ENSO Cycle: El Niño/La Niña
I. Surface Circulation of the North Atlantic: A Model
Focus Question: How does the ocean move in the North Atlantic?
Objectives:
1. Students should be able to explain the forces which produce the circulation patterns in the Gulf Stream.
2. Students should be able to predict current patterns or eddy development with variances in bathymetry.
Materials:
Heavy duty stainless steel baking tray (10 x 16)
Modeling clay
Laminated satellite images of the Gulf Stream
Laminated Bathymetric maps of the North Atlantic
Convection Fluid Bottles, Carolina Biological Supply Catalog #, Price, Qty. GEO8450,
Hair Dryer
Water, room temperature
Non permanent marking pens
Procedure:
1. In groups of 3-5, use clay to build a model of the North Atlantic. Use the bathymetric maps below and be sure to include the continental shelf, continental slope, capes, seamounts, and other seafloor features.
Maps:
Appendix 1: Bathymetry of the North Atlantic
Appendix 2: Bathymetry of the northern section of the North Atlantic
Appendix 3: Bathymetry of the south Atlantic and the Gulf of Mexico
Appendix 4: Bathymetry of the eastern North Atlantic.
2. Create the shoreline of the North Atlantic in your container using the clay. (no more than 1-2 inches thickness of clay on edges).
3. Pour in a diluted solution of Convection Fluid (or water to which you will add food coloring) to a depth which just covers the subsurface oceanic features.
4. Set up a gentle “wind” blowing from the south to start a current. Make observations on the current patterns that develop.
5. Illustrate your notes on the observations, especially the patterns affected by the shoreline or around surface features (e.g. Cape Hatters).
6. When finished, return the Convection Fluid to the container. Remove clay from container and roll into ball.
Surface Circulation of the North Atlantic Worksheet
1. Did the shelf, slope or capes affect the surface current? Describe.
2. Do you think the Gulf Stream might have a greater affect on weather of the southeast vs. the northeast of the USA? Explain.
3. What other factors besides wind might affect the Gulf Stream current?
Appendix 1. Bathymetry of the North Atlantic
Appendix 1. Data for Sea Level Rise
http://en.wikipedia.org/wiki/Sea_level_rise
www.ess.uci.edu/~famiglietti/grace/ppt/Theme_3_Nerem.ppt
posted by Art at 11:38 AM
|
0 comments
