Classes 14 and 15 – Plot Core Data

Core Data Analysis-2 Class assignment

Notebook/Homework 12

Due Wednesday March 20, 2024

This is a true story.  A few years ago I was working with a graduate student from Lamont/Columbia.  We were helping analyze soil for lead at a farmer’s marker in Williamsburg.  She wanted to expand her work and to look at lead in backyards in Brooklyn.  We flyered and used facebook to find people willing to let us sample their backyard.  We went into people’s backyards and collected soil cores.  We had not idea what we were going to find.  We only had data from studies published in other parts of the city.  We told the graduate student to present what they found and what they think.  For this homework you are that graduate student!  You are going to present on one of the cores from the study.    I will email everyone the core to use.

This week we are going to develop a hypothesis to test on core data.  When you come in for class we are going to sit down and read and discuss the Chillrud paper.  Read it so if you have questions we can discuss them.  The more you ask the better you will be.

Files That may be helpful

  1. All data and notebooks are in the core-data folder on GitHub.
  2. Read the Chillrud Paper (Chillrud-es9807892)
  3. Listen to the Podcast.  Here is the itunes Link.  Choose Chillrud_Lead
  4. Read the Earth Institute Blog post about Sampling in Brooklyn.
  5. notebook (pdf=plotcoredata-Brooklyn) for background
  6. The paper that Franziska Landes (pdf=Landes-1-s2.0-S0048969723040305-main-2) published and the data from the paper (excel=Landes_STOTEN or on github).
  7. Data from Table 2 in Chillrud
  8. Notebook with the simple answer (pdf=plotcoredata_Landes_answer-Brooklyn-Inventory)for adding axes

You are going to read a paper (Chillrud-es9807892) by Chillrud et al., 1999 titled Twentieth Century Atmospheric Metal fluxes into Central Park Lake, New York City.  They have some interesting conclusions.  This was all we had before we started to collect cores (there are a few other studies but this is the best for understanding processes).  As part of a new study we have collected soil samples and Cores from Northern Brooklyn.  You will analyze one core from the Landes paper.   The cores are highly contaminated.  We want to determine the source of that lead.    Your goal is to develop a hypothesis and test it.   (One plot of Pb v versus depth will not get you far and at best will get you a 50 for the assignment).  Plus you will need some writing to explain your thinking.  So use Markdown to explain the process and to create figure captions.

Remember that analyzing and thinking about data is hard and takes time.    You need to think of a strategy for analyzing the data and what you want to accomplish.  What is your hypothesis?  What are asking?  You know how to do a lot of different graphs and analyses, figure out what you want to apply.  You can make plots versus depth. You can correlate parameters.  You can do math to calculate numbers.  You can look at a lot of data in many different ways.   Use your knowledge to test your hypotheses. Remember you can iterate on your question/hypothesis as you analyze the data.  It is a two-way street.  Make some plots go back re-read.  Think some more.  Hone you hypothesis.   Look at all the graphs you have learned to make.  Think about what you can do with the data. Chillrud didn’t have course and fine grain data.  Can that help you think about sources?