I need answers to these 6 questions about the essay below.

Question

What Do Trees Know About Rain?

Did you know that Australia is the driest inhabited continent in the world? Because it is so dry, we need to be able to predict how often and how much rain will fall. Predictions about future droughts help farmers care for their crops, cities plan their water use, and scientists better understand how ecosystems will change. The typical climate of arid northwest Australia consists of long drought periods with a few very wet years sprinkled in.
Scientists predict that climate change will cause these cycles to become more extreme – droughts will become longer and periods of rain will become wetter. When variability is the norm, how can scientists tell if the climate is changing and droughts and rain events today are more intense than what we've seen in the past?
To make rainfall predictions for the future, scientists need data on past rainfall. However, humans have only recorded rainfall in Australia for the past 100 years. Because climate changes slowly and goes through long-term cycles, scientists need very long term datasets of rainfall.
The answer to this challenge comes from trees! Using dendrochronology, the study of tree rings, scientists get a window back in time. Many tree species add a ring to their trunks every year. The width of this ring varies from year to year depending on how much water is available. If it rains a lot in a year, the tree grows relatively fast and ends up with a wide tree ring. If there isn’t much rain in a year, the tree doesn't grow much and the ring is narrow. We can compare the width of rings from recent years to the known rain data humans have collected.
Then, assuming the same forces that determine tree ring width are operating today as in the past, we can go back and interpret how much rain fell in years where we have no recorded rainfall data. This indirect information from tree rings is known as a proxy, and helps us infer data about past climates.
For this study, the scientists used cypress-pine, or Callitris columellaris. This species is able to survive in Australia’s dry climates and is long lived enough to provide data far back in time. Fortunately, scientists don't have to cut down the trees to see their rings. Instead, they use a corer – a hollow metal drill with the diameter of a straw. They drill it through the tree all the way to its core, and extract a sample of the tissue that shows all the tree rings. The scientists took 40 cores from 27 different cypress-pine trees. The oldest trees in the sample were more than 200 years old. Next, they developed a chronology where they lined up ring widths from one tree with all the other trees, wide with wide and narrow with narrow. This chronology gives them many replicate samples, and data going back all the way to the 19th century! Next, they used a dataset of rainfall from rain gauges that have been set out in Australia since 1910. They then take this precipitation data and overlay it with the tree ring widths since 1910. For tree rings before 1910, they then project back in time using this formula: Rainfall = 125.85 + (104.973 x ring width)

Scientific Questions:

1. What do tree rings tell us about the past climates of Australia?

2. What do we learn about modern droughts and rain events by comparing them to what we’ve seen in the past?

3. What is the Scientific Question being asked?

What is the hypothesis?:

4. Find the hypothesis in the Research Background. A hypothesis is a proposed explanation for an observation, which can then be tested with experimentation or other types of studies.

Experimental Data:

5. What is the independent variable of this experiment?

6. What are the dependent variables of this experiment?

Answer 1

Here are the answers to your questions based on the essay "What Do Trees Know About Rain?":

1. What do tree rings tell us about the past climates of Australia?
   Tree rings provide insights into past climates by revealing information about the amount of rainfall in specific years. The width of the tree rings varies based on the water availability; wider rings indicate wetter years with more rainfall, while narrower rings correspond to drier years with less water. By analyzing these variations, scientists can infer historical rainfall patterns and climate conditions in Australia.

2. What do we learn about modern droughts and rain events by comparing them to what we’ve seen in the past?
   Comparing modern droughts and rain events to historical data derived from tree rings allows scientists to determine whether current droughts and rainfall events are becoming more extreme. They can assess if the frequency and intensity of these phenomena have increased relative to historical norms, which helps in understanding the impact of climate change.

3. What is the Scientific Question being asked?
   The scientific question being asked is how climate change may be affecting the intensity and frequency of droughts and rainfall events in Australia, and how can we use tree rings to gain insights into past rainfall patterns to make predictions about future climate conditions.

4. What is the hypothesis?
   The hypothesis can be inferred as: If the same factors that influence tree ring width in the past are still in operation today, then scientists can accurately use the width of tree rings as a proxy to estimate historical rainfall data, allowing for better predictions of future rainfall patterns in the context of climate change.

5. What is the independent variable of this experiment?
   The independent variable is the width of the tree rings, as this measurement is manipulated in the experiment to infer past rainfall amounts.

6. What are the dependent variables of this experiment?
   The dependent variables are the historical rainfall amounts deduced from the tree ring widths, as well as the predictions of future rainfall patterns based on the analysis of the tree ring data.