Doing climate and environmental sciences

Reconstructing history

Keywords

What do climate and environmental sciences look at?

Studying and reconstructing landscape changes over time and space, often focusing on larger time frames.

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Scientists do this to model past environmental phenomena and patterns.

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Where can we look for information on El Niño?

Evidence of El Niño can be found in the natural world.

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Different features, or indicators, are combined as pieces of the puzzle that makes up the complex story of the El Niño phenomenon.

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We are going to look at these primary sources to see how geographers study the phenomenon.

How do we do climate and environmental sciences?

Four of the research measures used:

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1. Precipitation
2. Geographic Information Science (GIS)
3. Cores
4. Tree rings

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These demonstrate the impacts of El Niño on landscapes – both individually and when put together.

1. Precipitation

The El Niño phenomenon centres around water.

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Because of this, scientists focus on collecting measures of precipitation (rain levels) to quantify an event.

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This data helps to model previous and future El Niño events.

Rain radars

What have we learnt from Dr Rodriguez?

1. Rain radars work by emitting waves which bounce off water.

2. They are very accurate for determining time and place.

3. In Peru, they form a network of radars which collect regional data.

Why are rain radars useful?

2. Layers of evidence: sediment cores

Faculty of Geosciences Utrecht University, 2016

The coring process 

Lake cores

Cores of lake sediment can indicate ENSO events in many ways, including:

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1. The quantity and type of sediment indicates movement of sediment due to floods.

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• Biological indicators in the sediment, such as pollen and fossils, can reveal ecosystem conditions.

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Deeper lake sediments: sub-bottom profiling

Sediment layers 

In the same way, other sediment layers also indicate the movement of soil that is transported during floods, carrying natural indicators of flooding events.

3. Tree rings

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They carry environmental indicators which can be dated, including:

1. Temperature
2. Rainfall and humidity
3. Forest fires

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Each tree ring indicates the growth of a tree over a year.

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Thicker rings indicate better growth conditions in terms of water availability and temperature and, in this case, can indicate an ENSO event.

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1 year

1 year

4. Geographic Information Systems (GIS)

GIS analyses and visualises geographic data. 

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El Niño event in 2017:

Top: 09/02/2017

Bottom: 23/03/2017

(SENTINEL Hub)

Remote sensing

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One type of GIS is remote sensing, which uses waves to collect data from a distance.

To measure agriculture, we use satellite data about vegetation which tells us how green the surface is.

Step 1: Satellite images �

August 2016; 2017; 2018

Step 2: Analysis

August 2016; 2017; 2018

After an El Niño event

Altogether now

Multiple measures create a more accurate picture of the environmental conditions.

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You can do this by finding data that supports a hypothesis.

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These measures can reconstruct past landscapes, explain present ones, or help us to prepare for future ones.

Conclusions

1. There are many ways to obtain primary data for climate and environmental sciences.
2. To study El Niño, some of these include measures of precipitation; natural records such as lake cores, sediment layers, and tree rings; and remote sensing.
3. When we group the different data, we can piece together the long-term history of El Niño in a specific area.
4. This is useful to predict and prepare for future El Niño events.

Data sources: 

Rain radar: Dr Rodolfo Rodriguez (Universidad de Piura, 2021). 

Coring process and sub-bottom profiling: Andrew Henderson (Newcastle University, 2022). 

Tree rings: Dr Rodolfo Rodriguez, Isabella Zapata, Nohelia Palacios (Universidad de Piura, 2021). 

Remote sensing: Torrey Sanseverino (University of St Andrews, 2021). 

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Videos: 

Fenómeno Con Oportunidades. (FENCO),2022. Radar de Lluvias UDEP. [Video] Available at: <https://www.youtube.com/watch?v=fqROxbDRvts>

Faculty of Geosciences Utrecht University, 2016. Hunting El Niño. [Video] Available at: <https://www.youtube.com/watch?v=hDwL6tTs2Is>