Palaeotempestology series: Introduction

In a previous blog, I talked about the various ways in which historical documents, records and anecdotal evidence are used in climatology. I mentioned briefly some of environmental proxies used to derive information about the climate throughout the whole of the Earth’s history using palaeoclimatological techniques. Studying past climates is an essential part of any debate on climate change and there has been a huge amount of science produced in this field both in terms of improved methods and developing datasets.

Depth of data

Ice cores, lake sediments, tree rings records, coral analyses and more, have been conducted around the world for the last few decades to build the picture of past climates that we have today. The National Oceanic and Atmosphere Administration (NOAA) in the U.S. has an online portal and interactive map (Figure 1) that shows the geographical spread of data. I knew there was a lot of data out there but this map really puts into perspective the amount of work that has been done to gather information around the world, but also shows that there are still many gaps and much more that could be done. Check out the Climate Data Online interactive map of palaeo records here.

Figure 1: Screen shot on NOAA's Paleoclimatology interactive map at Climate Data Online. Source: NOAA (https://gis.ncdc.noaa.gov/map/viewer/#app=cdo&cfg=paleo&theme=paleo)

Depth of study

As a snapshot to show the amount of research into palaeoclimatology, a useful list of just one year’s worth of research is compiled here by the team at the 'Skeptical Science' website.

Palaeoclimatological proxies are signatures left behind in the natural environment that can tell us something about the climate in the past. They require detective work and often sophisticated laboratory analysis, but can provide windows into the past to show us data that are otherwise not available.

They are often used to derive at temperature trends over thousands of years from which drought periods can be inferred, or to develop records of past atmospheric composition (useful for revealing changes in greenhouse gas concentrations) but certain proxies can also used to investigate past storm activity.

Pre-historical storm evidence

Since I am obsessed with storms, when thinking about pre-historical records, I couldn’t help but be drawn towards Palaeotempestology (a term coined by Professor Kerry Emanuel at MIT) which is the study of pre-historic storms. In this context 'pre-history' refers to the time before the beginning of observed instrumental record of weather and climate data, which is generally no more than 100-150 years long at best, shorter still if you consider that observations and full representation of all storms that occur has only really been possible since weather has been observed using satellites.

The first satellite used to observe weather conditions was TIROS I, launched on April 1^st 1960 and initially could only tell us some basics about locations of clouds, as analysed by hand. This image below (Figure 2) shows the very first image from this satellite.

Figure 2: The first image sent back from the first satellite used to observe the weather. SOURCE: NOAA/NESDIS

Satellite technology and application has come a long way since then (I’ll likely cover this in a future blog).

Palaeotempestology aims to look back hundreds or even thousands of years, so I’ll take a bit more time on this subject. In my next few blogs, I shall aim to investigate, and share, more on the various sources of data used to drill down in to using sediments (Figure 3), 

Figure 3: Heavy duty sediment core retrieval. Source: NOAA image by Ane Jennings. (ftp://ftp.ncdc.noaa.gov/pub/data/paleo/slidesets/heinrich/heinrich08.jpg)

swim through the information on coral cores (Figure 4),

Figure 4: SCUBA scientists extracting a core from coral. Source: NOAA image by Maris Kazmers. (ftp://ftp.ncdc.noaa.gov/pub/data/paleo/slidesets/coral/coral12.jpg)

and circle around the subject of tree rings (Figure 5).

Figure 5: Scientist preparing to take a sample from a Giant Sequoia tree. Source: NOAA image by Peter Brown. (ftp://ftp.ncdc.noaa.gov/pub/data/paleo/slidesets/treering/tree01.jpg)