Pollen

       One of the proxies that is used for paleoclimatology is pollen.  Pollen is a good proxy to utilize because it can be found in both ice core samples as well as lake sediments or mud cores.  This is due to the fact that pollen grains can be washed away by rainfall and blown around by wind sending it to various areas.  By doing so this allows there to be a record of the vegetation that was around during a certain time.
     

        Pollen counts can be used in order to see how much of a certain vegetation species was present during the specific year that the sample is taken from in a layer.  Knowing what plants are present will give paleoclimatologists knowledge about not only what species were present, but also predicted temperatures and precipitation for an area.  Certain plants will only grow under certain conditions which is what makes this kinda of proxy work.


      Pollen can be identified in a multitude of ways.  Such ways include shape, divets or cones/spikes, and color.  One such pollen grain that is easily identifiable is pine.  Pine pollen grains are also known as 'The Mickey Mouse Pollen".  This is due to its uncanny resemblance to a Mickey Mouse head.






NOAA. "Fossil and Surface Pollen Data."National Climate Data Center. N.p., 27 Sept. 2012. Web. 7 May 2013. <www.ncdc.noaa.gov/paleo/pollen.html>.

Wiki. "Paleoclimatology - Wikipedia, the free encyclopedia." Wikipedia, the free encyclopedia. N.p., n.d. Web. 8 May 2013. <http://en.wikipedia.org/wiki/Paleoclimatology>.

A Classroom Visit

       Last week Dr. Hanselman, a biology professor at Westfield State University, talked to my class about her research in paleoecology and palynology.  Looking at proxies, such as vegetation pollen, give insight to past climates in areas around the world.  The presence of pollen in core samples indicates what vegetation is, and was, around the lakes.  Pollens can be washed into lakes through rain runoff or blown into the area by means of wind movement.
       Pollen species have certain details such as pore spaces, textures, and grooves that can be used for identification.  Pollen from pine trees is in the shape of a mickey-mouse head.  Some species, such as polylepis, is used as an indicator plant because it can only grow in specific conditions.  It is also seen to grow during the beginning and ending of interglacial times, but isn’t present at the peak of interglacials.  Nowadays pollen samples of this species are lower due to harvesting by native peoples.
       Dr. Hanselman talked about a specific sample that she did at Lake Titicaca, which is between Bolivia and Peru.  Through analysis of the core samples that were taken from the lake she was able to see that most glacial taxa are the same and that most interglacial taxa are the same.  During the glacial times there is a decrease in both pollen and charcoal found in samples while during the interglacial times there is an increase in pollen and charcoal, which indicates a warmer and dryer time.  

More information about Dr. Hanselman can be found here: http://biology.westfield.ma.edu/faculty-and-staff/jenniferhanselman

Paleoclimatology

            Paleoclimatology, in short, is the study of past climates.  According to the National Climatic Data Center (NCDC) it is, “the study of climate prior to the widespread availability of records of temperature, precipitation, and other instrumental data” (NOAA, 2008).  These studies are preformed as a means to help establish a range of prior natural variation in the climate, before there was any recorded human influence.  The last few thousand years is what the NCDC has been particularly interested in.  This is due to the fact that it is the ‘best dated’ and sampled part of the climatic records that we have (NOAA, 2008).

            A variety of ‘proxy’ records are used to estimate past climate condition.  Proxy records are preserved in things such as coral reef skeletons, glacier and ice cap ice cores, lake and ocean sediments, and tree rings (NOAA, 2008).  Other proxy data includes historical, fossil pollens, fire history, and caves (NOAA, 2013).  Historical Data includes logs from farmers and travelers, coral skeletons reveal oxygen and traces of metals, pollen fossils show what kind of plants were growing, tree rings show influence by climate conditions, sediments show different fossils, and ice cores can show different air bubbles (NOAA, 2002).  All of these can show different interpretation of past climates in an area.

Sources:

NOAA. "Paleoclimate Data." National Climate Data Center. NCDC, n.d. Web. 3 Mar. 2013. <http://www.ncdc.noaa.gov/paleoclimate-data>.

 NOAA. "What is Paleoclimatology?." National Climate Data Center. NCDC, 20 Aug. 2008. Web. 3 Mar. 2013. <www.ncdc.noaa.gov/paleo/primer.html>.

NOAA. "Paleo Proxy Data." National Climate Data Center. NCDC, 18 July 2002. Web. 3 Mar. 2013. <www.ncdc.noaa.gov/paleo/primer_proxy.html>.