 |
| Titel |
Technical Note: Weight approximation of coccoliths using a circular polarizer and interference colour derived retardation estimates – (The CPR Method) |
| VerfasserIn |
J. Bollmann |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1726-4170
|
| Digitales Dokument |
URL |
| Erschienen |
In: Biogeosciences ; 11, no. 7 ; Nr. 11, no. 7 (2014-04-08), S.1899-1910 |
| Datensatznummer |
250117348
|
| Publikation (Nr.) |
 copernicus.org/bg-11-1899-2014.pdf |
|
|
|
|
|
| Zusammenfassung |
| A circular polarizer is used for the first time to image coccoliths without
the extinction pattern of crossed polarized light at maximum interference
colour. The combination of a circular polarizer with retardation
measurements based on grey values derived from theoretical calculations
allows for the first time accurate calculations of the weight of single
coccoliths thinner than 1.37 μm. The weight estimates of 364 Holocene
coccoliths using this new method are in good agreement with published
volumetric estimates. A robust calibration method based on the measurement
of a calibration target of known retardation enables the comparison of data
between different imaging systems. Therefore, the new method overcomes the
shortcomings of the error prone empirical calibration procedure of a
previously reported method based on birefringence of calcite. Furthermore,
it greatly simplifies the identification of coccolithophore species on the
light microscope as well as the calculation of the area and thus weight of a
coccolith. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|