 |
| Titel |
Microwave scattering coefficient of snow in MEMLS and DMRT-ML revisited: the relevance of sticky hard spheres and tomography-based estimates of stickiness |
| VerfasserIn |
H. Löwe, G. Picard |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1994-0416
|
| Digitales Dokument |
URL |
| Erschienen |
In: The Cryosphere ; 9, no. 6 ; Nr. 9, no. 6 (2015-11-16), S.2101-2117 |
| Datensatznummer |
250116869
|
| Publikation (Nr.) |
 copernicus.org/tc-9-2101-2015.pdf |
|
|
|
|
|
| Zusammenfassung |
| The description of snow microstructure in microwave models is often
simplified to facilitate electromagnetic calculations. Within dense
media radiative transfer (DMRT), the microstructure is commonly
described by sticky hard spheres (SHS). An objective mapping of real
snow onto SHS is however missing which prevents measured
input parameters from being used for DMRT. In contrast, the microwave emission model
of layered snowpacks (MEMLS) employs a conceptually different
approach, based on the two-point correlation function which is
accessible by tomography. Here we show the equivalence of both
electromagnetic approaches by reformulating their microstructural
models in a common framework. Using analytical results for the
two-point correlation function of hard spheres, we show that the
scattering coefficient in both models only differs by a factor which
is close to unity, weakly dependent on ice volume fraction and
independent of other microstructural details. Additionally, our
analysis provides an objective retrieval method for the SHS
parameters (diameter and stickiness) from tomography images. For a
comprehensive data set we demonstrate the variability of stickiness
and compare the SHS diameter to the optical equivalent diameter. Our
results confirm the necessity of a large grain-size scaling when
relating both diameters in the non-sticky case, as previously
suggested by several authors. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|