Knut Stamnes

Prof. Knut Stamnes


Research Focus & Metrics

Academic Career Length

28Years (1999-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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13 August 1999
Verified
Book
Closed access
GTGary E. Thomas
Gary E. Thomas
KSKnut Stamnes
Knut Stamnes
This text provides a foundation in both the theoretical and practical aspects of radiative transfer, for advanced students of atmospheric, oceanic and environmental sciences. The transfer of solar and infrared radiation through optically-thick clouds, aerosol layer, and the oceanic mixed layer is presented through the use of heuristic models of scattering and absorption, and a systematic approach to formulation and solution of the radiative transfer equation. Problems such as the transmission of ultraviolet radiation through the atmosphere and ocean, remote sensing, solar heating and infrared cooling processes, UV biological dose rates, and greenhouse warming are solved using a variety of methods. This self-contained, systematic treatment will prepare students from a range of disciplines in problems concerning the effects of solar and infrared radiation on natural systems. The hardback edition received excellent reviews.

1 March 2010 in Journal of Quantitative Spectroscopy and Radiative Transfer
Verified
Journal Article
Closed access
ESEndre R. Sommersten
Endre R. Sommersten
JLJon K. Lotsberg
Jon K. Lotsberg
KSKnut Stamnes
Knut Stamnes
JSJakob J. Stamnes
Jakob J. Stamnes

21 February 2015 in Journal of Quantitative Spectroscopy and Radiative Transfer
Verified
Journal Article
Closed access
ZLZhenyi Lin
Zhenyi Lin
SSS. Stamnes
S. Stamnes
ZJZ. Jin
Z. Jin
ILI. Laszlo
I. Laszlo
STS.-C. Tsay
S.-C. Tsay
KSKnut Stamnes
Knut Stamnes

19 December 2018 in Applied Sciences
Verified
Journal Article
Open access
PDF file
KSKnut Stamnes
Knut Stamnes
BHBørge Hamre
Børge Hamre
SSSnorre Stamnes
Snorre Stamnes
NCNan Chen
Nan Chen
YFYongzhen Fan
Yongzhen Fan
JSJakob Stamnes
Jakob Stamnes
A tutorial review is provided of forward and inverse radiative transfer in coupled atmosphere-snow/ice-water systems. The coupled system is assumed to consist of two adjacent horizontal slabs separated by an interface across which the refractive index changes abruptly from its value in air to that in ice/water. A comprehensive review is provided of the inherent optical properties of air and water (including snow and ice). The radiative transfer equation for unpolarized as well as polarized radiation is described and solutions are outlined. Several examples of how to formulate and solve inverse problems encountered in environmental optics involving coupled atmosphere-water systems are discussed in some detail to illustrate how the solutions to the radiative transfer equation can be used as a forward model to solve practical inverse problems.

8 August 2020 in Journal of Geophysical Research: Atmospheres
Verified
Journal Article
Open access
PDF file
TTTomonori Tanikawa
Tomonori Tanikawa
KKK. Kuchiki
K. Kuchiki
TAT. Aoki
T. Aoki
HIH. Ishimoto
H. Ishimoto
AHAkihiro Hachikubo
Akihiro Hachikubo
KSKnut Stamnes
Knut Stamnes
We proposed new snow grain model and snow impurity mixture models for the purpose of accurate retrievals of snow grain size and concentration of light‐absorbing particles (LAP) in snow from the optical remote sensing data. Two kinds of ice crystal models, irregularly shaped Voronoi columns, and Voronoi aggregates were employed. LAP can be captured by the snow through two processes: dry and wet deposition. Two different snow impurity mixture models were proposed. One is an external mixture model. We employed a coated sphere model in which soot were hydrophilic particles to represent a hygroscopic property of aerosol and assumed the hydrophilic soot particles to be externally mixed with snow particles. The other is an internal mixture model. We employed a dynamic effective medium approximation method in which soot particles were randomly located within snow particle with any size distribution and number concentration. Validation of these models is conducted using a ground‐based spectral radiometer system with in situ measurement data. For snow grain size retrievals, a Voronoi mixture model seamlessly representing a geometrical shape and an optical properties of various snow types can provide accurate retrievals. For the retrieval of LAP concentration in snow, employing different mixing state models depending on season and measurement site gives accurate results. We also discussed the uncertainty of retrieved snow parameters on the surface slope involved in the retrieval accuracy. These models are expected to be useful for advanced airborne/satellite remote sensing and climate studies via radiative transfer modeling in the atmosphere‐snow system.

8 March 2007 in Journal of Geophysical Research: Atmospheres
Verified
Journal Article
Closed access
PDF file
ASA. Sandvik
A. Sandvik
MBM. Biryulina
M. Biryulina
NKN. G. Kvamstø
N. G. Kvamstø
JSJ. J. Stamnes
J. J. Stamnes
KSKnut Stamnes
Knut Stamnes