› › Optimizing Dual Doppler Lidar Measurements Of Surface Layer Coherent Structures With Large Eddy Simulations

Optimizing Dual-Doppler Lidar Measurements of Surface Layer Coherent Structures with Large-Eddy Simulations

Author : Stawiarski, Christina

Publisher : KIT Scientific Publishing

Page : 262 pages

File Size : 11,41 MB

Release : 2014-07-10

Category : Science

ISBN : 373150197X

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Book Description

Coherent structures are patterns in the wind field of the atmospheric boundary layer. The deployment of two scanning Doppler lidars facilitates the measurement of the horizontal wind field, but the inherent averaging processes complicate an interpretation of the results. To assess the suitability of this technique for coherent structure detection large-eddy simulations are used as a basis for virtual measurements, and the effects of the lidar technique on the wind field structure are analyzed.



Convective precipitation simulated with ICON over heterogeneous surfaces in dependence on model and land-surface resolution

Author : Singh, Shweta

Publisher : KIT Scientific Publishing

Page : 198 pages

File Size : 35,16 MB

Release : 2021-08-16

Category : Science

ISBN : 3731510685

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Book Description

The impact of land-surface properties like vegetation, soil type, soil moisture, and the orography on the atmosphere is manifold. These features determine the evolution of the atmospheric boundary layer, convective conditions, cloud evolution and precipitation. The impact of model grid spacing and land-surface resolution on convective precipitation over heterogeneous surfaces is investigated using ICOsahedral Nonhydrostatic (ICON) simulations within the framework of the HD(CP)2 project.



Boundary-Layer Processes Producing Mesoscale Water-Vapour Variability over a Mountainous Island

Author : Adler, Bianca

Publisher : KIT Scientific Publishing

Page : 272 pages

File Size : 16,52 MB

Release : 2014-09-12

Category : Physics

ISBN : 373150247X

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Book Description

Over complex terrain, spatial inhomogeneities of pre-convective atmospheric conditions occur due to convection and mesoscale transport processes. This thesis focuses on the identification of these processes over the mountainous island of Corsica and on the evaluation of their impact on the spatial variability of water vapour, convection-related parameters and the evolution of deep convection by means of observations.



Contrails and Climate Engineering - Process Studies on Natural and Artificial High-Level Clouds and Their Impact on the Radiative Fluxes

Author : Gruber, Simon

Publisher : KIT Scientific Publishing

Page : 282 pages

File Size : 27,95 MB

Release : 2019-03-22

Category : Physics

ISBN : 3731508966

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Book Description

Two aspects of anthropogenic impacts on the atmosphere are investigated using means of numerical weather prediction. A case study is conducted to estimate the impact of such artificial clouds on the incoming solar radiation at the Earth's surface with special regard to photovoltaic power production. Furthermore, simulations are performed to assess the efficacy of injecting particles into the Arctic troposphere with the aim of modifying cirrus clouds for counteracting global warming.



Objective identification and climatology of mesoscale high-wind features within extratropical cyclones

Author : Eisenstein, Lea Andrea

Publisher : KIT Scientific Publishing

Page : 222 pages

File Size : 40,6 MB

Release : 2024-10-01

Category :

ISBN : 3731513749

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Book Description

Strong winds accompanying extratropical cyclones are commonly associated with various mesoscale features. This work introduces RAMEFI (RAndom-forest-based Mesoscale wind Feature Identification), an objective and flexible identification approach based on key surface characteristics to distinguish these features. RAMEFI is further applied to compile a climatology over Europe, offering a comprehensive analysis of feature frequency, distribution, and characteristics.







Representation of warm conveyor belts in sub-seasonal forecast models and the link to Atlantic-European weather regimes

Author : Wandel, Jan Lucas

Publisher : KIT Scientific Publishing

Page : 256 pages

File Size : 25,2 MB

Release : 2023-05-25

Category : Science

ISBN : 3731512491

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Book Description

This study systematically investigates the representation of warm conveyor belts (WCBs) in large reforecast data sets of different numerical weather prediction models and evaluates the role of WCBs for the onset and life cycle of Atlantic-European weather regimes. The results emphasize the importance of accurate forecast of WCBs for sub-seasonal prediction on time scales beyond two weeks and tie the low forecast skill of blocked weather regimes over Europe to misrepresented WCBs.



Perspectives on warm conveyor belts - sensitivities to ensemble configuration and the role for forecast error

Author : Pickl, Moritz

Publisher : KIT Scientific Publishing

Page : 250 pages

File Size : 10,64 MB

Release : 2023-03-30

Category : Science

ISBN : 373151236X

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Book Description

Warm conveyor belts (WCBs) are weather systems that substantially modulate the large-scale extratropical circulation. As they can amplify forecast errors and project them onto the Rossby wave pattern, they are of high relevance for numerical weather prediction. This work elaborates on two aspects of WCBs in the context of ensemble forecasts: (1) sensitivities of WCBs to the representation of initial condition and model uncertainties, and (2) the role of WCBs for forecast error growth.



Separating the Aerosol Effect in Case of a "Medicane"

Author : Kraut, Isabel

Publisher : KIT Scientific Publishing

Page : 196 pages

File Size : 34,48 MB

Release : 2015-08-06

Category : Physics

ISBN : 3731504057

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Book Description

This work addresses the interactions of aerosols, clouds and dynamics in case of a so-called Medicane. This type of cyclone occurs over the Mediterranean Sea, showing similarities to Hurricanes over the Atlantic and Pacific Ocean. Due to the high wind speed of the Medicane, a large amount of sea salt particles is emitted over the sea. This can influence the development of the Medicane, its associated clouds, and precipitation.