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studium:themen_fuer_masterarbeiten_exp [2019/11/07 22:42]
jakub [Topics for master thesis projects in the experimental group on radiation and remote sensing]
studium:themen_fuer_masterarbeiten_exp [2023/10/05 07:46] (aktuell)
julien.savre
Zeile 10: Zeile 10:
 ===== Topics for master thesis projects in the experimental group on radiation and remote sensing ===== ===== Topics for master thesis projects in the experimental group on radiation and remote sensing =====
  
-==== Scene Tomography: Generation of synthetic images from irradiance fields ==== 
-{{ :​studium:​mysticpano.png?​nolink&​400|}} 
-The quick generation of synthetic camera images from 3D LES scenes is at the core of next generation ​ retrieval methods and online diagnostics. 
-The concept of this work is to use the irradiance field as an illumination map for the scene and use raytracing techniques to generate approximate radiance measurements (i.e. virtual camera images) 
  
-The thesis likely encompasses the tasks of  
-  * develop a raytracing prototype 
-  * work with and implement your work into ICON 
-  * investigate possible pathways to parallelize the approach on massively parallel machines 
  
-Responsible ​ //​[[Fabian.Jakub@physik.uni-muenchen.de| Fabian Jakub]], [[bernhard.mayer@lmu.de| Bernhard Mayer]]// 
-==== Ground supersites and weather models: Cloud climatology in model and reality for three locations in Germany==== 
  
-Cloudnet is a network of ground stations for the observation of clouds set up across Europe. The standard Cloudnet suite of instruments comprises a cloud radar, a ceilometer, and a microwave radiometer to provide a cloud observation supersite. Using these instruments macro- and microphysical cloud parameters like cloud vertical distribution,​ ice and liquid water and rain differentiation,​ or liquid and ice water path/​distribution are derived continuously.+==== Cloud Modelling: Entrainment in Stratocumulus ====
  
-Details of topography are a challenge for each weather modelThe weather model version closest ​to real measurements should be a model reanalysistying model physics ​to a variety of observationsFor this project ​the systematic climatological comparison ​of the Cloudnet products ​to the optimum model cloud representation in weather model reanalysis is targeted. It will be analyses ​with respect to the three different Cloudnet sites' data sets with increasing topographic contrasts: 1) Jüllich, a low level site at the south-eastern edge of the Beneleux/​Northern German lowlands - 2) Munich at 500 m height in the pre-alpine foothills - and 3) Mount Zugspitze/ UFS Schneefernerhaus at about 2600 m height. Reanalysis data on different spatial resolution will be evaluated: ECMWF ERA interim on 80 km resolution obviously will not be able to represent cloudiness in mountainous terrain. In comparison COSMO-REA6 on 6 km and COSMO-REA2 on 2 km resolution is much more likely to reproduce large parts of the real measured cloud climatology.+Stratocumulus clouds play an essential role in the global radiation budgetDue to their high albedostratocumulus reflect large amounts of incident shortwave radiation back to spaceHowever, entrainment,​ i.e., the flux of warm and dry air from the free troposphere above, tends to dissipate this cloud type, with commensurate implications for the climate system.
  
-Data and Knowhow: ECMWF ERA interim publicly availableCOSMO-REA6 and 2 available at Uni KölnCloudnet data publicly available.+The entrainment in stratocumulus is linked classically to the so-called cloud-top entrainment instability (CTEI). CTEI describes a positive feedbackwhich postulates ever-increasing entrainment rates in stratocumulus until the cloud is evaporated completely. However, this theory is primarily built upon thermodynamic arguments ​and neglects the impact of cloud microphysics,​ i.e., the number and size of droplets. Accordingly,​ in this thesis, we want to analyze the impact of cloud microphysics on CTEI, especially how CTEI changes with regard to the number concentration of cloud droplets
  
-Tasks:+This thesis requires highly detailed modeling of the involved processes and will begin with idealized parcel simulations and end with realistic large-eddy simulations. This thesis is of interest to students interested in clouds, dynamics, microphysics,​ and numerical modeling.
  
-The thesis is jointly offered by Universität Köln and LMU. Responsible //[[tobias.zinner@lmu.de| Tobias Zinner]]//+Responsible//[[fa.hoffmann@physik.uni-muenchen.de| Fabian Hoffmann]]//
  
 +==== Cloud Modelling: Stratocumulus Liquid Water Steady States ====
  
-==== Ground supersites and weather models: High resolution modeling ​in mountainous terrain====+Stratocumulus clouds play an essential role in the global radiation budget. Due to their high albedo, stratocumulus reflect large amounts of incident shortwave radiation back to space. This ability is predominantly determined by the stratocumulus liquid water path, the vertically integrated liquid water content. ​
  
-Details ​of topography are challenge for each weather modelOn standard weather model resolution of several kilometerstopographic features like the Zugspitze range and the nearby Inn valley are smoothed outAtmospheric flowand related cloud development,​ will not have to follow ​the strong vertical gradients of reality. This will lead to deviations of forecasted flow and weather phenomena. On high spatial resolution mountain ranges are represented much more realistically. In this project ​the ability of two model setups to represent weather, cloudiness and flow in mountainous terrain will be evaluatedSetup is standard numerical weather model setup at xxx km spatial resolution, setup is a specialized high resolution LES setup run nested in a weather model.+While it is accepted that the stratocumulus liquid water path is a result ​of longwave radiative cooling and entrainment warming/​drying,​ it is disputed whether this liquid water path is in steady state, i.e., is constant in timeBased on a theoretical mixed-layer approachwe were able to determine analytical solutions for the steady-state liquid water path and the entrainment velocity ​in stratocumulus ([[https://​doi.org/​10.1175/​JAS-D-19-0241.1|Hoffmann et al. 2020]]). These analytical solutions have been compared successfully to wide range of (idealized) large-eddy simulations.
  
-Cloudnet is network ​of ground stations for the observation ​of clouds ​set up across Europe. The standard Cloudnet suite of instruments comprises a cloud radara ceilometer, and a microwave radiometerUsing these instruments macro- and microphysical cloud parameters like cloud vertical distribution,​ ice and liquid water and rain differentiation,​ or liquid and ice water path/​distribution are derived continuously. For this study a comparison ​of the Cloudnet products ​to specific weather simulations at different spatial resolution is targeted. Two different Cloudnet sites' present different challenges with respect to topography. 1) Munich at 500 m height ​in the pre-alpine foothills - and 2) Mount Zugspitze/ UFS Schneefernerhaus at about 2600 m height.+In this thesis, we want to go step further and compare the solutions to reanalysis data of the ECMWF or satellite measurements,​ covering a much wider range of realistic stratocumulus ​clouds, ​including their transition to cumulus convectionThis thesis is of interest ​to students interested ​in clouds, climate, ​and dynamical systems theory.
  
-Data and KnowhowWRF and ICON-LEM modeling experience available at Uni Köln (ICON-LEM) and LMU (WRF). Cloudnet data publicly available. +Responsible: //[[fa.hoffmann@physik.uni-muenchen.de| Fabian Hoffmann]]//
- +
-Tasks: +
- +
-The thesis is jointly offered by Universität Köln and LMU. Responsible  ​//[[tobias.zinner@lmu.de| Tobias Zinner]]//+
  
 +/**
 ==== Air chemistry and aerosol modelling: Estimating and monitoring emissions of air pollutants using Lagragian modeling and inverse methods ==== ==== Air chemistry and aerosol modelling: Estimating and monitoring emissions of air pollutants using Lagragian modeling and inverse methods ====
  
Zeile 71: Zeile 59:
  
 Responsible:​ //​[[christoph.knote@lmu.de| Christoph Knote]]// Responsible:​ //​[[christoph.knote@lmu.de| Christoph Knote]]//
 +**/
  
 ==== Radiation and weather modelling: Synthetic satellite images for improved aerosol forecasts ==== ==== Radiation and weather modelling: Synthetic satellite images for improved aerosol forecasts ====
Zeile 113: Zeile 102:
  
  
 +/*
 ==== Radiation and weather modelling: Analysis of a Temporal / Spectral Integration Scheme for Radiative Transfer Calculations in Numerical Weather Prediction Models ==== ==== Radiation and weather modelling: Analysis of a Temporal / Spectral Integration Scheme for Radiative Transfer Calculations in Numerical Weather Prediction Models ====
 Due to the computational complexity of radiative transfer computations,​ atmospheric models usually try to minimize the computational effort for this important boundary condition, the only energy source in the physical system. They sub-step the radiation module, i.e. call the radiation routines only every n-th timestep. Due to the computational complexity of radiative transfer computations,​ atmospheric models usually try to minimize the computational effort for this important boundary condition, the only energy source in the physical system. They sub-step the radiation module, i.e. call the radiation routines only every n-th timestep.
Zeile 122: Zeile 112:
  
 Responsible ​ //​[[Fabian.Jakub@physik.uni-muenchen.de| Fabian Jakub]], [[bernhard.mayer@lmu.de| Bernhard Mayer]]// Responsible ​ //​[[Fabian.Jakub@physik.uni-muenchen.de| Fabian Jakub]], [[bernhard.mayer@lmu.de| Bernhard Mayer]]//
 +*/
  
 ==== Radiation and weather modelling: Hat Strahlung einen Einfluss auf konvektive Bewoelkung?​==== ==== Radiation and weather modelling: Hat Strahlung einen Einfluss auf konvektive Bewoelkung?​====
Zeile 127: Zeile 118:
 In dieser Arbeit sollen dazu Simulationen konvektiver Bewoelkung mit dem an der Uni installierten ICON-LES durchgefuehrt werden. ICON wird in Zukunft zur Basis der DWD Wettermodellierung. Dazu muessen die im Rahmen von zwei Doktorarbeiten (Klinger, Jakub) neu konzipierten Strahlungsroutinen auf das Dreiecksgitter des ICON-LES angepasst und getestet werden. Dies ist eine anspruchsvolle und sehr interessante Aufgabe, die unter anderem die Entwicklung eines statistischen Monte-Carlo-Modells auf einem Dreiecksgitter sowie einer einfachen deterministischen Loesung des thermischen Strahlungstransports umfasst. Die zugrunde liegenden Methoden sind bei uns etabliert, aber eben "​nur"​ auf einem Rechtecksgitter. Die Arbeit ist zentrales Thema des Lehrstuhls fuer Experimentelle Meteorologie und wuerde die Arbeitsgruppe massgeblich voranbringen. In dieser Arbeit sollen dazu Simulationen konvektiver Bewoelkung mit dem an der Uni installierten ICON-LES durchgefuehrt werden. ICON wird in Zukunft zur Basis der DWD Wettermodellierung. Dazu muessen die im Rahmen von zwei Doktorarbeiten (Klinger, Jakub) neu konzipierten Strahlungsroutinen auf das Dreiecksgitter des ICON-LES angepasst und getestet werden. Dies ist eine anspruchsvolle und sehr interessante Aufgabe, die unter anderem die Entwicklung eines statistischen Monte-Carlo-Modells auf einem Dreiecksgitter sowie einer einfachen deterministischen Loesung des thermischen Strahlungstransports umfasst. Die zugrunde liegenden Methoden sind bei uns etabliert, aber eben "​nur"​ auf einem Rechtecksgitter. Die Arbeit ist zentrales Thema des Lehrstuhls fuer Experimentelle Meteorologie und wuerde die Arbeitsgruppe massgeblich voranbringen.
  
-Responsible ​ //​[[bernhard.mayer@physik.uni-muenchen.de | Bernhard Mayer]], [[carolin.klinger@physik.uni-muenchen.de | Carolin Klinger]], [[fabian.jankub@physik.uni-muenchen.de | Fabian Jakub]]//+Responsible ​ //​[[bernhard.mayer@physik.uni-muenchen.de | Bernhard Mayer]], [[fabian.jankub@physik.uni-muenchen.de | Fabian Jakub]]//
  
 +/*
 ==== Radiation and weather modelling: Radiative transfer in next-generation weather models ==== ==== Radiation and weather modelling: Radiative transfer in next-generation weather models ====
  
Zeile 148: Zeile 140:
 Responsible ​ //​[[Fabian.Jakub@physik.uni-muenchen.de| Fabian Jakub]], [[bernhard.mayer@lmu.de| Bernhard Mayer]]// Responsible ​ //​[[Fabian.Jakub@physik.uni-muenchen.de| Fabian Jakub]], [[bernhard.mayer@lmu.de| Bernhard Mayer]]//
  
 +*/
  
 ==== Radiation and climate modelling: Parameterization of sub-grid cloud-radiative effects in climate models ==== ==== Radiation and climate modelling: Parameterization of sub-grid cloud-radiative effects in climate models ====
Zeile 162: Zeile 154:
  
  
-Responsible ​ //[[carolin.klinger@physik.uni-muenchen.de| Carolin Klinger]], ​[[bernhard.mayer@lmu.de| Bernhard Mayer]]//+Responsible ​ //​[[bernhard.mayer@lmu.de| Bernhard Mayer]]//
  
  
Zeile 181: Zeile 173:
  
 Responsible ​ //​[[Fabian.Jakub@physik.uni-muenchen.de| Fabian Jakub]], [[bernhard.mayer@lmu.de| Bernhard Mayer]]// Responsible ​ //​[[Fabian.Jakub@physik.uni-muenchen.de| Fabian Jakub]], [[bernhard.mayer@lmu.de| Bernhard Mayer]]//
 +
 +/**
 ==== Sunphotometers:​ Extracting Atmospheric Parameters from Spectrometer Measurements and Comparison with Established Methods ==== ==== Sunphotometers:​ Extracting Atmospheric Parameters from Spectrometer Measurements and Comparison with Established Methods ====
  
Zeile 193: Zeile 187:
  
 Responsible ​ //​[[tobias.koelling@physik.uni-muenchen.de | Tobias Kölling]], [[S.Riedel@dlr.de | Sebastian Riedel (DLR)]], [[Peter.Gege@dlr.de | Peter Gege (DLR)]]// Responsible ​ //​[[tobias.koelling@physik.uni-muenchen.de | Tobias Kölling]], [[S.Riedel@dlr.de | Sebastian Riedel (DLR)]], [[Peter.Gege@dlr.de | Peter Gege (DLR)]]//
 +**/
  
 /** /**
Zeile 217: Zeile 212:
 The work is supervised jointly by LUM [[tobias.zinner@lmu | Tobias Zinner]] and Dexa Solar (www.dexasolar.com). The work is supervised jointly by LUM [[tobias.zinner@lmu | Tobias Zinner]] and Dexa Solar (www.dexasolar.com).
 **/ **/
-==== Cloud remote sensing using polarized multi-angle observations ==== 
- 
-A new mission to measure cloud and aerosol properties is currently 
-prepared by NASA-JPL. The satellite instrument will measure polarized 
-radiances from a large number of viewing directions at several 
-wavelengths from the UV to the NIR spectral region. Data from the 
-airborne demonstrator of this instrument (AirMSPI, 
-http://​airbornescience.jpl.nasa.gov/​instruments/​airmspi) is already 
-available. ​ The aim of this thesis is develop an algorithm to retrieve 
-parameters of the cloud droplet size distribution from these 
-measurements. The algorithm shall be validated by simulating the 
-observations using the 3D radiative transfer model MYSTIC. The 
-retrieval algorithm may then be applied to the synthetic data, and the 
-retrieved results may be compared to the real input. In particular the 
-impact of 3D effects shall be investigated using this method. Part of 
-the work can be performed at NASA-JPL in Pasadena, USA, if the student 
-is interested to go abroad. ​ 
- 
-Responsible: ​  --- //​[[claudia.emde@lmu.de|Claudia Emde]] // 
  
 ==== Ground-based remote sensing: Cloud and aerosol properties from simple polarized observations ==== ==== Ground-based remote sensing: Cloud and aerosol properties from simple polarized observations ====
Zeile 246: Zeile 222:
  
  
-==== Ceilometer: Spatial and temporal variability of aerosol and cloud parameters ==== 
-Backscatter signals of ceilometers of the "​Ceilonet"​ of the German Weather Service can be provided for several stations and years. They shall be used to determine mixing layer heights (with COBOLT developed in the framework of a phd-thesis at MIM), cloud base heights and sort of a cloud cover (in contrast to the conventional cloud cover that considers the whole hemisphere every few hours, a ceilometer measures continuously in zenith direction). Determine and compare local climatologies of different cloud- and aerosol parameters at different sites, and (optionally) with independent data sets, e.g. satellite based climatologies (literature) or numerical models. 
  
-Responsible:​ //​[[m.wiegner@lmu.de|Matthias Wiegner]]// /** 2016/01/01 00:01**/ 
  
  
Zeile 287: Zeile 260:
   - Installation of more cameras and implementation of a real-time evaluation   - Installation of more cameras and implementation of a real-time evaluation
  
-Responsible: ​  //​[[mark.wenig@lmu.de|Mark Wenig]] and [[m.wiegner@lmu.de|Matthias Wiegner]]//+Responsible: ​  //​[[mark.wenig@lmu.de|Mark Wenig]]//
  
 /** /**
Zeile 375: Zeile 348:
  
 **/ **/
 +
 +/**
 +==== Ground supersites and weather models: Cloud climatology in model and reality for three locations in Germany====
 +
 +Cloudnet is a network of ground stations for the observation of clouds set up across Europe. The standard Cloudnet suite of instruments comprises a cloud radar, a ceilometer, and a microwave radiometer to provide a cloud observation supersite. Using these instruments macro- and microphysical cloud parameters like cloud vertical distribution,​ ice and liquid water and rain differentiation,​ or liquid and ice water path/​distribution are derived continuously.
 +
 +Details of topography are a challenge for each weather model. The weather model version closest to real measurements should be a model reanalysis, tying model physics to a variety of observations. For this project the systematic climatological comparison of the Cloudnet products to the optimum model cloud representation in weather model reanalysis is targeted. It will be analyses with respect to the three different Cloudnet sites' data sets with increasing topographic contrasts: 1) Jüllich, a low level site at the south-eastern edge of the Beneleux/​Northern German lowlands - 2) Munich at 500 m height in the pre-alpine foothills - and 3) Mount Zugspitze/ UFS Schneefernerhaus at about 2600 m height. Reanalysis data on different spatial resolution will be evaluated: ECMWF ERA interim on 80 km resolution obviously will not be able to represent cloudiness in mountainous terrain. In comparison COSMO-REA6 on 6 km and COSMO-REA2 on 2 km resolution is much more likely to reproduce large parts of the real measured cloud climatology.
 +
 +Data and Knowhow: ECMWF ERA interim publicly available, COSMO-REA6 and 2 available at Uni Köln. Cloudnet data publicly available.
 +
 +Tasks:
 +
 +The thesis is jointly offered by Universität Köln and LMU. Responsible //​[[tobias.zinner@lmu.de| Tobias Zinner]]//
 +
 +**/
 +
 +/**
 +==== Ceilometer: Spatial and temporal variability of aerosol and cloud parameters ====
 +Backscatter signals of ceilometers of the "​Ceilonet"​ of the German Weather Service can be provided for several stations and years. They shall be used to determine mixing layer heights (with COBOLT developed in the framework of a phd-thesis at MIM), cloud base heights and sort of a cloud cover (in contrast to the conventional cloud cover that considers the whole hemisphere every few hours, a ceilometer measures continuously in zenith direction). Determine and compare local climatologies of different cloud- and aerosol parameters at different sites, and (optionally) with independent data sets, e.g. satellite based climatologies (literature) or numerical models.
 +
 +Responsible:​ //​[[m.wiegner@lmu.de|Matthias Wiegner]]// ** 2016/01/01 00:01**
 +
 +**/
 +
 +/*
 +==== Scene Tomography: Generation of synthetic images from irradiance fields ====
 +{{ :​studium:​mysticpano.png?​nolink&​400|}}
 +The quick generation of synthetic camera images from 3D LES scenes is at the core of next generation retrieval methods and online diagnostics.
 +The proposed method could be particularly interesting for modern data assimilation techniques to incorporate ground based camera systems into the assimilation cycle.
 +The concept of this work is to use the irradiance field of high resolution weather models (e.g. two-stream or ten-stream solutions)
 +as an illumination map for the scene and use raytracing techniques to generate approximate radiance measurements (i.e. virtual camera images)
 +A preliminary study involved the development of a raytracing prototype and yields promising results given a highly resolved radiance field as input.
 +
 +The next steps to take in the thesis likely are:
 +  * benchmark and enhance the raytracing model to see if the approach can work with coarse input data such as only irradiances
 +  * work with and implement your work into ICON or COSMO
 +  * investigate possible pathways to parallelize the approach on massively parallel machines
 +
 +We hope for a candidate with a strong interest in programming and creating nice pictures.
 +
 +Responsible ​ //​[[Fabian.Jakub@physik.uni-muenchen.de| Fabian Jakub]], [[bernhard.mayer@lmu.de| Bernhard Mayer]]//
 +*/
 +
 +/**
 +
 +==== Ground supersites and weather models: High resolution modeling in mountainous terrain====
 +
 +Details of topography are a challenge for each weather model. On standard weather model resolution of several kilometers, topographic features like the Zugspitze range and the nearby Inn valley are smoothed out. Atmospheric flow, and related cloud development,​ will not have to follow the strong vertical gradients of reality. This will lead to deviations of forecasted flow and weather phenomena. On high spatial resolution mountain ranges are represented much more realistically. In this project the ability of two model setups to represent weather, cloudiness and flow in mountainous terrain will be evaluated. Setup 1 is a standard numerical weather model setup at xxx km spatial resolution, setup is a specialized high resolution LES setup run nested in a weather model.
 +
 +Cloudnet is a network of ground stations for the observation of clouds set up across Europe. The standard Cloudnet suite of instruments comprises a cloud radar, a ceilometer, and a microwave radiometer. Using these instruments macro- and microphysical cloud parameters like cloud vertical distribution,​ ice and liquid water and rain differentiation,​ or liquid and ice water path/​distribution are derived continuously. For this study a comparison of the Cloudnet products to specific weather simulations at different spatial resolution is targeted. Two different Cloudnet sites' present different challenges with respect to topography. 1) Munich at 500 m height in the pre-alpine foothills - and 2) Mount Zugspitze/ UFS Schneefernerhaus at about 2600 m height.
 +
 +Data and Knowhow: WRF and ICON-LEM modeling experience available at Uni Köln (ICON-LEM) and LMU (WRF). Cloudnet data publicly available.
 +
 +Tasks:
 +
 +The thesis is jointly offered by Universität Köln and LMU. Responsible ​ //​[[tobias.zinner@lmu.de| Tobias Zinner]]//
 +
 +**/
 +
 ---- ----