IGF



Geophysical laboratory I / II (Academic year 2020/2021)

dr hab. Iwona S. Stachlewska

Rok akademicki: 2020/2021
Semestr: zimowy/letni

OPIS PRZEDMIOTU

Geophysical Laboratory  I (summer semester) / II (winter semester)

Rules for Academic year 2020/2021 (both semesters)

Field of study: Geophysics (Physics, II degree)

Organizational unit: Institute of Geophysics, Faculty of Physics, University of Warsaw

Coordinator: Iwona Stachlewska (iwona.stachlewska@fuw.edu.pl)

Tutors: Gustavo Abade, Daniel Albuquerque, Łucja Janicka, Konrad Kossacki, Szymon Malinowski, Krzysztof Markowicz, Fátima Mirza-Montoro, Pablo Ortiz-Amezcua, Hanna Pawłowska, Iwona Stachlewska, Dominika Szczepanik, Dongxiang Wang, Olga Zawadzka-Mańko, Piotr Żmijewski.

Description:

The aim of the Laboratory is to familiarize students with experimental and theoretical methods and advanced analysis of geophysical data. The thematic scope of the proposed exercises includes topics in atmospheric physics, lithosphere physics and planetology.

The laboratory consists of performing three (GL II winter semester) or four (GL I semester) exercises.

Descriptions of the proposed exercises with names of tutors are listed below.

Literature is determined by tutors, according to the individual topic and scope of the exercise.

Assessment of the final grade is based on the student's reports on the selected exercises (3 for GL II and 4 for GL I). Each report is evaluated by the tutor. The final grade is the average of the ratings obtained from the individual reports. Lack of performing the given above the obligatory number of exercises results in failing the subject!

The laboratory is realized solely in English.

Student workload:
- preparation for exercises 30h (GL II), 40h (GL I)
- exercises 30h (GL II), 30h (GL I)
- preparation of results and preparation of reports 30h (GL II), 40h (GL I)

IMPORTANT NOTES:

Due to the COVID-19 situation, there are no restrictions on the number of students performing each exercise and no restrictions on the number of exercises conducted by tutors!

Students that have performed a certain exercise in the previous semesters are not allowed to perform the same exercise in the current semester! In the submitted reports students are obligated to add information: "Herewith, I declare that I have not performed this exercise in any of the previous semesters".

Tutors are obligated to check for plagiarism and add information: "No plagiarism detected", along with the grade, date, and signature on the first page of each evaluated report. The scan/photo of this page has to be provided by the tutor to the coordinator asap.

Procedure:

1. The student selects the exercises from the list below and contacts the tutors to confirm that the exercise can be performed in a given semester.
2. Information about selected and confirmed exercises must be communicated by the student to the GL coordinator within 1 month of the beginning of the semester.
3. The student carries out each exercise under the tutor's supervision.
4. After completing the exercise, the student prepares a report and submits it for review by the tutor.
5. The coordinator receives an evaluated final report (with grade) from the student by the end of the exam session.
6. The report must contain the following information in the heather: Name of the laboratory: Geophysical Laboratory I (summer) or Geophysical Laboratory II (winter); academic year: 2020/2021; full title of the exercise; name and surname of tutor; name and surname of the student; student registration number at UW (USOS); date on which the first report is submitted to tutor, and if necessary - the date of the revision of the report.
7. The report must be written in the English language.
8. Failure to submit the graded report to the coordinator by the end of the exam session of a given semester means an unsatisfactory grade from the given exercise.
9. The final grade obtained by the student is the average of the ratings of the individual reports (3 grades for GL II and 4 grades for GL I, including the unsatisfactory grades.
10. The coordinator proposes the final grade to the student no later than one week before the end of the exam session.
11. The final grade is inserted to USOS on the last day of the exam session.
12. It is possible to improve each report until the end of the make-up session of a given semester.
13. The final grade is then the average of 3 (GLII) or 4 (GL I) grades (highest grade per exercise).

Materiały do zajęć

FILTR
Zajęcia / Prowadzący Typ zajęć

The finite inertia of droplets in a turbulent fluid causes droplets to diverge from regions of high vorticity and to converge preferentially in regions of low vorticity. This creates strong deviations from uniformity in droplet concentration. The aim of the exercise is to simulate the motion of droplets (modeled as point-particles) in a synthetic turbulent flow under the influence of gravity. Simulation results should explain to what extent droplet inertia, gravity, and turbulence affect droplet spatial distribution.

Laboratorium

The aim of this exercise is to study processes of formation and evolution of cloud droplets. It will be realized using an existing numerical parcel model (https://github.com/igfuw/parcel). Main tasks include:  getting acquainted with the model documentation, installation of the model, running of a set of numerical simulations. Results obtained will have to be thoroughly analyzed in order to identify parameters having impact on droplet size distribution. Realization of this exercise will result in effective understanding of parcel model as a tool used in numerical simulations of cloud processes, and also deeper understanding of cloud microphysical processes.

Laboratorium

The rate of sublimation is commonly calculated using simple Hertz-Knudsen equation. This equation was derived ignoring microstructure of material and assuming equilibrium distribution of the velocities of molecules condensing on the surface and leaving it. Thus, is it gives only approximate result. It can be corrected using temperature dependent sublimation coefficient (e.g. Kossacki et al. 1999; Gundlach et al. 2011; Kossacki et al. 2017). 

Exercise: Sublimation of ice is investigated in laboratory, using cooled vacuum chamber. Measured parameters are: position of the surface and the temperature. Student is expected to perform measurement and derive the temperature dependent rate of sublimation.

This exercise is dedicated to advanced student.

Note that, due to the COVID-19 situation, the student will receive raw measurement data for analysis.

Laboratorium

The exercise is aimed at determination of the thermal conductivity of granular ice, or natural snow (if it is available) without sampling the test material. The measurement is made using linear probe technology. It is used in practice in situations when taking a sample of the material is inexpedient or technically impossible. This method is applied to investigate directly (in-situ) properties of cosmic bodies using automatic landing probes, e.g. comet Churyumov-Gerasimenko (mission Rosetta, experiment MUPUS).

Idea is the following: changes of the temperature of a long thin heater inserted in a solid material is a function of its thermal conductivity. When the heating power is known it is sufficient to register  changes of the temperature. The latter can be done automatically. 

Student is expected to perform 2 -3 measurements and analyze the source data. 

This exercize is dedicated to advanced student.

Note that, due to the COVID-19 situation, the student will receive raw measurement data for analysis.

Laboratorium

The purpose of the exercise is to analyze EMORAL lidar measurement data collected during field campaign over the Natura 2000 peatland in Rzecin. The profiles of particle extinction and backscattering coefficients, depolarization ratio and water vapor mixing ratio will be derived. The student will use available lidar measurements and a set of calibration measurements for this purpose. He will write numerical programs for calculation of profiles and estimate measurement errors. Finally he/she will interpret the obtained results.

Laboratorium

The aim of the exercise is to derive profiles of aerosol optical properties, depolarization ratio and relative humidity, so as to characterize the atmosphere using the signals of ADR-PollyXT lidar and NARLa lidar. The student will use available lidar observations in combination with weather profiling of radiosounding and photometric measurements. The data will be processed using available numerical programs, including estimates of measurement errors. For the analysis and interpretation of the processed data, the student will use the methodology proposed by him/herself.

Laboratorium

The exercise is to define a methodology for synergistic data analysis of the ESA EMORAL lidar and the LATMOS BASTA cloud radar profiles to predict the tempo-spatial distribution of aerosol and clouds in the atmosphere. The key issue here will be (a) correctly calibrating the measurements taken by both devices and b) setting and optimising signal thresholds to distinguish different types of aerosol and clouds.

Laboratorium

The aim of the exercise is to retrieve the aerosol size distribution on the basis of spectral aerosol optical depth measurements by MICROTOPS sun photometer. The aerosol size distribution will be approximated by two log-normal distributions based on minimizing the cost function. During minimization, 2 or 4 parameters describing the size distribution are determined.

Laboratorium

The exercise aims at familiarizing students with the basic microphysical properties of clouds (concentration and size of cloud droplets), their variability in space, and their dependence on the type of cloud. The exercise will involve the analysis of the measurement data from the ACE2 (Second Aerosol Characterization Experiment, Canary Islands) and the RICO (Rain in Cumulus over the Ocean; Caribbean, 2004-2005) experiments carried out in Stratocumulus and Cumulus clouds, respectively. The implementation of this exercise will allow students to effectively learn the basic (and more advanced) parameters characterizing clouds, understand and remember which are the most important processes that govern clouds.

Dokumenty do zajęć:
Instrukcja do ćwiczenia z eksperymentu ACE2
Instruction_microphysics_ACE2.pdf
ReadMe
ReadMe_ACE2.txt
Dane z lotu fr9721 eksperymentu ACE2
113747.2H0001
Dane z lotu fr9730 eksperymentu ACE2
121129.4H0001
Publikacja ACE2
Brenguier_etal_JGR_2003.pdf
Publikacja ACE2
Brenguier_etal_Tellus_2000_CloudyColumn.pdf
Publikacja ACE2
Pawlowska_etal_Tellus_2000.pdf
Publikacja ACE2
Raes_etal_Tellus2000_ACE2_overview.pdf
Instrukcja do ćwiczenia z eksperymentu RICO
Instruction_microphysics_RICO.pdf
ReadMe
ReadMe_RICO.txt
Dane z lotu RF06 eksperymentu RICO
RF06_hc0407_162400.0R0001
Dane z lotu RF07 eksperymentu RICO
RF07_hc0408_150000.0R0001
Publikacja RICO
Arabas_et_al_2009_GRL.pdf
Publikacja RICO
Rauber_etal_2007_RICO.pdf
Laboratorium

Mixed-phase clouds are three-phase systems consisting of water vapor,
ice particles and supercooled liquid droplets. In this exercise the
student will model and simulate the phase partitioning of water
condensate in mixed-phase clouds using a bulk microphysical
approach. Simulations will be made for the adiabatic cloud parcel
model. We plan the following course of the exercise: learning the
model equations and the thermodynamics of mixed-phase systems, developing
the numerical code and conducting calculations for various model
parameters. The simple modeling approach used in this exercise should
provide reference results for testing and development of more
sophisticated microphysical schemes.

Laboratorium

The exercise is aimed at determination of the thermal conductivity of sand without sampling the test material. The measurement is made by linear probe technology. It is used in practice in situations when taking a sample of the material is inexpedient or technically impossible. This method is applied to investigate directly (in-situ) properties of cosmic bodies using automatic landing probes, e.g. comet Churyumov-Gerasimenko (mission Rosetta, experiment MUPUS).

Idea is the following: changes of the temperature of a long thin heater inserted in a solid material is a function of its thermal conductivity. When the heating power is known it is sufficient to register changes of the temperature. The latter can be done automatically.

Student is expected to perform 2 -3 measurements and analyze the source data.

Alternatively, student may process the existing source data.

This exercise is dedicated for beginner student.

Laboratorium
Laboratorium

The aim of the exercise is to derive the aerosol depolarization profiles (UV and VIS) and the water vapour mixing ratio from the European Space Agency Mobile Aerosol Raman EMORAL lidar signals. Student will use available lidar measurements for three cases: 1) Rayleigh atmosphere, 2) air-mass of biomass combustion, and 3) air mass of mineral dust. She/He will write numerical programs for the retrieval of water vapor profiles and depolarization in the atmosphere, estimate the measurement uncertainties, and perform a comparative analysis of the three cases.

Laboratorium

The exercise aims at familiarizing students with the topics of satellite remote sensing, widely used in atmospheric research. As part of the classes, student will conduct analyses of satellite data for a given case study (to be determined together with supervisor), in terms of various parameters, such as atmospheric aerosols, cloudiness, anthropogenic pollution.

 

Laboratorium

Size distribution of droplets and their concentration in a unit volume are basic microphysical properties characterizing the cloud. Knowing both, one can also calculate total liquid water content. The goal of the exercise is to introduce the method of measuring those parameters with shadowgraphy. Student’s tasks include the lab measurement of droplet sizes and concentrations in the streams generated by a few different devices (e.g. pond mist maker, household humidifier, flower sprayer, nasal hygiene spray), comparing the properties of the obtained size distributions and estimating total liquid water content.

For ambitious: The second goal of the exercise is to introduce optical techniques for measuring size distribution and fall velocity of rain drops, as well as rainfall rate. Student task’s involve selecting the proper experiment time based on weather forecast, measuring rain drop sizes and velocities at the roof of the institute building with shadowgraphy technique and comparing the results with routine observations performed with a disdrometer.

Dokumenty do zajęć:
Measurement of cloud droplet size and concentration with shadowgraphy - instructions - Skrypt do ćwiczeń
shadowgraph_intro_JN2020.pdf
Laboratorium

Turbulent Kinetic Energy (TKE) dissipation rate is a key physical quantity characterizing turbulent air motions present in the atmosphere. According to Kolmogorov’s theory, its value can be derived from velocity fluctuations, measured e.g. with a stationary ultrasonic anemometer or various airborne instruments. The goal of the exercise is to learn several approaches for estimation of TKE dissipation rate (power spectrum, structure functions, number of crossings), apply them for the velocity data collected routinely at the top of the institute building and compare the results for the period of a few days.

Laboratorium

The ultrasonic anemometer installed ontop of the institute building records three components of the air flow velocity and virtual temperature at a rate up to 32 Hz. Measured fluctuations of velocity and virtual temperature allow for the calculation of turbulent fluxes of momentum and heat in the boundary layer of the atmosphere with the use of eddy correlation method. Relationship between those quantities determines, in turn, the dynamic stability in the layer, which is customarily expressed by the Monin-Obukhov length. Student’s tasks involve performing Reynolds decomposition of the recorded signals, calculating respective turbulent fluxes, deriving Monin-Obukhov length and analyzing its variability in the course of a few selected days.

Laboratorium

 The exercise aims at determining effects of relative humidity on optical and microphysical properties of aerosol in laboratory conditions. Measurements will be conducted using the aerosol condition system (ACS1000), which allows for applying controlled changes of relative humidity upon the air collceted using the inlet located on the measuring platform. The chamber consists of two measuring paths: one that contains dehumidified air with low relative humidity (approx. < 30%), while the other contains air that moves through a special moisturizing system enabling the setting of desired humidity value in the range from 40 to 90%. Both measurements take place simultaneously with the used of miniature OPC-N3 particle counters. This enables to determine changes in the particle size distribution and the scattering coefficient as the air humidity changes.

Laboratorium

The aim of the exercise is Langley calibration of the Multifilter Rotating Shadowband Radiometer and deriving aerosol optical depth and Angstrom exponent. Student will work with data from MFR-7 mounted in Radiative Transfer Laboratory at the roof platfor of the Institute of Geophysics. During the exercise, the data processing will be done, including several corrections.

Laboratorium