PhD project: Observations of concentrations and isotopic compositions of greenhouse gases in the stratosphere using AirCore
Name: Joram Hooghiem
Supervisor: Dr. Huilin Chen (Centre for Isotope Research, ESRIG/RUG)
Period: November 2016 - November 2020
Summary of PhD project:
AirCore is a coil of tubing, opened at one end. When flown on a balloon it is capable of obtaining a vertical profile of Greenhouse Gas (GHG) concentrations of CO2 and CH4. While ascending in the atmosphere the ambient pressure drops, and air is pushed out of the tube. When descending, the atmospheric pressure increases and air is pushed into the tube. When analyzed on continues analyzer for GHG a vertical profile can be obtained. Air can be recaptured for analysis of the isotopic composition. These greenhouse gases and the isotopic composition can be used as tracers for transport dynamics in the atmosphere. In the stratosphere, known best for the ozone layer, these dynamics are currently not well understood. Model predictions lack observational constraints, and hence the known climate feedback mechanisms in the stratosphere are subjected to relative large uncertainties. The profiles obtained from AirCore can be used to validate transport models that are used to derive surface fluxes of greenhouse gases. Secondly these profiles can be used to calibrate and validate remote sensing techniques like the Fourier Transform Infrared Spectroscopy instrument utilized by TCCON and retrievals from several satellites. The aim of this PhD project is to obtain regular vertical profiles of greenhouse gases up to 30 km. Furthermore, AirCore stratospheric air will be sampled for measurements of the isotopic compositions of CO2 and CH4. The data can be used to obtain a better understanding of stratospheric dynamics and chemistry, which is relevant to the carbon cycle and climate sciences.
|Last modified:||15 May 2017 4.21 p.m.|