TPEx
⇒ Visit the TPEx Blog for News about the measurement campaign
TPEx (TropoPause compositon gradients and mixing Experiment) is the central field campaign of the TPChange research center. It will take place in early summer 2024 with measurement flights in the time window from 10 to 21 June 2024.
The scientific questions are
- Water vapor distribution in the UTLS region across central Europe
- Identification of mixing at and across the tropopause induced by diabatic processes
- Vertical transport of arosols and trace species from the boundary layer to the UTLS (e.g. by convection or frontal uplift) and effect of UTLS composition and new particle formation events
- Source apportionment of aerosols and ice-nucleating particles (INPs) for understanding the main pathways of transport towards UTLS
We use in-situ aerosol and trace gas measurements in a novel experimental approach: a towed sensor shuttle (TOSS) is attached to an aircraft (type Learjet 35A) in order to simultaneously resolve highly transient tracer and temperature fluctuations at the tropopause, which are induced by e.g. rapid updrafts, strong shear or extended cirrus decks (B01, C01). This will be combined with measurements focusing on aerosol processing during upward transport to the UTLS and the impact on aerosol composition in the UTLS (B02, A04, A03). It also includes sampling of aerosols providing material for laboratory analysis (A05, A06).
The Learjet aircraft with the towed sensor shuttle (TOSS) during a mission 2013 (photo: M. Klingebiel)
Flights with the TOSS are limited to the restricted air space at the North Sea (white), while flights without the TOSS range over central Europe (red/green circle).
The following instruments are deployed on the Learjet aircraft, on the towed sensor shuttle (TOSS) and in the wingpod of the aircraft (Knuffi):
Trace gas species
| Project | Instrument | Species | Learjet | TOSS | Knuffi |
| C01 | FISH | H2O (water vapor) | x | ||
| C01 | WASUL | Total water, water vapor | x | ||
| B01 | UMAQS | CO, N2O | x | ||
| B01 | 2BTech ozone monitor | O3 | x | x | |
| C01 | IAGOS humidity sensor | RH, T | x | x | |
| B01 | Acceleration, pressure, position | Exact determination of coordinates for Learjet and TOSS | x | x |
Trace gas species
| Project | Instrument | Species | Learjet | TOSS | Knuffi |
| C01 | FISH | H2O (water vapor) | x | ||
| C01 | WASUL | Total water, water vapor | x | ||
| B01 | UMAQS | CO, N2O | x | ||
| B01 | 2BTech ozone monitor | O3 | x | x | |
| C01 | IAGOS humidity sensor | RH, T | x | x | |
| B01 | Acceleration, pressure, position | Exact determination of coordinates for Learjet and TOSS | x | x |
Aerosol and cloud particles
| Project | Instrument | Species | Learjet | TOSS | Knuffi |
| A04 | UHSAS | Aerosol size distribution (60 nm – 2 μm) | x | x | |
| A03 | CPC | Aerosol number concentration (2 nm and 10 nm – 3 μm) | x | ||
| A06 | FRIDGE | Ice nucleating particles | x | ||
| A04 | CARIBIC AMS with Sky OPC | Mass concentrations of aerosol components sulfate, nitrate, ammonium and organics, aerosol size distribution in 31 channels from 250nm to 32 μm |
x | ||
| C01 | Backscatter cloud probe | Particle diameter and number concentration, LWC | x | x | |
| C01 | NIXE-CAPS | size and number density of cloud particles (0.6 – 900 μm) | x | ||
| Aerosol filter samples (impactor,thermoporetic) | Offline single particle analysis | x | |||
| A05 | SOAP | organic aerosol sampling for offline chemical analysis | x |
Other projects involved in TPEx campaign
| Project | Involvement |
| A02 | Provision of satellite data for flight planning and data interpretation |
| B02 | BISTUM: Vertical transport and processing of aerosols, trace gases (measured on MoLa, drone, balloon out of Spielberg/Vogelsberg, 50 km north-west of Frankfurt/Main) |
| B04 | Analysis of structure formation and stratosphere-troposphere-exchange, case study of tracer distribution from campaign |
| B07 | Small scale distribution of ice clouds in tropopause for theory of nucleation processes |
| B08 | Flight planning, provide tool to identify target regions |
| C01 | Provide CLaMS ice forecast, include campaign data in JULIA database |
| C07 | Effects of parameterised versus resolved convective transport and associated scavenging of UTLS relevant tracers |