04/10/2024 - KITsonde assembling week for NAWDIC

Bild Amadeus Bramsiepe, KIT
Fig. 1. Components of the KITsonde.
Bild Amadeus Bramsiepe, KIT
Fig. 2. Parachutes and engines of the release containers.

The KITsonde is a modular multi-sensor dropsonde system that allows to simultaneously launch up to four meteorological measurement sondes from a research aircraft. Shortly after being dropped from more than 10 km above ground, the sondes are released from a discharge container and drift on diverging trajectories due to differently sized parachutes. When reaching the ground, the sondes have separated by up to 70 km, depending on the prevailing wind profile. Meteorological measurements and position data are sent to the aircraft every second, which allows to capture both vertical profiles of temperature, humidity, and wind at a resolution of around 10 m and the mesoscale variability of the troposphere.

During the planned North Atlantic Waveguide, Dry Intrusion, and Downstream Impact Campaign (NAWDIC, https://www.nawdic.kit.edu/) in January and February 2026, the KITsonde system will be used together with remote sensing instruments on board of the German high-altitude and long-range research aircraft HALO (https://halo-research.de/). The central goal of NAWDIC is to sample dry intrusion air streams and frontal boundaries in extra-tropical cyclones over the North Atlantic to better understand and predict the processes leading to damaging wind storms and heavy precipitation events.

The unique and specially designed KITsonde system was developed at IMKTRO in collaboration with enviscope GmbH and Graw Radiosondes GmbH & Co. KG and is prefabricated only in small numbers. Members of the NAWDIC team as well as highly motivated colleagues of the institute now spent a whole week assembling release containers, cutting parachutes, and packing measurement sondes (Figs. 1 & 2). Thanks to this great collaborative effort, we have completed more than 20 release containers packed with a total of 60 sondes, which will be deployed for preparatory measurements during the ASCCI campaign (https://halo-research.de/sience/future-missions/ascci/) in March 2025. For NAWDIC, another 110 release containers equipped with 340 sondes will be prepared for airborne deployment. The measurements taken with the KITsonde system during both campaigns will be sent in real-time to the Global Telecommunication System (GTS) of WMO. This will make the data available to meteorological centers worldwide and allow the data to be assimilated into their numerical weather prediction systems.

26/03/2024 - Welcome Jason Furtado

Bild INTL

The “Meteorological Data Science” group warmly welcomes Prof. Jason Furtado (https://ifurtado.org/) from University of Oklahoma. Jason will stay with us for the next three months funded through a KIT International Excellence Fellowship. Jason and his group research the dynamics of different internal modes of variability in the Earth System and how these interact with each other. A particular focus is on the subseasonal time-scale and the role of the stratosphere and ENSO in providing windows of opportunity through teleconnections. During his stay at KIT, Jason and the Meteorological Data Science group will study the forecast skill of subseasonal North American Weather regime predictions and how this skill is affected by modes of variability and midlatitude cyclone activity. We wish Jason a joyful and productive stay in the institute!

23/03/2024 - Fabian Mockert was awarded the Climate Prize of the Reinhard-Süring Foundation

Bild Pittke
right: Fabian Mockert, IMKTRO; left: Frank Beyrich, DWD and Chairman of the RSS) Copyright: Gregor Pittke, FU Berlin

Fabian Mockert was awarded the Climate Prize of the Reinhard-Süring Foundation during the 13th German Climate Conference at the Telegrafenberg in Potsdam. The prize honors his research on Dunkelflauten (a compound event of low wind and solar energy yield) in Germany and their relation with large-scale weather patterns [1]. The meteorological Reinhard-Süring Foundation awards the €1500 prize as part of the triennial German Climate Conference to outstanding young scientists. This year, the prize was awarded in the field of "climatological data for the Energy and Agricultural transition". We would like to congratulate Fabian on this award!

[1] Mockert, F., Grams, C. M., Brown, T., & Neumann, F. (2023). Meteorological conditions during periods of low wind speed and insolation in Germany: The role of weather regimes. Meteorological Applications, 30(4), e2141. https://doi.org/10.1002/met.2141

Further information:

Homepage Fabian Mockert: https://www.imk-tro.kit.edu/14_11644.php

Reinhard-Süring Foundation: https://www.rs-stiftung.org/ (in German)

13th German Climate Conference: https://dkt-13.de/ (in German)

News Article on “Dunkelflauten”: https://www.imk-tro.kit.edu/english/12085.php

05/02/2024 - Welcome Meng Wang

Bild Wang

The “Meteorological Data Science” group welcomes Meng Wang as a visiting PhD student. Meng is currently doing her PhD at the School of Atmospheric Sciences, Sun Yat-sen University, China with Professor Xiuzhen Li focusing on the interaction of high- and low-latitude Rossby waves leading to extreme cold-wet weather conditions in South China. During her stay, she will specifically investigate to what extent the excitation of these waves is linked to the large-scale circulation over the North Atlantic. Meng Wang successfully applied for scholarship funded by the China Scholarship Council which will allow her to stay with us for 12 months until January 2025. We look forward to learning about her research and wish her a joyful stay at IMKTRO! If you would like to learn more about cold-wet extremes in South China, please meet Meng at Campus North, Building 435, Room 219.

19/01/2024 - New Paper on WCB modulation by the MJO

Bild WCD
Modulation of North Atlantic Weather Regimes stratified according to different MJO phases and (a) normal, (b) low, (c) high WCB activity.

Over the past few decades, research has elucidated the significant role of warm conveyor belts (WCBs), characterized by ascending airstreams within extratropical cyclones, in the dynamics of extratropical atmospheric systems. However, there has been limited investigation into the modulation of WCB occurrence frequency, referred to herein as WCB activity, on subseasonal timescales. Additionally, the potential impact of WCB activity on tropospheric teleconnection patterns, which contribute to predictability on these timescales, remains unclear. A new paper which was now published in the journal Weather and Climate Dynamics utilizes reanalysis data to examine how the Madden–Julian Oscillation (MJO) modulates WCB activity.

A primary discovery is the notable increase in WCB activity over the western North Pacific when MJO convection occurs over the Indian Ocean. This augmented WCB activity, particularly pronounced during La Niña conditions, is attributed to intensified poleward moisture fluxes propelled by the circulation of subtropical Rossby gyres associated with the MJO. Conversely, when MJO convection is situated over the western North Pacific, there is a significant increase in WCB activity over the eastern North Pacific, owing to a southward displacement and eastward elongation of the North Pacific jet stream.

Nevertheless, while overall increases in WCB activity are observed, individual MJO events exhibit considerable variability, with some events displaying anomalously low WCB activity. Events of the same MJO phase with anomalously low WCB activity over the North Pacific tend to be succeeded by canonical teleconnection patterns in the Atlantic–European region. Specifically, the occurrence frequency of the positive phase of the North Atlantic Oscillation (NAO) is increased during MJO convection over the Indian Ocean, and conversely for the negative phase of the NAO during MJO convection over the western North Pacific. However, when individual events of the same MJO phase coincide with anomalously high WCB activity over the North Pacific, these canonical teleconnection patterns are altered, notably weakening the linkage between the MJO and the negative phase of the NAO.

Reanalysis data and experiments employing an idealized general circulation model reveal that this phenomenon is associated with anomalous ridge formation over western North America, facilitated by increased WCB activity. Overall, this study underscores the potential influence of WCBs on tropical–extratropical teleconnection patterns and emphasizes the necessity of accurately representing them in numerical weather prediction models to fully harness the predictability sources emerging from tropical dynamics.

 

Quinting, J. F., Grams, C. M., Chang, E. K.-M., Pfahl, S., and Wernli, H.: Warm conveyor belt activity over the Pacific: modulation by the Madden–Julian Oscillation and impact on tropical–extratropical teleconnections, Weather Clim. Dynam., 5, 65–85, https://doi.org/10.5194/wcd-5-65-2024, 2024.

03/11/2023 - Welcome Bastian Kirsch

Bild Kirsch

We warmly welcome Bastian Kirsch in the WG „Meteorological Data Science“. Bastian grew up near Hamburg where he studied Meteorology focusing on radar meteorology. In 2022, Bastian completed his PhD under the supervision of Prof. Felix Ament and Cathy Hohenegger entitled “Illuminating convective cold pools with a dense station network”. During his PhD Bastian was heavily involved in the FESSTVaL campaign which took place near the Lindenberg observatory. In the coming years, Bastian will bring in this expertise at IMK-TRO to coordinate the “North Atlantic Waveguide, Dry Intrusion and Downstream Impact Campagin (NAWDIC)”. We are very happy to have Bastian in the NAWDIC team and look forward to the campaign preparation and implementation in winter 2025/2026.

20/09/2023 - Welcome Siyu Li

Bild Li

We warmly welcome Siyu Li in the WG „Meteorological Data Science“. Siyu Li completed her BSc at Nanjing University of Information Science and Technology (NUIST) in June 2020 where she evaluated the representation of major sudden stratospheric warming events in the CESM-WACCM. Siyu then moved to Karlsruhe to complete her Master's degree at the IMK. For her Master’s thesis, Siyu joined the working group „Atmospheric risks“ where she developed a machine learning model for hail prediction in Germany. The PhD project will also include machine learning. As part of the project "Advancing subseasonal predictions at reduced computational effort", Siyu will address the question of how short-term forecast errors in the tropics affect the reliability of subseasonal predictions in Central Europe.