Dr. Sinikka Jasmin Paulus

Current Research Interest

In my research, I primarily investigate non-rainfall water inputs, such as dew, fog, frost, rime, and vapor absorption/adsorption). Unlike rainfall—where droplets condense aloft and return to the surface under gravity—non-rainfall water inputs form at or near the Earth’s surface. As this is ultimately the 'biotic zone', non-rainfall water inputs are considered key to ‘habitability’, as they provide a continuous input of liquid water, even during periods without rain. Thereby, non-rainfall water inputs influence soil hydraulic conductivity, microbial activity, and the reaction rates of biogeochemical processes. Therefore, despite being quantitatively small, they can have a significant impact on ecosystem processes.

My research aims to improve our ability to detect and quantify non-rainfall water inputs in order to better understand their combined importance across ecosystems worldwide. A clearer picture of these often overlooked water sources is essential for assessing how climate change may alter their formation and what this means for ecosystem water balances.

My work focuses on developing and providing observational evidence of these processes. Through collaborations with other research groups, we use these data to explore their consequences at the ecosystem scale; in models but also other data products. By linking insights about the physical forces governing water interactions at the molecular scale with ecosystem observations, we can begin to understand how small-scale processes shape large-scale water and carbon dynamics.

News: Learn more about my work at EGU 2026

Tuesday, 5 May 2026 | EGU26-16325
Differences in soil water retention properties and plant available water below trees and grasses in a Mediterranean savanna
by Max Wittig et al. https://doi.org/10.5194/egusphere-egu26-16325

Wednesday, 6 May 2026 | EGU26-14924
Tracking Water Status and Drought Response with GNSS-T VOD Across Tropical to Temperate Forest Ecosystems
by Konstantin Schellenberg et al. https://doi.org/10.5194/egusphere-egu26-14924

Also consider joining our Splinter Meeting SPM38 to learn more about our initiative on Co-Developing Metadata Standards for In-Situ ET Measurements 

Community service:

• until January 2024: Elected deputy of the equal opportunities officer of the MPI-BGC
  
• Supervision of students, assistance in university lectures (FSU Jena, UNI Freiburg)
  
• Scientific reviewer for Hydrology and Earth System Sciences (HESS), Journal of Hydrology, Agricultural and Forest Meteorology

Former research as Undergraduate Student:

University of Freiburg - Institute of Ecosystem Physiology:

In the group of Maren Dubbert we analysed the water uptake of roots in a temperate grassland using stable water isotopes. We combined two measurement methods to measure "live" and without disturbance in situ (i.e. without removing material) the isotopy of soil water vapour and leaf transpiration during a drought. We compared these results with the isotopic signature of destructively sampled material to characterise the methodological differences. Such method comparisons are important development steps to evaluate the potential applications of new methods and are often the basis for many follow-up studies. (Link Master thesis) (Link Paper)

University of Freiburg - Institute of Soil Ecology:

Under the supervision of Martin Maier, I conducted research as a student assistant in the field of soil gas transport. We measured trace gas concentrations in the soil column using a portable in situ sampling rod developed within the group. In various measurement campaigns we have combined this technique with others to gain information on

• the drivers of variability in methane consumption on a small scale (link)
  
• the effects of turbulence-induced pressure pumping on gas transport in the soil (Link)
  
• the correlation between methane production in the soil and methane emission from the trunk of beech trees (Fagus sylvatica) (link)