Climate: Past, Present & Future

Ulrike Niemeier

Ulrike Niemeier is a senior scientist at the Max Planck Institute for Meteorology in Hamburg, working in the Climate Dynamics Department. She gained experience with regional high-resolution modeling well before global high-resolution climate models became standard, already in the 1990s. She is an expert on geoengineering and the climatic impacts of sulfur and sulfate aerosols in the stratosphere—from both volcanic and artificial sources. She uses global climate and aerosol-chemistry models such as ECHAM5-HAM, MPI-ESM, and ICON to study aerosol microphysics, transport processes, and their dynamical feedbacks, and serves on the steering committee of the Geoengineering Model Intercomparison Project (GeoMIP).

When small-scale turbulence imprints on the global atmospheric circulation: Uncovering the Cause of the Double Intertropical Convergence Zone Bias in ICON

Clarissa Kroll, Robert Jnglin Wills, Ulrike Niemeier, Luis Kornblueh and Andrea Schneidereit January 12, 2026

One feature stands out in any map of tropical rainfall from satellites: a narrow band of intense precipitation encircling the globe near the equator. This is the Intertropical Convergence Zone, a key feature of the global atmospheric circulation that imports moisture into the tropics and exports energy to higher latitudes. But for decades, climate models have struggled to simulate this feature cor ...[Read More]