NaFoLiCA: Namib Fog Life Cycle Analysis

The goal of NaFoLiCA is to improve our understanding of the temporal and spatial patterns of fog in the Namib region, as well as the factors driving fog development. In-situ observations are combined with satellite-based remote sensing and numerical weather prediction.

Background

The Namib Desert is a hyper arid coastal desert with annual precipitation levels typically well below 50 mm. The dry climate can partly be attributed to the cold upwelling of the Benguela current along the Namibian coast. On the other hand the upwelling contributes to the formation of fog, which happens with such a high frequency that some plants and animals in the Namib have developed the ability to harvest fog water in order to survive. In addition to the Benguela current, the fog formation is influenced by interactions between the two major pressure systems in the area, namely the South-Atlantic Anticyclone and the thermal low over southern Africa. In combination with local conditions, a complex process of fog formation and advection develops. These processes are still, to a large degree, not understood.

Project description

Using In-situ observations combined with satellite-based remote sensing and numerical weather prediction, we examine spatial and temporal patterns in both fog occurrence and fog physical properties. Our aim is to identify the factors controlling the development and the life cycle stages of the coastal-desert fog. These factors cover several disciplines, from the microphysical process level to landscape-scale spatial patterns. Therefore, Nafolica is divided into three complementary sub-projects, each of which is indispensable for the overall aim:

• NaFoLiCA-F: Ground-based observations of fog properties. Highly detailed observations of fog optical and microphysical properties as well as temporal changes in relation to other observed parameters are used as a basis for high-resolution process studies.
• NaFoLiCA-S: Satellite-based observations of fog patterns and properties. Based on a combination of geostationary and polar-orbiting systems, spatial and temporal patterns of fog, as well as microphysics retrievals, will help understand large-scale dynamics.
• NaFoLiCA-M: Numerical weather prediction modeling. A 3D model of fog development will yield insights into the factors determining microphysical properties and the spatial extent of fog.

About

NaFoLiCA is an international collaboration between three universities, with each being responsible for a sub-project: University of Basel (NaFoLiCA-F), Karlsruhe Institute of Technology (NaFoLiCA-S) and the University of Bonn (NaFoLiCA-M). Additionally, a cooperation with Gobabeb Research and Training Centre in Namibia offers local young scientists and graduate students a possibility to profit from project findings. The project is funded by Deutsche Forschungsgemeinschaft (DFG) and the Swiss National Science Foundation (SNSF).

The stations are aligned in a T-like shape, essentially allowing sampling of fog occurance along a north-south and a est-west transcect. This allows to trace the fog occurance and its relation to the landscape and height thereof as the fog often results from a stratus connecting to the ground (thus becoming fog) along its way inland.

The thumbnails on the left give an impression of posters, respectively PICO(s) and, on click, lead to the corresponding material (PDF/PPTX).

At the EGU 2019, two posters and one PICO have been presented.

At the IFDA 2019, three posters have been presented.

Robert Spirig; Roland Vogt; Jarl Are Larsen; Christian Feigenwinter; Andreas Wicki; Joel Franceschi; Eberhard Parlow; Bianca Adler; Norbert Kalthoff; Jan Cermak; Hendrik Andersen; Julia Fuchs; Andreas Bott; Maike Hacker; Niklas Wagner; Gillian Maggs-Kölling; Theo Wassenaar; Mary Seely (2019). Probing the Fog Life Cycles in the Namib DesertBulletin of the American Meteorological Society, 100 (12), 2491-2507.
doi:10.1175/BAMS-D-18-0142.1 

Andersen, H.; Cermak, J.; Solodovnik, I.; Lelli, L.; Vogt, R. (2019). Spatiotemporal dynamics of fog and low clouds in the Namib unveiled with ground- and space-based observations  Atmospheric chemistry and physics, 19 (7), 4383–4392.
doi:10.5194/acp-19-4383-2019 

Andersen, H.; Cermak, J. (2018). First fully diurnal fog and low cloud satellite detection reveals life cycle in the Namib  Atmospheric measurement techniques, 11 (10), 5461–5470.
doi:10.5194/amt-11-5461-2018