NAWDIC-ARM

North Atlantic Waveguide, Dry Intrusion, and Downstream Impact Campaign

12 January 2026 - 19 February 2026

Lead Scientist: Julian Quinting

Observatory: ENA (Eastern North Atlantic)

The North Atlantic Waveguide, Dry Intrusion, and Downstream Impact Campaign (NAWDIC) is an international field campaign focusing on mid-latitude atmospheric dynamics with the aim to provide detailed observations for improving the understanding and modelling of the mesoscale tropopause structure, the interaction of the dry intrusion air stream with the planetary boundary layer (PBL) and cold front, and their relation to high impact weather in the North Atlantic region in winter.

NAWDIC aims to advance our understanding of the synoptic- to micro-scale dynamical and physical processes associated with the triggering of severe wind gusts, heavy precipitation, and cold air outbreaks in the North Atlantic, Euro-Mediterranean region and of their representation in NWP models. More specifically, NAWDIC will focus on the physical understanding and quantification of the dry intrusion airstream for the evolution of high-impact weather related to extratropical cyclones in winter.

NAWDIC-ARM will enhance NAWDIC by providing additional radiosounding observations during IOPs of NAWDIC components.

The North Atlantic Waveguide, Dry Intrusion, and Downstream Impact Campaign (NAWDIC) is an international field campaign focusing on mid-latitude atmospheric dynamics with the aim to provide detailed observations for improving the understanding and modeling of the mesoscale tropopause structure, the interaction of the dry intrusion air stream with the planetary boundary layer (PBL), and their relation to high-impact weather in the North Atlantic region in winter. Two central science goals of NAWDIC are:

1.         To strengthen our understanding of momentum transport into the PBL and its role in the formation of severe wind gusts and convection. This will be achieved by high-resolution observations of wind, temperature, all phases of water, and cloud microphysical properties where dry intrusions descend to the top of the PBL, the PBL, and surface beneath, as well as the neighboring cold fronts.

2.         To clarify the importance of the model representation of surface fluxes in the cold sector and near fronts of extratropical cyclones for high-impact weather (HIW) and subsequent cyclogenesis over the ocean. To this end, detailed observations of turbulent heat, moisture, and momentum fluxes at the air-sea interface are planned.

During the measurement period and according to the forecasted weather systems in the Eastern North Atlantic, intensive operational periods (IOPs) will be defined, for which at least one airborne platform of NAWDIC will operate. During IOPs, two additional radiosondes at the ARM-Eastern North Atlantic (ENA) site will be released, making four sondes per day at standard times (00, 06, 12, 18 UTC).

The additional sounding profiles will (i) enhance the array of atmospheric observations during IOPs of interest including DI and atmospheric rivers in a critical, data-scarce area such as the Central Atlantic; (ii) provide detailed structure of the cold front and PBL before, during, and recovering from DIs; (iii) be compared to remotely sensed data and will be used for calibration and assessment of uncertainties; (iv) serve to better initialize numerical weather prediction (NWP) models and help evaluate their representation of the atmospheric processes by data-denial experiments; (v) complement additional radiosondes launched by universities in Europe and through EUMETNET – Automated Shipboard Aerological Programme (E-ASAP) from ships over the North Atlantic.