English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Three extended airborne Differential Absorption Lidar (DIAL) sections oftropospheric water vapour across the tropical and sub-tropical Atlantic inMarch 2004 are compared to short-term forecasts of the European Centre forMedium Range Weather Forecasts (ECMWF). The humidity fields between 28° Sand 36° N exhibit large inter air-mass gradients and reflect typicaltransport patterns of low- and mid-latitudes like convection (e.g. Hadleycirculation), subsidence and baroclinic development with stratosphericintrusion. These processes re-distribute water vapour vertically such thatlocations with extraordinary dry/moist air-masses are observed in thelower/upper troposphere, respectively. The mixing ratios range over 3 ordersof magnitude. Back-trajectories are used to trace and characterize theobserved air-masses.  Overall, the observed water vapour distributions are largely reproduced bythe short-term forecasts at 0.25° resolution (T799/L91), the correlationranges from 0.69 to 0.92. Locally, large differences occur due to comparablysmall spatial shifts in presence of strong gradients. Systematic deviationsare found associated with specific atmospheric domains. The planetaryboundary layer in the forecast is too moist and to shallow. Convectivetransport of humidity to the middle and upper troposphere tends to beoverestimated. Potential impacts arising from data assimilation and modelphysics are considered. The matching of air-mass boundaries (transport) isdiscussed with repect to scales and the representativity of the 2-D sectionsfor the 3-D humidity field. The normalized bias of the model with respect tothe observations is 6%, 11% and 0% (moist model biases) for thethree along-flight sections, whereby however the lowest levels are excluded

Evaluation of ECMWF water vapour fields by airborne differential absorption lidar measurements: a case study between Brazil and Europe