Atmospheric River Signatures in Radiosonde Profiles and Reanalyses at the Dronning Maud Land Coast, East Antarctica


Contact
Holger.Schmithuesen [ at ] awi.de

Abstract

Atmospheric rivers (ARs) are an important component of the hydrological cycle linking moisture sources in lowerlatitudes to the Antarctic surface mass balance. We investigate AR signatures in the atmospheric vertical profiles at theDronning Maud Land coast, East Antarctica, using regular and extra radiosonde measurements conducted during the Yearof Polar Prediction Special Observing Period November 2018 to February 2019. Prominent AR events affecting thelocations of Neumayer and Syowa cause a strong increase in specific humidity extending through the mid-troposphere anda strong low-level jet (LLJ). At Neumayer, the peak in the moisture inversion (up to 4 g kg−1) is observed between 800 and900 hPa, while the LLJ (up to 32 m s−1) is concentrated below 900 hPa. At Syowa the increase in humidity is lesspronounced and peaks near the surface, while there is a substantial increase in wind speed (up to 40 m s−1) between 825 and925 hPa. Moisture transport (MT) within the vertical profile during the ARs attains a maximum of 100 g kg−1 m s−1 at bothlocations, and is captured by both ERA-Interim and ERA5 reanalysis data at Neumayer, but is strongly underestimated atSyowa. Composites of the enhanced MT events during 2009−19 show that these events represent an extreme state of thelower-tropospheric profile compared to its median values with respect to temperature, humidity, wind speed and,consequently, MT. High temporal- and vertical-resolution radiosonde observations are important for understanding thecontribution of these rare events to the total MT towards Antarctica and improving their representation in models.



Item Type
Article
Authors
Divisions
Primary Division
Programs
Primary Topic
Research Networks
Peer revision
ISI/Scopus peer-reviewed
Publication Status
Published
Eprint ID
52660
DOI 10.1007/s00376-020-9221-8

Cite as
Gorodetskaya, I. V. , Silva, T. , Schmithüsen, H. and Hirasawa, N. (2020): Atmospheric River Signatures in Radiosonde Profiles and Reanalyses at the Dronning Maud Land Coast, East Antarctica , Advances in Atmospheric Sciences, 37 (5), pp. 455-476 . doi: 10.1007/s00376-020-9221-8


Share


Citation

Research Platforms

Campaigns


Actions
Edit Item Edit Item