Inferring atmospheric dynamics from aerosol observations in 4D-Var

Zaplotnik, Žiga (author), Žagar, Nedjeljka (author), Benedetti, Angela (author), Semane, Noureddine (author)

The paper explores the potential of aerosol observations to provide wind information in four-dimensional variational data assimilation (4D-Var). It is shown that the relative horizontal gradients, crucial for the wind extraction from tracers, are on average greater for the aerosol mixing ratio than for the specific humidity, whose observations are known to provide significant information on the wind field. The aerosols potential to infer atmospheric dynamics is investigated in the tropics where the wind information is most critical. An intermediate-complexity incremental 4D-Var system MADDAM has been developed with a forecast model that simulates most dominant processes involving moisture, aerosols and dynamics: the nonlinear advection, condensation andwet deposition. The results of 4D-Var experiments reveal a detrimental impact of saturation-related nonlinearities and aerosol wet deposition on the extraction of wind from aerosol data. The fraternal-twin experiments show about 30% smaller impact of the aerosol data on the wind analysis compared to humidity data, mainly due to the greater aerosol observation error and suboptimal background-error covariance model. However, the assimilation of aerosol data together with temperature and humidity observations shows a significant added value for the wind analyses.

• Language: English
• Keywords: meteorology, atmospheric physics, aerosols, 4D-Var, wind, humidity, data assimilation
• Work type: Article
• Typology: 1.01 - Original Scientific Article
• Organization: FMF - Faculty of Mathematics and Physics
• Publication status: Published
• Publication version: Author Accepted Manuscript
• Publication date: 18.02.2020
• Year: 2020
• Number of pages: Str. 1403-1422
• Numbering: Vol. 146, iss. 728
• PID: 20.500.12556/RUL-161049-a7afe3c1-079c-6e4c-3306-a41d8fe40859
• UDC: 551.501
• ISSN on article: 0035-9009
• DOI: 10.1002/qj.3743
• COBISS.SI-ID: 387497
• Publication date in RUL: 06.09.2024

Record is a part of a journal

• Title: Quarterly Journal of the Royal Meteorological Society
• Shortened title: Q. J. R. Meteorol. Soc.
• Publisher: Royal Meteorological Society
• ISSN: 0035-9009
• COBISS.SI-ID: 26227200

Secondary language

• Language: Slovenian
• Keywords: meteorologija, atmosferska fizika, aerosoli, 4D-var, veter, vlažnost zraka, asimilacija podatkov