Observations of carbon dioxide and turbulent fluxes during fog conditions in north India

• Published in: Journal of Earth System Science 2020-12, Vol.129 (1), p.51, Article 51
• Main Authors: Patil, M N, Dharmaraj, T, Waghmare, R T, Singh, Surender, Pithani, Prakash, Kulkarni, Rachana, Dhangar, Narendra, Siingh, Devendraa, Chinthalu, G R, Singh, Raj, Ghude, Sachin
• Format: Article
• Language: English
• Subjects: Accuracy; Aerosols; Atmospheric boundary layer; Atmospheric conditions; Atmospheric turbulence; Aviation; Boundary layers; Carbon dioxide; Carbon dioxide concentration; Clear sky; Cooling; Dew point; Earth and Environmental Science; Earth Sciences; Eddy covariance; Evaporation; Experiments; Fog; Fog formation; Heat; Heat flux; Heat transfer; High humidity; Humidity; Latent heat; Latent heat flux; Low wind speeds; Lower troposphere; Meteorological parameters; Moisture content; Neighborhoods; Neutral stability; Parameters; Radiation; Relative humidity; Rural areas; Sensible and latent heat; Sensible and latent heat flux; Sky; Space Exploration and Astronautics; Space Sciences (including Extraterrestrial Physics; Surface boundary layer; Surface layers; Surface stability; Surface temperature; Temperature inversion; Temperature inversions; Troposphere; Turbulence; Turbulent fluxes; Urban areas; Water content; Wind; Wind speed; Winter
• ISSN: 2347-4327; 0253-4126; 0973-774X
• DOI: 10.1007/s12040-019-1320-5

The occurrence of thick fog for longer duration in the northern regions of India disturbs the aviation, road transportation and other day to day activities. To understand the turbulence properties during fog period, we measured the atmospheric turbulent parameters along with carbon dioxide concentrations in the atmospheric boundary layer using eddy covariance system. These measurements were conducted over the agricultural station, Hisar, India, during the months of January–February of the year 2017 and 2018. During this period, total five thick fog events and three moderate fog events were captured. The turbulent parameter such as friction velocity, stability, sensible and latent heat fluxes are presented with respect to fog events. During the study period, the western disturbance persists over the north Pakistan and neighborhood region which advects the large amount of moisture into the lower troposphere and further through evaporation. It enforces stable and clear sky atmospheric conditions and reduces the surface temperature leading to the formation of strong surface-based temperature inversion which facilitates the fog formation in the study region. The land surface processes with neutral stability conditions in the surface layer, play significant role to sustain fog in the study region. The observations show substantial increase of carbon dioxide concentration during the thick fog events. The foggy days did not depict the diurnal pattern in flux of CO 2 . The anomalies of the meteorological parameters during foggy days and clear sky are analyzed. The foggy conditions (04:00–10:00 h, IST) are found to be characterized with low wind speed, high relative humidity with remarkable fluctuations in dew point temperature. Also, the sensible and latent heat flux shows remarkable changes during foggy and clear sky conditions.