Figure - available from: Frontiers in Environmental Science
This content is subject to copyright.
Diurnal cycle averaged over 2012–2019 for all days of the year for (A) 1.5-m temperature (°C), (B) temperature difference (°C) between 1.5 and 60 m as an indication of the stability of the near-surface atmosphere, (C) relative humidity (RH) at 1.5-m (%).
Source publication
In this study, we characterize the meteorological conditions and planetary boundary layer dynamics in western United Arab Emirates based on 2012–2020 in-situ measurements. This multi-year analysis is then complemented by an intensive field-campaign in winter 2021 from which we address the main patterns of the atmospheric circulation and the boundar...
Similar publications
Plain Language Summary
Low‐altitude marine layer clouds shade and cool coastal California in spring and summer. When these clouds are low enough that the base of the cloud intercepts terrain (which is known as fog), they additionally add moisture to the landscape during a typically dry time of year in California. Future trends in coastal low cloudi...
Citations
... IRBT is a widely recognized metric utilized to infer convection on regional and global scales (e.g., Machado et al., 1998;Nelli et al., 2022;Rao et al., 2013;Reddy & Rao, 2018). In order to discern cloud types at the WISE-UAE site, we adopted the IRBT thresholds specified by Rao et al. (2013) and Reddy and Rao (2018). ...
... This observation is expected, as the SHAMS location is further inland compared to other coastal locations, such as Barakah and Abu Dhabi. Previous studies conducted at Barakah reported the persistent occurrence of strong northwesterly winds for several days when the location is under the influence of favorable synoptic conditions (Abida et al., 2022;Nelli et al., 2022;Weston et al., 2022). ...
... This study determines fog events using metrics such as horizontal visibility and relative humidity (RH). Initially, fog occurrence times are detected during periods when the horizontal visibility is less than or equal to 1 km and RH is greater than 93% (e.g., Fonseca et al., 2023;Nelli et al., 2022;Thota et al., 2020;Weston et al., 2022). Subsequently, a visual inspection of 15-min SEVIRI Fog RGB images is conducted to confirm the presence of fog at the detected times. ...
The Empty Quarter Desert, one of Earth's major dust sources, frequently experiences dust storms due to wind erosion. Despite its significance as a primary dust source on a global scale, in‐situ observations from this region had not been reported until very recently. In summer 2022, the WInd‐blown Sand Experiment (WISE) Phase‐1 was initiated in the Empty Quarter Desert of the United Arab Emirates, and continued until 7 February 2023. Utilizing a diverse array of instruments, we measured winds, temperature, humidity, radiation fluxes, saltation, and the physical and optical properties of dust aerosols, atmospheric electric fields, and soil characteristics. A total of 38 distinct sand‐saltation events were recorded from September 2022 to February 2023, with activity peaking between 13:00 and 14:00 local time. Key findings include the identification of dominant wind patterns, and the measurement of the average aerodynamic roughness length (z0) at 0.8 ± 0.6 mm, and the thermal roughness length (zh) at 0.3 ± 0.5 mm—the first estimation of zh for this area. In‐situ observations revealed that dust particle concentrations near the surface increased 1.7‐fold on days with saltation compared to days without it. Moreover, we determined a wind‐speed threshold for initiating saltation at 7.70 m s⁻¹. This comprehensive data set significantly advances our understanding of atmospheric‐soil interactions and sand movement dynamics, providing invaluable insights for ongoing research into desert environments and the global dust cycle.
... The presence of dust also impacts the surface radiation fields ( Fig. 1c-e,d), in particular the longwave radiation flux. In the Arabian Peninsula, dust emission is mostly associated with the Shamal winds, which arise from the pressure gradient between the subtropical high over northern Saudi Arabia and the eastern Mediterranean and the monsoon trough 55,[121][122][123] . Dry cyclones 43,124 and cut-off lows 58 are also important dust lifting mechanisms here. ...
... In winter, the Siberian anticyclone over Asia, and the subtropical high over the northeastern Atlantic extending into northern Africa, with central pressures in excess of 1020 hPa, exert the largest control, with the African thermal low shifting equatorwards 115 (Fig. 2b). In both North Africa and the Arabian Peninsula, the dust emission is reduced in the colder months ( Fig. 2d), but it does occur, mostly in association with mid-latitude weather systems 122,125,126 . ...
Observational and reanalysis datasets reveal a northward shift of the convective regions over northern Africa in summer and an eastward shift in winter in the last four decades, with the changes in the location and intensity of the thermal lows and subtropical highs also modulating the dust loading and cloud cover over the Middle East and North Africa region. A multi-model ensemble from ten models of the Coupled Model Intercomparison Project—sixth phase gives skillful simulations when compared to in-situ measurements and generally captures the trends in the ERA-5 data over the historical period. For the most extreme climate change scenario and towards the end of the twenty-first century, the subtropical highs are projected to migrate poleward by 1.5°, consistent with the projected expansion of the Hadley Cells, with a weakening of the tropical easterly jet in the summer by up to a third and a strengthening of the subtropical jet in winter typically by 10% except over the eastern Mediterranean where the storm track is projected to shift polewards. The length of the seasons is projected to remain about the same, suggesting the warming is likely to be felt uniformly throughout the year.
... Summer convective events occur predominantly i) around the Al Hajar and Sarawat mountains, where they are primarily driven by the interaction of the daytime sea-breeze flow with the topographic circulation and can lead to local accumulations of more than 100 mm of rain (Branch et al., 2020;Francis et al., 2021;Parajuli et al., 2022); ii) in coastal parts of Oman and Yemen, associated with the Asian monsoon (Kwarteng et al., 2009), with more than 400 mm of precipitation on average falling in the mountainous terrain in Yemen in a given year (Hasanean and Almazroui, 2015). Air temperatures are typically in the range 5°C-25°C in winter and 25°C-45°C in the summer, with the northwestern region being the coldest year-round and with the highest temperatures in the Rub' Al Khali (or Empty Quarter) desert, except in winter where the warmest areas are those bordering the Red Sea Ajjur and Al-Ghamdi, 2021;Nelli et al., 2022). The whole region witnesses frequent dust storms (Francis et al., 2020;Francis et al., 2023a) mostly driven by Shamal winds (Bou Karam Francis et al., 2017), dry cyclones associated with reduced amounts of moisture and clouds but important drivers of dust emission (Bou Karam et al., 2009;Francis et al., 2019a;Francis et al., 2020), density currents from convection (Francis et al., 2019b;Francis et al., 2023a), and cold fronts from mid-latitudes Nelli et al., 2022). ...
... Air temperatures are typically in the range 5°C-25°C in winter and 25°C-45°C in the summer, with the northwestern region being the coldest year-round and with the highest temperatures in the Rub' Al Khali (or Empty Quarter) desert, except in winter where the warmest areas are those bordering the Red Sea Ajjur and Al-Ghamdi, 2021;Nelli et al., 2022). The whole region witnesses frequent dust storms (Francis et al., 2020;Francis et al., 2023a) mostly driven by Shamal winds (Bou Karam Francis et al., 2017), dry cyclones associated with reduced amounts of moisture and clouds but important drivers of dust emission (Bou Karam et al., 2009;Francis et al., 2019a;Francis et al., 2020), density currents from convection (Francis et al., 2019b;Francis et al., 2023a), and cold fronts from mid-latitudes Nelli et al., 2022). Figure 2A shows the total CO 2 anthropogenic emissions, as given by the EDGARv8 dataset, for 2015 and the difference between 2022 and 2015 expressed as the ratio of the emissions in the 2 years. ...
The Middle East has major sources of anthropogenic carbon dioxide (CO2) emissions, but a dearth of ground-based measurements precludes an investigation of its regional and temporal variability. This is achieved in this work with satellite-derived estimates from the Orbiting Carbon Observatory-2 (OCO-2) and OCO-3 missions from September 2014 to February 2023. The annual maximum and minimum column (XCO2) concentrations are generally reached in spring and autumn, respectively, with a typical seasonal cycle amplitude of 3–8 ± 0.5 ppmv in the Arabian Peninsula rising to 8–10 ± 1 ppmv in the mid-latitudes. A comparison of the seasonal-mean XCO2 values with the CO2 emissions estimated using the divergence method stresses the role played by the sources and transport of CO2 in the spatial distribution of XCO2, with anthropogenic emissions prevailing in arid and semi-arid regions that lack persistent vegetation. In the 8-year period 2015–2022, the XCO2 concentration in the United Arab Emirates (UAE) increased at a rate of about 2.50 ± 0.04 ppmv/year, with the trend empirical orthogonal function technique revealing a hotspot over northeastern UAE and southern Iran in the summer where anthropogenic emissions peak and accumulate aided by low-level wind convergence. A comparison of the satellite-derived CO2 concentration with that used to drive climate change models for different emission scenarios in the 8-year period revealed that the concentrations used in the latter is overestimated, with maximum differences exceeding 10 ppmv by 2022. This excess in the amount of CO2 can lead to an over-prediction of the projected increase in temperature in the region, an aspect that needs to be investigated further. This work stresses the need for a ground-based observational network of greenhouse gas concentrations in the Middle East to better understand its spatial and temporal variability and for the evaluation of remote sensing observations as well as climate models.
... In-situ measurements of fog droplets carried out over western UAE, reveal a bimodal distribution in droplet number concentration, with modes at 4.5 μm and 22-25 μm (Abida et al., 2023;Nelli et al., 2022;Weston et al., 2022). The primary factors contributing to fog creation in the region encompass local-scale circulations (land-sea-breeze), calm conditions during the night, and a stable nocturnal boundary layer. ...
... The above-mentioned data is analyzed for WISE-UAE Phase-1 period, which spanned from 25 July 2022 to 07 February 2023, to quantify the impact of foggy conditions on the measured electric field. We gain insight into the fog's spatial extent by analyzing false-color red-green-blue (RGB) satellite images from the Spinning Enhanced Visible and Infrared Imager (SEVIRI) on the Meteosat Second Generation spacecraft Nelli et al., 2022). These RGB images are updated every 15 min and offer a spatial resolution of approximately 5.6 km (0.05 • × 0.05 • ), covering the geographic bounds of 60 • S-60 • N and 60 • W-60 • E. For atmospheric field data, we utilized the European Center for Medium Range Weather Forecasting's (ECMWF) ERA-5 reanalysis datasets, as detailed in Hersbach et al. (2018aHersbach et al. ( , 2018bHersbach et al. ( , 2019aHersbach et al. ( , 2019b. ...
... In this study, fog cases are detected using horizontal visibility measurements, relative humidity (RH, 2-m height), and wind speed (2.25 m and 10-m heights). Initially, fog is detected subject that the horizontal visibility is less than or equal to 1 km, and that RH is greater than 90% (Temimi et al., 2020a;Mohan et al., 2020;Weston et al., 2022;Nelli et al., 2022;Fonseca et al., 2023). Subsequently, a visual inspection of 15-min SEVIRI Fog RGB images is conducted to confirm the presence of fog at the detected times Nelli et al., 2022). ...
For the first time, the changes in the atmospheric electric field (Ez) during foggy conditions is studied in a hyper-arid region; the United Arab Emirates (UAE), using comprehensive measurements during the Wind-blown Sand Experiment (WISE)-UAE. The longer the fog persists, the more variable Ez becomes, primarily due to the fog's ability to absorb and redistribute the charges of the atmospheric small ions. This absorption alters the ion balance, affecting electrical conductivity within the atmosphere, which in turn leads to sustained alterations in Ez. A record high Ez value of 2571 V m-1 was measured during a long-lasting fog event. Ez values returned to normal during the fog dissipation phase. The results of this work can be applied to develop techniques for fog harvesting and to improve fog forecasting by accounting for the effect of the electric field on fog lifetime and characteristics
... The Fernald-method (Fernald, 1984) is used to retrieve the aerosol extinction coefficient profile from backscattered signals. The dust impact on surface radiation fluxes was quantified utilizing netradiometer (Kipp and Zonen, 2022) measurements from a micrometeorological tower located at Barakah (asterisk in Fig. 1c; Nelli et al., 2022). In situ observations are also taken at Barakah by a portable weather station Nelli et al., 2022). ...
... The dust impact on surface radiation fluxes was quantified utilizing netradiometer (Kipp and Zonen, 2022) measurements from a micrometeorological tower located at Barakah (asterisk in Fig. 1c; Nelli et al., 2022). In situ observations are also taken at Barakah by a portable weather station Nelli et al., 2022). It measures 2-m temperature, relative humidity and 10-m wind speed and direction data every 60 s by a Lufft WS501-UMB (Weather Sensor 501 -Universal Measurement Bus system) smart weather sensor (Lufft, 2022). ...
Dust events have occurred over the Urmia Lake Basin in northwestern Iran for many years. In this study, we identified the mechanism and source of dust events in the region and assessed the ability of the Regional Climate Model (RegCM) to simulate these events. The observation data includes horizontal visibility and present weather phenomena achieved in Tabriz, Urmia, and Saqez stations. The ERA5, MERRA-2, and CAMS data were prepared for this research. The long-term dusty day analysis was conducted from 2000 to 2019. The synoptic-dynamic analysis and RegCM simulations were done during dust events on 28-31 October 2017—the HYSPLIT model and MODIS image usage to consider more detail. The results show that the Urmia Basin experiences two peaks, dusty days in the May and autumn months, including September and October. The persistent and widespread dust event in Urmia resulted from the approaching trough at 500 hPa to the north of Saudi Arabia and Iraq, trigged low pressure and increasing wind speed over the area. Based on the synoptic-dynamic analysis, MODIS satellite images, and the outputs of HYSPLIT, Iraq deserts were the primary source of dust on 28-31 October 2017. The dust distribution in the RegCM model, MERRA-2 data, and MODIS image agree. The RegCM aerosol optical depth (AOD) output time series agreed with MERRA-2 data, with a correlation coefficient of 0.84 and an index of agreement (IOA) of 0.56 in Urmia stations. The local dust source detected by the surface emission flux in the eastern Lake Urmia close to Tabriz can be a reason for the dustiest day in Tabriz. The AOD diurnal variation obtained from RegCM, MERRA-2, and CAM are similar in Tabriz and Urmia. The AOD of RegCM is underestimated compared to MERRA-2 and CAM in three selected stations.
... The country is relatively flat except for the Al Hajar mountains located in the northeastern part, with the highest peak (Jebel Jais) reaching around 1,700 m above ground level. The UAE features an arid climate, with air temperatures generally in the range 15-20°C in winter to 30-40°C in the summer Nelli et al., 2022), Figure 2A, and annual precipitation amounts ranging from around 30 mm in the inland (Rub' Al Khali or the Empty Quarter) desert to 120 mm at the Al Hajar mountains , Figure 2B The vast majority of the precipitation falls in the cold months from December to March in association with mid-latitude weather disturbances (Wehbe et al., 2017;Wehbe et al. 2018;Wehbe et al. 2020). Summertime rainfall, although less common, does occur, and is more frequent on the eastern side along the Al Hajar mountains, Figure 2B Here, convection develops due to the interaction of the sea-breeze and topography-driven flows with the cyclonic circulation associated with the thermal/heat low, occasionally aided by the presence of a mid-level trough (Branch et al., 2020;Francis et al., 2021;Fonseca et al., 2022). ...
... Summertime rainfall, although less common, does occur, and is more frequent on the eastern side along the Al Hajar mountains, Figure 2B Here, convection develops due to the interaction of the sea-breeze and topography-driven flows with the cyclonic circulation associated with the thermal/heat low, occasionally aided by the presence of a mid-level trough (Branch et al., 2020;Francis et al., 2021;Fonseca et al., 2022). The prevailing wind flow is from the northwest, with typical speeds of 1-3 m s −1 (Naizghi and Ouarda, 2017;Nelli et al., 2022), Figure 2A, and with a marked sea-breeze circulation on a daily scale (Eager et al., 2008;Weston et al., 2021). The moist air arriving in the UAE comes primarily from the Arabian Gulf, Figure 2A However, and in particular in the colder months, the Red Sea, Arabian Sea and Mediterranean Sea are also important moisture sources for the eastern Arabian Peninsula (Massoud et al., 2020;Nelli et al., 2021;Fonseca et al., 2023). ...
... Javadinejad et al. (2019) noted a positive relationship between the methane gas concentration and the 2-m temperature, and a negative relationship with the vegetation, precipitation and relative humidity. As reported in Nelli et al. (2020), Nelli et al. (2022), and as seen in Figure 2, summer months feature the highest air temperatures and the lowest precipitation and relative humidity values (the specific humidity is higher due to the strong evaporation from the Arabian Gulf, but the relative humidity is lower owing to the higher temperatures). This is in line with the findings of Javadinejad et al. (2019), with the region largely devoid of vegetation (e.g. ...
Methane (CH4) is a potent greenhouse gas with an important contribution to global warming. While national and international efforts have been put in place to reduce methane emissions, little is known about its variability, especially in hotspot regions where natural and anthropogenic emissions are compounded. In this study, the current state of CH4 concentrations and their trends over the United Arab Emirates (UAE) and surrounding region are investigated with satellite and reanalysis data. CH4 concentrations have increased over the last 5 years, with a trend in the satellite-derived column values (XCH4) of about 9 ppb/year. A clear annual cycle is detected in XCH4, with an amplitude of up to 75 ppb and peak values in the warmer months. The largest concentrations are found in coastal sites, where sabkhas and landfills are present, and along the Al Hajar mountains, where agricultural activities and microhabitats that may host CH4-producing microbes occur and where advection by the background flow is likely an important contributor. The reanalysis data shows a good agreement with the satellite-derived estimates in terms of the spatial pattern, but the magnitudes are smaller by up to 50 ppb, due to deficiencies in the data assimilated. Surface CH4 concentrations in the reanalysis data account for more than 50% of the corresponding XCH4 values, and exhibit a seasonal cycle with the opposite phase due to uncertainties in the emissions inventory. Our findings provide an overview of the state of CH4 concentration in the UAE and surrounding region, and may aid local authorities to propose the appropriate emission reduction strategies in order to meet the proposed net-zero greenhouse gas emission target by 2050. This study highlights the need for the establishment in the Arabian Peninsula region of a ground-based observational network for greenhouse gas concentrations which is still lacking to date.
... The Fernald-method (Fernald, 1984) is used to retrieve the aerosol extinction coefficient profile from backscattered signals. The dust impact on surface radiation fluxes was quantified utilizing netradiometer (Kipp and Zonen, 2022) measurements from a micrometeorological tower located at Barakah (asterisk in Fig. 1c; Nelli et al., 2022). In situ observations are also taken at Barakah by a portable weather station Nelli et al., 2022). ...
... The dust impact on surface radiation fluxes was quantified utilizing netradiometer (Kipp and Zonen, 2022) measurements from a micrometeorological tower located at Barakah (asterisk in Fig. 1c; Nelli et al., 2022). In situ observations are also taken at Barakah by a portable weather station Nelli et al., 2022). It measures 2-m temperature, relative humidity and 10-m wind speed and direction data every 60 s by a Lufft WS501-UMB (Weather Sensor 501 -Universal Measurement Bus system) smart weather sensor (Lufft, 2022). ...
Large amounts of dust in the air can disrupt daily activities and pose a threat to human health. In May 2022, consecutive major dust storms occurred over the Middle East resulting in severe environmental, social and health impacts. In this study, we investigate the exceptional factors driving these storms and the effects of the dust clouds. Using a combination of satellite, in-situ and reanalysis datasets, we identify the atmospheric triggers for the occurrence of these severe dust storms, characterize their three-dimensional structure and evaluate the dust radiative impact. The dust emission was promoted by density currents emanating from deep convection over Turkey. The convective systems were triggered by cut-off lows from mid-latitudes fed by moisture from African atmospheric rivers. The dust clouds were transported southward at 4 km in altitudes but sunk to ground levels when they reached the southern Arabian Peninsula due to strong subsidence. At a station in coastal UAE, the dust caused a 350 W m-2 drop in the surface downward shortwave flux and a 70W m-2 increase in the longwave one during the dust episodes. This contributed to a 9ºC increase in nighttime temperatures which exacerbated the effects of the heat for the population. The newly highlighted mechanism for dust emission in the Middle East, in which a cut-off low interacts with an atmospheric river, as well as direct observations of the dust impact on the radiative budget can contribute to reducing associated uncertainties in climate models.
... A comparison with the radiation fluxes observed in fog events elsewhere suggests the fog in the UAE is more optically opaque. This is consistent with Weston et al. (2022) who noted that the concentration of cloud droplets in a fog event over western UAE was up to seven times higher than that reported in the literature, likely due to the close proximity to a major aerosol source (Kaku et al., 2016;Francis et al., 2022;Nelli et al., 2022). ...
In this study, the link between the occurrence of consecutive fog days in the United Arab Emirates (UAE) and the associated synoptic-scale circulation is investigated. This is particularly pertinent, as such a link may provide an important predictive skill for a phenomenon that has a pronounced impact on road and air traffic but is still poorly simulated by numerical models. A cluster analysis of all consecutive fog days from January 1983 to December 2021 indicated that the positive phase of the East
Atlantic/Western Russia teleconnection pattern, Eastern Pacific La Nina events, and the circumglobal wavenumber 5 pattern promote the occurrence of multiple fog days in the UAE. The fog’s radiative impacts, as estimated from satellite data, revealed that the fog in the UAE is more optically thick than that observed elsewhere. A trend analysis over the period 1983 to 2021 revealed that consecutive fog events have become more frequent and longer-lasting but less intense (i.e., associated with higher values of visibility). The fog’s spatial extent over the UAE at its mature stage has also decreased over time. An analysis of the trends in the surface and top of atmosphere (TOA) radiative fluxes indicated that over the period 2000-2021, the fog clouds have likely become less reflective, with a statistically significant decrease in the surface downward shortwave and TOA upward longwave radiation fluxes. Long-term measurements of fog microphysics in the region are needed to better understand the variability in the properties of the fog cloud droplets.
Arid regions like the United Arab Emirates (UAE) face a dire challenge of scarce water resources and unpredictable climate patterns. This study investigates the efficacy of advanced Machine Learning (ML) techniques in enhancing rainfall prediction within hyper-arid environments. Leveraging an extensive 30-year dataset from 1991 to 2020, this study harnessed the power of XGBoost, LSTM, Random Forest (RF), Gradient Boost (GB), Support Vector Machine (SVM), Multilayer Perceptron (MLP), Linear Regression (LR), and ensemble methods to significantly enhance the prediction accuracy of monthly rainfall over UAE. In the initial univariate analysis, focused solely on rainfall as the predictor, the ML models displayed encouraging performance during the training phase, achieving an impressive correlation coefficient (CC) of 0.88 for both XGBoost and the ensemble models. However, their predictive efficacy witnessed a decline during the testing phase, where the maximum CC reached 0.45. In contrast, traditional models like Linear Regression and SVM, yielded subpar results in both training and testing, exhibiting correlation values lower than 0.3. To address these limitations, a multivariate analysis is conducted by incorporating additional meteorological parameters, including wind speed, temperature, humidity, and evapotranspiration. This augmentation proved highly beneficial as it substantially enhanced the models' predictive capacities during the testing period. The XGB achieves a CC of 0.76, LSTM improves from 0.21 to 0.71, and stacked models exhibit promising behavior jumping from an average of 0.44 to 0.82 during the testing periods. Additionally, we performed a sensitivity analysis utilizing LASSO regression, which revealed that wind speed and minimum temperature emerged as the most influential parameters for monthly rainfall prediction in the arid context. These two meteorological factors exerted a substantial impact on the accuracy of our predictive models, underscoring their significance in understanding and forecasting rainfall patterns in hyper-arid regions, such as the United Arab Emirates. The identification of these key drivers further strengthens the foundation for effective water resource management and climate adaptation strategies in such challenging environments. This study provides valuable insights for water resource planning, agriculture, and climate resilience strategies in hyper-arid regions. Further research can build upon these results to enhance rainfall prediction models and support sustainable development in arid regions.
Fog augments the wet deposition of airborne particles entrained in its hydrometeors. This article aims to characterize fog deposition processes around the Barakah nuclear power plant (BNPP), in the United Arab Emirates (UAE), and assess the potential impact of fog on the deposition rate of radionuclides in case of an accidental release. To this end, the microphysics of twelve radiation fog events, typical in such arid climate, were measured during the winter seasons of 2021 and 2022 using a fog monitor that was deployed at the BNPP. The impact of fog deposition on the settling of radionuclides is investigated based on model simulations using the Weather Research Forecasting (WRF) model with the MYJ PBL scheme and FLEXPART. All fog events are found to share a common feature of a bimodal distribution in droplet number concentration (Nc), with modes at 4.5 μm and 23.16 μm. It was pointed out that despite the high proportion of smaller droplets in the fog associated with the fine mode, the greatest contribution to the liquid water content (LWC) comes essentially from medium to large droplets between 10 and 35 μm. The deposition flux of fog water at the site and the fog droplet deposition velocity were estimated using an Eddy Covariance (EC) onsite. Typical mean values for fog droplet deposition velocity are found to range between 2.11 and 7.87 cm s-1. The modeling results show that fog deposition contributed by 30–40 % to the total ground deposition of 137Cs, highlighting the importance of incorporating fog deposition as an additional scavenging mechanism in dispersion modeling under foggy conditions.
