scholarly journals Urban population exposure to NO<sub><i>x</i></sub> emissions from local shipping in three Baltic Sea harbour cities – a generic approach

2019 ◽  
Vol 19 (14) ◽  
pp. 9153-9179 ◽  
Author(s):  
Martin Otto Paul Ramacher ◽  
Matthias Karl ◽  
Johannes Bieser ◽  
Jukka-Pekka Jalkanen ◽  
Lasse Johansson
Keyword(s):  
Baltic Sea ◽  
Large Scale ◽  
Transport Model ◽  
Population Data ◽  
Outdoor Exposure ◽  
Population Exposure ◽  
Population Activity ◽  
Port Area ◽  
Dynamic Population ◽  
The Impact

Abstract. Ship emissions in ports can have a significant impact on local air quality (AQ), population exposure and therefore human health in harbour cities. We determined the impact of shipping emissions in harbours on local AQ and population exposure in the Baltic Sea harbour cities Rostock (Germany), Riga (Latvia) and the urban agglomeration of Gdańsk–Gdynia (Poland) for 2012. An urban AQ study was performed using a global-to-local chemistry transport model chain with the EPISODE-CityChem model for the urban scale. We simulated NO2, O3 and PM concentrations in 2012 with the aim of determining the impact of local shipping activities on population exposure in Baltic Sea harbour cities. Based on simulated concentrations, dynamic population exposure to outdoor NO2 concentrations for all urban domains was calculated. We developed and used a novel generic approach to model dynamic population activity in different microenvironments based on publicly available data. The results of the new approach are hourly microenvironment-specific population grids with a spatial resolution of 100 m × 100 m. We multiplied these grids with surface pollutant concentration fields of the same resolution to calculate total population exposure. We found that the local shipping impact on NO2 concentrations is significant, contributing 22 %, 11 % and 16 % to the total annually averaged grid mean concentration for Rostock, Riga and Gdańsk–Gdynia, respectively. For PM2.5, the contribution of shipping is substantially lower, at 1 %–3 %. When it comes to microenvironment-specific exposure to annual NO2, the highest exposure to NO2 from all emission sources was found in the home environment (54 %–59 %). Emissions from shipping have a high impact on NO2 exposure in the port area (50 %–80 %), while the influence in home, work and other environments is lower on average (3 %–14 %) but still has high impacts close to the port areas and downwind of them. Besides this, the newly developed generic approach allows for dynamic population-weighted outdoor exposure calculations in European cities without the necessity of individually measured data or large-scale surveys on population data.

scholarly journals Urban population exposure to NO<sub>x</sub> emissions from local shipping in three Baltic Sea harbour cities – a generic approach

2019 ◽  
Author(s):  
Martin Otto Paul Ramacher ◽  
Matthias Karl ◽  
Johannes Bieser ◽  
Jukka-Pekka Jalkanen ◽  
Lasse Johansson
Keyword(s):  
Baltic Sea ◽  
Large Scale ◽  
Transport Model ◽  
Population Data ◽  
Population Exposure ◽  
Population Activity ◽  
Port Area ◽  
The Baltic ◽  
Dynamic Population ◽  
The Impact

Abstract. Ship emissions in ports can have a significant impact on local air quality (AQ), population exposure, and therefore human health in harbour cities. We determined the impact of shipping emissions on local AQ and population exposure in the Baltic Sea harbour cities Rostock (Germany), Riga (Latvia) and the urban agglomeration of Gdansk-Gdynia (Poland) for 2012. An urban AQ study was performed using a global-to-local Chemistry Transport Model chain with the EPISODE-CityChem model for the urban scale. We simulated NO2, O3 and PM concentrations in 2012 with the aim to determine the impact of local shipping activities to outdoor population exposure in Baltic Sea harbour cities. Based on simulated concentrations, dynamic population exposure on outdoor NO2 concentrations for all urban domains was calculated. We developed and used a novel generic approach to model dynamic population activity in different microenvironments based on publicly available data. The results of the new approach are hourly microenvironment-specific population grids with a spatial resolution of 100 × 100 m2. We multiplied these grids with surface pollutant concentration fields of the same resolution to calculate total population exposure. We found that the local shipping impact on NO2 concentrations is significant, contributing with 22 %, 11 %, and 16 % to the total annually averaged grid mean concentration for Rostock, Riga and Gdansk-Gdynia, respectively. For PM2.5, the contribution of shipping is substantially lower with 1–3 %. When it comes to microenvironment-specific exposure to annual NO2, the highest exposure to NO2 from all emission sources was found in the home environment (54–59 %). Emissions from shipping have a high impact on NO2 exposure in the port area (50–80 %) while the influence in home, work and other environments is lower on average (3–14 %), but still with high impacts close to the port areas and downwind of them. Besides this, the newly developed generic approach allows for dynamic population exposure calculations in European cities without the necessity of individually measured data or large-scale surveys on population data.

scholarly journals The impact of ship emissions on air quality and human health in the Gothenburg area – Part II: Scenarios for 2040

2020 ◽  
Vol 20 (17) ◽  
pp. 10667-10686
Author(s):  
Martin O. P. Ramacher ◽  
Lin Tang ◽  
Jana Moldanová ◽  
Volker Matthias ◽  
Matthias Karl ◽  
...  
Keyword(s):  
Air Quality ◽  
Health Effects ◽  
Urban Areas ◽  
Large Scale ◽  
Health Effect ◽  
Population Exposure ◽  
Future Scenarios ◽  
Port Area ◽  
The Future ◽  
The Impact

Abstract. Shipping is an important source of air pollutants, from the global to the local scale. Ships emit substantial amounts of sulfur dioxides, nitrogen dioxides, and particulate matter in the vicinity of coasts, threatening the health of the coastal population, especially in harbour cities. Reductions in emissions due to shipping have been targeted by several regulations. Nevertheless, effects of these regulations come into force with temporal delays, global ship traffic is expected to grow in the future, and other land-based anthropogenic emissions might decrease. Thus, it is necessary to investigate combined impacts to identify the impact of shipping activities on air quality, population exposure, and health effects in the future. We investigated the future effect of shipping emissions on air quality and related health effects considering different scenarios of the development of shipping under current regional trends of economic growth and already decided regulations in the Gothenburg urban area in 2040. Additionally, we investigated the impact of a large-scale implementation of shore electricity in the Port of Gothenburg. For this purpose, we established a one-way nested chemistry transport modelling (CTM) system from the global to the urban scale, to calculate pollutant concentrations, population-weighted concentrations, and health effects related to NO2, PM2.5, and O3. The simulated concentrations of NO2 and PM2.5 in future scenarios for the year 2040 are in general very low with up to 4 ppb for NO2 and up to 3.5 µg m−3 PM2.5 in the urban areas which are not close to the port area. From 2012 the simulated overall exposure to PM2.5 decreased by approximately 30 % in simulated future scenarios; for NO2 the decrease was over 60 %. The simulated concentrations of O3 increased from the year 2012 to 2040 by about 20 %. In general, the contributions of local shipping emissions in 2040 focus on the harbour area but to some extent also influence the rest of the city domain. The simulated impact of onshore electricity implementation for shipping in 2040 shows reductions for NO2 in the port of up to 30 %, while increasing O3 of up to 3 %. Implementation of onshore electricity for ships at berth leads to additional local reduction potentials of up to 3 % for PM2.5 and 12 % for SO2 in the port area. All future scenarios show substantial decreases in population-weighted exposure and health-effect impacts.

scholarly journals The impact of ship emissions on air quality and human health in the Gothenburg area – Part II: Scenarios for 2040

2020 ◽  
Author(s):  
Martin O. P. Ramacher ◽  
Lin Tang ◽  
Jana Moldanová ◽  
Volker Matthias ◽  
Matthias Karl ◽  
...  
Keyword(s):  
Air Quality ◽  
Health Effects ◽  
Urban Areas ◽  
Large Scale ◽  
Health Effect ◽  
Population Exposure ◽  
Future Scenarios ◽  
Port Area ◽  
The Future ◽  
The Impact

Abstract. Shipping is an important source of air pollutants, from the global to the local scale. Ships are emitting substantial amounts of sulphur dioxides, nitrogen dioxides and particulate matter in the vicinity of coasts, threatening the health of the coastal population, especially in harbour cities. Reductions of emissions due to shipping have been targeted by several regulations. Nevertheless, effects of these regulations come into force with temporal delays, global ship traffic is expected to grow in the future, and other land-based anthropogenic emissions might decrease. Thus, it is necessary to investigate combined impacts to identify the impact of shipping activities on air quality, population exposure and health-effects in the future. We investigated the future effect of shipping emissions on air quality and related health effects considering different scenarios of the development of shipping under current regional trends of economic growth and already decided regulations in the Gothenburg urban area in 2040. Additionally, we investigated the impact of a large-scale implementation of shore electricity in the port of Gothenburg. For this purpose, we established a one-way nested chemistry transport modelling (CTM) system from the global to the urban scale, to calculate pollutant concentrations, population weighted concentrations and health-effects related to NO2, PM2.5 and O3. The simulated concentrations of NO2 and PM2.5 in future scenarios for the year 2040 are in general very low with up to 4 ppb for NO2 and up to 3.5 µg/m3 PM2.5 in the urban areas which are not close to the port area. From 2012 the simulated overall exposure to PM2.5 decreased by approximately 30 % in simulated future scenarios, for NO2 the decrease was over 60 %. The simulated concentrations of O3 increased from year 2012 to 2040 by about 20 %. In general, the contributions of local shipping emissions in 2040 focus on the harbour area but to some extent also influence the rest of the city domain. The simulated impact of wide use of shore-site electricity for shipping in 2040 shows reductions for NO2 in the port with up to 30 %, while increasing O3 of up to 3 %. Implementation of on-shore electricity for ships at berth leads to additional local reduction potentials of up to 3 % for PM2.5 and 12 % for SO2 in the port area. All future scenarios show substantial decreases in population weighted exposure and health-effect impacts.

A novel approach for dynamic population activity in urban-scale exposure estimates

2020 ◽  
Author(s):  
Martin Otto Paul Ramacher ◽  
Matthias Karl ◽  
Eleni Athanasopolou ◽  
Anastasia Kakouri ◽  
Orestis Speyer ◽  
...  
Keyword(s):  
Air Pollution ◽  
Human Health ◽  
Transport Model ◽  
Population Level ◽  
Horizontal Resolution ◽  
Population Exposure ◽  
Night Time ◽  
Population Activity ◽  
Activity Data ◽  
Dynamic Population

&lt;p&gt;Population exposure estimates are used in epidemiological studies to evaluate health risks associated with impacts of air pollution on human health. Traditional approaches in exposure modelling assume that air pollutants' concentrations at the residential address of the study population are representative of overall exposure. This approach is acknowledged to introducing bias in the quantification of human health effects, as individual and population-level mobility is non-existent. To sufficiently model population numbers for exposure estimates, the dynamic population activity (DPA) must be known. Information on DPA is mostly derived from national or municipal surveys and is scarce.&lt;/p&gt;&lt;p&gt;We developed a generic approach to model DPA integrating the Copernicus Urban Atlas land use and land cover product with literature based and microenvironment-specific diurnal activity data (Ramacher et al. 2019) and moreover taking into account gridded monthly day- and night-time populations as derived in the ENACT project (https://ghsl.jrc.ec.europa.eu/enact.php), while also considering indoor and outdoor environments. This approach produces maps with distribution of citizens in various microenvironments (MEs) and hours of the day. These maps can consequently be used to calculate population-level outdoor exposure when paired with consistent spatio-temporal air pollution concentration fields. In this study, we applied the generic DPA approach to the cities of Hamburg (DE) and Athens (GR). Hourly, urban-scale pollutant concentrations were produced by the Chemistry Transport Model (CTM) EPISODE-CityChem (Karl et al. 2019) driven by detailed local emission inventories, 4D meteorological fields and regional pollutant boundary conditions for 2015. Both the concentrations for NO&lt;sub&gt;x&lt;/sub&gt;, O&lt;sub&gt;3&lt;/sub&gt; and PM&lt;sub&gt;2.5&lt;/sub&gt; as well as the DPA maps for Hamburg and Athens were simulated on a 100 m horizontal resolution grid, and were then combined to calculate population exposure. We additionally used gridded population densities (based on residential addresses) to calculate population exposure, i.e. following a static population approach. We compared the exposures from the two approaches to capture the effect of a population moving in space and time.&amp;#160;&lt;/p&gt;&lt;p&gt;The presented approach to account for dynamic instead of static population activity in urban population exposure calculations is beneficial for cities in European regions where relevant population data are missing. It is found that by taking into account movement of population through different urban environments as well as commuting per se, the overall exposure estimates are elevated when compared to a static approach. Furthermore, we have shown that by considering infiltration of outdoor concentrations to indoor environments there are substantial decreases in population exposure estimates. This approach and the implications on exposure estimates is believed to be of interest to air pollution health studies.&lt;/p&gt;

scholarly journals The Population Tracking Model: A Simple, Scalable Statistical Model for Neural Population Data

2017 ◽  
Vol 29 (1) ◽  
pp. 50-93 ◽  
Author(s):  
Cian O’Donnell ◽  
J. Tiago Gonçalves ◽  
Nick Whiteley ◽  
Carlos Portera-Cailliau ◽  
Terrence J. Sejnowski
Keyword(s):  
Statistical Model ◽  
Large Scale ◽  
Population Data ◽  
Population Coding ◽  
Network Activity ◽  
Neural Population ◽  
Population Activity ◽  
Tracking Model ◽  
Population Rate ◽  
Neural Population Activity

Our understanding of neural population coding has been limited by a lack of analysis methods to characterize spiking data from large populations. The biggest challenge comes from the fact that the number of possible network activity patterns scales exponentially with the number of neurons recorded ([Formula: see text]). Here we introduce a new statistical method for characterizing neural population activity that requires semi-independent fitting of only as many parameters as the square of the number of neurons, requiring drastically smaller data sets and minimal computation time. The model works by matching the population rate (the number of neurons synchronously active) and the probability that each individual neuron fires given the population rate. We found that this model can accurately fit synthetic data from up to 1000 neurons. We also found that the model could rapidly decode visual stimuli from neural population data from macaque primary visual cortex about 65 ms after stimulus onset. Finally, we used the model to estimate the entropy of neural population activity in developing mouse somatosensory cortex and, surprisingly, found that it first increases, and then decreases during development. This statistical model opens new options for interrogating neural population data and can bolster the use of modern large-scale in vivo Ca[Formula: see text] and voltage imaging tools.

Cropland carbon uptake delayed by 2019 U.S. Midwest floods

2020 ◽  
Author(s):  
Yi Yin ◽  
Branden Byrne ◽  
Junjie Liu ◽  
Paul Wennberg ◽  
Philipp Köhler ◽  
...  
Keyword(s):  
Large Scale ◽  
Transport Model ◽  
Atmospheric Transport ◽  
Gross Primary Production ◽  
Early Summer ◽  
Satellite Observations ◽  
Mitigation Strategies ◽  
Carbon Uptake ◽  
Vegetation Activity ◽  
The Impact

&lt;p&gt;While large-scale floods directly impact human lives and infrastructures, they also profoundly impact agricultural productivity. New satellite observations of vegetation activity and atmospheric CO&lt;sub&gt;2&lt;/sub&gt; offer the opportunity to quantify the effects of such extreme events on cropland carbon sequestration, which are important for mitigation strategies. Widespread flooding during spring and early summer 2019 delayed crop planting across the U.S. Midwest. As a result, satellite observations of solar-induced chlorophyll fluorescence (SIF) from TROPOspheric Monitoring Instrument (TROPOMI) and Orbiting Carbon Observatory (OCO-2) reveal a shift of 16 days in the seasonal cycle of photosynthetic activity relative to 2018, along with a 15% lower peak photosynthesis. We estimate the 2019 anomaly to have led to a reduction of -0.21 PgC in gross primary production (GPP) in June and July, partially compensated in August and September (+0.14 PgC). The extension of the 2019 growing season into late September is likely to have benefited from increased water availability and late-season temperature. Ultimately, this change is predicted to reduce the crop yield over most of the midwest Corn/Soy belt by ~15%. Using an atmospheric transport model, we show that a decline of ~0.1 PgC in the net carbon uptake during June and July is consistent with observed CO&lt;sub&gt;2&lt;/sub&gt; enhancements from Atmospheric Carbon and Transport - America (ACT-America) aircraft and OCO-2. This study quantifies the impact of floods on cropland productivity and demonstrates the potential of combining SIF with atmospheric CO&lt;sub&gt;2&lt;/sub&gt; observations to monitor regional carbon flux anomalies.&lt;/p&gt;

scholarly journals Droplet number uncertainties associated with CCN: an assessment using observations and a global model adjoint

2013 ◽  
Vol 13 (8) ◽  
pp. 4235-4251 ◽  
Author(s):  
R. H. Moore ◽  
V. A. Karydis ◽  
S. L. Capps ◽  
T. L. Lathem ◽  
A. Nenes
Keyword(s):  
Large Scale ◽  
Transport Model ◽  
Cloud Droplet ◽  
Number Concentration ◽  
Chemical Transport Model ◽  
Anthropogenic Aerosol ◽  
Cloud Properties ◽  
Stratiform Clouds ◽  
The Impact ◽  
Indirect Forcing

Abstract. We use the Global Modelling Initiative (GMI) chemical transport model with a cloud droplet parameterisation adjoint to quantify the sensitivity of cloud droplet number concentration to uncertainties in predicting CCN concentrations. Published CCN closure uncertainties for six different sets of simplifying compositional and mixing state assumptions are used as proxies for modelled CCN uncertainty arising from application of those scenarios. It is found that cloud droplet number concentrations (Nd) are fairly insensitive to the number concentration (Na) of aerosol which act as CCN over the continents (∂lnNd/∂lnNa ~10–30%), but the sensitivities exceed 70% in pristine regions such as the Alaskan Arctic and remote oceans. This means that CCN concentration uncertainties of 4–71% translate into only 1–23% uncertainty in cloud droplet number, on average. Since most of the anthropogenic indirect forcing is concentrated over the continents, this work shows that the application of Köhler theory and attendant simplifying assumptions in models is not a major source of uncertainty in predicting cloud droplet number or anthropogenic aerosol indirect forcing for the liquid, stratiform clouds simulated in these models. However, it does highlight the sensitivity of some remote areas to pollution brought into the region via long-range transport (e.g., biomass burning) or from seasonal biogenic sources (e.g., phytoplankton as a source of dimethylsulfide in the southern oceans). Since these transient processes are not captured well by the climatological emissions inventories employed by current large-scale models, the uncertainties in aerosol-cloud interactions during these events could be much larger than those uncovered here. This finding motivates additional measurements in these pristine regions, for which few observations exist, to quantify the impact (and associated uncertainty) of transient aerosol processes on cloud properties.

scholarly journals Wpływ zmiany pełnionych funkcji na fizjonomię portu w Ustce

2021 ◽  
Vol 24 (3) ◽  
pp. 64-75
Author(s):  
Tomasz Michalski
Keyword(s):  
Functional Analysis ◽  
Large Scale ◽  
Wind Farms ◽  
Residential Facilities ◽  
The Other ◽  
Recreational Fishing ◽  
The Past ◽  
Port Area ◽  
Production Activity ◽  
The Impact

Celem artykułu jest przedstawienie wpływu zmiany funkcji pełnionych przez port w Ustce na jego fizjonomię. Analiza funkcjonalna dotyczy głównie okresu 2016-2019. Natomiast analizę fizjonomii przeprowadzono dla 2021 r. Stwierdzono, że podstawowa dla portów funkcja przeładunkowa jest w Ustce pełniona w minimalnym stopniu. Funkcja turystyki morskiej jest realizowana w stopniu niewystarczającym (brak mariny jachtowej), a żeglugi pasażerskiej nie jest realizowana. Port pełni nadal funkcję rybołówstwa i wędkarstwa rekreacyjnego, ale w stopniu mniejszym, niż w przeszłości. Działalność produkcyjna na terenie portu nie jest już prowadzona, chociaż w przeszłości była realizowana na dużą skalę. Istnieje szansa, że w porcie rozwinie się funkcja związana z konserwacją i eksploatacją farm wiatrowych. Obecnie w porcie rozwijają się silnie funkcja turystyczna (gastronomia, hotele itd.) oraz mieszkaniowa. Wprowadzenie tej ostatniej funkcji do portu uznano za błąd. Zmiany funkcji powodują zmiany w fizjonomii portu. Znikają obiekty przemysłowe i przeładunkowe, a na ich miejsce pojawiają się obiekty z funkcją hotelową i gastronomiczną oraz mieszkaniowe, aczkolwiek zmiany te zachodzą z dużym opóźnieniem. The impact of changes in the performed functions on the physiognomy of the port in Ustka The aim of the article is to present the impact of changes in the functions performed by the port in Ustka on its physiognomy. The functional analysis mainly covers the period of 2016-2019, while the analysis of the physiognomy was conducted for 2021. It was found that the basic trans-shipment function is played to a minimum extent in Ustka. The function of sea tourism is insufficiently realized (no yacht marina), and the function of passenger shipping is not performed. The function of recreational fishing and angling is still performed by the port, but to a lesser extent than in the past. There is no longer any production activity in the port area, although in the past it was carried out on a large scale. There is a chance that the port will develop a function related to the maintenance and operation of wind farms. On the other hand, the tourist function (gastronomy, hotels, etc.) and housing are strongly developing in the port. Introducing the latter function into the port was considered a mistake. Changes in functions result in changes to the port physiognomy. Industrial and trans-shipment facilities are disappearing and replaced with hotel, catering and residential facilities. However, these changes are long delayed.

scholarly journals Modeling lightning-NO<sub><i>x</i></sub> chemistry at sub-grid scale in a global chemical transport model

2015 ◽  
Vol 15 (23) ◽  
pp. 34091-34147 ◽  
Author(s):  
A. Gressent ◽  
B. Sauvage ◽  
D. Cariolle ◽  
M. Evans ◽  
M. Leriche ◽  
...  
Keyword(s):  
Large Scale ◽  
Transport Model ◽  
Chemical Transport ◽  
Horizontal Resolution ◽  
Parameter Estimates ◽  
Plume Dispersion ◽  
Chemical Transport Model ◽  
Tropical Regions ◽  
The Impact ◽  
Lightning Nox

Abstract. For the first time, a plume-in-grid approach is implemented in a chemical transport model (CTM) to parameterize the effects of the non-linear reactions occurring within high concentrated NOx plumes from lightning NOx emissions (LNOx) in the upper troposphere. It is characterized by a set of parameters including the plume lifetime, the effective reaction rate constant related to NOx-O3 chemical interactions and the fractions of NOx conversion into HNO3 within the plume. Parameter estimates were made using the DSMACC chemical box model, simple plume dispersion simulations and the mesoscale 3-D Meso-NH model. In order to assess the impact of the LNOx plume approach on the NOx and O3 distributions at large scale, simulations for the year 2006 were performed using the GEOS-Chem global model with a horizontal resolution of 2° × 2.5°. The implementation of the LNOx parameterization implies NOx and O3 decrease at large scale over the region characterized by a strong lightning activity (up to 25 and 8 %, respectively, over Central Africa in July) and a relative increase downwind of LNOx emissions (up to 18 and 2 % for NOx and O3, respectively, in July) are derived. The calculated variability of NOx and O3 mixing ratios around the mean value according to the known uncertainties on the parameter estimates is maximum over continental tropical regions with ΔNOx [−33.1; +29.7] ppt and ΔO3 [−1.56; +2.16] ppb, in January, and ΔNOx [−14.3; +21] ppt and ΔO3 [−1.18; +1.93] ppb, in July, mainly depending on the determination of the diffusion properties of the atmosphere and the initial NO mixing ratio injected by lightning. This approach allows (i) to reproduce a more realistic lightning NOx chemistry leading to better NOx and O3 distributions at the large scale and (ii) focus on other improvements to reduce remaining uncertainties from processes related to NOx chemistry in CTM.

scholarly journals Impact of upper-level jet-generated inertia-gravity waves on surface wind and precipitation

2007 ◽  
Vol 7 (6) ◽  
pp. 15873-15909 ◽  
Author(s):  
C. Zülicke ◽  
D. H. W. Peters
Keyword(s):  
Baltic Sea ◽  
Gravity Waves ◽  
Large Scale ◽  
Surface Wind ◽  
Synoptic Situation ◽  
Strong Wind ◽  
The Baltic Sea ◽  
The Baltic ◽  
The Impact ◽  
Inertia Gravity Waves

Abstract. A meteorological case study for the impact of inertia-gravity waves on surface meteorology is presented. The large-scale environment from 17 to 19 December 1999 was dominated by a poleward breaking Rossby wave transporting subtropical air over the North Atlantic Ocean upward and north-eastward. The synoptic situation was characterized with an upper tropospheric jet streak passing Northern Europe. The unbalanced jet spontaneously radiated inertia-gravity waves from its exit region. Near-inertial waves appeared with a horizontal wavelength of about 200 km and an apparent period of about 12 h. These waves transported energy downwards and interacted with large-scale convection. This configuration is simulated with the nonhydrostatic Fifth-Generation Mesoscale Model. Together with simplified runs without orography and moisture it is demonstrated that the imbalance of the jet (detected with the cross-stream ageostrophic wind) and the deep convection (quantified with the latent heat release) are forcing inertia-gravity waves. This interaction is especially pronounced when the upper tropospheric jet is located above a cold front at the surface and supports deep frontal convection. Weak indication was found for triggering post-frontal convection by inertia-gravity waves. The realism of model simulations was studied in an extended validation study for the Baltic Sea region. It included observations from radar (DWDPI, BALTRAD), satellite (GFZGPS), weather stations (DWDMI) and assimilated products (ELDAS, MESAN). The detected spatio-temporal patterns show wind pulsations and precipitation events at scales corresponding to those of inertia-gravity waves. In particular, the robust features of strong wind and enhanced precipitation near the front appeared with nearly the same amplitudes as in the model. In some datasets we found indication for periodic variations in the post-frontal region. These findings demonstrate the impact of upper tropospheric jet-generated inertia-gravity waves on the dynamics of the boundary layer. It also gives confidence to models, observations and assimilation products for covering such processes. In an application for the Gotland Basin in the Baltic Sea, the implications of such mesoscale events on air-sea interaction and energy and water budgets are discussed.

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