Problem Introduction/Project Focus Madani, Elisa; Hartmann, Flora L; Trebs, Lisa ...
Exploring the Effectiveness of International Knowledge Cooperation,
2024
Book Chapter
Innovation and Co-creation Madani, Elisa; Hartmann, Flora L; Trebs, Lisa ...
Exploring the Effectiveness of International Knowledge Cooperation,
2024
Book Chapter
This dissertation investigates the behavior of water-soluble inorganic trace gases and related aerosol species in the tropical boundary layer. Mixing ratios of ammonia (NH3), nitric acid (HNO3), ...nitrous acid (HONO), hydrochloric acid (HCl), sulfur dioxide (SO2) and the corresponding water-soluble aerosol species, ammonium (NH4 +), nitrate (NO3- ), nitrite (NO2 - ), chloride (Cl- ) and sulfate (SO4 2-) were measured at a pasture site in the Amazon Basin (Rondônia, Brazil). Sampling was performed from 12 Sep. to 14 Nov. 2002, covering the late dry (biomass burning) season, the transition period and the onset of the wet season (clean conditions) (LBA-SMOCC* ). Measurements were made continuously using a wet—annular denuder (WAD) in combination with a Steam-Jet Aerosol Collector (SJAC) followed by on-line analysis. Real-time data were combined with measurements of the aerosol compounds sodium (Na+), potassium (K+), calcium (Ca2+), magnesium (Mg2+) and low-molecular weight polar organic acids determined using integrated filter samples. Additionally, on-line measured mixing ratios of nitric oxide (NO), nitrogen dioxide (NO2) and ozone (O3) as well as (micro)-meteorological quantities are considered. Gaseous NH3 was present in mixing ratios an order of magnitude higher than those of HNO3, HONO, HCl and SO2. Thermodynamic equilibrium models are used to explore the impact of mineral cations (particularly pyrogenic K+) and LMW polar organic acids on the NH4 +N-O3 — -Cl— -SO4 2- H2O aerosol system. Mineral cations present in Amazonian fine mode aerosols significantly balanced aerosol NO3 — and SO4 2- during daytime and (NH4)2 SO4 appeared to be only a minor aerosol component. Thermodynamic equilibrium permitted the formation of aqueous NH4NO3 and NH4Cl only during nighttime at RH > 90 %. During daytime, excess NH3 neutralized LMW polar organic acids, forming aerosol NH4 +. Local dry and wet deposition rates of inorganic N are presented. Dry N deposition was inferred using the “big leaf multiple resistance approach” and a canopy compensation point model. Dry N deposition is dominated by NH3 and NO2, which featured highest mixing ratios as a consequence of biomass burning activities during the dry season. The pasture site was likely to have a strong potential for daytime NH3 (re-)emission, owing to high canopy compensation points, which are related to high surface temperatures and to direct NH3 emissions from cattle excreta. Total (dry + wet) N deposition was estimated to be 7.3 — 9.8 kgN ha-1 yr-1, which exceeds predictions for the Amazon region by global chemistry and transport models by at least factor of two.
It's physical work, but so satisfying Thompson, Trebs
Countryside and small stock journal (1985),
11/2008, Letnik:
92, Številka:
6
Journal Article, Magazine Article
Rodale, Acres U.S.A., American Livestock Breeds Conservancy, your extension office, etc. are all great places to help you figure out what you want to do and how to do it. Solar panels, energy ...efficient new appliances, geo thermal or radiant heat, a metal roof, and that neat recycled composite decking for the porch will all add up. If someone had told me how much work would go into totally replacing the top four feet of soil here, the fencing, building, constant maintenance, the learning about insects and plant viruses and parasites in animals, about how my cat would climb into the truck's engine to get warm and be killed...
Real‐time measurements of ammonia, nitric acid, hydrochloric acid, sulfur dioxide and the water‐soluble inorganic aerosol species, ammonium, nitrate, chloride, and sulfate were performed at a pasture ...site in the Amazon Basin (Rondônia, Brazil). The measurements were made during the late dry season (biomass burning), the transition period, and the onset of the wet season (clean conditions) using a wet‐annular denuder (WAD) in combination with a Steam‐Jet Aerosol Collector (SJAC). Measurements were conducted from 12 September to 14 November 2002 within the framework of LBA‐SMOCC (Large‐Scale Biosphere Atmosphere Experiment in Amazonia ‐ Smoke Aerosols, Clouds, Rainfall, and Climate: Aerosols From Biomass Burning Perturb Global and Regional Climate). Real‐time data were combined with measurements of sodium, potassium, calcium, magnesium, and low‐molecular weight (LMW) polar organic acids determined on 12‐, 24‐, and 48‐hours integrated filter samples. The contribution of inorganic species to the fine particulate mass (D
p
≤ 2.5 μm) was frequently below 20% by mass, indicating the preponderance of organic matter. The measured concentration products of NH
3
× HNO
3
and NH
3
× HCl persistently remained below the theoretical equilibrium dissociation constants of the NH
3
/HNO
3
/NH
4
NO
3
and NH
3
/HCl/NH
4
Cl systems during daytime (RH < 90%). The application of four thermodynamic equilibrium models (EQMs) indicates that the fine mode aerosol anions NO
3
−
, Cl
−
, and SO
4
2−
were balanced predominantly by mineral cations (particularly pyrogenic K
+
) during daytime. At nighttime (RH > 90%) fine‐mode NH
4
NO
3
and NH
4
Cl are predicted to be formed in the aqueous aerosol phase. Probably, Cl
−
was driven out of the aerosol phase largely by reaction of pyrogenic KCl with HNO
3
and H
2
SO
4
. As shown by an updated version of the equilibrium simplified aerosol model (EQSAM2), which incorporates mineral aerosol species and lumped LMW polar organic acids, daytime aerosol NH
4
+
was mainly balanced by organic compounds.
Mecanismos de vento local, tal como as brisas, influenciam o transporte e dispersão dos gases. Medidas da direção do vento e concentração de ozônio (O3) à 10 metros de altura foram realizadas durante ...a execução do projeto LBA/CLAIRE-2001 (Large Scale Biosphere-Atmosphere Experiment in Amazônia / Cooperative LBA Airbone Regional Experiment - 2001), no período de 02 a 28.07.2001, nas dependências do Laboratório de Limnologia (01º 55' S, 59º28' W, 174 m) pertencente à Usina Hidrelétrica de Balbina, Amazonas. O lago artificial tem uma área de 2.360 km², sendo suficientemente grande para estabelecer um regime de brisas. As brisas de lago e floresta apresentam-se de forma bem definidas, sendo que a brisa de lago fica melhor caracterizada no período mais quente do dia (10 às 14 horas), enquanto a brisa de floresta evidencia-se no período de 16 às 08 horas com o resfriamento radiativo mais intenso da floresta, o que acarreta um forte contraste térmico. Enquanto isso, a concentração média diária (24 h) de O3 foi de 8,7 ppbv com média de 10,6 ppbv no período diurno e 3,5 ppbv no período noturno. Os resultados também indicaram que quando a brisa é de lago, mesmo a noturna, a concentração de O3 é muito maior do que correspondente a concentração referente a brisa de floresta.Local wind systems, such as sea or lake breezes, strongly affect the transport and dispersion of atmospheric trace gases. Based on its size and location, the artificial lake of Balbina in the Amazon - can be expected to give rise to a lake/forest breeze regime. During the period 2 to 28 July 2002, within the LBA/CLAIRE-2001 experiment, we have continually measured the ozone concentrations (O3) and the wind directions close to the Balbina dam. We found that there is indeed a well established breeze system, with lake breezes prevailing during mid-day (10 to 14 LT) while forest breezes prevail from the afternoon to early morning (16 to 8 LT). During the latter period radioactive cooling in the forest creates a strong local thermal contrast. The average daily ozone concentration was 8.7 ppbv, with an average of 10.6 ppbv during the day, and 3.5 ppbv at night. When local winds came from the lake, even at night, ozone concentrations were greater compared to breezes coming from the forest.
Mecanismos de vento local, tal como as brisas, influenciam o transporte e dispersão dos gases. Medidas da direção do vento e concentração de ozônio (O3) à 10 metros de altura foram realizadas durante ...a execução do projeto LBA/CLAIRE-2001 (Large Scale Biosphere-Atmosphere Experiment in Amazônia / Cooperative LBA Airbone Regional Experiment - 2001), no período de 02 a 28.07.2001, nas dependências do Laboratório de Limnologia (01º 55' S, 59º28' W, 174 m) pertencente à Usina Hidrelétrica de Balbina, Amazonas. O lago artificial tem uma área de 2.360 km², sendo suficientemente grande para estabelecer um regime de brisas. As brisas de lago e floresta apresentam-se de forma bem definidas, sendo que a brisa de lago fica melhor caracterizada no período mais quente do dia (10 às 14 horas), enquanto a brisa de floresta evidencia-se no período de 16 às 08 horas com o resfriamento radiativo mais intenso da floresta, o que acarreta um forte contraste térmico. Enquanto isso, a concentração média diária (24 h) de O3 foi de 8,7 ppbv com média de 10,6 ppbv no período diurno e 3,5 ppbv no período noturno. Os resultados também indicaram que quando a brisa é de lago, mesmo a noturna, a concentração de O3 é muito maior do que correspondente a concentração referente a brisa de floresta.
Local wind systems, such as sea or lake breezes, strongly affect the transport and dispersion of atmospheric trace gases. Based on its size and location, the artificial lake of Balbina in the Amazon - can be expected to give rise to a lake/forest breeze regime. During the period 2 to 28 July 2002, within the LBA/CLAIRE-2001 experiment, we have continually measured the ozone concentrations (O3) and the wind directions close to the Balbina dam. We found that there is indeed a well established breeze system, with lake breezes prevailing during mid-day (10 to 14 LT) while forest breezes prevail from the afternoon to early morning (16 to 8 LT). During the latter period radioactive cooling in the forest creates a strong local thermal contrast. The average daily ozone concentration was 8.7 ppbv, with an average of 10.6 ppbv during the day, and 3.5 ppbv at night. When local winds came from the lake, even at night, ozone concentrations were greater compared to breezes coming from the forest.
Dry deposition of peroxyacetyl nitrate (PAN) is known to have a phytotoxic impact on plants under photochemical smog conditions, but it may also lead to higher productivity and threaten species ...richness of vulnerable ecosystems in remote regions. However, underlying mechanisms or controlling factors for PAN deposition are not well understood and studies on dry deposition of PAN are limited. In this study, we investigate the impact of PAN deposition on a nutrient-poor natural grassland ecosystem situated at the edge of an urban and industrialized region in Germany. PAN mixing ratios were measured within a 3.5 months summer to early autumn period. In addition, PAN fluxes were determined with the modified Bowen ratio technique for a selected period. The evaluation of both stomatal and nonstomatal deposition pathways was used to model PAN deposition over the entire summer-autumn period. We found that air masses at the site were influenced by two contrasting pollution regimes, which led to median diurnal PAN mixing ratios ranging between 50 and 300 ppt during unpolluted and between 200 and 600 ppt during polluted episodes. The measured PAN fluxes showed a clear diurnal cycle with maximal deposition fluxes of similar to -0.1 nmol m(-2) s(-1) (corresponding to a deposition velocity of 0.3 cm s(-1)) during daytime and a significant non-stomatal contribution was found. The ratio of PAN to ozone deposition velocities was found to be similar to 0.1, which is much larger than assumed by current deposition models. The modelled PAN flux over the entire period revealed that PAN deposition over an entire day was 333 mu g m(-2) d(-1) under unpolluted and 518 mu g m(-2) d(-1) under polluted episodes. Additionally, thermochemical decomposition PAN deposition accounted for 32% under unpolluted episodes and 22% under polluted episodes of the total atmospheric PAN loss. However, the impact of PAN deposition as a nitrogen source to the nutrient-poor grassland was estimated to be only minor, under both unpolluted and polluted episodes.
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