Complex topography influences atmospheric nitrate deposition in a neotropical mountain rainforest

Giannoni, Sandro Makowski; Rollenbeck, Rütger; Fabian, P.; Bendix, Jörg

doi:10.1016/j.atmosenv.2013.06.023

Cited by 11 publications

(6 citation statements)

References 40 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…1). Carboxylates were not measured in the Ecuadorian cloud water measurements (Makowski Giannoni et al, 2016), but we find from the model that the carboxylic acids contribute about 50 % of the H + . GEOS-Chem shows similar pH values to those observed at Cape Grim (mean of 5.5), reflecting the low concentrations of acidic and basic species from continental sources.…”

Section: Global Distribution Of Cloud Water Ph and Compositionmentioning

confidence: 63%

Global modeling of cloud water acidity, precipitation acidity, and acid inputs to ecosystems

et al. 2020

View full text Add to dashboard Cite

Abstract. Cloud water acidity affects the atmospheric chemistry of sulfate and organic aerosol formation, halogen radical cycling, and trace metal speciation. Precipitation acidity including post-depositional inputs adversely affects soil and freshwater ecosystems. Here, we use the GEOS-Chem model of atmospheric chemistry to simulate the global distributions of cloud water and precipitation acidity as well as the total acid inputs to ecosystems from wet deposition. The model accounts for strong acids (H2SO4, HNO3, and HCl), weak acids (HCOOH, CH3COOH, CO2, and SO2), and weak bases (NH3 as well as dust and sea salt aerosol alkalinity). We compile a global data set of cloud water pH measurements for comparison with the model. The global mean observed cloud water pH is 5.2±0.9, compared to 5.0±0.8 in the model, with a range from 3 to 8 depending on the region. The lowest values are over East Asia, and the highest values are over deserts. Cloud water pH over East Asia is low because of large acid inputs (H2SO4 and HNO3), despite NH3 and dust neutralizing 70 % of these inputs. Cloud water pH is typically 4–5 over the US and Europe. Carboxylic acids account for less than 25 % of cloud water H+ in the Northern Hemisphere on an annual basis but 25 %–50 % in the Southern Hemisphere and over 50 % in the southern tropical continents, where they push the cloud water pH below 4.5. Anthropogenic emissions of SO2 and NOx (precursors of H2SO4 and HNO3) are decreasing at northern midlatitudes, but the effect on cloud water pH is strongly buffered by NH4+ and carboxylic acids. The global mean precipitation pH is 5.5 in GEOS-Chem, which is higher than the cloud water pH because of dilution and below-cloud scavenging of NH3 and dust. GEOS-Chem successfully reproduces the annual mean precipitation pH observations in North America, Europe, and eastern Asia. Carboxylic acids, which are undetected in routine observations due to biodegradation, lower the annual mean precipitation pH in these areas by 0.2 units. The acid wet deposition flux to terrestrial ecosystems taking into account the acidifying potential of NO3- and NH4+ in N-saturated ecosystems exceeds 50 meqm-2a-1 in East Asia and the Americas, which would affect sensitive ecosystems. NH4+ is the dominant acidifying species in wet deposition, contributing 41 % of the global acid flux to continents under N-saturated conditions.

show abstract

Section: Global Distribution Of Cloud Water Ph and Compositionmentioning

confidence: 63%

Global modeling of cloud water acidity, precipitation acidity, and acid inputs to ecosystems

et al. 2020

View full text Add to dashboard Cite

show abstract

“…However, this assumption is not corroborated by our field samples from southern Ecuador. In the concentration of sodium and chloride from rain and OP samples we did not find any correlation between nitrate and sulfate, the products of biomass burning (Fabian et al, 2009;Makowski Giannoni et al, 2013, 2014, and sodium and chloride (Table 2). Furthermore, the mass fraction of biomass-burning sodium (maximum 0.07 %) and chloride (maximum values in the order of 3.5 %, see Fig.…”

Section: Discussionmentioning

confidence: 91%

“…Locally driven winds, such as thermally induced anabatic winds, can contribute to the transport of local sodium and chloride from the valley to the upper parts of the catchment. In a previous study, however, Makowski Giannoni et al (2013) showed that anabatic winds do not impact MSs located on mountain tops, where synoptic winds predominate. Figure 4a and b show relative frequencies of the wind direction at ECSF and Cerro del Consuelo, respectively.…”

Section: Sodium and Chloride Concentrationmentioning

confidence: 99%

See 1 more Smart Citation

Atmospheric salt deposition in a tropical mountain rainforest at the eastern Andean slopes of south Ecuador – Pacific or Atlantic origin?

Giannoni¹,

Trachte²,

Rollenbeck³

et al. 2016

Atmos. Chem. Phys.

Self Cite

View full text Add to dashboard Cite

Abstract. Sea salt (NaCl) has recently been proven to be of the utmost importance for ecosystem functioning in Amazon lowland forests because of its impact on herbivory, litter decomposition and, thus, carbon cycling. Sea salt deposition should generally decline as distance from its marine source increases. For the Amazon, a negative east-west gradient of sea salt availability is assumed as a consequence of the barrier effect of the Andes Mountains for Pacific air masses. However, this generalized pattern may not hold for the tropical mountain rainforest in the Andes of southern Ecuador. To analyse sea salt availability, we investigated the deposition of sodium (Na + ) and chloride (Cl − ), which are good proxies of sea spray aerosol. Because of the complexity of the terrain and related cloud and rain formation processes, sea salt deposition was analysed from both, rain and occult precipitation (OP) along an altitudinal gradient over a period between 2004 and 2009. To assess the influence of easterly and westerly air masses on the deposition of sodium and chloride over southern Ecuador, sea salt aerosol concentration data from the Monitoring Atmospheric Composition and Climate (MACC) reanalysis data set and back-trajectory statistical methods were combined. Our results, based on deposition time series, show a clear difference in the temporal variation of sodium and chloride concentration and Na + / Cl − ratio in relation to height and exposure to winds. At higher elevations, sodium and chloride present a higher seasonality and the Na + / Cl − ratio is closer to that of sea salt. Mediumto long-range sea salt transport exhibited a similar seasonality, which shows the link between our measurements at high elevations and the sea salt synoptic transport. Although the influence of the easterlies was predominant regarding the atmospheric circulation, the statistical analysis of trajectories and hybrid receptor models revealed a stronger impact of the north equatorial Atlantic, Caribbean, and Pacific sea salt sources on the atmospheric sea salt concentration in southern Ecuador. The highest concentration in rain and cloud water was found between September and February when air masses originated from the north equatorial Atlantic, the Caribbean Sea and the equatorial Pacific. Together, these sources accounted for around 82.4 % of the sea salt budget over southern Ecuador.

show abstract

“…The questions pursued may range from understanding broad-scale regional teleconnections through atmospheric transport (Yim et al 2019) to providing estimates of day-today human exposure to atmospheric contaminants (Soares et al 2014). The questions may also aim to understand nutrient balances and ecosystem integrity (Makowski et al 2013;Duce et al 2008;Boy et al 2008), or they may look towards assessing the loss in agricultural production (Van Dingenen et al 2009;Feng et al 2019) due to plant's exposure to ground-level ozone (Silva and Heald 2018). Each one of those questions unveils new layers of complexity, each with its own modelling needs.…”

Section: Introductionmentioning

confidence: 99%

On the mathematical modelling and data assimilation for air pollution assessment in the Tropical Andes

Montoya

Niño-Ruiz

Pinel

2020

Environ Sci Pollut Res

View full text Add to dashboard Cite

Air pollution assessment in the Tropical Andes requires a multidisciplinary approach. This can be supported from the understanding of the underlying biological dynamics and atmospheric behavior, to the mathematical approach for the proper use of all available information. This review paper touches on several aspects in which mathematical models can help to solve challenging problems regarding air pollution in reviewing the state-of-the-art at the global level and assessing the corresponding state of development as applied to the Tropical Andes. We address the complexities and challenges that modelling atmospheric dynamics in a mega-diverse region with abrupt topography entails. Understanding the relevance of monitoring and facing the problems of data scarcity, we call attention to the usefulness of data assimilation for uncertainty reduction, and how these techniques could help tackle the scarcity of regional monitoring networks to accelerate the implementation and development of modelling systems for air quality in the Tropical Andes. Finally, we suggest a cyberphysical framework for decision-making processes based on the data assimilation of chemical transport models, the forecast of scenarios, and their use in regulation and policy making.

show abstract

Complex topography influences atmospheric nitrate deposition in a neotropical mountain rainforest

Cited by 11 publications

References 40 publications

Global modeling of cloud water acidity, precipitation acidity, and acid inputs to ecosystems

Global modeling of cloud water acidity, precipitation acidity, and acid inputs to ecosystems

Atmospheric salt deposition in a tropical mountain rainforest at the eastern Andean slopes of south Ecuador – Pacific or Atlantic origin?

On the mathematical modelling and data assimilation for air pollution assessment in the Tropical Andes

Contact Info

Product

Resources

About