PISAC (Pollution and its Impact ... collaboration of interested scientists with ...

The PISAC (Pollution and its Impact on the South American Cryosphere) initiative is a
collaboration of interested scientists with multiple expertise ranging from atmospheric
measurements and modeling to policy making with the aim to investigate key sources and
impacts of aerosols (including black carbon) and co-emitted reactive gases in the Andean and
Patagonian regions. The PISAC initiative will design research activities to close knowledge gaps
in the region and policy options to address mitigation for climate protection and air quality
improvement.
Air pollution associated with biomass burning and urban sources affects extended areas of South
America, and it is an issue of concern for scientific and policy communities in the region mainly
due to detrimental health effects. Additionally, there is a growing awareness regarding the cobenefits of mitigating actions for short-lived climate pollutants (SLCPs) in key sectors, which
could bring rapid and multiple benefits for human well-being by protecting public health and the
environment, promoting food, water, and energy security, and addressing near-term climate
change. SLCPs are harmful substances with a relatively short lifetime in the atmosphere –a few
days to a few decades – and a warming effect on near-term climate. The main SLCPs are black
carbon (BC), methane (CH4), and tropospheric ozone (O3). Because of their short atmospheric
lifetime, reducing SLCPs will have a noticeable effect on global temperature almost
immediately.
Black carbon is emitted directly into the atmosphere in the form of fine particles (PM2.5) and is
produced by both natural processes and human activities from the incomplete combustion of
fossil fuels, biofuels, and biomass. Primary sources of black carbon include diesel engines,
industrial sources, residential coal and solid biofuels for cooking and heating, and agricultural
and forest fires and open burning of solid waste. BC contributes to the adverse impacts on human
health, ecosystems, and visibility associated with PM2.5. Black carbon has been shown to have a
warming impact on the Earth's climate by absorbing incoming radiation in the atmosphere at the
global but also at the regional level. Another, more subtle, aspect of its impact is observed when
BC is deposited over snow and ice, reducing the surface reflectivity (albedo) of sunlight, in
essence “darkening” the surface of snow and ice and increasing their melting rate, thus affecting
water resources.
1
Methane (CH4) is a potent greenhouse gas with an atmospheric lifetime of about 12 years and is
included as one of the substances controlled under the Kyoto Protocol. Methane has both natural
and anthropogenic sources: approximately 40% is emitted by wetlands and termites, and about
60% is emitted from ruminant livestock, rice cultivation, microbial waste processing (landfills,
manure, and waste water), coal mining, and oil and natural gas systems. The variety of human
activities associated with methane provides ample possibilities of measures to reduce emissions.
Methane directly influences the climate system but also has indirect impacts on human health
and ecosystems through its role as a precursor of tropospheric ozone.
Tropospheric ozone is a secondary pollutant, formed in the atmosphere through photochemical
processes and has to be controlled by reducing its precursor pollutants, primarily nitrogen oxides
(NOx), carbon monoxide (CO) and volatile organic compounds (VOCs), as well as methane. It is
a major component of urban photochemical smog and a highly reactive oxidant that is harmful to
human health as well as agricultural production.
Mitigation actions require a sound scientific understanding of the underlying processes leading to
air quality degradation and climate impacts by SLCPs, which are largely region and country
specific. Given these concerns, a team of multi-disciplinary scientists and policy experts
launched an international scientific initiative known as the Pollution and its Impacts on the South
American Cryosphere (PISAC, http://www.mce2.org/activities/pisac), in October 2013 in
Santiago de Chile.1
The Andes constitute a unique mountain range extending for ca. 7000 km along western coast of
South America, spanning tropical, subtropical and mid-latitude climate regimes. It has an
average height of 4000 m.a.s.l., with several peaks exceeding 6500 m.a.s.l., many of which host
glaciers. The Andes straddle parts of seven countries in South America - Argentina, Bolivia,
Chile, Colombia, Ecuador, Peru, and Venezuela - with a population of ca. 85 million people.
There are a wide variety of emissions sources along the Andes. Biomass burning in the Amazon
is by far the largest source of carbonaceous aerosols in the region. Currently urban emission
inventories developed by local authorities in South America do not account for BC; thus, global
inventories are the only estimate of BC and co-pollutants emissions covering most of the sources
in South America. Global inventories are based on general methodologies, and they do not
consider unique regional specificities. This is particularly relevant for BC emissions, for which
distinctive regional patterns exist in South America in contrast to other regions in the world.
1
A team of science and policy experts in the regions surrounding the Andes, as well as international
experts, met on October 10-11, 2013 at a workshop convened by Dr. Luisa T. Molina (Molina Center for
Energy and the Environment), Dr. Laura Gallardo (Center for Climate and Resilience Research,
University of Chile) and Dr. Marcelo Mena (University of Andres Bello, currently Chile Vice Minister of
Environment) to discuss the production of a White Paper addressing emissions sources, measurements
and transport of pollutants, monitoring stations, modeling potential impacts of black carbon and copollutants on the Andean cryosphere, as well as policy options addressing the impacts.
2
There is a need to characterize emissions of BC in the region in order to define and implement
effective mitigation plans to improve not only air quality in the urban areas but also to reduce
anthropogenic impact on climate.
Recent scientific evidence indicates that the Andean cryosphere has already shown the impacts
of rapid climate change with generally receding glaciers and snow cover. Andean glaciers and
snow fall constitute the most important source of fresh water for population centers along the
western coast of South America. Thus glacier retreat and changes in snow fall could have
potentially large implications for water resources and local agriculture, especially for local
indigenous populations living in high-altitude communities that may not have the financial
resources to expand water acquisition, as well as for large urban centers at relatively lower
surrounding altitudes that may already be tapping all of the accessible local water resources.
Explaining factors for the observed changes in glaciers and snow cover include increasing
temperatures, changes in location and timing of precipitation, and also deposition of absorbing
aerosols. These factors are inherently linked and their relative importance may vary substantially
among different Andean regions.
Of interest for understanding the trends in Andean cryosphere extent are the temporal and spatial
distributions of: the meteorological properties of the atmosphere, solar and terrestrial radiative
fluxes, trace gas concentrations, and aerosol particle concentrations and properties in the region.
However, there is a striking paucity of systematic observations along the Andes, independently
of the parameter of interest. For instance, surface weather stations in South America add up to a
few hundred stations, of which ca. 260 are included in the Global Climate Observing System
(GCOS) under the World Meteorological Organization (WMO). About 30 of them are relevant
for the Andean region, and there are only six radiosonde stations, all located on the western side
of the Cordillera. There are ca. 100 precipitation gauges along the 7000-km mountain range.
Radiation and composition measurements of the regional background atmosphere are even
scarcer. The Global Atmospheric Watch (GAW) Program counts one active global station in
Ushuaia in southern South America, 4 stations measuring surface ozone, 3 stations measuring
aerosol properties, 2 vertical profilers (LIDAR) and only one addressing precipitation chemistry
in South America. Nevertheless, there are new and expanded stations starting to operate in the
region.
A new WMO-GAW station in the Andean mountains was setup on December 2011 and has been
working continuously since then. The station is located at 5240 m.a.s.l. (16°21'1.78"S and 68°
7'53.44"W) at the western side of Mount Chacaltaya and hosts an important number of
instruments for monitoring physical and chemical properties of gases and particles arriving at
this high altitude. Chacaltaya GAW station (CHC/GAW for short) is run by a consortium of
international scientific institutions led by the Laboratory for Atmospheric Physics, Department of
Physics at Universidad Mayor de San Andrés in La Paz, Bolivia. European institutions from
3
France, Germany, Italy, Sweden and the United States of America are part of the consortium.
The goal of the group is to have the station running under high standards of calibration and
quality control/quality assurance of the data on a long term. Local scientists run the CHC/GAW
station and young scientists are being trained not only to keep the station functioning but also to
understand the associated science.
Air quality data is regularly sampled in various urban centers including Santiago, Lima, Quito,
and Bogota. These networks collect criteria pollutants including particulate matter; however,
speciation studies and characterizations of aerosol optical properties are performed only
sporadically. Satellite borne instruments can provide potentially useful information; however, the
sharp gradients and reflectivity of the Andes pose particular challenges for remote sensing. It is
clear that currently there is a serious paucity of data that can be evaluated for determining the
factors that contribute to the cryosphere loss, and assessing health and climate impacts close to
source regions for absorbing aerosols.
PISAC initiative seeks to improve scientific understanding regarding the origin and effects of
absorbing aerosols by addressing both observations and research on the emissions and impacts of
short-lived climate pollutants, with emphasis of black carbon on the Andean cryosphere.
WMO/GAW and PISAC Collaboration
The PISAC initiative recently signed an agreement with WMO/GAW to establish and maintain
cooperation relative to matters of common interest in both programs, in particular the
establishment of the observational stations in Andes and quality assurance of those observations.
The Parties will undertake the following activities to implement collaboration under this
agreement:
- Develop potential observation sites in the Andes that will utilize recommendations of
WMO/GAW related to the measurement of aerosol and reactive gases and serve the
purpose of the both Parties
- Facilitate the formation of a South America regional Global Cryosphere Watch groups
and surface network of cryosphere observation (CryoNet) in South America
- Promote scientific collaboration between the research groups supporting PISAC initiative
and WMO/GAW and facilitate exchange of data and other relevant information between
PISAC and WMO/GAW communities
- Promote the research on the connection between air pollution and mountain climate
through joint workshops and publications
- Organize training events and undertake capacity building activities for local investigators
in South America
4
Measurements and Monitoring
Several field studies affiliated with PISAC are currently underway; they are described briefly in
the following sections
Measurements of light absorbing particles on tropical glaciers by the American Climber
Science Program in the tropical Andes
The American Climber Science Program (ACSP) has been sampling glacial snow in the
Cordillera Blanca Mountains in Peru since 2011 in an effort to quantify the impact of light
absorbing particles. ACSP research projects include measurement of light absorbing impurities,
including black carbon and dust, on the glaciers of the region and spectroradiomater readings on
the glaciers. Snow samples are collected by volunteer climbers and scientists while climbing
different mountains in the region. The ACSP uses a filter based technique to sample particles in
snow. Results of the filter technique have been shown to be well correlated with mass estimates
of refractory black carbon measured by the Single Particle Soot Photometer-2 (SP2) instrument
(see figures below).
The ACSP has collected four years of data (2011-2014) which show significant trends in the
contaminants on glaciers in the Cordillera Blanca. Glaciers that are close to human population
centers have substantially higher levels of contaminants than more remote glaciers, suggesting
that glaciers near population centers could be experiencing higher melting rates than more distant
glaciers.
The ACSP is working with several local researchers as well as some local university student who
are now collecting samples on a monthly basis. Samples are being collected in two locations, one
near Huaraz, the largest local city and one remote location. Preliminary measurements suggest
that snow in the wet season is relatively clean in contrast to the dry season measurements.
ACSP project leader Dr. Carl Schmitt (Project Scientist at the National Center for Atmospheric
Research) also participated in a 3-day expedition organized by Dr. Julio Warthon at the
Universidad Nacional de San Antonio Abad del Cusco in August 2014. The group collected
samples in the mountains near Ausangate mountain. Measurements indicated that effective BC
values are substantial in the mountains near Cusco, likely due to the high population in the
region. Several students will be collecting samples regularly in different locations in the region.
Due to the much higher population in the Cusco region as well as the prevalence of fire in the
dry season, ACSP is planning to visit the region with a larger team in 2015.
Filter samples as well as samples for SP2 analysis were also collected from Mururata mountain
in Bolivia in collaboration with Dr. Marcos Andrade of the University Mayor de San Andres de
La Paz and Dirk Hoffmann of the Bolivian Mountain Institute in June 2014, well before the
5
typical burn season (for the Amazon). Results from filter analysis suggest moderate amounts of
BC in the region.
The Pollution Impact on Snow in the Cordillera-Experiments and Simulations (PISCES)
A new pilot project, Pollution Impact on Snow in the Cordillera-Experiments and Simulations
(PISCES), to support the PISAC initiative was successfully deployed in September-October
2014. The measurement site is located at the midpoint between the Queltehue hydroelectric plant
and the highest point from which water is drawn. The coordinates of the site are 33°49'5.93"S,
70°13'2.79"W, 1500 m altitude (see figures below).
The goal of PISCES is to test the following hypothesis: “The increase in concentrations of
aerosol particles in the atmosphere over the Andes have made a significant contribution to the
receding cryosphere in that region.” Given that precipitation is one of the key components in
glacier mass balance as well an in yearly snowpack volume, the project seeks to determine how
urban emissions are processed within the frontal clouds and deposited onto the surface in the
high mountains and to determine if the deposition of BC onto the cryosphere occurs via cloud
processing (wet scavenging) or via dry deposition onto the fresh snow, but in between the
passages of frontal systems.
The project was led by Drs. Darrel Baumgardner and Graciela Raga in collaboration with
researchers from NOAA, NCAR, University of Valparaiso, University of Leon, University of
Grenoble and University of Granada.
Glacier Bello Field Campaign
Environmental Technology Centre (CETAM) from Technical University Federico Santa María
has been developing environmental monitoring campaigns in glaciers such as Cerro El Plomo
(near Santiago metropolitan region), Nevados de Chillán (Bio-Bio region), Grey Glacier
(Patagonia) and up to Chilean Antarctica, among others. In this context, CETAM is currently
developing an ambitious glaciochemical research project funded by the Snow and Glaciology
Unit from the General Water Direction, Public Works Ministry, and the Chilean Government.
This initiative, developed by CETAM´s researchers and directed by Francisco Cereceda, seeks to
identify evidence of pollutants transport from large cities to the mountain and its impact on
climate change by the chemical characterization of snow samples and monitoring of meteorology
and albedo; concentration and distribution of atmospheric particulate matter; total deposition;
and black carbon concentration present in glacier’s environment.
A monitoring campaign has been successfully deployed in September-October 2014 in Bello
Glacier (33°31'34.00"S; 69°56'58.00"W), located at 4,300 m.a.s.l. This monitoring campaign
required challenging logistics to transport and install, on the glacier, atmospheric monitoring
equipment, clean energy generation systems (750W solar panels with charge regulators and
6
batteries) and a suitable camp site for CETAM scientists to perform the necessary tasks of
sampling and equipment supervision. Equipment used in this campaign included a Laser Aerosol
Spectrometer capable of measuring in real time concentration of PM10, PM2.5 and PM1 and
particles size distribution in 31 parallel channels between 0.27 and 34 µm, a micro-Aethalometer
for black carbon measurement. Additionally, firn and snowpit samples were collected for
chemical speciation (pH, conductivity, ions, trace elements, and organic compounds like
polyaromatic and physical parameter measurement (snow density and snow profile). Finally
Albedo was measured using a net radiometer (see figures below).
In parallel to glacier campaign, atmospheric aerosol samples and measurements of PM
(concentration and distribution) and BC were collected in the city of Santiago de Chile. Aerosol
samples of organic (polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls
(PCBs) and anhydrosacharides; gas phase and particulate matter) and inorganic (ions and trace
elements) aerosols were collected using a low-vol sampler. In addition, a high-vol sampler was
used for organic speciation of aerosol samples. PM concentration and distribution were measured
using a second Laser Aerosol Spectrometer and BC concentration was measured using a Multi
Angle Absorption Photometer.
Preliminary results for Bello Glacier showed minor anthropogenic influence, as evidenced by,
for example, low anthropogenic ions concentrations (nitrate and sulfate).
A second monitoring campaign will be carried out in Olivares Alpha Glacier, located about
4,500 m.a.s.l., northeast of the metropolitan area and adjacent to two major mining operations.
CETAM scientists plan to replicate the methodology described for Bello Glacier.
Black Carbon in West Andean Cryosphere
A multidisciplinary team of physicists, chemists, glaciologists and engineers affiliated with five
leading Chilean universities is proposing to measure BC aerosol optical depth and BC content of
snow in the western side of the Andes.
The team proposed to set up two new stations (equipped with sunphotometers) aiming at groundbased measurements of the aerosol optical properties. The new stations will be deployed in the
Mapocho basin (at about 2,500 m.a.s.l. in the area surrounding Santiago), and at Paranal
Observatory (2,635 m.a.s.l. in the Atacama Desert); they will join the existing AERONET station
in downtown Santiago (about 500 m.a.s.l.) and will be used also to validate satellite-derived
estimates of the aerosol optical properties over the Andean region. Validated satellite data will be
further exploited for building an aerosol climatology for the Andean Region.
Extensive campaigns will be conducted for sampling the BC content in the snow across a northsouth transect of the Chilean Andes using a meltwater filtration (MF) sampling technique.
7
Selected glaciers will range from Glacier Tapado in northern Chile (~30°S) to Glacier Grey in
the Southern Patagonia Icefield (~51°S). Subsequent spectrophotometric analysis will allow to
assess the BC concentration and to estimate the associated albedo reduction.
The team proposed to deliver a map of the BC content in the Andean cryosphere, highlighting
BC-impacted zones (useful for further studies on the effects of BC on glacier melting). In
addition, elemental characterization of particles in samples collected on MF filters will be used
for identification of soot and mineral dust. Information will be provided on the mixing of BC
with other aerosol components (which is also required for assessing the effects of BC on the
climate system), as well as on traces of pollutants (which can be useful for relating the BC
content with sources). Modeling studies will be conducted to simulate the transport and impact
of BC in the Andean region and to assess local climate responses to the detected BC content in
the Andean cryosphere.
8
9
10
Glacier Bello Campaign (Sept – Oct, 2014)
11