From BASE-ASIA Toward 7-SEAS: A Satellite-Surface Perspective of Boreal Spring Biomass-Burning Aerosols and Clouds in Southeast Asia

In this paper, we present recent field studies conducted by NASA's SMART-COMMIT (and ACHIEVE, to be operated in 2013) mobile laboratories, jointly with distributed ground-based networks (e.g., AERONET, http://aeronet.gsfc.nasa.gov/ and MPLNET, http://mplnet.gsfc.nasa.gov/) and other contributing instruments over northern Southeast Asia. These three mobile laboratories, collectively called SMARTLabs (cf. http://smartlabs.gsfc.nasa.gov/, Surface-based Mobile Atmospheric Research & Testbed Laboratories) comprise a suite of surface remote sensing and in-situ instruments that are pivotal in providing high spectral and temporal measurements, complementing the collocated spatial observations from various Earth Observing System (EOS) satellites. A satellite-surface perspective and scientific findings, drawn from the BASE-ASIA (2006) field deployment as well as a series of ongoing 7-SEAS (2010-13) field activities over northern Southeast Asia are summarized, concerning (i) regional properties of aerosols from satellite and in situ measurements, (ii) cloud properties from remote sensing and surface observations, (iii) vertical distribution of aerosols and clouds, and (iv) regional aerosol radiative effects and impact assessment. The aerosol burden over Southeast Asia in boreal spring, attributed to biomass burning, exhibits highly consistent spatial and temporal distribution patterns, with major variability arising from changes in the magnitude of the aerosol loading mediated by processes ranging from large-scale climate factors to diurnal meteorological events. Downwind from the source regions, the tightly coupled-aerosolecloud system provides a unique, natural laboratory for further exploring the micro- and macro-scale relationships of the complex interactions. The climatic significance is presented through large-scale anti-correlations between aerosol and precipitation anomalies, showing spatial and seasonal variability, but their precise cause-and-effect relationships remain an open-ended question. To facilitate an improved understanding of the regional aerosol radiative effects, which continue to be one of the largest uncertainties in climate forcing, a joint international effort is required and anticipated to commence in springtime 2013 in northern Southeast Asia

The GLAS Polar Orbiting Lidar Experiment: First Year Results and Available Data

The first polar orbiting satellite lidar instrument, the Geoscience Laser Altimeter System (GLAS), was launched in 2003 and is approaching six months of data operations. As part of the NASA Earth Observing System (EOS) project, the GLAS instrument is intended as a laser sensor fulfilling complementary requirements for several earth science disciplines including atmospheric and surface applications on the Ice, Cloud and Land Elevation Satellite. In this paper we present examples of atmospheric measurement results and explain access to data for the international science community

Analysis of Measurements of Saharan Dust by Airborne and Ground-based Remote Sensing Methods during the Puerto Rico Dust Experiment (PRIDE)

For 26 days in mid-June and July 2000, a research group comprised of U.S. Navy, NASA, and university scientists conducted the Puerto Rico Dust Experiment (PRIDE). In this paper we give a brief overview of mean meteorological conditions during the study. We focus on findings on African dust transported into the Caribbean utilizing Navajo aircraft and AERONET Sun photometer data. During the study midvisible aerosol optical thickness (AOT) in Puerto Rico averaged 0.25, with a maximum less than 0.5 and with clean marine periods of _0.08. Dust AOTs near the coast of Africa (Cape Verde Islands and Dakar) averaged _0.4, 30% less than previous years. By analyzing dust vertical profiles in addition to supplemental meteorology and MPLNET lidar data we found that dust transport cannot be easily categorized into any particular conceptual model. Toward the end of the study period, the vertical distribution of dust was similar to the commonly assumed Saharan Air Layer (SAL) transport. During the early periods of the study, dust had the highest concentrations in the marine and convective boundary layers with only a, weak dust layer in the SAL being present, a state usually associated with wintertime transport patterns. We corroborate the findings of Maring et al. that in most cases, there was an unexpected lack of vertical stratification of dust particle size. We systematically analyze processes which may impact dust vertical distribution and determine and speculate that dust vertical distribution predominately influenced by flow patterns over Africa and differential advection couple with mixing by easterly waves and regional subsidence

Observing and understanding the Southeast Asian aerosol system by remote sensing: An initial review and analysis for the Seven Southeast Asian Studies (7SEAS) program

Southeast Asia (SEA) hosts one of the most complex aerosol systems in the world, with convoluted meteorological scales, sharp geographic and socioeconomic features, high biological productivity, mixtures of a wide range of atmospheric pollutants, and likely a significant susceptibility to global climate change. This physical complexity of SEA is coupled with one of the world\u27s most challenging environments for both in situ and remote sensing observation. The 7-Southeast Asian Studies (7SEAS) program was formed to facilitate interdisciplinary research into the integrated SEA aerosol environment via grass roots style collaboration. In support of the early 7SEAS program and the affiliated Southeast Asia Composition, Cloud, Climate Coupling Regional Study (SEAC4RS), this review was created to outline the network of connections linking aerosol particles in SEA with meteorology, climate and the total earth system. In this review, we focus on and repeatedly link back to our primary data source: satellite aerosol remote sensing and associated observability issues. We begin with a brief rationale for the program, outlining key aerosol impacts and, comparing their magnitudes to the relative uncertainty of observations. We then discuss aspects of SEA\u27s physical, socio-economic and biological geography relevant to meteorology and observability issues associated with clouds and precipitation. We show that not only does SEA pose significant observability challenges for aerosol particles, but for clouds and precipitation aswell. With the fundamentals of the environment outlined, we explore SEA\u27s most studied aerosol issue: biomass burning. We summarize research on bulk aerosol properties for SEA, including a short synopsis of recent AERONET observations. We describe long range transport patterns. Finally, considerable attention is paid to satellite aerosol observability issues, with a face value comparison of common aerosol products in the region including passive and active aerosol products as well as fluxes. Weshowthat satellite data products diverge greatly due to a host of known artifacts. These artifacts have important implications for how research is conducted, and care must be taken when using satellite products to study aerosol problems. The paper ends with a discussion of how the community can approach this complex and important environment

Monitoring Surface PM2.5: An International Constellation Approach to Enhancing the Role of Satellite Observations

Exposure to particulate pollution is a severe burden to public health worldwide. Information on near-surface concentrations of particulate matter (PM) is needed on a global scale: as input to air quality services for citizens, to support policy makers in evaluating the efficacy of pollution abatement measures, and to help environmental agencies verify compliance with standards on pollution levels and related emissions. Satellite observations do offer valuable information on PM. However, they alone are not sufficient to provide the needed PM products. A combination of ground-based measurements, satellite observations, and information from atmospheric chemistry and transport models is needed for monitoring and forecasting near-surface PM concentrations. At present, satellite observations are not yet optimally exploited for PM estimation. A host of space-borne sensors capture different aspects of PM: multispectral broadband imagers observe the horizontal distribution of the vertically integrated burden, multi-angle and polarimetric broadband imagers also allow constraining particle size and type, hyperspectral spectrometers provide some information on the vertical distribution as well as spectral absorption and speciation fractions of absorbers in smoke and dust, and lidars capture the vertical distribution of the particle load along narrow tracks. These capabilities and their synergistic exploitation offer a great potential to improve PM estimation. The present white paper takes stock of the current and planned sensors with strong potential for constraining PM, and of schemes used for generating particulate pollution products and services. Specific and actionable recommendations are made to strengthen the role of satellites in constraining PM levels and to help in creating satellite-informed particulate pollution products

Observing and understanding the Southeast Asian aerosol system by remote sensing: An initial review and analysis for the Seven Southeast Asian Studies (7SEAS) program

10.1016/j.atmosres.2012.06.005Atmospheric Research122403-46