About HIPPO
HIPPO Image Gallery
HIPPO II Hard-Down Day #1 :: Kona, HI
HIPPO Field Catalog
Glossary of Acronyms
Aerosols & Cloud Physics
Aerosols & Cloud Physics Instruments
CDP | Cloud Droplet Probe
The Cloud Droplet Probe (CDP), is a miniature, light weight, low-power cloud particle spectrometer that measures droplets in the range of 3-50 µm in concentrations as high as 2000 cm-3.
SP2 | Single Particle Soot Photometer (SP2)
Monitored by: David Fahey, Ru-Shan Gao & Shuka Schwarz
The Single Particle Soot Photometer is an instrument that directly measures the black carbon, known as soot, in individual aerosol particles. The high sensitivity, fast response, and specificity to elemental carbon makes it the instrument for characterizing pollution sources, soot in snow, ice or water, and documenting thin, atmospheric layers of contamination.
Refractory black carbon (rBC) aerosol is the most important particulate absorber of solar radiation in the atmosphere, causing dramatic regional forcings in places like India and China. In addition to direct aerosol absorption, rBC has the potential to significantly impact climate through indirect (by cloud particle seeding), semi-direct (dehydration of clouds), and snow albedo (increased snow melt) effects. Traditionally, rBC has been a difficult species to measure. Although it is responsible for most of the aerosol absorption in the visible wavelength range, rBC typically forms only a small fraction of total aerosol mass and extinction. The fact that rBC is non-soluble and refractory (surviving high temperatures) means that traditionally effective techniques used to quantify sulfate, salt and organic aerosols are generally insensitive to rBC. Aerosol absorption has long been used as a proxy for rBC mass, but as its absorption properties depend on mixing state and age, relying on absorption measurements alone is not a robust approach.
The Single Particle Soot Photometer (SP2) has become increasingly recognized as a valuable tool for quantifying rBC aerosol. There are several ways in which the SP2 provides previously unavailable information. First, it unambiguously measures the mass of rBC in individual aerosol particles in the accumulation mode. Second, the SP2 is able to identify the presence of other non-rBC materials with rBC in individual particles and provide some information about their amount. Third, as the instrument detects individual aerosol particles, it is able to quantify rBC loadings even in very clean air; it is the most sensitive tool available to this end. During the HIPPO project the SP2 is configured to maximize its sensitivity, thus providing measurements of rBC loadings with high spatial resolution even in the relatively clean and remote areas explored. It's inclusion in the instrument payload allowed unprecedented latitudinal coverage of in situ rBC mass loadings. Measurements of rBC mass loadings are especially sparse in the Southern Hemisphere. Through these observations of the latitudinal and vertical distribution of rBC mass loadings, as well as their correlation to age-of-air and tracers such as CO, the SP2 data from HIPPO will provide powerful constraints on the global models that are used to assess rBC's impact on climate.
UHSAS
Ultra-High Sensitivity Aerosol Spectrometer: This 100 channel (programmable), airborne optical spectrometer measures aerosol particles in the range from 0.055 µm to 1 µm.
