# Presentation: 815092

## Los Alamos GoMACCS Payload: Houston, August 2006

*Airborne in situ* photo-acoustic measurements of absorption (Babs) and single scattering albedo (SSA) of black carbon (BC) aerosols at 780nm
- Low noise, airborne, fast (1 sec), sensitive (Babs> few (mM)-1)
- Ability to separate BC in cloud water and interstitial air BC by employing CVI on/off inlet on the CIRPAS Twin Otter, as was done during MASE
- Add fast CO2 LICOR and CO resonance fluorescence instruments
- Science strategy and goals
- Source BC/aerosol emission characterizations
- Quantify aging/mixing states/time-constants (SSA changes)
- Ideal complement (fills key gap) for all aerosol data on the Twin otter airplane
- Will be used to separate dynamics from microphysics/chemistry to maximize process level closure studies

- _[http://aerosols.lanl.gov](http://aerosols.lanl.gov/)_ M. Dubey dubey@lanl.gov

**Notes:**
The Los Alamos team led by Manvendra Dubey and including Claudio Mazzolenni and Thom Rahn will deploy a photoacoustic instrument to measure the optical properties of black carbon containing aerosols as well as CO2 and CO gases on the CIRPAS Twin Otter for the GoMACCS campaign in Houston led by Graham Feingold of NOAA and John Seinfeld of Caltech (DOE-ASP funded scientist).

This works builds on experience and partnerships gained from the DOE’s Marine Stratus Experiment (MASE) off Pt Reyes CA last summer

For GoMACCs the Los Alamos Team will add fast CO2 and CO sensors to their black carbon photoacoustic instrument to facilitate the analysis of emission factors and aging and mixing of carbon aerosols

This work is funded by Los Alamos’s LDRD program, and the team has coordinated its activities with ASP to generate synergy and raise DOE’s profile in climate change science program. Dr. Dubey is a member of the ASP science team and has participated in the MASE and Max-MEX field campaigns and will also participate in the proposed CHAPS campaign next summer.

## Science questions and deliverables

- Quantify black carbon (BC) emissions and their state (Babs, SSA) by normalizing them to CO and CO2 measurements, and relate them to “combustion efficiency”
- Sample dirty plumes (>5mM-1) cumulus clouds (km scale) to look at BC partitioning in cloud drops and interstitial air (see our MASE results).
- What is the distribution of light absorbing and scattering by combustion aerosols over Houston and the Gulf of Mexico?
- What is the rate of mixing of combustion aerosols (BC with sulfate and chloride) and how does it effect the optical property and atmospheric heating rates?
- How does BC containing aerosol effect clouds and how do cloud processes influence aerosols?
- How does BC effect the macroscopic cloud single scatter albedo in a regime much more polluted than interrogated by us with DOE during MASE?
- Opportunity to fly by Ron Brown and so comparisons with the new NOAA multipass photo-acoustic and cavity ring-down instruments.

## Build on Los Alamos Black Carbon Measurements During

**Build on Los Alamos Black Carbon Measurements During**
**DOE’s Marine Stratocumulus Experiment (MASE): July 05**

- Navy CIRPAS
- Twin Otter
- (Seinfeld et al)

- DOE-ARM Mobile

- CIRPAS
- Monterrey

- Inlet

## Marine Stratus Experiment: Photoacoustic setup

- Rear of Twin-Otter

**Notes:**
Picture of the Photoacoustic experiment in the rear of the CIRPAS Twin Otter

## Intercepted Pollution Plume In Cloud: 6 July 05  

**Intercepted Pollution Plume In Cloud: 6 July 05  **

- Absorbing (BC)
-  Plume inside cloud

**Notes:**
The aircraft intercepted a large pollution plume “inside” a marine startus cloud deck at around 18.30, the LHS in black shows the absorption signal rises to close to 5 inverse megameters in the plume. The two peaks represent two passes through the same polluted cloud area. The red is the aircraft pressure that is related to the aircraft altitude.

## Location of Event

- Wind Direction NW

- Flight Direction

- Point Reyes

**Notes:**
The plume was located just off the coast of Pt. Reyes CA

## Chemical Composition: Mixed SO4+BC+Inorg

- Absorbing (BC-SO4-Cl)
-  plume inside cloud

**Notes:**
In addition to our photoacoustic instrument there was a Particle in Liquid Spectrometer (PILS) that clearly shows a large sulfate and chloride spikes (top)  together with our absorption signal (bottom). This is clear evidnece of the mixing of black carbon with sulfate and chloride and we also see that this increases the single scatter albedo of the aerosols in polluted cloud plume