# Presentation: 480527

## Biosphere Atmosphere Exchange

- 1) Directly emitted GHGs
- 		CO2, CH4, N2O
- 2) Chemical sources of GHGs and SOA
- 		BVOCs  CO  CO2
- 		BVOC  aerosol
- 3) Effects of biogenic emissions on O3, OH and NO3
- 		NOx
- 		BVOC  H2CO
- 		BVOC + O3  OH

## What are the magnitudes of these sources?

- How are they distributed, in time and space?
- How do they impact atmospheric chemistry & global greenhouse gases?
- What are the emissions of “natural systems”?
- What are the effects of management, e.g. fertilizer, timber forests?

**Notes:**
NACP copnnection—in startup and wrapup
Is there a Nox paper with Ag data (Fehsenfeld??)  Give a strategy;  bring max photochem payload !  Rural Air chem!
=>>connect to NACP, greenhouse gases.  Sesons

## Molecules: 

- CO2, CO, CH4, NO2, O3, H2CO, glyoxal
- Aerosol properties

- Satellite observations that will
- contribute

## SOURCES OF ATMOSPHERIC METHANE

**SOURCES OF ATMOSPHERIC METHANE**

**ANIMALS**
**90**

**LANDFILLS**
**50**

**GAS**
**60**

**COAL**
**40**

**RICE**
**85**

**TERMITES**
**25**

**WETLANDS**
**180**

**BIOMASS**
**BURNING**
**20**

**GLOBAL METHANE**
**SOURCES (Tg CH****4**** yr****-1****) **

**Notes:**
NB need to add MBM paper on NOx sources from agr in China

## Growth of CH4  slowed dramatically after  1991. Will increases resume?

- CH4 over North Dakota

- Summer, 2000 (COBRA)

- Growth of CH4  slowed dramatically after  1991. Will increases resume?
- The vertical gradient over the Midwest is comparable to the gradient in the Amazon.

## S. Del Grosso, S. Ogle and B. Parton, in review

**S. Del Grosso, S. Ogle and B. Parton, in review**
***Total ~ 0.6 TgN/yr, 15% of global total***

## PRESENT-DAY GLOBAL BUDGET OF ATMOSPHERIC N2O 

**Although a closed budget can be constructed, uncertainties in sources are large! **
**(N****2****O atm mass = 5.13 10****18 ****kg x 3.1 10****-7**** x28/29 = 1535 Tg )**

**IPCC**
**[2001]**

**Notes:**
Big imbalance, small change due to long lifetime.  Big inertia/momentrum

## 2) Chemical Sources of GHGs and aerosol(BVOCs, 1000’s of compounds)

**2) Chemical Sources of GHGs and aerosol****(BVOCs, ****1000’s of compounds)**

- Isoprene (C5H8)
- Monoterpenes (C10H16)
- Oxygenated VOC
- Sesquiterpenes (C15H24)

**Amount Known**

## Agriculture produces a wide variety of highly reactive hydrocarbons, often in large quantities.

*C.Warneke et al., 2002*

*Concentrations and fluxes of oxygenated  HCs over an alfalfa field in Colorado.*

**Methanol**

**Acetaldehyde**

**Acetone**

- Methanol

- Acetaldehyde

- Acetone

- Mixing ratio (ppb)

- Flux (mg m-2 hr-1)

## Secondary Organic Aerosol (SOA) Production from biogenic VOC emissions

- Graphic from M. Lunden

## Nga et al., ES&T, 2006

**Nga et al., ES&T, 2006**

## Goldstein and Galbally, ES&T 2007

## 3) O3, OH, NO3

- Biogenic NOx emissions:  OH, NO3, and O3
- BVOC  H2CO, aerosol oxidation?
- O3 + BVOC  OH + products

## Partitioning of Global NOx Sources

- Cohen Group Meeting    31 August 2005

- Partitioning of Global NOx Sources

| Source | Tg N year -1 |
| --- | --- |
| Fuel Consumption | 25 |
| Biomass Burning | 6 |
| Soil Emission | 9 |
| Lightning | ~10 |
| Total | ~50 |

- Based on Jaegle et al. *Faraday Discussions*, 130, 407-423, DOI: 10.1039/b502128f, **2005**

## SCIAMACHY Soil NOx Observations - Montana

- Cohen Group Meeting    31 August 2005

- SCIAMACHY Soil NOx Observations - Montana

- Bertram et al GRL 2005

## Local Tuning of Y&L Soil NOx Model

- Cohen Group Meeting    31 August 2005

- Local Tuning of Y&L Soil NOx Model

## Terpenes and isoprene are source of H2CO

- Lee et al., JGR, 2006.

- Terpenes and isoprene are source of H2CO

## Terpenes + O3  OH + OxProducts

- Growing body of evidence that BVOC emissions are a strong source of OH both within the forest canopy and above.

## Goldstein et al. GRL and ACP
Chemical O3 deposition
Rapid Production of secondary VOC products 

Helmig et al. ES&T
Sesquiterpene emissions are 20% of monoterpene emissions for 	several pine species

Brune et al.  JGR/Science
Excess OH observed in regions of high biogenic emissions including ground sites in Alabama, Nashville and Michigan and from the aircraft.  

Higher OH reactivity than accounted for by measured VOC associated with biogenics

Cohen ACP
HNO3 flux over a pine forest is upward implying 5-10 times more OH in the forest canopy than above

Martinez (MPI-Mainz)
Excess OH correlated with isoprene over Surinam

Kulmala et al.
Evidence in modeling and aerosol over forest in Finland

- Chemical O3 deposition
- Rapid Production of secondary VOC products
- Helmig et al. ES&T
- Sesquiterpene emissions are 20% of monoterpene emissions for 	several pine species
- Brune et al.  JGR/Science
- Excess OH observed in regions of high biogenic emissions including ground sites in Alabama, Nashville and Michigan and from the aircraft.
- Higher OH reactivity than accounted for by measured VOC associated with biogenics
- Cohen ACP
- HNO3 flux over a pine forest is upward implying 5-10 times more OH in the forest canopy than above
- Martinez (MPI-Mainz)
- Excess OH correlated with isoprene over Surinam
- Kulmala et al.
- Evidence in modeling and aerosol over forest in Finland

## Ren, Brune, et al.

## Summer (June-August) Blodgett Forest

- 									Farmer and Cohen,
- 									in preparation

- flux (ppb m s-1)

- NO2

- ∑PNs

- ∑ANs

- HNO3

- mixing ratio (ppb)

**Notes:**
N exchange...

## Summer—HNO3 flux

- Summer—HNO3 flux

- Focus on noon

**Notes:**
OH gradient causes a PHNO3 grad --- need 3x107 OH for Phno3 to  be faster thancanopy

## Summer—HNO3 flux

- Summer—HNO3 flux

- Calculated based on deposition velocity

- Based on
- flux-gradient relationships

- 0.46

- 0.48

- 0.50

- 5

- 6

- 7

- 8

- 9

- 10

- 11

- 12

**Height (m)**

- HNO3

-  (ppb)

- Chemistry

**Notes:**
OH gradient causes a PHNO3 grad --- need 3x107 OH for Phno3 to  be faster thancanopy

## OH+NO2HNO3 	OHcanopy  = 3.1 x 107 molec∙cm-3 

- OH+NO2HNO3 	**OH****canopy****  = 3.1 x 10****7**** molec∙cm****-3**

- background OH ~5 x 106 molec∙cm-3

**NO****2**** = 300ppt**
**Solve for OH needed to produce HNO****3**** that is identified as chemical.**
**OH  = 3.1 x 10****7**** molec∙cm****-3**** **

- Residence time in the canopy is about 600 sec

**Notes:**
not unprecedented

## -Di Carlo et al. [2004]

**Measured– Calculated OH Loss**
**Inferred unmeasured reactive BVOCs.**

**-Kulmala et al., [2000] **
**Aerosol growth Hyytiala  Forest, Finland**
**From BVOC?**

**-Ciccioli et al. [1999]***** *****sesquiterpenes in leaf enclosures were not observed above the canopy – Burriana orange orchard, Spain.**

## Mission

- Direct GHG and NOx emissions
- 	Industrial agriculture—target areas just after rain on recently fertilized fields, follow evolution over several days.  Key goal verify/understand timing patterns so that can interpret satellite observations at one time of day.
- Forest Emissions: Reactivity, Aerosol
- 	Visit forests at that experience high T (maximum emissions).  Bring new instruments capable of establishing links between BVOC emissions, OH and aerosol composition.

## Conclusions

- Conclusions

- A focussed effort aimed at understanding:
-   	the timing and spatial patterns of 	biogenic emissions
-  	the propagation of these emissions as a 	result of exchange across the PBL and 	convection and
-  	the gas and aerosol chemistry of 	emissions
- would likely provide exciting new scientific results.