# Presentation: 457268

## ATMOSPHERIC CHEMISTRY:FROM AIR POLLUTION TO GLOBAL CHANGE AND BACK

**Daniel J. Jacob**

## NUMBER OF PEOPLE LIVING IN U.S. COUNTIES VIOLATING NATIONAL AIR QUALITY STANDARDS, 1999

**NUMBER OF PEOPLE LIVING IN U.S. COUNTIES VIOLATING NATIONAL AIR QUALITY STANDARDS, 1999**

**EPA [2001]**

**124 ppbv**

**84 ppbv**

**            ****Carbon **
**monoxide (CO)**

**Lead**

**Nitrogen **
**dioxide**

**Ozone (O****3****)**

**Particles < 10 ********m**
**(PM****10****)**

**Particles < 2.5 ********m**
**(PM****2.5****)**

**Sulfur dioxide**
**(SO****2****)**

**Any pollutant**

## MEAN NUMBER OF SUMMER DAYS (1980-1998)  EXCEEDING THE U.S. OZONE AIR QUALITY STANDARD (84 ppbv, 8-hour average)

**EPA/AIRS data [Lin et al., 2001]**

## SOURCES OF TROPOSPHERIC OZONE

**?**

**?**

**?**

**Fires**

**Biosphere**

**Human**
**activity**

**Lightning**

**Ocean**

**physics**
**chemistry**
**biology**

**Nitrogen oxides (NO****x****)**
**      ****CO,  Hydrocarbons**

**h******

**Ozone (O****3****)**

**h********, H****2****O**

**Hydroxyl (OH)**

**The Pacman of the atmosphere!**

**Complex non-linear chemistry**

**Tropopause (8-18 km)**

**Stratospheric ozone**

**STRATOSPHERE**

**TROPOSPHERE**

**O****2 ****+ h******

## LARGE-SCALE POLLUTION IN THE TROPICS:BIOMASS BURNING

** **

## TRANSPACIFIC TRANSPORT OF ASIAN DUST

**R. Husar**

**TRANSPACIFIC TRANSPORT OF ASIAN DUST**

**April 1998 event**

## CLIMATE FORCING BY AIR POLLUTANTSGLOBAL RADIATIVE FORCING OF CLIMATE,  1750-present [IPCC, 2001]

**POLLUTANT-RELATED**

## BLACK CARBON: A MAJOR “GREENHOUSE” AEROSOL

**Chin et al. [2000]**

**DIESEL**

**DOMESTIC**
**COAL BURNING**

**BIOMASS**
**BURNING**

## INCREASE IN TROPOSPHERIC OZONE BACKGROUNDFROM INTERCONTINENTAL TRANSPORT OF POLLUTION

**1870-1990 ozone trend at European mountain sites [Marenco et al.,1994]**

**Preindustrial ozone assumed in IPCC models**

**}**

## PRESENT OZONE BACKGROUND IS SIZABLE INCREMENT TOWARDS VIOLATION OF U.S. AIR QUALITY STANDARDS(even more so in Europe!)

**0                20               40               60               80              100              120 ppbv**

**   ****Europe**
**(seasonal)**

**    ****U.S.**
**(8-h avg.)**

**   ****U.S.**
**(1-h avg.)**

**preindustrial**

**present**
**background**

**  ****Europe**
** ****(8-h avg.)**

## EFFECT OF NORTH AMERICAN SOURCESON EXCEEDANCES OF EUROPEAN AIR QUALITY STANDARD (55 ppbv, 8-h average)

**GEOS-CHEM model**
**results, summer 1997**

**Number of **
**exceedance days**
**(out of 92)**

**# of exceedance days that**
**would not have happened**
**in absence of U.S. emissions**

**Li et al. [2002]**

## Growth of Asian emissions over next decades will increase role of background for ozone air quality in U.S.

**10****9**** atoms N cm****-2**** s****-1**

**Anthropogenic**
**NOx emissions**
**[IPCC, 2001]**

**2000**

**2020**

**“****Optimistic” IPCC**
**scenario:**
**OECD, U.S. down 20%**
**Asia up 50%**

## WHAT DOES THE FUTURE HOLD?Future emission scenarios from IPCC [2001] 

**A1, A2, B1, B2: different socioeconomic story lines**

**A2: “dirty world”**
**B2: “clean world”**

**NO****x**

**SO****2**

## FUTURE EMISSIONS MAY BE LESS THAN PRESENT FORECASTS IF PUSH IS MADE FOR ENERGY EFFICIENCY AND AIR QUALITY IN DEVELOPING WORLD

**FUTURE EMISSIONS MAY BE LESS THAN PRESENT FORECASTS IF PUSH IS MADE FOR ENERGY EFFICIENCY AND AIR QUALITY IN DEVELOPING WORLD**

**Streets et al. [2001]**

## GETTING A BIG BANG FOR THE BUCK:controlling methane emissions

**A 50% reduction in anthropogenic methane emissions would:**
** ****yield a fast negative global radiation forcing of 0.37 W m****-2  **
**  ****(-0.30 W m****-2**** from methane, -0.07 W m****-2 ****from ozone)**
** ****decrease the incidence of ozone > 80 ppbv in surface air**
**  ****over U.S. by more than 50%**
***[A.M. Fiore, GEOS-CHEM model results, 2002]***

**Historical methane trend**

**Recent methane trend**

## IPCC PROJECTION OF FUTURE METHANE EMISSIONS

**Can we try to **_**decrease**_** methane emissions instead? **

## FUTURE MONITORING OF EMISSIONS BY INVERSE MODELING OF ATMOSPHERIC OBSERVATIONS

**3-D CHEMICAL **
**TRANSPORT MODEL**

**Assimilated **
**meteorological **
**data**

**Aerosol**
**and chemical**
**processes**

**OPTIMIZED **
**EMISSIONS**

**A PRIORI **
**EMISSIONS**
**(from process model)**

**INVERSE MODEL**

**OBSERVATIONS**
** ****surface**
** ****satellite**
** ****aircraft**

## GLOBAL MAPPING OF NOx EMISSIONS FROM SPACE:GOME observations of nitrogen dioxide (July 1996)

**Martin et al. [2002]**

**GOME**

**GEOS-CHEM**
**model**

## NASA/TRACE-P AIRCRAFT MISSION TO THE PACIFIC RIM(MARCH-APRIL 2001)Quantifying the export of Asian pollution

**NASA/TRACE-P AIRCRAFT MISSION TO THE PACIFIC RIM****(MARCH-APRIL 2001)****Quantifying the export of Asian pollution**

**DC-8 and P-3 aircraft**

**Satellite data:**
**MOPITT (CO)**
**TOMS (ozone)**
**SEAWIFS, **
** ****TOMS (aerosols)**

**3-D chemical transport**
**model forecasts**

**Flight tracks were designed to optimize **
**model testing and satellite validation**

## INTEGRATION OF AIRCRAFT, SATELLITES, AND MODELS:quantifying the Asian dust source in TRACE-P

**INTEGRATION OF AIRCRAFT, SATELLITES, AND MODELS:****quantifying the Asian dust source in TRACE-P**

**Dust forecast for 3/21/01 (Carmichael, U. Iowa)**

**DC8 flight track **
**and TOMS absorbing aerosol index**

**SEAWIFS aerosol optical depth**

**SEAWIFS visible image**

**Notes:**
On March 19 there was a strong dust outbreak, with dust concentrations greater than 100 g/m3 predicted to be transported into the Yellow Sea. The dust forecast in the upper right shows clearly the outflow pattern. This plume was consistent with that observed by TOMS and Seawifs. Note the extension of the dust plume over over Japan. This was sampled by the P-3 on their return to Yokota. 

## FUTURE SATELLITE MEASUREMENTS OF TROPOSPHERIC CHEMISTRY

**FUTURE SATELLITE MEASUREMENTS ****OF TROPOSPHERIC CHEMISTRY**

**MODIS/**
**MISR**

**TERRA**

**ENVISAT**

**AURA**