287
11
Inversion of Atmospheric
CO 2 Concentrations
Ian G. Enting
CONTENTS
11.1 Introduction .................................................................................................. 287
11.2 Techniques .................................................................................................... 288
11.2.1 Estimation and Statistics ................................................................... 288
11.2.2 Early Inversion Techniques............................................................... 290
11.2.3 Gradient Methods ............................................................................. 292
11.2.4 Process Inversions............................................................................. 293
11.2.5 Other Tracers .................................................................................... 294
11.3 Statistical Characteristics ............................................................................. 296
11.3.1 Ill-Conditioning ................................................................................ 296
11.3.2 Characterizing Resolution ................................................................ 297
11.3.3 Errors in Transport Models .............................................................. 298
11.3.4 Experimental Design ........................................................................ 299
11.4 CO 2 ................................................................................................................ 301
11.4.1 Context .............................................................................................. 301
11.4.2 Budgets .............................................................................................302
11.4.3 Results from Inversions .................................................................... 305
11.5 Emerging Trends ...........................................................................................307
11.6 Concluding Remarks ....................................................................................308
Acknowledgments ..................................................................................................309
References ..............................................................................................................309
The space–time distribution of concentrations of long-lived tracers, most notably
CO 2 , contains considerable information about sources and sinks. However, atmospheric transport and mixing makes the estimation of source–sink strengths a challenging mathematical problem. This chapter reviews the main inversion techniques
and the results that have been obtained.
11.1 INTRODUCTION
Carbon dioxide (CO 2 ) is the most important of the so-called anthropogenic greenhouse gases. The complexities of the carbon cycle (Falkowski et al., 2000), along
with the perceived diffi culties in achieving reductions of fossil carbon emissions,
© 2010 by Taylor and Francis Group, LLC
11
Inversion of Atmospheric
CO 2 Concentrations
Ian G. Enting
CONTENTS
11.1 Introduction .................................................................................................. 287
11.2 Techniques .................................................................................................... 288
11.2.1 Estimation and Statistics ................................................................... 288
11.2.2 Early Inversion Techniques............................................................... 290
11.2.3 Gradient Methods ............................................................................. 292
11.2.4 Process Inversions............................................................................. 293
11.2.5 Other Tracers .................................................................................... 294
11.3 Statistical Characteristics ............................................................................. 296
11.3.1 Ill-Conditioning ................................................................................ 296
11.3.2 Characterizing Resolution ................................................................ 297
11.3.3 Errors in Transport Models .............................................................. 298
11.3.4 Experimental Design ........................................................................ 299
11.4 CO 2 ................................................................................................................ 301
11.4.1 Context .............................................................................................. 301
11.4.2 Budgets .............................................................................................302
11.4.3 Results from Inversions .................................................................... 305
11.5 Emerging Trends ...........................................................................................307
11.6 Concluding Remarks ....................................................................................308
Acknowledgments ..................................................................................................309
References ..............................................................................................................309
The space–time distribution of concentrations of long-lived tracers, most notably
CO 2 , contains considerable information about sources and sinks. However, atmospheric transport and mixing makes the estimation of source–sink strengths a challenging mathematical problem. This chapter reviews the main inversion techniques
and the results that have been obtained.
11.1 INTRODUCTION
Carbon dioxide (CO 2 ) is the most important of the so-called anthropogenic greenhouse gases. The complexities of the carbon cycle (Falkowski et al., 2000), along
with the perceived diffi culties in achieving reductions of fossil carbon emissions,
© 2010 by Taylor and Francis Group, LLC