Commonality between simulations using GFEDv2 and J3LRCv2 during summers of 2000 and 2006 using TM4

Commonality between simulations using GFEDv2 and

J3LRCv2 during summers of 2000 and 2006 using TM4

J.E.Williams, P.F.J. van Velthoven and Rinus Scheele

2000 2006

Differences in monthly emission fluxes for Africa

Peak in emissions shifts towards the summer period for both years as seen by van der Werf et al., ACP, 2006.

Saharan Sahel

Guinea South Africa

2000 2006

GFEDv2 L3JRCv2

GFEDv2 L3JRCv2

2000 2006

Emission dataset

Emission of CO

(Tg CO yr-

1)

Oxidation of CO

(Tg CO yr-

1)

%OH Scavenge

d

%OH scavenged <750hPa

%OH scavenged UTLS

GFEDv2 2000

676 1543 41 35.7 72.1

J3LRCv22000

741 1584 42 36.8 72.2

GFEDv22006

733 1643 41 35.9 71.8

L3JRCv22006

812 1696 42 37.1 71.9

Changes in the Oxidation budget of CO

Twice the mass of the CO emitted in the tropics is oxidized2006 Trop burden of CO : 396Tg CO (GFEDv2), 412TgCO

(L3JRCv2)2006: (CH4) = 10.55 yrs (GFEDv2), 10.72yrs (L3JRCv2)

2000 2006

GFEDv2 L3JRCv2

2000 2006

Emission dataset

Emission of NOx

(Tg N yr-1)

Tg O3 from JNO2

(< 750 hPa)

Tg O3 via NO + O3(<750 hPa)

Tg O3 from JNO2

(> 200 hPa to 95hPa)

Tg O3 via NO + O3(> 200 hPa to 95hPa)

GFEDv2 2000

25.5 4354 317 3550 279

J3LRCv22000

28.2 5066 459 3531 277

GFEDv22006

26.5 4743 347 2989 241

L3JRCv22006

29.4 5558 465 2971 240

Changes in the budget of O3

Changes in LT mimic the changes in NOx emissions where transport/processing effects alter UTLS O3

budget

Emission dataset

Chemical O3

Production

(Tg O3 yr-

1)

Chemical O3 Loss

(Tg O3 yr-

1)

Dry Depositio

n(Tg O3 yr-

1)

Strat-Trop Exchange(Tg O3 yr-1)

O3(days)

IPCC 4AR

4506 4354 679 526 23.3

Royal Society

4622 4453 696 531 22.9

GFEDv2RETRO

4080 3920 650 489 24.1

L3JRCv2RETRO

4124 3958 655 489 24.0

L3JRCv2RETROMeteo 2000

3899 3861 624 586 23.8

Changes in chemical activity

Multi-model ensemble means (Stevenson et al, 2006) are 4974233 Tg O3 yr-1, 4577291 Tg O3 yr-1, 953154 Tg O3 yr-1, 556154 Tg O3

yr-1 and 22.22.22 days

Commonality of Sonde comparisons at Irene(25.9°S, 28.2°E)

1.3°S,38.6°

E

25.9°S, 28.2°E

Origin of air-masses seem to be independent on the season even though ITCZ shifts. Seen in trajectory

studies (Mari et al, ACP, 2008)

6.2°N, 2.2°E

5.8°N, 55.2°W

Effects at other tropical locations : South America

Conclusions Some commonality does exist between the meteorology of

2000 and 2006 as exhibited by the distribution of the passive tracers/monthly mean temps.

Analysing at a higher frequency (weekly) for WAM period is necessary to determine true variability.

In general the seasonal differences in trace gases introduced as a result of applying the L3JRCv2 dataset have similarity between both years. The maximal concentrations for the AMMA measurement region occur over the South Atlantic Ocean.

Using L3JRCv2 increases the chemical activity of the model and increases methane lifetime by a few % as a result of CO (5% increase in the CO burden).

For 2006 the effect on the UTLS maybe somewhat weaker than the evaluation year.

Comparisons with seasonal sondes values in Africa reveals that the application of the L3JRCv2 dataset improves the correlation with sonde measurements for TM4 at the surface upto the middle troposphere.

The origin of air-masses effects to extent of the improvement when applying the new database (emission maps needed).

Most Shadoz sites are relatively unaffected by the increases in the emissions in Africa