comparisons of simulated radicals and reservoirs with observations

November 5, 2003 A. Douglass, GMI Irvine 1

Comparisons of Simulated Radicals Comparisons of Simulated Radicals and Reservoirs with Observationsand Reservoirs with Observations

Anne Douglass, Peter Connell, Anne Douglass, Peter Connell,

Rich Stolarski, Susan StrahanRich Stolarski, Susan Strahan

Focus the comparisons on those that provide Focus the comparisons on those that provide insight into the forecasts, particularly the insight into the forecasts, particularly the differences between themdifferences between them


Cly - MKIV, HALOE HCl + CLAES Cly - MKIV, HALOE HCl + CLAES ClONO2 ClONO2

(latter courtesy of Andy Dessler)(latter courtesy of Andy Dessler)

Simulation with FVGCM winds has higher Cly than that with Simulation with FVGCM winds has higher Cly than that with FVDAS winds. Data is “close enough” and simulations are FVDAS winds. Data is “close enough” and simulations are close enough to each other that this does comparison does close enough to each other that this does comparison does not discriminate. not discriminate.


HCl columns from NDSCHCl columns from NDSC

HCl columns from the two GMI simulations (blue FVGCM; red FVDAS) HCl columns from the two GMI simulations (blue FVGCM; red FVDAS) exhibit the same seasonal behavior as the NDSC data at 46N and at 28 exhibit the same seasonal behavior as the NDSC data at 46N and at 28 N. In the tropics (19.5N) the seasonal issues in FVDAS appear. The N. In the tropics (19.5N) the seasonal issues in FVDAS appear. The seasonal behavior at Lauder is not as organized as at Jungfrau in either seasonal behavior at Lauder is not as organized as at Jungfrau in either the simulations or the observations.the simulations or the observations.


HCl columns 1oo - 1 hPa from HCl columns 1oo - 1 hPa from HALOEHALOE

Each point is a column calculated from a HALOE profile Each point is a column calculated from a HALOE profile within the specified latitude range. Neither HALOE nor within the specified latitude range. Neither HALOE nor the simulations show an organized seasonal cycle. The the simulations show an organized seasonal cycle. The larger column in FVGCM is consistent with higher Cly (and larger column in FVGCM is consistent with higher Cly (and older age of air) in that simulation. older age of air) in that simulation.


HCl partial pressure at 46 N HCl partial pressure at 46 N from the two GMI Simulationsfrom the two GMI Simulations

The summer decrease in the HCl column seen The summer decrease in the HCl column seen in the NDSC data is due to changes in the in the NDSC data is due to changes in the composition of the middleworld (below 100 composition of the middleworld (below 100 hPa). hPa).


ClONO2 Diurnal variation - 40N-50 NClONO2 Diurnal variation - 40N-50 N

31 hPa

21 hPa 14 hPa

10 hPa

6 hPa 4 hPa

ClONO2 agrees better with GMIClONO2 agrees better with GMIFVGCMFVGCM (green) than GMI (green) than GMIFVDAS FVDAS

(dark red) in the middle stratosphere. Sunrise drop well (dark red) in the middle stratosphere. Sunrise drop well simulated in both. Sunset rise not quite right on at lower simulated in both. Sunset rise not quite right on at lower pressures. pressures.


MLS ClOMLS ClO

In the middle latitudes, ClO from GMIIn the middle latitudes, ClO from GMIFVDASFVDAS agrees better with agrees better with MLS than that from GMIMLS than that from GMIFVGCMFVGCM. In the tropics, both simulations . In the tropics, both simulations are too high.are too high.


NOx from sunset HALOE NO + NO2NOx from sunset HALOE NO + NO2

NOx from GMIFVGCM is lower than that from GMIFVDAS by a NOx from GMIFVGCM is lower than that from GMIFVDAS by a few ppbv in the middle latitudes, and falls outside the range of few ppbv in the middle latitudes, and falls outside the range of HALOE in the SH. The seasonal behavior is nothing like the HALOE in the SH. The seasonal behavior is nothing like the data in either simulation.data in either simulation.


NOx from sunset HALOE NO + NO2 NOx from sunset HALOE NO + NO2 (ctd)(ctd)

Simulated NOx is below observations in the SH and Simulated NOx is below observations in the SH and in the tropics. NH looks fine. Seasonal character is in the tropics. NH looks fine. Seasonal character is better here than at 3 hPa.better here than at 3 hPa.


GMI total ozone compared with TOMSGMI total ozone compared with TOMS

TOMS - GMIFVGCM is positive most places - also some TOMS - GMIFVGCM is positive most places - also some high latitude “features”; TOMS-GMIFVDAS shows that high latitude “features”; TOMS-GMIFVDAS shows that the simulation is low biased in the tropics (symptom of the simulation is low biased in the tropics (symptom of too much upwelling), and low biased at high latitudes.too much upwelling), and low biased at high latitudes.


PDF’s of HALOE ozone - TropicsPDF’s of HALOE ozone - Tropics

These comparisons show that FOR OZONE the simulations These comparisons show that FOR OZONE the simulations are more similar to each other than you might expect are more similar to each other than you might expect (given the difference sin the radicals). Especially at 10 (given the difference sin the radicals). Especially at 10 hPa, agreement with HALOE is good.hPa, agreement with HALOE is good.


HALOE summer decrease in

O3 at 46 hPafar exceeds simulations

Simulated annualcycle and variabilityreflect observations

PDF’s of HALOE ozone -45PDF’s of HALOE ozone -45ooNN

summer ozone lowin both simulations comp’d with HALOE


PDF’s of HALOE ozone -45PDF’s of HALOE ozone -45ooSS

The summer most probably value is too low compared The summer most probably value is too low compared to HALOE, making the amplitude of the seasonal cycle to HALOE, making the amplitude of the seasonal cycle too large at 2 hPa. Lower stratosphere shows too too large at 2 hPa. Lower stratosphere shows too little seasonal cycle in both simulations.little seasonal cycle in both simulations.


The net chemical loss of ozone The net chemical loss of ozone GMIGMIFVDASFVDAS GMI GMIFVGCMFVGCM

Even though the transport is different, the ozone and the Even though the transport is different, the ozone and the chemical loss of ozone look “the same” in the two chemical loss of ozone look “the same” in the two simulationssimulations


Losses due to different catalytic Losses due to different catalytic cycles 3 hPacycles 3 hPa

GMIGMIFVGCMFVGCM GMIGMIFVDASFVDAS

Top two panels are NOX (left) and Clx (right) for each Top two panels are NOX (left) and Clx (right) for each simulation.simulation.

Obvious that Clx is more important in the GMIObvious that Clx is more important in the GMIFVGCMFVGCM than in the GMIthan in the GMIFVDASFVDAS; for NOx the opposite is true.; for NOx the opposite is true.


Losses due to different catalytic Losses due to different catalytic cycles 46 hPacycles 46 hPa

GMIGMIFVGCMFVGCM GMIGMIFVDASFVDAS

Losses are more similar in the lower stratosphere; both show an Losses are more similar in the lower stratosphere; both show an increased importance of NOx processes in the summer high increased importance of NOx processes in the summer high latitudes, but not enough to drive the summer ozone loss observed latitudes, but not enough to drive the summer ozone loss observed by HALOE. NOx processes are more important in GMIby HALOE. NOx processes are more important in GMIFVGCMFVGCM for high for high latitude summer; HOx processes are more important in GMIlatitude summer; HOx processes are more important in GMIFVDASFVDAS. . The total loss tries to be constant, and neither simulation The total loss tries to be constant, and neither simulation reproduces the steep summertime fall-off.reproduces the steep summertime fall-off.


ConclusionConclusion• Ozone PDFs comparable to HALOE (similar positive Ozone PDFs comparable to HALOE (similar positive

points and deficiencies)points and deficiencies)• TOMS differences consistent with circulation TOMS differences consistent with circulation

characteristicscharacteristics• Upper stratospheric NOx differs from HALOE in both Upper stratospheric NOx differs from HALOE in both

simulations; NOx is lower in GMIsimulations; NOx is lower in GMIFVGCMFVGCM than in GMI than in GMIFVDASFVDAS..• Upper stratospheric ClO from GMIUpper stratospheric ClO from GMIFVDASFVDAS is lower than is lower than

that from GMIthat from GMIFVGCMFVGCM and looks more like MLS and looks more like MLS• Total loss similar at 3.4 and 46 hPaTotal loss similar at 3.4 and 46 hPa

– Clx is more important at 3.4 hPa in GMIClx is more important at 3.4 hPa in GMIFVGCMFVGCM; NOx is more ; NOx is more important in GMIimportant in GMIFVDASFVDAS

– NOx is more important at 46 hPa in GMINOx is more important at 46 hPa in GMIFVGCMFVGCM; HOx is more ; HOx is more important in GMIimportant in GMIFVDASFVDAS..

• Transport controls these differences - CH4 differences Transport controls these differences - CH4 differences change the partitioning of chlorine reservoirs; NOx change the partitioning of chlorine reservoirs; NOx transport out of the tropics is insufficient in GMItransport out of the tropics is insufficient in GMIFVGCMFVGCM..

• Expect different sensitivity to chlorine in the upper Expect different sensitivity to chlorine in the upper stratosphere.stratosphere.

comparisons of simulated radicals and reservoirs with observations

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