Nonorographic generation of Arctic polar stratospheric clouds during December 1999

Hitchman, Matthew H.; Büker, Marcus L.; Tripoli, Gregory J.; Browell, Edward V.; Grant, William B.; McGee, Thomas J.; Burris, J.

doi:10.1029/2001jd001034

Cited by 33 publications

(40 citation statements)

References 32 publications

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“…Weak stratospheric winds severely suppressed amplitudes of mountain waves that radiated from these islands on this day. Our forecasts support recent conclusions that stratospheric mountain waves from Franz Josef Land played no role in the formation of these clouds (Hitchman et al 2003;Pagan et al 2004).…”

Section: Discussionsupporting

confidence: 80%

“…Thus, the MWFM-2 forecasts and postanalyses argue that local mountain wave activity played no role in producing these solid NAT particles, supporting similar conclusions of Hitchman et al (2003) and Pagan et al (2004). While Hitchman et al (2003) found evidence for jetgenerated gravity waves organizing type I PSC structures observed in DC-8 lidar data near Novaya Zemlya and Severnaya Zemlya on 7 and 12 December, Pagan et al (2004) argued that the amplitudes of these waves were too weak to form ice as nucleation sites for NAT. So, while local synoptic temperatures are cold enough to maintain these NAT particles (see Fig.…”

Section: E 10 December 1999: Pscs Near Franz Josef Landsupporting

confidence: 49%

See 1 more Smart Citation

Mountain Wave–Induced Polar Stratospheric Cloud Forecasts for Aircraft Science Flights during SOLVE/THESEO 2000

Eckermann

Dörnbrack²,

Vosper³

et al. 2006

Weather and Forecasting

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The results of a multimodel forecasting effort to predict mountain wave-induced polar stratospheric clouds (PSCs) for airborne science during the third Stratospheric Aerosol and Gas Experiment (SAGE III) Ozone Loss and Validation Experiment (SOLVE)/Third European Stratospheric Experiment on Ozone (THESEO 2000) Arctic ozone campaign are assessed. The focus is on forecasts for five flights of NASA's instrumented DC-8 research aircraft in which PSCs observed by onboard aerosol lidars were identified as wave related. Aircraft PSC measurements over northern Scandinavia on 25-27 January 2000 were accurately forecast by the mountain wave models several days in advance, permitting coordinated quasiLagrangian flights that measured their composition and structure in unprecedented detail. On 23 January 2000 mountain wave ice PSCs were forecast over eastern Greenland. Thick layers of wave-induced ice PSC were measured by DC-8 aerosol lidars in regions along the flight track where the forecasts predicted enhanced stratospheric mountain wave amplitudes. The data from these flights, which were planned using this forecast guidance, have substantially improved the overall understanding of PSC microphysics within mountain waves. Observations of PSCs south of the DC-8 flight track on 30 November 1999 are consistent with forecasts of mountain wave-induced ice clouds over southern Scandinavia, and are validated locally using radiosonde data. On the remaining two flights wavelike PSCs were reported in regions where no mountain wave PSCs were forecast. For 10 December 1999, it is shown that locally generated mountain waves could not have propagated into the stratosphere where the PSCs were observed, confirming conclusions of other recent studies. For the PSC observed on 14 January 2000 over northern Greenland, recent work indicates that nonorographic gravity waves radiated from the jet stream produced this PSC, confirming the original forecast of no mountain wave influence. This forecast is validated further by comparing with a nearby ER-2 flight segment to the south of the DC-8, which intercepted and measured local stratospheric mountain waves with properties similar to those predicted. In total, the original forecast guidance proves to be consistent with PSC data acquired from all five of these DC-8 flights. The work discussed herein highlights areas where improvements can be made in future wave PSC forecasting campaigns, such as use of anelastic rather than Boussinesq linearized gridpoint models and a need to forecast stratospheric gravity waves from sources other than mountains.

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Section: Discussionsupporting

confidence: 80%

Section: E 10 December 1999: Pscs Near Franz Josef Landsupporting

confidence: 49%

Mountain Wave–Induced Polar Stratospheric Cloud Forecasts for Aircraft Science Flights during SOLVE/THESEO 2000

Eckermann

Dörnbrack²,

Vosper³

et al. 2006

Weather and Forecasting

View full text Add to dashboard Cite

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“…This is to be expected because Type Ia PSC formation requires average temperatures below the T NAT threshold for a period. The exact temperature value required varies dependent on whether NAT only forms by heterogeneous nucleation on pre-existing ice particles, requiring temperatures below T ICE (Carslaw et al, 1994), or NAT nucleation mechanisms independent of the existence of ice particles (Hitchman et al, 2003;Pagan et al, 2004;Svendsen et al, 2005). The POAM III observations predict between 60 and 85% of the occurrence identified by the T NAT temperature threshold in all the years except 2004 where only 45% of the PSC predicted by the T NAT threshold is observed.…”

Section: Resultsmentioning

confidence: 99%

“…Voigt et al (2005) detailed measurements where the conditions of particle formation are well enough constrained to conclude that a PSC is observed in air parcels that spent less than a day (approximately 18 h) at temperatures no lower than 3K below T NAT . Hitchman et al (2003) also suggests that a formation mechanism for Type Ia PSC must exist without the requirement for temperatures significantly below T NAT . Their study also highlights the potential importance of non-orographic gravity waves on PSC formation in the Arctic.…”

Section: Introductionmentioning

confidence: 99%

Can gravity waves significantly impact PSC occurrence in the Antarctic?

2009

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Abstract.A combination of POAM III aerosol extinction and CHAMP RO temperature measurements are used to examine the role of atmospheric gravity waves in the formation of Antarctic Polar Stratospheric Clouds (PSCs). POAM III aerosol extinction observations and quality flag information are used to identify Polar Stratospheric Clouds using an unsupervised clustering algorithm.A PSC proxy, derived by thresholding Met Office temperature analyses with the PSC Type Ia formation temperature (T NAT ), shows general agreement with the results of the POAM III analysis. However, in June the POAM III observations of PSC are more abundant than expected from temperature threshold crossings in five out of the eight years examined. In addition, September and October PSC identified using temperature thresholding is often significantly higher than that derived from POAM III; this observation probably being due to dehydration and denitrification. Comparison of the Met Office temperature analyses with corresponding CHAMP observations also suggests a small warm bias in the Met Office data in June. However, this bias cannot fully explain the differences observed.Analysis of CHAMP data indicates that temperature perturbations associated with gravity waves may partially explain the enhanced PSC incidence observed in June (relative to the Met Office analyses). For this month, approximately 40% of the temperature threshold crossings observed using CHAMP RO data are associated with small-scale perturbations. Examination of the distribution of temperatures relative to T NAT shows a large proportion of June data to be close to this threshold, potentially enhancing the importance of gravity wave induced temperature perturbations. Inspection of the longitudinal structure of PSC occurrence in June 2005 also shows that regions of enhancement are geographically Correspondence to: A. J. McDonald (adrian.mcdonald@canterbury.ac.nz) associated with the Antarctic Peninsula; a known mountain wave "hotspot". The latitudinal variation of POAM III observations means that we only observe this region in June-July, and thus the true pattern of enhanced PSC production may continue operating into later months.The analysis has shown that early in the Antarctic winter stratospheric background temperatures are close to the T NAT threshold (and PSC formation), and are thus sensitive to temperature perturbations associated with mountain wave activity near the Antarctic peninsula (40% of PSC formation). Later in the season, and at latitudes away from the peninsula, temperature perturbations associated with gravity waves contribute to about 15% of the observed PSC (a value which corresponds well to several previous studies). This lower value is likely to be due to colder background temperatures already achieving the T NAT threshold unaided. Additionally, there is a reduction in the magnitude of gravity waves perturbations observed as POAM III samples poleward of the peninsula.

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“…The Arctic stratospheric vortex is generally warmer and more disturbed due to planetary wave activity, possibly making gravity waves an even more important source of PSCs in the Northern Hemisphere . Although most case studies focus on gravity waves from orographic sources, Hitchman et al (2003) and Shibata et al (2003) showed that non-orographic gravity waves can also trigger PSC formation.…”

Section: Introductionmentioning

confidence: 99%

A decadal satellite record of gravity wave activity in the lower stratosphere to study polar stratospheric cloud formation

et al. 2017

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Abstract. Atmospheric gravity waves yield substantial small-scale temperature fluctuations that can trigger the formation of polar stratospheric clouds (PSCs). This paper introduces a new satellite record of gravity wave activity in the polar lower stratosphere to investigate this process. The record is comprised of observations of the Atmospheric Infrared Sounder (AIRS) aboard NASA's Aqua satellite from January 2003 to December 2012. Gravity wave activity is measured in terms of detrended and noise-corrected 15 µm brightness temperature variances, which are calculated from AIRS channels that are the most sensitive to temperature fluctuations at about 17-32 km of altitude. The analysis of temporal patterns in the data set revealed a strong seasonal cycle in wave activity with wintertime maxima at mid-and high latitudes. The analysis of spatial patterns indicated that orography as well as jet and storm sources are the main causes of the observed waves. Wave activity is closely correlated with 30 hPa zonal winds, which is attributed to the AIRS observational filter. We used the new data set to evaluate explicitly resolved temperature fluctuations due to gravity waves in the European Centre for Medium-Range Weather Forecasts (ECMWF) operational analysis. It was found that the analysis reproduces orographic and non-orographic wave patterns in the right places, but that wave amplitudes are typically underestimated by a factor of 2-3. Furthermore, in a first survey of joint AIRS and Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) satellite observations, nearly 50 gravity-wave-induced PSC formation events were identified. The survey shows that the new AIRS data set can help to better identify such events and more generally highlights the importance of the process for polar ozone chemistry.

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Nonorographic generation of Arctic polar stratospheric clouds during December 1999

Cited by 33 publications

References 32 publications

Mountain Wave–Induced Polar Stratospheric Cloud Forecasts for Aircraft Science Flights during SOLVE/THESEO 2000

Mountain Wave–Induced Polar Stratospheric Cloud Forecasts for Aircraft Science Flights during SOLVE/THESEO 2000

Can gravity waves significantly impact PSC occurrence in the Antarctic?

A decadal satellite record of gravity wave activity in the lower stratosphere to study polar stratospheric cloud formation

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