Characteristics of atmospheric gravity wave activity in the polar regions revealed by GPS radio occultation data with CHAMP

Hayato Hei, Toshitaka Tsuda, Toshihiko Hirooka

Research output: Contribution to journalArticle

45 Citations (Scopus)

Abstract

Using GPS radio occultation data during 2001-2005, we studied the climatological behavior of atmospheric gravity waves in the polar stratosphere. We calculated temperature fluctuations with vertical wavelengths shorter than 7 km and then determined the wave potential energy, Ep, every month in a longitude-latitude cell of 20° × 10° between 12 km and 33 km. In the Arctic region (50-90°N), Ep shows an annual variation with maximum in winter, consistent with the zonal mean horizontal wind, V, and the Eliassen-Palm (E-P) flux, Fz. The large Fz values indicate higher planetary wave activity, resulting in distortion of the polar vortex. The unbalanced flow can then excite gravity waves through geostrophic adjustment. In the Antarctic region (50-90°S), Ep gradually increases during winter and reaches its maximum in spring before decreasing rapidly. The time derivative of V coincides with the Ep peak and the horizontal distribution of Ep has a similar structure to V, suggesting that the Ep enhancement is closely related to the decay of the polar vortex. During major warming events over the Arctic, the divergence of E-P flux, ΔF, was enhanced, coinciding with large Ep. In the Antarctic, ΔF strongly correlates with Ep in spring. Gravity waves seem to be effectively generated through planetary wave transience and/or breaking. Orographic generation of gravity waves seems to be important in limited areas only, such as Scandinavia and the Antarctic Peninsula, showing that it is less important than the polar night jet in determining the climatological behavior of gravity waves.

Original languageEnglish
Article numberD04107
JournalJournal of Geophysical Research Atmospheres
Volume113
Issue number4
DOIs
Publication statusPublished - Feb 27 2008

Fingerprint

radio occultation
Polar Regions
CHAMP
atmospheric wave
Gravity waves
gravity waves
polar region
gravity
gravity wave
polar regions
radio
Global positioning system
GPS
polar vortex
planetary wave
planetary waves
winter
Arctic region
Vortex flow
horizontal distribution

All Science Journal Classification (ASJC) codes

  • Geophysics
  • Forestry
  • Oceanography
  • Aquatic Science
  • Ecology
  • Water Science and Technology
  • Soil Science
  • Geochemistry and Petrology
  • Earth-Surface Processes
  • Atmospheric Science
  • Earth and Planetary Sciences (miscellaneous)
  • Space and Planetary Science
  • Palaeontology

Cite this

Characteristics of atmospheric gravity wave activity in the polar regions revealed by GPS radio occultation data with CHAMP. / Hei, Hayato; Tsuda, Toshitaka; Hirooka, Toshihiko.

In: Journal of Geophysical Research Atmospheres, Vol. 113, No. 4, D04107, 27.02.2008.

Research output: Contribution to journalArticle

@article{7fe4a2f0c9ee4dbba717ba270da78c7e,
title = "Characteristics of atmospheric gravity wave activity in the polar regions revealed by GPS radio occultation data with CHAMP",
abstract = "Using GPS radio occultation data during 2001-2005, we studied the climatological behavior of atmospheric gravity waves in the polar stratosphere. We calculated temperature fluctuations with vertical wavelengths shorter than 7 km and then determined the wave potential energy, Ep, every month in a longitude-latitude cell of 20° × 10° between 12 km and 33 km. In the Arctic region (50-90°N), Ep shows an annual variation with maximum in winter, consistent with the zonal mean horizontal wind, V, and the Eliassen-Palm (E-P) flux, Fz. The large Fz values indicate higher planetary wave activity, resulting in distortion of the polar vortex. The unbalanced flow can then excite gravity waves through geostrophic adjustment. In the Antarctic region (50-90°S), Ep gradually increases during winter and reaches its maximum in spring before decreasing rapidly. The time derivative of V coincides with the Ep peak and the horizontal distribution of Ep has a similar structure to V, suggesting that the Ep enhancement is closely related to the decay of the polar vortex. During major warming events over the Arctic, the divergence of E-P flux, ΔF, was enhanced, coinciding with large Ep. In the Antarctic, ΔF strongly correlates with Ep in spring. Gravity waves seem to be effectively generated through planetary wave transience and/or breaking. Orographic generation of gravity waves seems to be important in limited areas only, such as Scandinavia and the Antarctic Peninsula, showing that it is less important than the polar night jet in determining the climatological behavior of gravity waves.",
author = "Hayato Hei and Toshitaka Tsuda and Toshihiko Hirooka",
year = "2008",
month = "2",
day = "27",
doi = "10.1029/2007JD008938",
language = "English",
volume = "113",
journal = "Journal of Geophysical Research",
issn = "0148-0227",
number = "4",

}

TY - JOUR

T1 - Characteristics of atmospheric gravity wave activity in the polar regions revealed by GPS radio occultation data with CHAMP

AU - Hei, Hayato

AU - Tsuda, Toshitaka

AU - Hirooka, Toshihiko

PY - 2008/2/27

Y1 - 2008/2/27

N2 - Using GPS radio occultation data during 2001-2005, we studied the climatological behavior of atmospheric gravity waves in the polar stratosphere. We calculated temperature fluctuations with vertical wavelengths shorter than 7 km and then determined the wave potential energy, Ep, every month in a longitude-latitude cell of 20° × 10° between 12 km and 33 km. In the Arctic region (50-90°N), Ep shows an annual variation with maximum in winter, consistent with the zonal mean horizontal wind, V, and the Eliassen-Palm (E-P) flux, Fz. The large Fz values indicate higher planetary wave activity, resulting in distortion of the polar vortex. The unbalanced flow can then excite gravity waves through geostrophic adjustment. In the Antarctic region (50-90°S), Ep gradually increases during winter and reaches its maximum in spring before decreasing rapidly. The time derivative of V coincides with the Ep peak and the horizontal distribution of Ep has a similar structure to V, suggesting that the Ep enhancement is closely related to the decay of the polar vortex. During major warming events over the Arctic, the divergence of E-P flux, ΔF, was enhanced, coinciding with large Ep. In the Antarctic, ΔF strongly correlates with Ep in spring. Gravity waves seem to be effectively generated through planetary wave transience and/or breaking. Orographic generation of gravity waves seems to be important in limited areas only, such as Scandinavia and the Antarctic Peninsula, showing that it is less important than the polar night jet in determining the climatological behavior of gravity waves.

AB - Using GPS radio occultation data during 2001-2005, we studied the climatological behavior of atmospheric gravity waves in the polar stratosphere. We calculated temperature fluctuations with vertical wavelengths shorter than 7 km and then determined the wave potential energy, Ep, every month in a longitude-latitude cell of 20° × 10° between 12 km and 33 km. In the Arctic region (50-90°N), Ep shows an annual variation with maximum in winter, consistent with the zonal mean horizontal wind, V, and the Eliassen-Palm (E-P) flux, Fz. The large Fz values indicate higher planetary wave activity, resulting in distortion of the polar vortex. The unbalanced flow can then excite gravity waves through geostrophic adjustment. In the Antarctic region (50-90°S), Ep gradually increases during winter and reaches its maximum in spring before decreasing rapidly. The time derivative of V coincides with the Ep peak and the horizontal distribution of Ep has a similar structure to V, suggesting that the Ep enhancement is closely related to the decay of the polar vortex. During major warming events over the Arctic, the divergence of E-P flux, ΔF, was enhanced, coinciding with large Ep. In the Antarctic, ΔF strongly correlates with Ep in spring. Gravity waves seem to be effectively generated through planetary wave transience and/or breaking. Orographic generation of gravity waves seems to be important in limited areas only, such as Scandinavia and the Antarctic Peninsula, showing that it is less important than the polar night jet in determining the climatological behavior of gravity waves.

UR - http://www.scopus.com/inward/record.url?scp=42549127315&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=42549127315&partnerID=8YFLogxK

U2 - 10.1029/2007JD008938

DO - 10.1029/2007JD008938

M3 - Article

AN - SCOPUS:42549127315

VL - 113

JO - Journal of Geophysical Research

JF - Journal of Geophysical Research

SN - 0148-0227

IS - 4

M1 - D04107

ER -