ISSN:0094-8276    

DOI:10.1029/GL017i004p00313

年代:1990

数据来源: WILEY

摘要:

Total ozone values measured by the Total Ozone Mapping Spectrometer (TOMS) during January, February and March 1989 are analyzed. During this period, polar total ozone values did not reveal clear depletions, although average winter total ozone values indicate that a 2–6% ozone reduction has occurred in northern mid to high latitudes over the last 10 years. Rapid total ozone increases were seen during mid‐February, resulting from a wave 2 major stratospheric warming. In order to track polar air over the warming period, total ozone trends are further analyzed using Ertel's potential vortic

ISSN:0094-8276    

DOI:10.1029/GL017i004p00317

年代:1990

数据来源: WILEY

摘要:

Ozone soundings are performed from Spitzbergen (79°N, 12°E) by an ozone LIDAR and balloon sondes, the development of the ozone layer from January until the end of March 1989 shows no major depletion, but a significant increase in mid‐February due to the stratospheric warming. In march a secondary concentration maximum occured above the tropopa

ISSN:0094-8276    

DOI:10.1029/GL017i004p00321

年代:1990

数据来源: WILEY

摘要:

Large‐scale distributions of ozone (O3) were measured with an airborne lidar system as part of the 1989 Airborne Arctic Stratospheric Expedition (AASE). Measurements of O3distributions were obtained between January 6 and February 15, 1989, on 15 long‐range flights into the polar vortex from the Sola Air Station, Norway. The observed O3distribution was found to clearly indicate the edge of the polar vortex and to be an effective tracer of dynamical processes in the lower stratosphere. On the last two flights of the expedition, large regions with reduced O3levels were observed by the lidar inside the polar vortex. Ozone had decreased by as much as 17% in the center of these areas, and using the in situ measurements made on the ER‐2 aircraft, it was concluded that this decline was due to chemical O3destru

ISSN:0094-8276    

DOI:10.1029/GL017i004p00325

年代:1990

数据来源: WILEY

摘要:

The Airborne Arctic Stratospheric Expedition (AASE) was conducted during January and February 1989. The polar stratosphere during this period was characterized by cold conditions from January to mid‐February. A mid‐February wave 2 major warming considerably warmed the polar stratosphere, but did not immediately lead to a lower stratospheric vortex breakup. As inferred from temperature data, January temperatures were sufficient for polar stratospheric cloud (PSC) formation. PSC regional extent was greater than the long‐term average, but not significantly larger than in previous

ISSN:0094-8276    

DOI:10.1029/GL017i004p00329

年代:1990

数据来源: WILEY

摘要:

Lower stratospheric temperatures during the Airborne Arctic Stratospheric Expedition are compared with temperatures available since January, 1964. January, 1989, was the coldest average January in the last 26 years at high latitude, lower stratospheric levels. There have been other months with temperatures almost as low as the level of January, 1989, and localized temperatures (e.g., minimum polar vortex temperatures) have been lower than that encountered in January 1989. February, 1989, was warmer than average and March, 1989, had some of the highest polar vortex temperatures in the last 26 years. Conditions were therefore not very favorable for Polar Stratospheric Cloud (PSC) formation into early spring.

ISSN:0094-8276    

DOI:10.1029/GL017i004p00333

年代:1990

数据来源: WILEY

摘要:

Comparisons of temperatures from the research analysis system STRATAN to radiosonde data, Meteorological Measurement System (MMS) data, and the National Meteorological Center (NMC) analyses are presented for the Airborne Arctic Stratospheric Expedition (AASE). The STRATAN analyses show consistent quality throughout AASE. The comparisons to MMS show that STRATAN more accurately represented low temperatures than NMC. This, coupled with forecast quality, show that STRATAN temperature fields are a valuable tool for diagnosing and forecasting polar stratospheric clouds.

ISSN:0094-8276    

DOI:10.1029/GL017i004p00337

年代:1990

数据来源: WILEY

摘要:

The ER‐2 Meteorological Measurement System provides accurate in‐situ measurements of atmospheric state variables. During the Airborne Arctic Stratospheric Expedition (AASE) the ER‐2 flew over the polar region on 14 occasions in January and February, 1989. Vertical temperature profiles, during aircraft takeoff at ≈ 60°N and during mid‐flight descent and ascent at high latitudes, are presented. Latitudinal variations of the horizontal wind measurement are illustrated and discussed. Based on observational data, model atmospheres at 60° and 75°N, representative of the environment of the AASE campaign, a

ISSN:0094-8276    

DOI:10.1029/GL017i004p00341

年代:1990

数据来源: WILEY

摘要:

A radiative transfer model and observed temperature and ozone profiles are used to compute three dimensional fields of heating rates for the Northern Hemisphere during the 1989 Airborne Arctic Stratospheric Experiment. For a clear atmosphere, an average cooling of 0.2 to 0.4 K/day is computed in the regions of the ER‐2 aircraft during flight days. Tropospheric clouds will increase the cooling by 0.1 to 0.2 K/day. These cooling rates are in good agreement with the diabatic cooling estimated from N2O data. Net heating rather than cooling is computed in tie area of the ozone “minihole” which had its maximum on 1/31/89 and 2/1/89 in the vicinity of the mission. On 1/31/89 the 50 and 30 mb net heating rates are 0.1 to 0.2 K/day for clear skies, and 0.05 to 0.1 K/day for cloudy

ISSN:0094-8276    

DOI:10.1029/GL017i004p00345

年代:1990

数据来源: WILEY

摘要:

Variability on scales of 200 km or less in the lower stratosphere is examined using potential temperature data collected during the AASE campaign. Enhanced variability is found over regions containing topography presumably due to gravity waves. The effect of gravity wave critical levels on topographically induced variability is examined. A significant reduction in variability is found when a critical level is present.

ISSN:0094-8276    

DOI:10.1029/GL017i004p00349

年代:1990

数据来源: WILEY