1 / 11

Tropopause Height Diagnostics

Tropopause Height Diagnostics. Motivation tropopause is important feature of the observed atmosphere determined by conditions in both tropo- and stratosphere position of tropopause is relevant for climate studies: e.g. cross tropopause transport

elvis
Télécharger la présentation

Tropopause Height Diagnostics

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Tropopause Height Diagnostics • Motivation • tropopause is important feature of the observed atmosphere • determined by conditions in both tropo- and stratosphere • position of tropopause is relevant for climate studies: • e.g. cross tropopause transport • indicator of climate change • Method • apply same criterion as for determination from radiosondes: • a. lowest level at which lapse rate decreases to 2 K/km • b. 2 km deep layer above must not exceed critical lapse rate • problem of coarse vertical resolution > vertical interpolation • limit for heights to be valid: 450-75 hPa • failure rate: overall 0.1%, mostly over Antarctica during JJA • rms: 30-40 hPa in extratropics, 10-20 hPa in tropics • Input Data • 3D temperature field: daily or monthly data • all comparisons on standard pressure levels

  2. Tropopause pressure (hPa)daily reanalysis-1: CDC vs. TJR DJF 1983-1998 JJA CDC TJR

  3. reanalysis-1 vs. reanalysis-2 DJF 1983-1998 JJA rean. 2 rean. 1

  4. reanalysis-1: daily vs. monthly data DJF 1983-1998 JJA monthly data daily data

  5. p11/exp55dan DJF 1983-1998 JJA AM2 monthly r1 monthly

  6. exp42 vs. exp55dan DJF 1983-1998 JJA exp42 - r1 exp55dan - r1

  7. p12L32_3 vs. exp55dan DJF 1983-1998 JJA p12L32_3 - r1 exp55dan - r1

  8. CAM 2.0.1 DJF 1983-1998 JJA CAM monthly r1 monthly

  9. NSIPP DJF 1983-1998 JJA NSIPP monthly r1 monthly

  10. NCEP SFM DJF 1983-1998 JJA SFM monthly r1 monthly

  11. Summary • AM2 tropopause height is generally too low (too high pressure), consistent with a too cold troposphere and too warm stratosphere • biases over northern extratropics: • +30 hPa in DJF (ca. -600 m) • +10 hPa in JJA (ca. -200 m) • tropical biases: • +8 hPa in DJF (ca. -600 m) • +3 hPa in JJA (ca. -200 m) • biases over southern extratropics: • -20 hPa in DJF • +20 hPa in JJA • global mean rms of tropopause pressure (hPa):

More Related