Meteorological update and modeling plans within GEOMON Peter van Velthoven, KNMI Meteo status: almost complete up to April 2008

Overview From my presentation of last year: WAS-trajectories Supersaturation in ECMWF New: 2-day forward trajectories static and dynamical tropopause height planned: TTL base height, eq.PV latitude Geomon Act. 5.1 demonstration plans: Greenhouse gases pilot Reactive gases pilot

WAS-trajectories 8 day backward trajectories every 6 seconds (0.1 min) WAS-samples are taken within a minute so the trajectories stick very close together, therefore: 15 additional trajectories are calculated in a cube centred around the sample to indicate uncertainty. p was 1.03 p was 0.97 p was 0.8  longitude 0.8  latitude WAS pressure

WAS sample 22 from flight May 2006 WAS trajectories (each 6 secs) WAS “volume” trajectories Ordinary trajectories for 1 flight hour (5-day backward)

New ECMWF scheme for water vapour (super)saturation over ice From 13 september 2006 onward Tompkins, Gierens & Rädel: QJRMS, 133, 622, p.53, 2006 ECMWF newsletter 109, p. 26, 2006

New ECMWF scheme for water vapour (super)saturation over ice

Static tropopause WMO-definition: the lowest level at which the lapse rate decreases to 2 °C/km or less, provided that the average lapse rate between this level and all higher levels within 2 km does not exceed 2 °C/km. lapse rate = dT/dz

Potential vorticity, PV A conserved quantity for adiabatic, frictionless motions (material contours!) Not conserved when there is latent heating (precipitation, evaporation) friction (at the earth’s surface) turbulence/wave-background flow interaction at scales not resolved by the model PV= .  /   -g(f +  v/  x -  u/  y)  /  p 1 PVU =10 -6 K m 2 kg -1 s -1

Tropopause “calculation” on ECMWF model levels Flight 220 More noisy Not valid in tropics Dynamic TP (3.5 PVU) Static TP (WMO definition) To be included in merged files …?

New: 2-day forward trajectories calculated for each flight Questions? Produced at request of IFT Data+plots are on website

Questions?

The end Questions? and CARIBIC.

GEOMON Act 5.1: Greenhouse gases pilot Objectives: Demonstrate use of GEOMON GG observations (Act.1) Use GEOMON CARIBIC obs. (CH 4, CO) to evaluate model simulated large scale gradients in the upper troposphere/lower stratosphere Use GEOMON surface obs. (CH 4, CO) to evaluate surface large scale/interhemispheric gradient and seasonal cycle IPSL: Compare modelled and observed climatologies of CO 2

GEOMON Act. 5.1 Greenhouse gases pilot set-up 3 global models driven by ECMWF meteo: TM4 (KNMI), LMDZ-INCA (CEA/LSCE), CTM2 (Un. Oslo) Free running methane (no surface BC for CH 4 but emissions) Output: modelled mixing ratios of CH 4 and CO at the surface stations (at hourly resolution) and along the CARIBIC flight paths (at 3 minute resolution) Time planning : June 2009: Report on preliminary model evaluation (2005) Dec 2010: Report on final model evaluation (1997- Apr 2002, Dec 2004 onward)

GEOMON Act 5.1: Reactive gases pilot Objectives: Demonstrate use of GEOMON reactive gas observations (Act.2) Use GEOMON CARIBIC and satellite observations to evaluate the ability of the model(s) to simulate oxygenated hydrocarbons incl. their seasonal cycle – important for upper tropospheric HO x production Would use CARIBIC obs. of O 3, HCHO, acetone, (methanol), NO y..

WP5.1 Evaluation of forward models with GEOMON observations of greenhouse and reactive gases

The end Questions?