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.

pwas

1.03 pwas

0.97 pwas

0.8 longitude

0.8 latitude

WAS

pressure

WAS sample 22 from flight 153 31 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 iceFrom 13 september 2006 onward

Tompkins, Gierens & Rädel: QJRMS, 133, 622, p.53, 2006ECMWF newsletter 109, p. 26, 2006

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

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 m2 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. (CH4, CO) to evaluate

model simulated large scale gradients in the upper troposphere/lower stratosphere

Use GEOMON surface obs. (CH4, CO) to evaluate surface large scale/interhemispheric gradient and seasonal cycle

IPSL: Compare modelled and observed climatologies of CO2

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 CH4 but emissions) Output: modelled mixing ratios of CH4 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 HOx production

Would use CARIBIC obs. of O3, HCHO, acetone, (methanol), NOy ..

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

The end

Questions?