13.06.2012. ALARO-0 experience in Hungary 1

ALARO-0 experience in HungaryALARO-0 experience in Hungary

Mihály SzűcsHungarian Meteorological Service

ALARO-1 Working Days, 13-15 June 2012, Ljubljana, Slovenia

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ContestsContests

ALARO in operation First general experiences:

Improvements in high-atmospheric scores Good precipitation patterns

Some problematic questions: Screen level diagnostics – new formula Cloud settings – namelist modifications Too strong wind gusts

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ALARO in operationALARO in operation ‘Deterministic’ system:

With data assimilation ALARO is operational from March of 2012

Ensemble system: Dynamical adaptation of the first 11 members

from PEARP ALARO is operational from November of 2011

Resolution:

8km horizontal 49 vertical levels 300s timesteps

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First experiences – high-atmosperic scoresFirst experiences – high-atmosperic scores

Improvements in most of the variables and levels Similar experiences with and without assimilation (deterministic and EPS)

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First experiences – precipitation patternFirst experiences – precipitation pattern

Global hydrostatic models usually under-estimate the bigger precipitation events and give rain for bigger areas.

NH models could over-estimate and generate dotted patterns for frontal precipitation

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Screen level diagnostics - problemsScreen level diagnostics - problems

2mT over-estimation and RH under-estimation especially in stable night situations

The situation was worse in EPS (shown here):

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Screen level diagnostics – new formulaScreen level diagnostics – new formula 2 meter temperature and relative humidity is calculated by ACNTCLS

In neutral cases we have a logarithmic profile between the surface and the lowest model level

This profile is modified on a stability dependent way

In this modification ah is a parameter

which:

Was a constant original ALARO version

We introduced a new Richardson number dependent formulation

Surface heat capacity was also modified:

Original: RCGMAX= RCTVEG(:)= 8*10-6

New value: RCGMAX=RCTVEG(:)= 2*10-5

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Screen level diagnostics – resultsScreen level diagnostics – results A two-weeks periods which was full with stable situations (EPS showed

bigger improvement – figures here)

2meter temperature was mostly even better than in ALADIN reference

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Screen level diagnostics – resultsScreen level diagnostics – results A two-weeks periods which was full with stable situations (EPS showed

bigger improvement – figures here)

Relative humidity was just slightly better than originally in ALARO

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Cloud settings – problems with ALAROCloud settings – problems with ALARO During the winter-tests we had hardly any cases with 98–100% cloud cover

It is very problematic in blocking situation when the Carpathian Basin could be cloud covered for more weeks

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Cloud settings – old ALADIN versionCloud settings – old ALADIN version During the winter tests we had hardly any cases with 98–100% cloud cover

It is very problematic in blocking situation when the Carpathian Basin could be cloud covered for more weeks

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Cloud settings – new ALARO settingsCloud settings – new ALARO settings

Modified variables in ACNEBN.F90 to Xu-Randall formulation

More tests run but QXC was found as the best for 49 levels

default alaro alaro_QXA alaro_QXB alaro_QXC

LQXRTGH FALSE TRUE FALSE TRUE TRUE

QXRTGH 3.5 1.6 3.5 3.5

QXRAL 1000 100 130 100 130

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Cloud settings – new ALARO settingsCloud settings – new ALARO settings With the new settings we had more realistic cloud patterns

The area of ~100% cloud cover became quite good

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Cloud settings – new ALARO settingsCloud settings – new ALARO settings Verification for a three-week long period in January 2012

Better total cloudiness results

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Cloud settings – new ALARO settingsCloud settings – new ALARO settings

Verification for a three-week long period in January 2012

Better 2meter temperature results

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Cloud settings – new ALARO settingsCloud settings – new ALARO settings

Sometimes too much clouds in summer – AROME is ok, which is initialized from ALARO

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Cloud and temperature error connection (?)Cloud and temperature error connection (?)

“x” is the cloud error and “y” is the max/min temperature error.

Diurnal periods on the left side, overnight periods on the right side

-2 -1 0 1 2 3 4

-4.5

-4

-3.5

-3

-2.5

-2

-1.5

-1

-0.5

0

T

Linear (T)

-2 -1 0 1 2 3 4 5

-3

-2

-1

0

1

2

3

4

T

Linear (T)

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Too strong wind gusts – problemsToo strong wind gusts – problems 12.05.2012. - Strong cold front through Hungary – Strong wind especially in

NW part of the country – 10 meter wind forecast was quite good

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Too strong wind gusts - formulationToo strong wind gusts - formulation

The formulation of wind gust calculation was not modified in ALARO

PCD (surface exchange coefficint) calculation has changed in this formula

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Too strong wind gusts - FACRAFToo strong wind gusts - FACRAF FACRAF was simply modified from 15 to 10 – it decreased the wind gust over-

estimation

Further investigations (?)

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Thank you for your attention!Thank you for your attention!