Modeled vs. observed total cloud cover

Monthly means of C

^tot

at NP-35 start position (102.81

^◦

E; 81.40

^◦

N)

20 30 40 50 60 70 80 90 100

Aug07 Sep07 Oct07 Nov07 Dec07 Jan08 Feb08 Mar08 Apr08 May08 Jun08 Jul08 Aug08

Ctot[%]

Month

ERA-Interim MODIS NP-35 HIRHAM5-SCM (PS) HIRHAM5-SCM (RH)

MODIS features moderate (high) cloudiness during winter period (summer period) In general, HIRHAM5-SCM agrees qualitatively but systematically overestimatesC^tot PS-Scheme shows reduced biases and good agreement from November 2007 to January 2008 Transition seasons worst reproduced with largest biases in October 2007 and May 2008

Best(worst) agreement between MODIS andHIRHAM5-SCM(PS)(ERA-Interim) but systematic overestimation of cloudiness regardless of whether model or reanalysis

Monthly means of C at NP-35 start position (102.81 E; 81.40 N)

20 30 40 50 60 70 80 90 100

Aug07 Sep07 Oct07 Nov07 Dec07 Jan08 Feb08 Mar08 Apr08 May08 Jun08 Jul08 Aug08

Ctot[%]

Month

ERA-Interim MODIS NP-35 HIRHAM5-SCM (PS) HIRHAM5-SCM (RH) HIRHAM5 (PS)

MODIS features moderate (high) cloudiness during winter period (summer period) In general, HIRHAM5-SCM agrees qualitatively but systematically overestimatesC^tot PS-Scheme shows reduced biases and good agreement from November 2007 to January 2008 Transition seasons worst reproduced with largest biases in October 2007 and May 2008

Best(worst) agreement between MODIS andHIRHAM5-SCM(PS)(ERA-Interim) but systematic overestimation of cloudiness regardless of whether model or reanalysis

Introduction of AWI Motivation Outline Model description Results from HIRHAM5-SCM Results from HIRHAM5 Summary/Outlook

Modeled vs. observed total cloud cover

Monthly means of C

^tot

at NP-35 start position (102.81

^◦

E; 81.40

^◦

N)

20 30 40 50 60 70 80 90 100

Aug07 Sep07 Oct07 Nov07 Dec07 Jan08 Feb08 Mar08 Apr08 May08 Jun08 Jul08 Aug08

Ctot[%]

Month

ERA-Interim MODIS NP-35 HIRHAM5-SCM (PS) HIRHAM5-SCM (RH) HIRHAM5 (PS)

MODIS features moderate (high) cloudiness during winter period (summer period) In general, HIRHAM5-SCM agrees qualitatively but systematically overestimatesC^tot PS-Scheme shows reduced biases and good agreement from November 2007 to January 2008 Transition seasons worst reproduced with largest biases in October 2007 and May 2008

Best(worst) agreement between MODIS andHIRHAM5-SCM(PS)(ERA-Interim) but systematic overestimation of cloudiness regardless of whether model or reanalysis

Monthly means of C at NP-35 start position (102.81 E; 81.40 N)

20 30 40 50 60 70 80 90 100

Aug07 Sep07 Oct07 Nov07 Dec07 Jan08 Feb08 Mar08 Apr08 May08 Jun08 Jul08 Aug08

Ctot[%]

Month

ERA-Interim MODIS NP-35 HIRHAM5-SCM (PS) HIRHAM5-SCM (RH) HIRHAM5 (PS)

MODIS features moderate (high) cloudiness during winter period (summer period) In general, HIRHAM5-SCM agrees qualitatively but systematically overestimatesC^tot PS-Scheme shows reduced biases and good agreement from November 2007 to January 2008 Transition seasons worst reproduced with largest biases in October 2007 and May 2008

Best(worst) agreement between MODIS andHIRHAM5-SCM(PS)(ERA-Interim) but systematic overestimation of cloudiness regardless of whether model or reanalysis

Introduction of AWI Motivation Outline Model description Results from HIRHAM5-SCM Results from HIRHAM5 Summary/Outlook

Modeled vs. observed total cloud cover

Monthly means of C

^tot

at NP-35 start position (102.81

^◦

E; 81.40

^◦

N)

20 30 40 50 60 70 80 90 100

Aug07 Sep07 Oct07 Nov07 Dec07 Jan08 Feb08 Mar08 Apr08 May08 Jun08 Jul08 Aug08

Ctot[%]

Month

ERA-Interim MODIS NP-35 HIRHAM5-SCM (PS) HIRHAM5-SCM (RH) HIRHAM5 (PS)

MODIS features moderate (high) cloudiness during winter period (summer period) In general, HIRHAM5-SCM agrees qualitatively but systematically overestimatesC^tot PS-Scheme shows reduced biases and good agreement from November 2007 to January 2008 Transition seasons worst reproduced with largest biases in October 2007 and May 2008

Best(worst) agreement between MODIS andHIRHAM5-SCM(PS)(ERA-Interim) but systematic overestimation of cloudiness regardless of whether model or reanalysis

Monthly means of C at NP-35 start position (102.81 E; 81.40 N)

20 30 40 50 60 70 80 90 100

Aug07 Sep07 Oct07 Nov07 Dec07 Jan08 Feb08 Mar08 Apr08 May08 Jun08 Jul08 Aug08

Ctot[%]

Month

ERA-Interim MODIS NP-35 HIRHAM5-SCM (PS) HIRHAM5-SCM (RH) HIRHAM5 (PS)

MODIS features moderate (high) cloudiness during winter period (summer period) In general, HIRHAM5-SCM agrees qualitatively but systematically overestimatesC^tot PS-Scheme shows reduced biases and good agreement from November 2007 to January 2008 Transition seasons worst reproduced with largest biases in October 2007 and May 2008

Best(worst) agreement between MODIS andHIRHAM5-SCM(PS)(ERA-Interim) but systematic overestimation of cloudiness regardless of whether model or reanalysis

Introduction of AWI Motivation Outline Model description Results from HIRHAM5-SCM Results from HIRHAM5 Summary/Outlook

Modeled vs. observed total cloud cover

Monthly means of C

^tot

at NP-35 start position (102.81

^◦

E; 81.40

^◦

N)

20 30 40 50 60 70 80 90 100

Aug07 Sep07 Oct07 Nov07 Dec07 Jan08 Feb08 Mar08 Apr08 May08 Jun08 Jul08 Aug08

Ctot[%]

Month

ERA-Interim MODIS NP-35 HIRHAM5-SCM (PS) HIRHAM5-SCM (RH) HIRHAM5 (PS)

MODIS features moderate (high) cloudiness during winter period (summer period) In general, HIRHAM5-SCM agrees qualitatively but systematically overestimatesC^tot PS-Scheme shows reduced biases and good agreement from November 2007 to January 2008 Transition seasons worst reproduced with largest biases in October 2007 and May 2008

Best(worst) agreement between MODIS andHIRHAM5-SCM(PS)(ERA-Interim) but systematic overestimation of cloudiness regardless of whether model or reanalysis

20

Aug07 Sep07 Oct07 Nov07 Dec07 Jan08 Feb08 Mar08 Apr08 May08 Jun08 Jul08 Aug08 Ctot[%]

Aug07 Sep07 Oct07 Nov07 Dec07 Jan08 Feb08 Mar08 Apr08 May08 Jun08 Jul08 Aug08 Ctot[%]

Aug07 Sep07 Oct07 Nov07 Dec07 Jan08 Feb08 Mar08 Apr08 May08 Jun08 Jul08 Aug08 Ctot[%]

Aug07 Sep07 Oct07 Nov07 Dec07 Jan08 Feb08 Mar08 Apr08 May08 Jun08 Jul08 Aug08 Ctot[%]

Aug07 Sep07 Oct07 Nov07 Dec07 Jan08 Feb08 Mar08 Apr08 May08 Jun08 Jul08 Aug08 Ctot[%]

Aug07 Sep07 Oct07 Nov07 Dec07 Jan08 Feb08 Mar08 Apr08 May08 Jun08 Jul08 Aug08 Ctot[%]

Month

MODIS p = q0 = 2 p = F(q), gthr=0.05mgkg-1

Suitable tuning parameters

˜

q₀−Shape parameter threshold

Controls the shape of the symmetric beta distribution acting as probability density function (PDF)

CWmin−Cloud water threshold

Avoids negative cloud water/ice contents and controls the occurrence of clear-sky conditions in the PS-Scheme

γ1−Autoconversion rate

Controls the efficiency of rain drop formation by collision and coalescence

γthr−Cloud ice threshold

Controls the efficiency of the Bergeron-Findeisen process

Reduction ofC^totthroughhigherCWminorγ1as well aslower˜q₀orγthr

Most significant improvement through lowerγthrthat also correct the ratio of liquid to solid water content

Klaus et al. (2012): Evaluation of Two Cloud Parameterizations and Their Possible Adaptation to Arctic Climate Conditions,Atmosphere2012, 3, 419 – 450.

Introduction of AWI Motivation Outline Model description Results from HIRHAM5-SCM Results from HIRHAM5 Summary/Outlook

Im Dokument Arctic: Energy sink of the Earth (Seite 43-51)