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Cloud fraction and IWC

Malcolm Brooks, 19/10/04, Delft

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Contents

Cloud Fraction and RegimesAscent/DescentBoundary Layer Stability

Summary of IWC Sampling BiasOther Sampling Strategies

Leads into open discussion

The presentation covers the following sections

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Regimes

Ascent/Descent defined by splitting distritution of w into 1/3.

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Regimes

Ascent/Descent defined by splitting distritution of w into 1/3.

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Regimes

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Regimes

Ascent at 750hPA

STABLE > > > > > > > > > > > > > > > NEUTRAL

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Regimes

Descent at 750hPA

STABLE > > > > > > > > > > > > > > > NEUTRAL

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IWC sampling biases

CLOUD FRACTION IWC

Sampling Biases of IWC much more significant than for Cloud fraction

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Effect of different Exclusion policies

BLUE – do not exclude IWC based on surface rainrate

RED – Exclude Surface rain rates > 0.5 mmhr-1

(from Chilbolton ’99-’00 period)

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Effect of different Exclusion policies

Mid Level IWC (3-7km)

BLUE – do not exclude IWC based on surface rainrate

RED – Exclude Surface rain rates > 0.5 mmhr-1

(from Chilbolton ’99-’00 period)

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Effect of different Exclusion policies

High Level IWC (7+ km)

BLUE – do not exclude IWC based on surface rainrate

RED – Exclude Surface rain rates > 0.5 mmhr-1

(from Chilbolton ’99-’00 period)

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Open Discussion

OPEN DISCUSSION