-integral to VOCALS objectives -we want to do the best we can:

* marine stratus over ocean is the idealization many retrievals of warm cloud properties are based on

* VOCALS an opportunity to both nail down retrievals & use “retrieval-breakdowns” to better understand cloud/aerosol/precip behavior

* unique characteristic/opportunity for VOCALS

Remote sensing of south east Pacific stratus

Paquita Zuidema, RSMAS/U of Miami

Reading, Sept. ,2008

Topics:1. Liquid water paths2. Drizzle3. Satellite-shipboard comparisons (if interest)

Used cloud volume extinction coefficients constructed from cloud radar+microwave as input into SHDOM

6 ~month-long cruises to the southeast Pacific since 2001

epic

includes a week at 20S, 85W each cruise

TMI SST

Shipboard instruments :

•ceilometer (CT-25K)•Surface radiative & turbulent fluxes•Cloud radar•Wind profiler (if Ron Brown)•Lasair-II aerosol counter (but not EPIC)•Rawindsondes•Microwave Radiometer(s)

During EPIC, LWPs used to assess models

and construct further microphysical retrievals

c

re

Nd

Factor of -1in slope,as expectedfrom theory

110 < LWP <121 g m-2

121 < LWP <133 g m-2

133 < LWP <146 g m-2

Pt Reyes, CAARM data

NCCN Aerosol scattering Aerosol index

McComiskey and Feingold 2007

LWPs useful for quantifying aerosol indirect effects

PMS Lasair-II particle countercompares well to a TAMU DMA(but we haven’t been able to characterize the Twomey AIE)

More modern gaseous/liquidabsorption models producelower LWPs that comparebetter to adiabatic values

But they remain noisy….

Current NOAA radiometers have an approximateaccuracy of 30 g m-2 at 10-minute resolution

Zuidema et al. 2005

Okay for diurnal composite, statistical evaluations

adiabatic LWP

retrieved LWP

Local time

adiabatic LWP

retr

ieve

d LW

P

For aerosol-cloud-precip evaluations at the eddy scale & re retrievals, would prefer higher accuracy

For VOCALS-Rex:

Liquid water path measurements 1. C-130 Andrew Pazmany’s 183 GHz MWRupward-pointing (NSF)

2. Ron Brown: non-NOAA 2-channel MWR +ARM Radiometrics 183 GHz MWR(technically not supported, personalloan + ARM instrument request w/Dr. Maria Cadeddu)

Cimini et al. 2007

183-GHz radiometer wing lines still sensitive toliquid water and not saturated by SEP water vapor

for an instrument noise level of 0.2 K @ 200 ms (Pazmany,2006), a LWP uncertainty of ~ 2 g m-2 all else - WVP - assumed constant

14

7 14

Using an EPIC sounding

Using epic soundings,

Physical retrieval + neural net both find10 g m-2 clear-sky LWP error for individual measurements,4 g m-2 bias relative to simulated LWPs

Excludes instrument calibration issues, but Radiometrics183 Ghz performed well in Barrow.

=> Have some confidence in ship-based measurements

C-130 will lack a 20 Ghz MWRwith which to separately retrievewater vapor, however.

183 Ghz wing line measurements not enough information forboth water vapor and liquid water path retrievals

What to do?

-assume water vapor field more homogeneous than LWP ?-use ship-based data to assess wvp variability?-even if LWPs not absolutely known, their variability can be?-can be bounded by adiabatically-determined LWPs?

Overflights of the Ron Brown by the C-130 valuablecomparison opportunities

In addition am hoping for one high-altitude climb by the C130 for a good cold-space-calibration brightness temperaturereading.

QuickTime™ and a decompressor

are needed to see this picture.

SEP region remarkably drizzly: what is the relationship toLWP, aerosol, mesoscale organization?

day night

Leon, Wang & Liu, 2008

Note that in SEP region much drizzle evaporates before reaching the surface,changing traditional views on the role of drizzle

A depth-dependent boundary lapse rate that accounts for boundary layer decouplingwas empirically deduced from radiosondes and applied to develop a MODIS cloudtop height estimate

modis

shipmodis

ship

Aerosol Cloud depth

current work: assess synoptic influence on cloud droplet number concentrationbuilds on Brenguier and collaborators type of ACE analysis

Suggestions, thoughts ?

NOAA Lidar:

Epic radar+ lidar

Lidar could provide insight into mesoscale organization

Janet Intrieri

-integral to VOCALS objectives -we want to do the best we can:

* marine stratus over ocean is the idealization many retrievals of warm cloud properties are based on

* VOCALS an opportunity to both nail down retrievals & use “retrieval-breakdowns” to better understand cloud/aerosol/precip behavior

* unique characteristic/opportunity for VOCALS

Remote sensing of south east Pacific stratus

Paquita Zuidema, RSMAS/U of Miami

Reading, Sept. ,2008

Topics:1. Liquid water paths2. Drizzle3. Satellite-shipboard comparisons (if interest)