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Abstract: The second ARM Mobile Facility (AMF2) is designed to support ocean-based deployments. Two deployments have completed: Marine ARM GPCI Investigation of Clouds (MAGIC) (2012 – 2013) and the ARM Cloud Aerosol Precipitation Experiment (ACAPEX) (2015). Currently under way is the Measurements of Aerosols, Radiation, and CloUds over the Southern Ocean (MARCUS). The Australian Antarctic supply vessel, Aurora Australis, carries the AMF2 between Hobart, Australia, and the Antarctic from 30 October 2017 - 1 April 2018. MARCUS Ship Navigation and Tilt Corrections: A look at ARSCL-related data from the campaign so far Tami Toto 1 , Scott E. Giangrande 1 , Greg McFarquhar 2 , Adam Theisen 2,3 , Karen Johnson 1 , Meng Wang 1 , Aifang Zhou 1 1 Brookhaven National Laboratory 2 CIMMS, University of Oklahoma 3 ARM Data Quality Office Corresponding author: Tami Toto, [email protected] Voyage #1: 1 st leg Bruny Island, Australia to Davis, Antarctica MWACR-based Cloud Fraction Voyage #1: 2 nd leg Davis, Antarctica to Hobart, Australia MWACR-based Cloud Fraction Voyage #2: 1 st leg Hobart, Australia to Casey, Antarctica Voyage #2: 2 nd leg Casey, Antarctica to Hobart, Australia MWACR-based Cloud Fraction MWACR-based Cloud Fraction Sounding data unavailable at time of printing Sounding data unavailable at time of printing Wind Speed from Soundings Temperature from Soundings RH from Soundings Path of ship MWACR-based, tilt-corrected cloud fraction Bins: .25 km, .25 o of longitude Beam Angle by day: Maximum 75 th Percentile Median 25 th Percentile Minimum East Longitude (degrees) East Longitude (degrees) A look at each MARCUS leg so far …. Key Point #1: ARM Translators are producing the following navigation and inertial measurement-related or -impacted data for MARCUS: NAVBE: navigation and inertial data with added value of en route flag, beam angle, and beam angle orientation NAVBE1M: 1-min averaged NAVBE quantities with addition of course over ground and speed over ground CEILSHIPCOR: tilt and heave corrected ceilometer cloud bases MPLSHIPCOR: tilt and heave corrected Micropulse Lidar (MPL) data MWACRSHIPCOR: tilt and heave corrected moments, heave velocity corrected mean Doppler velocity MWACRARSCL: ARSCL from corrected ceilometer, MPL, and MWACR data Data is expected to be available from the ARM Archive by August 2018. Key Point #2: The MWACR is installed on a stabilized table to keep it zenith-pointing; however the table was not always zenith-pointing. We derive corrections that currently are sufficient for reflectivity, but extra corrections may be necessary for mean Doppler velocities to account for the contribution from horizontal winds. Ceilometer Correction for First Cloud-Base Height: The plots show distributions of the corrections for pitch, roll, and heave on the first cloud base height (CBH) determined from the ceilometer. For each original height bin, the color range is normalized to the pixel with the most points. V1: 1 st leg V1: 2 nd leg V2: 1 st leg V2: 2 nd leg MWACR Mean Doppler Velocity Correction: Shown for each leg is the relationship between 5-min average beam angle from the MWACR and the SEANAV (left 2 columns) and original and corrected Mean Doppler velocity CFADs (right columns). Original Corrected The 1 st column to the right compares for cloud points the 5-min average beam angle from the MWACR and the SEANAV. The color bar is normalized to the logarithmic bin with the greatest number of points. The 2 nd column shows how “good” the MDV correction is, based on the texture of the MDV field. MWACR vs. SEANAV Beam Angle CFADs of Mean Doppler Velocity Concentration of Points “Goodness” of MDV Correction MWACR and SEANAV consistent, indicating the stable table is locked and the MWACR is in a position perpendicular to the deck of the ship BEST: Stable table is working well Stable table is not keeping up with the pitch and roll of the ship V1,leg1 V1,leg2 V2,leg1 V2,leg2 This poster presents the status of the MARCUS navigation and ship correction data and first looks at corrected W-band (95 GHz) ARM Cloud Radar Active Remote Sensing of CLouds (WACR-ARSCL) VAP. The histograms at right show beam angle (angle off zenith) for the MAGIC, ACAPEX, and MARCUS campaigns. (degrees) (degrees) (degrees) (degrees) (degrees) (degrees) 5-min median standard deviation of MDV 5-min median standard deviation of MDV 5-min median standard deviation of MDV 5-min median standard deviation of MDV (m/s) (m/s) North Latitude (degrees) North Latitude (degrees) North Latitude (degrees) North Latitude (degrees) East Longitude (degrees) East Longitude (degrees)

MARCUS Ship Navigation and Tilt Corrections: A look at ... · 5-min average beam angle from the MWACR and the SEANAV. The color bar is ... deck of the ship ... Stable table is not

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Page 1: MARCUS Ship Navigation and Tilt Corrections: A look at ... · 5-min average beam angle from the MWACR and the SEANAV. The color bar is ... deck of the ship ... Stable table is not

Abstract: The second ARM Mobile Facility (AMF2) is designed to support ocean-baseddeployments. Two deployments have completed: Marine ARM GPCI Investigation of Clouds(MAGIC) (2012 – 2013) and the ARM Cloud Aerosol Precipitation Experiment (ACAPEX) (2015).Currently under way is the Measurements of Aerosols, Radiation, and CloUds over theSouthern Ocean (MARCUS). The Australian Antarctic supply vessel, Aurora Australis, carries theAMF2 between Hobart, Australia, and the Antarctic from 30 October 2017 - 1 April 2018.

MARCUS Ship Navigation and Tilt Corrections: A look at ARSCL-related data from the campaign so far

Tami Toto1, Scott E. Giangrande1, Greg McFarquhar2 , Adam Theisen2,3, Karen Johnson1, Meng Wang 1, Aifang Zhou1

1Brookhaven National Laboratory 2 CIMMS, University of Oklahoma 3 ARM Data Quality OfficeCorresponding author: Tami Toto, [email protected]

Voyage #1: 1st leg Bruny Island, Australia to Davis, Antarctica

MW

ACR-

base

d Cl

oud

Frac

tion

Voyage #1: 2nd leg Davis, Antarctica to Hobart, Australia

MW

ACR-

base

d Cl

oud

Frac

tion

Voyage #2: 1st leg Hobart, Australia to Casey, Antarctica

Voyage #2: 2nd leg Casey, Antarctica to Hobart, Australia

MW

ACR-

base

d Cl

oud

Frac

tion

MW

ACR-

base

d Cl

oud

Frac

tion

Sounding data unavailable at time of printing Sounding data unavailable at time of printing

Wind Speed from Soundings

Temperature from Soundings

RH from Soundings

Path of ship

MWACR-based, tilt-corrected cloud fractionBins: .25 km, .25o of longitude

Beam Angleby day:

Maximum75th PercentileMedian25th PercentileMinimum

East Longitude (degrees) East Longitude (degrees)

A look at each MARCUS leg so far ….

Key Point #1: ARM Translators are producing the following navigation and inertialmeasurement-related or -impacted data for MARCUS:

NAVBE: navigation and inertial data with added value of en route flag, beam angle, and beam angle orientationNAVBE1M: 1-min averaged NAVBE quantities with addition of course over ground and speed over groundCEILSHIPCOR: tilt and heave corrected ceilometer cloud basesMPLSHIPCOR: tilt and heave corrected Micropulse Lidar (MPL) dataMWACRSHIPCOR: tilt and heave corrected moments, heave velocity corrected mean Doppler velocityMWACRARSCL: ARSCL from corrected ceilometer, MPL, and MWACR data

Data is expected to be available from the ARM Archive by August 2018.Key Point #2: The MWACR is installed on a stabilized table to keep it zenith-pointing; howeverthe table was not always zenith-pointing. We derive corrections that currently are sufficient forreflectivity, but extra corrections may be necessary for mean Doppler velocities to account forthe contribution from horizontal winds.

Ceilometer Correction for First Cloud-Base Height: The plots show distributions of the corrections for pitch, roll, and heave on the first cloud base height (CBH) determined from the ceilometer. For each original height bin, the color range is normalized to the pixel with the most points.

V1: 1st leg V1: 2nd leg V2: 1st leg V2: 2nd leg

MWACR Mean Doppler Velocity Correction: Shown for each leg is the relationship between 5-min average beam angle from the MWACR and the SEANAV (left 2 columns) and original and corrected Mean Doppler velocity CFADs (right columns).

Original Corrected

The 1st column to the right compares for cloud points the 5-min average beam angle from the MWACR and the SEANAV. The color bar is normalized to the logarithmic bin with the greatest number of points.

The 2nd column shows how “good” the MDV correction is, based on the texture of the MDV field.

MWACR vs. SEANAV Beam AngleCFADs of Mean Doppler Velocity

Concentrationof Points

“Goodness” of MDVCorrection

MWACR and SEANAV consistent, indicating the stable table is

locked and the MWACR is in a position perpendicular to the

deck of the ship

BEST: Stable table is working well

Stable table is not keeping up with the pitch and roll of the ship

V1,leg1

V1,leg2

V2,leg1

V2,leg2

This poster presents the status of the MARCUSnavigation and ship correction data and first looks atcorrected W-band (95 GHz) ARM Cloud Radar ActiveRemote Sensing of CLouds (WACR-ARSCL) VAP.

The histograms at right show beam angle (angle off zenith)for the MAGIC, ACAPEX, and MARCUS campaigns.

(deg

rees

)(d

egre

es)

(deg

rees

)(d

egre

es)

(degrees) (degrees)

5-min m

edian standard deviation of MDV

5-min m

edian standard deviation of MDV

5-min m

edian standard deviation of MDV

5-min m

edian standard deviation of MDV

(m/s) (m/s)

Nor

th L

atitu

de (d

egre

es)

Nor

th L

atitu

de (d

egre

es)

Nor

th L

atitu

de (d

egre

es)

Nor

th L

atitu

de (d

egre

es)

East Longitude (degrees) East Longitude (degrees)