# Presentation: 897272

## The Tropical Warm Pool International Cloud Experiment

**TWP-ICE**
**Darwin, Jan/Feb 2006**
**Peter May, Jim Mather, Christian Jakob **
**And a host of others...      **

## A Few Acknowledgements

**TWP-ICE Participants:****	**ARM, BOM, CSIRO, NASA, and many Universities
**ACTIVE:****                             **Geraint Vaughan and Keith Bower**  **
**Our hosts:****  ****	****               **Northern Territory Regional Forecast Centre
- 		               Charles Darwin University
- 		               Darwin RAAF Base
**Logistics coordination:****         **Andrew Hollis
**Operations web site:****             **Tim Hume
**Forecast team:****                      ** Lori Chappel and Mick Pope
**Ground site maintenance:****    **Brad Atkinson and Anthony Noonan

- And don’t forget all those contracts!  (Bev Johnson and Margaret Hughes)

## TWP-ICE Science Goals:

- 1)   **Make detailed measurements of the cirrus microphysics** and how they relate to storm intensity and proximity (spatial and temporal) to the parent convection including high thin cirrus.
- 2)   **Verification of remotely sensed microphysical measurements.**
- 3)   **Provide data sets for forcing cloud resolving and single column models** that will attempt to simulate the observed characteristics and impacts.
- 4)   **Document the evolution of oceanic convective clouds** from the early convection phase through to the remnant cirrus with particular emphasis on their microphysics.

## ACTIVE Goals

- Relate these to model simulations of the storms
- Place these results in context by comparing with measurements in the background TTL and predictions from larger-scale models.

- (Aerosol and Chemical Transport in Tropical Convection)

## TWP ARM Sites

**Manus**

**Nauru**

**Darwin**

## TWP-ICE Observation Network

**Egrett (UK)**

**Proteus**

**Dimona**

**Dornier (UK)**

## BOM profiler site including 

- 50 MHz and 920 MHz profilers and NOAA’s 2.8 GHz (S-band) profiler

**Darwin ARM site** including a 50 MHz profiler from U. Adelaide and a 14 Channel microwave from U. Munich

**BOM radars**: scanning 5 cm polarimetric radar (C-POL) and scanning operational weather radar

**Flux network** with radiation and turbulent flux sites operated by Monash U., Charles Darwin U.,  and PNNL

**Radiosonde Network**:  Darwin airport, four additional land sites, and the Southern Surveyor

**CSIRO Research Vessel **Southern Surveyor:  remote sensing, fluxes, ocean state

**Surface Observations**

## TWP-ICE/ACTIVE Aircraft

- 20 m–2 km

-  3 km

- 14 km

- 16 km

**Twin Otter: In-situ, upward-looking remote**
**NERC Dornier: aerosols, state (also Nov-Dec)**

**ARA Egrett: In-situ  microphysics, aerosols (also Nov-Dec)**

**ARA Dimona:  Fluxes, BL structure**

- 0.5-4 km

**DOE Proteus:  In-situ microphysics, remote sensing, radiation**

## Key Airborne Instruments

- 		Cloud Particle Imager (CPI)		Hi-res images
- 		Cloud Integrating Nephelometer (CIN)	Extinction
- 		Cloud Spectral Imager (CSI)		Total Water
- 		Tunable Diode Laser (TDL)		Water vapor
- 		Lidar
- 		Broadband Radiometers
- Twin Otter	Airborne Cloud Radar (CloudSat/JPL)
- 		Lidar (Whiteway/U. Toronto)

## TWP-ICE Weather ...

- active   “dry” monsoon   dry   break

- ~15 mm/day

- ~5 mm/day

- ~7 mm/day

- 45 mm in a day

- Courtesy Peter May

## Radiosonde data also illustrates progression of meteorological regimes

## TWP-ICE  Aircraft Missions

|  | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | 32 | 33 | 34 | 35 | 36 | 37 | 38 | 39 | 40 | 41 | 42 | 43 | 44 |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| Proteus |  |  |  |  | A |  | A |  | S |  |  |  | H |  | A |  | H |  |  |  | H |  | A |  |
| Egrett |  | S | T |  | A |  | A |  |  |  | S | S |  | N |  |  | H |  | H |  | H |  | A | H |
| Twin Otter |  | S | T |  | A |  | A |  | S |  |  |  | H | T |  |  | H |  | H | H | H |  | A |  |
| Dornier |  | S |  |  | N | S | S |  |  | N |  | S | S | N |  |  | H |  | H | H | H |  | A |  |
| Dimona | L |  |  |  | L |  |  |  | L |  | L | B | H |  | O | O | O |  | H |  | H |  | A |  |

- Dry monsoon

- Dry

- Break

- Active

**Active**:  Sampled outflow from active convective systems
**Dry monsoon**:  Sampled aged cirrus outflow from cyclone located south of Darwin
**Dry**:  Very clear conditions – no cirrus missions
**Break**:  Sampled afternoon convection over islands and along coasts

- A=ARM Site            T=Timor Sea            S=South of Darwin            N= North of Darwin
- H=Hector                 L=Land flux sites     O=Ocean flux sites            B=Boundary layer

## Coordination of day to day operations involved many people ...

- Mission Control at BOM
- Regional Forecast Center

- Operations Center at Charles Darwin U.

- Aircraft operations at RAAF

**	****Operations Groups**
**Mission planning ****	**** Decision team**
**Operations office    Media coordinators**
**Aircraft groups  ****	**** Ship scientists and crew**
**Sounding crews****	**** ARM site staff**
**Satellite support****	**** Report teams**

## Flight mission schedule

- _Day prior to mission_
- 3pm	Debrief of previous day’s flight
- 4pm	Daily weather briefing at Charles Darwin University (CDU)
- 5pm	Decision team meeting – general plans for following day (at CDU)
- _Day of mission_
- 7-10am	Follow-up decision team meeting – specific plans for the flight
- 	at Regional Forecast Centre (RFC)
- 1-3pm    Take off times
- 4pm 	Daily weather briefing
- 6-7pm  	Aircraft return to base
- 8-9pm	Mission control representatives meet with flight teams at RAAF

## February 2, 2006:  Thick anvil mission

- The low to the south had weakened but there were still strong surface winds so storms were expected to move quickly.
- At 9:00 Local time, there was a band of quite thick cirrus moving to the
- north and a line of convection to the NW coming towards Darwin.
- Take-off times (LT):  1100 Proteus, 1130 Twin Otter, 1200 Dimona

## Scanning centimeter radar combined with satellite observations provide spatial context for missions.

- Minnis et al.

- J. Cetrone and C. Schumacher

## C-Pol Cross sections, 01:30 – 03:00 UTC

- 0130

- 0200

- 0230

- 0300

- Altitude (0 to 20 km)

- Horizontal Distance Along Cross Section (0 to 127 km)
- (Courtesy Cetrone and Schumacher)

## 95 GHz Airborne Cloud Radar:  February 2 under Proteus spiral

- 0

- 10

- 20

- 0

- 10

- 20

- Altitude (km)

- 0224

- 0248

- 0312

- 0336

- 0400

- Time (UTC)

- Reflectivity (-50 to 10 dBZ)

- Courtesy Steve Dinardo and Richard Austin

## Slide 19

## Analysis of 850 mb winds from BOM TXLAPS Model, 27 January 2006

## January 27, aged cirrus case

- MTSAT-1R, 09:33Z
- IR window channel
- (Pat Minnis)

- MPL Backscatter at Darwin ARM site

## Jan 27 Cloud Particle Imager (CPI) composite from Proteus

- McFarquhar and Um

## Total water measured from Proteus over ARM site

- Courtesy, G. McFarquhar and M. Freer

## In addition to aged cirrus, the dry monsoon also brought high wind speeds...

## Slide 25

## CSIRO Research Vessel

- The Southern Surveyor

- Radiosonde launches
- Surface fluxes
- Ocean properties
- Remote sensing

- PARSL 94 GHz radar
- January 24

## Flux Network:  Significant Positive SW Cloud Effect

** ****Downwelling SW significantly greater than clear-sky amount is not unusual in the TWP. Positive cloud effect (CE) occurred at all sites during TWP-ICE (top).**
** ****During January, CE greater than 20 Wm****-2**** occurred about 3% of the daylight hours, compared to about 20% of the time in February at Garden Point, 13% at Cape Don and 28% at Darwin ARM.**

- Courtesy Chuck Long

## NOAA S-Band Profiler

- Located for duration of wet season at profiler site in Darwin – near ARM site.
- Other guest instruments for TWP-ICE include The U. Adelaide 50 MHz profiler and the U. Munich 14 channel microwave radiometer – both at the ARM site.

- Courtesy Chris Williams

## The Darwin ARM Site Radar

- Diurnal Cycle of Cloud Occurrence

- Heating rates derived from ARM radar and microwave radiometer combined with BOM radiosondes

- McFarlane and Mather

## Outreach (the other kind)

- TWP-ICE “Open Day” at Charles Darwin University

- K-12 Classroom visits

## Science highlights:

- In situ and remote sensing cloud data in aged tropical cirrus including in situ spirals over the ARM site
- Aircraft cloud data including thorough characterization of the convective boundary layer in multiple convection cases – over 20 missions
- High temporal resolution radiosonde data at multiple sites (~1000 flights)
- 14-channel microwave profiler within radiosonde network
- Radiosonde network encompassing developing tropical cyclone (prior to system crossing over land and becoming a landphoon).
- Surface radiation and turbulent fluxes over a variety of representative surface types
- Extended low altitude (20m) aircraft surface flux missions
- Airborne aerosol observations throughout the region courtesy ACTIVE

## For more information:

- http://science.arm.gov/twpice
- And check out posters by:  Chuck Long, Jay Mace, Jim Mather, Peter May, Greg McFarquhar, Bob McCoy, Pat Minnis, Courtney Schumacher, and Tim Tooman