PI: Hugh Coe Co-investigators: Manchester:Tom Choularton; Gordon McFiggans; Paul Connolly; Keith Bower; Jonathan Crosier; Martin Gallagher; Geraint Vaughan Leeds: Alan Blyth; Alan Gadian; James McQuaid Reading:Julia Slingo; Len Shaffrey; Thomas Toniazzo Collaborators: Met Office:Phil Brown; Steve Abel VOCALS-UK Bridging the scales between climate and cloud processes VOCALS-UK is the UK Contribution to the VAMOS Ocean- Cloud-Atmosphere-Land Study

RATIONALE Aerosol-Cloud Interactions may have a significant impact on climate on global and regional scales. HOWEVER: The detailed processes are poorly known and the bases for their representation in global models is at present limited

The South East Pacific in Climate Models All the stratocumulus regions (including the SEP) are poorly simulated in climate models. The SEP is important for the global radiative budget and climate variability (especially El Nino). Top: Interannual variability of SST in HadCM3 Bottom: Fractional change in SST variability when SSTs are relaxed back to model climatology.

VOCALS Bridging the scales between climate and cloud processes VOCALS will act to bridge the gap between climate models and key cloud processes by: 1)Diagnosing and testing important aspects of Climate model performance in Sc cloud regions – nested model resolution is key to this 2)Developing new process knowledge and parameterising it in a way that is effective for climate models Doing this collaboratively through a Consortium will deliver useable parameterisations that have been developed in conjunction with their end users It will provide process studies with a climate backdrop to the VOCALS experiment – an important context

Spring season (SON) mean cloud droplet effective radius from MODIS; mean surface winds from Quikscat; Sulphur sources are also shown Component of SON shortwave cloud forcing [W m-2] due to geographic variations in effective radius, inferred from MODIS

Universities Arizona State U. U. Concepci ó n, Ch CSU Drexel U. U. Hawaii U. Manchester UK U. Miami North Carolina State Oregon State U. U. Reading UK U. Arizona U. Chile UCLA U. Colorado UCSD U. Leeds UK U. Washington U. Wyoming Research Labs Brookhaven Nat. COLA CNRS/LMD France IMARPE IPRC LEGOS NASA GSFC NCAR NOAA/CIRES NOAA/GFDL NRL Pacific Northwest Woods Hole Operational Centers BMRC Australia CPTEC Brazil ECMWF Int. JMA Japan NCEP US UKMO UK Funding $25M+ Logistic Support: UCAR JOSS

Models in VOCALS RAMS AGCM ROMS OGCM LES Trajectory Models

VOCALS-Mod UK Contribution RAMS AGCM ROMS OGCM LES Trajectory Models WRF HadGEM HiGEM ADDEM

WP7: Integration WP6: Climate of the SEP: predictability, wider influence WP5: Regional scale studies WP3: Cloud studies WP4: Radiation interactions WP2: Aerosol and CCN properties WP1:ARSF,FAAM,sondes HADLEY CENTRE JC NWP testing Review of Sc in regional climate models Legacy MODELS ACPIM/LEM WRF WRF-CHEM NuGAM HiGEM HadGEM HadCM3 MEASURE- MENTS REANALYSIS Ships, buoys satellites Twin Otter,G-1,C130 Outputs VOCALS-UK Activities Analysis Tools Data Inputs Scale Increasing scale Cloud Meso Regional Global UCLA RAMS

WP1: PLANNING (lead Bower; Coe; Brown; Crosier; Gallagher, Blyth) The Calendar (additional teleconferences will be conducted) June 2007 VOCALS-REx Preparatory Workshop, Boulder, CO (HC and Steve Abel, Met Office) 1 st -11 th October 2007 Site Survey by NCAR JOSS team Jan 2008 NSF and NOAA funding decisions March st VOCALS Science and Operations Meeting, Boulder, CO (HC, Thomas Toniazzo, Reading, Abel, MO) 5 th -11 th April 2008 FAAM recce to Chile (Bob Wells, FAAM; DirectFlight; Phil Brown, MO) Confirmed Arica will be the 146 base jointly with NSF June 2008 ARSF Do-228 recce to Arica jointly with G-1 team 17 th -20 th Oct Test Flying in the UK 21 st -24 th Oct Preparation and transit 25 th Oct Set up in Chile 26 th Oct-14 th Nov inclusive – scientific operations in Chile

C-130 BAe-146Do-228 Multi-platform sampling along the 20°S cross section will deliver: 1.a synthesised data set for testing of climate model representations of the SEP boundary layer. 2.A series of important case studies WP1: PLANNING (lead Bower; Coe; Brown; Crosier; Gallagher, Blyth)

UK-VOCALS – co-ordinated cloud process modelling activities WP3: Connolly (lead), Gadian, Crosier, Choularton, Gallagher, Brown, Blyth, Coe WP 5: Blyth (lead), Connolly, Gadian, Crosier, McFiggans, Brown, Toniazzo WP2.2; WP3.1Aerosols, drizzle formation and turbulence. High resolution process studies. ADDEM/ LEM / ACPIM models l WP d dynamical Stratocumulus structure, aerosol properties and validation with WP3.1 LEM / WRF models WP4.1 3-d cloud properties heterogeneity on larger scales: formation and maintenance of POCS. WRF / LEM models Increasing domain size Increasing resolution WP2.3/5.2/5.3 Case studies of aerosol transformation and reactions. Assess predicted pollution and CDNC on regional scale WRF- CHEM WP 5.1 Regional scale cloud processes modelling WRF Improved Sc model skill Testing and refinement Parameterisation development

Experiment based in Antigua to study warm rain formation in trade wind Cu. Study utilised data from 3 aircraft (FAAM, NSF C-130, King Air) to compare in-situ measurements of updraft characteristics with those simulated in the Met Office LEM. Model shown to produce significantly better simulations of warm rain when changes to the default parameters made. Demonstrates the importance of multi-aircraft compilation datasets Default Modified

WP4 UK-VOCALS – Cloud radiation studies A unique contribution to VOCALS Lead: Vaughan, Coe, Haywood (Met Office) Cloud properties such as cloud optical depth; cloud droplet concentration and mean cloud droplet size can be retrieved from satellite spectrometers such as MODIS Imaging spectrometers on the Do-228 and the FAAM 146 will perform similar remote sensing roles but with higher spatial resolution. Overflying other aircraft making in situ measurements will allow us to observe cloud radiative properties and link them to in situ properties Arica Andes Twin Otter Do-228 G-1 Polluted cloudy column closure studies

The SEP Ocean in Climate Models IMET Buoy at 85 o W 20 o S RV Ron Brown Ocean Eddies in the SEP Right: The ocean heat budget in HiGEM along 20 o S How does the ocean determine the climate of the SEP? To investigate this we’ll be using HiGEM – a new coupled climate model where the resolution is high enough to permit ocean eddies. Data from the IMET buoy suggests eddies are fundamental to the SEP heat budget. HiGEM appears to capture this key process. Ships observations from VOCALS-REX will increase understanding of these processes. WP6: Slingo (lead); Shaffrey; Toniazzo

Understanding SEP cloud in Climate Models HadCM3 sensitivity experiment where the Andes are moved a grid point to the east. This has a dramatic impact on the coastal jet and the SST errors in the SEP The stratocumulus decks are better represented at higher resolution. Why? Better coastal jets? Better representation of coastal processes? Perform an initial tendency analysis of the n216 climate model. Start from observations and understand how model errors “spin-up”. Sea surface temperature and meridional wind errors in HadCM3 Cloud fraction and vertical profile of temperature from HiGEM. WP6: Slingo (lead); Shaffrey; Toniazzo

DELIVERABLES The VOCALS-UK Consortium will deliver new insights into the influence of marine stratocumulus clouds on global and regional climate and provide much needed improvements in our ability to quantify the processes that influence stratocumulus clouds and man’s influences on them. Specific deliverables are: A unique dataset on the SEP that will act as an important future resource for research An assessment of the regional distribution of pollution aerosol and its influence on clouds. Improvements in the ability to quantify the roles of aerosol in controlling marine Sc cloud compared to other processes The identification of key processes necessary to improve the simulation skill of Sc in regional models. An evaluation of the HadGEM/HiGEM models in the SEP region. Assessment of the processes underpinning the maintenance of the climate in the SEP region and regulating the variability of the Tropical Pacific The transfer of VOCALS-UK knowledge to the climate and weather prediction communities

VOCALS WORKING GROUP – Chair: Mechoso PI: CoeVOCALS-UK ADVISORY TEAM Mechoso, Wood, member of Hadley Centre and MO NWP Scientific Steering Group (PI; co-Is; Met Office OBR, coordinators WP1: Bower WP3: Connolly WP5: Blyth WP4: Vaughan WP6: Slingo WP2: Coe Process studies coordinator Regional/Climate model coordinator WP7: Coe/ Slingo BADC VOCALS- Rex Planning Team VOCALS-UK OFFICE Project coordinator, secretary NCAS Afiliations: Slingo: NCAS Director Climate Research Vaughan:NCAS Director of Weather Research Blyth:NCAS Head of Ground based Observations and aircraft instruments Coe:NCAS Director of Airborne Observation

Project Management Project Meetings: 6 monthly to ensure that the main milestones are reached and that the future interaction necessary to achieve the goals is carried out. Activity reports will be requested from the PIs partner after each of these. These will be collated by the Project Coordinator and copied to the Programme Manager at Swindon A website will be maintained by the Project Coordinator (Grant Allen). PI will direct the VOCALS project and chair the Scientific Steering Committee. He will be responsible for the delivery of the scientific programme and its overall management The Scientific Steering Group comprises: the co-investigators; the project coordinator and the scientific coordinators; and members of the Met Office Observation Research Group team, led by Phil Brown. The function of this group is to scrutinize the science being carried out in the project and also its financial management. It will meet every 6 months. The VOCALS-UK Advisory Team: will be composed of Roberto Mechoso (UCLA), the chair of the International VOCALS working group; Rob Wood (Washington), the coordinator of the VOCALS-REx; Phil Brown (Met Office Observational Research), a member of the Hadley Centre Climate modeling team and a member of the Met Office Numerical Weather Prediction model group.

Project Management Two science coordinators will work with the WP leaders in the areas of aerosol and cloud process (Crosier) and at the interface between the HiGEM and WRF modeling activities (Toniazzo) to ensure that the work packages interface seamlessly. Project Office Project Coordinator (Grant Allan): (25%) -Organisation of the meetings -Collating 6 month reports and reporting them to NERC -Collating and preparing OPM returns -Preparation of the end of contract report -Auditing the milestones of the WPs and reporting to Steering Committee -Overall Data Management – ensuring data is delivered to BADC by partners -Developing project website Project Secretary (Linda Foxley): (10%) - Provide a central service for the project. - archive project documentation - distribute meetings information, - organize the VOCALS-UK meeting logistics, - disseminate project information - act as a first point of contact for people interested in the project.

VOCALS Bridging the scales between climate and cloud processes WP7: Coe and Slingo VOCALS will act to bridge the gap between climate models and key cloud processes by 1)Diagnosing and testing important aspects of Climate model performance in Sc cloud regions – nested model resolution is key to this 2)Developing new process knowledge and parameterising it in a way that is effective for climate models Doing this collaboratively through a consortium will deliver useable parameterisations that have been developed in conjunction with their end users It will provide process studies with a climate backdrop to the VOCALS experiment – an important context