A Study of Persian Gulf Aerosol Microphysics, Radiation, and Transport Phenomenology in the United Arab Emirates

1. A Study of Persian Gulf Aerosol Microphysics, Radiation, and Transport Phenomenology in the United Arab Emirates Jeffrey S. Reid, Anthony Bucholtz, Douglas Westphal Naval Research Laboratory, Marine Metrology Division, Monterey CA. Piotr Flatau Scripps Institution of Oceanography, La Jolla CA. November 2003

2. NRL Marine Meteorology Division • The Naval Research Laboratory is the US Navy’s corporate laboratory for basic research. • The Marine Meteorology Division (MMD) is tasked with developing weather models and improving our understanding of ocean- atmosphere interaction. • NRL MMD is staffed by over 60 Ph.D.s researching both global and mesoscale modeling, data assimilation, remote sensing and aerosol science. • Currently performing strong international collaboration with such countries as Canada, Germany ,Great Britain,, Netherlands, Poland, and Sweden (to name a few) • Almost all research at NRL is unclassified and open for public release. All research in the Aerosol Section is unclassified. http://www.nrlmry.navy.mil

3. Aerosol & Radiation Modeling Section PIs Diversity in Aerosol Studies Douglas L. Westphal (Section Head): Aerosol transport modeling & numerical weather prediction. Anthony Bucholtz: Experimental radiative transfer. Piotr Flatau (Scripps/UCAR): Radiative transfer. Ming Liu: Mesoscale meteorology and numerical weather prediction. Elizabeth A. Reid: Remote sensing & QA. Jeffrey S. Reid: Particle microphysics & radiation. Product development & validation. Annette Walker: Meteorology and source functions.

4. Aerosol & Radiation Modeling Section NRL Aerosol Analysis and Prediction System (NAAPS) • NAAPS is the Navy’s operational global aerosol model. • Currently has sulfate, dust and smoke. • Sea salt and organics will likely be integrated this year. • Produces aerosol mass concentrations on a 1x1 degree grid at 27 levels. • Meteorology based on the Navy Operational Global Atmospheric Prediction System (NOGAPS). • NAAPS runs twice a day to give 5 day forecasts. • Will have a 5 year climatology run to monitor trends.

5. Aerosol & Radiation Modeling Section Coupled Ocean Atmosphere Mesoscale Prediction System (COAMPSTM) • Aerosol model is fully coupled to COAMPS (at each time step, grid point and grid mesh). • 1 to 3-day forecasts dust particles and passive tracers at typical 9 km resolution (can go down as far as 1 km). • Tracers can be present at initial time or injected as plumes or puffs. • Two-way interaction on aerosols between nested grids. • Dust emission depends on threshold velocity, wind stress, ground wetness, and vegetation type. • Size distribution: log-normal or power law. • Dry deposition: function of specie, stress, stability, surface type. • Wet removal: function of precipitation rate, specie, cloud type. • More aerosol components (smoke, sea salt and sulfate) are under development.

6. 30 Hour Forecast, Valid 06Z 10 October, 2001 Aerosol & Radiation Modeling Section COAMPS Dust Performance

7. Mobile Atmospheric Aerosol and Radiation Characterization Observatory MAARCO • Breaks down to fully deployable 20‘ CONEX Box • 240 V 3-phase, 220 V or 110 V ready. • Climate control (heating and cooling) • Multiple input-output ports • Lidar is eye safe • Data from most instruments can be viewed in real-time on-line • Part of the AERONET and MPL networks Meteorology Radiosondes T, P, RH, Wind speed/direction Flux capability Cloud fraction Visibility Aerosol/Gas Properties Spectral Optical Depth Vertical Distribution Particle Size Particle Composition Optical/EO effects Ozone, SO2 Radiative Balance Total Solar Direct Solar Diffuse Solar Total Infrared

8. Why does NRL want to study in UAE? 1. Model performance in the Persian Gulf is only fair due to the presence of organics and pollution from oil industry.

9. Why does NRL want to study in UAE? 2.The microphysical properties of dust are complicated. We want to evaluate dust measurement techniques and assess dust properties. • Currently there is a factor of two discrepancy in the literature due to instrumentation error. • Dust shape make satellite remote sensing of plumes difficult. • Dust cloud droplet nucleation properties likely vary due to interaction with pollution. Size Distribution Measurements from African Dust

10. Why does NRL want to study in UAE? 3.The cloudless sky conditions and variable aerosol concentrations often found in the UAE make ground based radiative transfer studies feasible. • Isolating the radiative effects of aerosols is difficult in the presence of clouds • => what’s due to aerosols and what’s due to clouds? • The UAE region with its cloud-free skies and varying amounts of atmospheric aerosols • offers an ideal location for carrying out radiative transfer studies • We intend to make surface measurements • in the UAE of the total amount of aerosols • in the atmosphere, the vertical distribution • of the aerosols, and the amount of sunlight • and infrared energy reaching the surface • in order to accurately determine the effects • of aerosols on the radiative balance of • the region. Lidar image showing an example of the vertical distribution of clouds and aerosols

11. Why does NRL want to study in UAE? 4.The sharp contrasts between land and water, as well as the high surface heating and evaporation over the Persian Gulf makes the region a good place to stress meteorology models. Shifts in air sea temperature in 8 hours

12. Proposed NRL Research in the UAE Ground Based • Deploy MAARCO container to UAE in a coastal location for three to six months. • Use micropulse lidar and AERONET Sun photometer to monitor dust and pollution vertical distribution. • Make fundamental measurements of aerosol particle size, shape and chemistry. For short time periods, measure particle hygroscopicity, absorption and mass scattering efficiency. • Measure the clear sky radiative forcing at the surface. • Provide baseline data on visibility, meteorology, and soundings.

13. Proposed NRL Research in the UAE Airborne • We propose to add the following instrumentation to the research aircraft (if possible): • KT90 infrared thermometer to measure sea surface temperature. Can also be used t measure cloud top temperature. • Filter sampler to measure aerosol particle mass concentration and chemistry. • Aerodynamic particle sizer to measure dust particle size. • Three wavelength nephelometer to measure light scattering. • Solar and IR radiometers to measure vertical profiles of radiative flux and heating rates

14. Proposed NRL Research in the UAE Modeling • NAAPS forecast data will remain available for the Persian Gulf area. • Special COAMPSTM mesoscale runs will be performed during mission operations with a better than 9 km inner grid resolution over UAE. • Special public focus page will be developed to support mission. • Use remote sensing data to validate model cloud products. • Radiative forcing calculations will be made to help control for semi-direct effects on clouds.

15. Proposed NRL Research in the UAE Support Request • We would appreciate any support in the following areas: • Logistical support moving MAARCO from the port of Abu Dhabi to the final operation site. • Engineering support in connecting MAARCO to power and telecommunications. • Technical support in maintaining instrumentation. • In return, we will make all collected data available to mission collaborators and UAE personnel. We will also train all requesting UAE personnel in aspects of instrumentation usage, calibration and application.

16. Proposed NRL Research in the UAE Summary • The Naval Research Laboratory Marine Meteorology Division would like to cooperate with planned cloud seeding experiments in the United Arab Emirates. • Goals include studying aerosol microphysics, chemistry and radiation. • We wish to set up a complete aerosol and meteorology ground station (complete with lidar) at a coastal site. • If possible we also wish to participate in airborne campaigns. • We will provide extensive modeling support.