Clouds and Climate Through a Soda Straw Mark Miller Quantity of Radiation Sun s Radiation 6000 K Earth s Radiation 288 K Visible Infrared 0 5 3 10 Wavelength micrometers Visible Satellite Photo Infrared Satellite Image Source NASA Earth Radiation Budget Experiment The study of climate and climate change is hindered by a lack of information on the effect of clouds on the radiation balance of earth Ramanathan et al 1989 Science 243 57 62 Figure 2 10 IPCC Working Group I 2007 Representing Clouds in Climate Models CLIMATE MODEL GRID CELL 60 N Weather Forecast Model Grid Cell 55 N 172 W 157 W Cloud Resolving Models Less Than Width Of Lines What Cloud Properties Change the Net Radiation Received at the Surface 1 Amount of the sky that is covered 2 Thickness 3 Composition Contain ice crystals liquid water or both Particle sizes Particle concentrations 4 Height in the atmosphere How Does the Location of Cloud Impact the Surface Temperature Space High Clouds 10 km Low Clouds 2 km COOLING WARMING What We Know About Solar Radiation and Clouds Solid theoretical foundation for interaction between a single spherical liquid cloud droplet and sunlight Cloud Droplet Sun Scattered Light What We Know About Solar Radiation and Clouds Some theoretical foundation for interaction of sunlight and simple ice crystal shapes The Real World What We Wish We Knew About Solar Radiation and Clouds 1 How do we compute the total impact of a huge collection of diverse individual cloud particles 2 What are the regional differences in cloud composition coverage thickness and location in the atmosphere 3 If we knew 1 and 2 how do we summarize all of this information so that it can be incorporated into a climate model What We Know About Outgoing Terrestrial Radiation and Clouds Good theoretical foundation for interaction of terrestrial radiation and cloud water content liquid clouds Particle radius somewhat important in thin liquid clouds shape and size somewhat important in high level ice clouds cirrus Aerosols Clouds Through a SODA STRAW 2 km Meteorological Tower Multiple Radars Calibration Facility Multiple Lidars Surface Radiation The ARM Southern Great Plains Site SGP Central Facility SODA STRAW Extended Measurement Facilities Wichita Oklahoma City What types of remote sensors do we use to make cloud measurements Visible and Infrared Sky Imagers Vertically Pointing Lasers LIDARs Measure the height of the lowest cloud base Below cloud concentrations of aerosol and water vapor Beam quickly disperses inside cloud Cloud Radars Information about cloud location and composition Microwave Radiometers Measure the total amount of liquid water in atmosphere Can t determine location of liquid Presently not measuring total ice content Visual Images of the Sky cloud coverage versus cloud fraction simple digitize images and daytime only integrated quantity A Time Series The Past Few Days in Oklahoma have been for the birds 3 20 08 3 21 08 3 22 08 3 23 08 Sky Imaging 500 nm AMF RV Ron Brown Central Pacific AOT 0 08 Sea of Japan Niamey Niger AOT 0 98 AOT 2 5 3 Laser Data from Southern Great Plains 20 km No Signal 10 km Low Clouds Ice Clouds 7 00 pm Negligible Return time 7 00 am 24 Hours Cloud and Aerosol Particles Surface 7 00 pm Cloud droplets V 4500m V 700m Mass Concentration 1 700 g m 3 Niamey Niger Africa Height km 20 Cloud Droplets 15 10 5 Cloud and or Aerosol LIQUID CLOUDS Biomass Burning Dust 0 0000 1200 Time UTC Negligible Return 0000 Dust product upper and GERB OLR lower for 1200UT on 8 March 2006 Cloud Dust Lake Chad radius6 Size of Cloud Particle A Cloud Particle At Different Wavelengths Energy Returned to Radar Energy Returned to Radar At a Given Wavelength wavelength 4 Radar Wavelength Energy Absorbed by Atmosphere 94 GHz 35 GHz Maximum Propagation Distance 10 15 km 20 30 km 3 2 mm 8 mm Radar Wavelength The DOE Cloud Radars Cloud Radar Data from Southern Great Plains 20 km Black Dots Laser Measurements Of Cloud Base Height 7 00 pm Small Cloud Particles 10 km time 7 00 am Typical Cloud Particles Surface 7 00 pm Very Light Precipitation Cloud Radar Data from Southern Great Plains 20 km Black Dots Laser Measurements Of Cloud Base Height 10 km Thin Clouds Insects 7 00 pm Small Cloud Particles time 7 00 am Typical Cloud Particles Surface 7 00 pm Very Light Precipitation 10 km Top Low Radar Sensitivity Radar Echo Base Base Radar Echo Top 2 km Radar Echo Emission Laser Radar Microwave Radiometer Surface Evolution of Cloud Radar Science Cloud Structure and Processes Cloud Statistics Cloud Composition Applications of Surface Based Cloud Observing Systems Example Marine Cloud Transitions Solid Overcast Cloud Transition Broken Cloud Azores Application of Surface Based Remote Sensing to a Cloud Problem Marine Stratocumulus Transition THEORY Mid latitudes Tropics 2 km 0 5 km Ocean Surface OBSERVED Mid latitudes Tropics 2 km 0 5 km Ocean Surface Tropical Western Pacific Jan 1999 15 km June 1999 10 km 5 km Cloud Top Height 1 3 Probability 10 1 3 Probability 10 Retrieving Liquid Cloud Composition Height Particle Size Number Concentration Radar Echo Intensity Total Liquid Water Microwave Radiometer Mode Radius Height Width Height Number Mode Radius Number Concentration Liquid Cloud Particle Mode Radius Height km 6 4 2 0 7 00 pm 1 time 7 00 am 4 10 Micrometers 7 00 pm 17 25 Active and Passive Cloud Remote Sensors cont Wind Profiler 75 m 6 min resolution 915 MHz 1270 1400 MHz COPS Minimum Height 120 m Maximum height 5 5 km Atmospheric Emitted Radiance Interferometer AERI 3 19 2 m 1 cm 1 resolution 6 min resolution 20 30 sec possible for COPS 1 3 degree field of view AERI Spectra Analysis of the Impact of Clouds on Radiation Remotely Sensed Information about Cloud Structure and Composition Existing Theoretical Models of Radiation Transfer Through Clouds Compute the Energy Budgets at the Surface and Top of Atmosphere Compare with Coincident Measurements of the Energy Budget Meteorological Models Global Climate Model GCM Forecast Period Decades to Centuries Resolution 300 km x 300 km Crude Representations of Many Processes Numerical Weather Prediction Model NWP Forecast Period Hours to a Few Days Resolution 29 km x 29 km Better Representations of Many Processes Cloud Resolving Model CRM Forecast Period Hours Resolution 1 km x 1 km Detailed Representations of Processes Super Parameterizations The Grabowski Randall and Arakawa Scheme CLIMATE MODEL GRID CELL 60 N 2 Dimensional Cloud Resoving Model 5 10 years 3 D Simulation 55 N 172 W 157