Remote SensingSlide 1: TitleRadar Bright Bands And Applications In Meteorology And ClimatologySlide 2: Objectives• Explain And Interpret Radar Bright Bands• Discuss Importance Of The Bright Band• Discuss Specific Applications Of The Bright Band– TRMM• Overview• Specific Case Study: Detecting Tropical Cyclone Structural Changes– CloudSat• Overview• Specific Case Studies: Analysis Of Tropical SystemsSlide 3: What Is a radar bright band?A Bright Band Is A Melting Layer Of Snow And Ice That Usually Lies Above The Stratiform Type Of Rain. On The Meteorological Radar, A Bright Band Can Be Seen As A Nearly Horizontal Thin Bright Echo Layer With A Large Radar Reflectivity Factor. Slide 4: Radar bright band• An Area Of Higher Reflectivity Within A Radar “Sounding”• It Is Associated With The Melting Layer Between Rain And Snow• Defines Layered Depth Of Precipitation• Can Be Used To Estimate The Height Of The 0° IsothermSlide 5: What causes?• The Reflectivity Of Liquid Water Is Much Higher Than That Of Ice• Larger Objects Have A Higher Reflectivity Than Smaller ObjectsSlide 6: Ditto• As Snow Falls To Areas Where The Temperature Is Above Freezing, It Will BeingTo Melt From The Outside-In. • This Will Result In Large Wet Spongy Spheres (large ice-centered pellets covered in a layer of liquid water) Being Formed In A Layer Immediately Below The 0° Isotherm. (picture)Slide 7: Again(Using picture) Additionally, as the wet spongy spheres continue to fall they will continueto melt and obviously decrease in size and will fall faster, which will lessen the reflectivity right below the bright band.• Thus, These Hydrometeors Maximize Reflectivity And As A Result A Bright Band Appears In The Radar Sounding Slide 8: Typical Example-VPR (vertical reflectivity profile) signal is affected by precip, thus less reflectivity behind melting layer.-As you can see, an area of strong reflectivity just under 3 km. Thus we can assume the 0 degree isotherm is at about 3000 meters from the ground. Can also determine the strengthof the precip falling which has its obvious importance. -Important to know for type of precip (rain/snow). Freezing layer height determines whether or not hail will form.Slide 9: Applications• Rainfall Retrieval Rates– Difficult To Procure Accurately– Use Of PR Improve Estimates– The Thicker The Bright Band The More Intense The Precipitation– Can Be Used To Strengthen Rainfall Processes Modeling – Understanding Of How Rainfall Heat Energy Steers Atmospheric Circulation• Changes In Location Of The 0° Isotherm– Effects From ENSO – Climate Change Indications• Improve Numerical Weather PredictionRRR – Especially difficult over oceans where traditional land based measurement methods are not practical/applicable. Rainfall heat energy is the largest and most important energy source for driving global atmospheric circulations. Important For Flood Prone Areas…Deployment of resources, evac strategies, etc ZDI – See The effects of ENSO to understand further, NWP – Clouds influence on the weatherOthers – Applications in disaster management, air quality, water management, amongst others… Slide 10: TRMM• Tropical Rainfall Measuring Mission• A Joint Project Between The US and Japan• Launched From Japan And Placed In A Low Earth Orbit• First Satellite That Monitors Rainfall Over The Tropics (35° North to 35° South Latitude)Slide 11: Instruments Of TRMM• Visible And Infrared Scanner (VIRS)– Indirect Gauge Of Rain– Links Measurements With Other Satellite Measurements• Clouds And Earth Radiant Energy System Instrument (CERES)– Examines Energy Balances Between The Sun, Space, The Earth’s Surface,Atmosphere, And Clouds.• Lightning Imaging Sensor (LIS)– Detects LightningBut the most important are…Slide 12: Important instruments of TRMM• Precipitation Radar– Provides Three Dimensional Images Of Storm Structure– Intensity, Distribution Of Rain, Storm Depth, And Height Of The Melting Layer– Improve Global Circulation Models• TRMM Microwave Imager (TMI)– Measures The Amount Of Rainfall– Can Quantify Water Vapor, Cloud Water, And Rainfall IntensityPR – Use estimates of the heat released into the atmosphere at different heights to improve GCM. TMI – Passive Microwave sensor. Measures amount of microwave energy emitted by earth/atmosphere. By carefully measuring this microwave energy emitted by the Earth and its atmosphere, TMI will be able to quantify the water vapor, the cloud water, and therainfall intensity in the atmosphere.Slide 13: TRMM’s Value• First Mission Devoted To Measuring Rainfall In The Tropics/Subtropics Using Space Based Microwave And Infrared Sensors• Additionally, The Precipitation Radar Is The First Space Based Radar For RainfallThe PR measures the echo backscattered from rain, the PR produces very accurate estimates of rain profiles. Slide 14: TRMM’s Value continued• It Is Difficult To Measure Rainfall Over The Ocean• Two-Thirds Of Global Rainfall Occurs In The Tropics• The Latent Heat Release From Condensation Is The Paramount Force That DrivesCirculation In The Troposphere• TRMM Provides Much More Accurate Measurements Of Rainfall Over The Tropics Which Can Be Used To Determine Latent Heat Release• Thus By Understanding Rainfall And Rainfall Variability We Can Gain A Greater Understanding Of Climate Change Across The Globe As Well As The Heat Balances Between The Ocean, Atmosphere, And LandSlide 15: CloudSat• Provides Images Of The Vertical Structure Of Clouds As Well As Cloud Composition• Cooperative Mission With Canada• On The A-Train• Sun-Synchronous OrbitSlide 16: CloudSat• Operates By Taking A Vertical Cross Section From The Top Of The Atmosphere To The Surface Of The Earth• The First Satellite With A Millimeter-Wavelength Cloud Radar• This Cloud Profiling Radar Is Much More Sensitive Than Other Radars• As A Result, CloudSat Can Distinguish Smaller Water And Ice Particles That Provide The Composition Of Clouds Slide 17: CloudSat’s Value• Clouds Are Very Important Meteorologically and Climatologically• Provides Data On Cloud Layer Thickness, Altitudes Of Cloud Tops And Cloud Bases, Optical Properties, And Water And Ice Content Of Clouds• Using This Data Numerical Prediction Models Can Be Improved Which Will Lead To More Accurate Weather Forecasts Slide 18: Climate-wise• Climatologically Speaking, Clouds Are The Most Prominent