METR 125 Physical Meteorology: Radiation and Cloud Physics Lecture 1: Green-sheet and Introduction Professor Menglin Susan Jin San Jose State University, Department of Meteorology and Climate Science

Outline of today’s lecture 1.Introduction and Welcome 2.Discussion on the “greensheet” 3.Learning Contract 4.First glance on class roadmap 5.Survey

For greensheet, class ppt notes, homework, reading materials

About Professor to be an effective teacher 3. Research projects: funded by NASA, NSF, Department of Defense On land surface climate change, urbanization, remote sensing 20 leading author papers on top journals

Goal of METR125 METR125 discusses the fundamentals of Solar Radiation Radiation Transfer Basics Cloud and Rainfall Formation Aerosol-Cloud interaction Atmospheric Electricity Satellite Observations Broaden knowledge with Important papers Enhance student self study and team-study skills

Content (see greensheet schedule) Part 1: Atmospheric Optics and Radiative Transfer Part 2: CLOUD Macrophysics and Microphysics Clouds Formation Warm Cloud Cold Cloud Aerosol-cloud-rainfall interaction Part 3. Lightning and Atmospheric Electricity

Book and Reading: A First Course in Atmospheric Radiation by Grant W. Petty (Required) 2006 Wallace and Hobbs Atmospheric Science (Required) more materials will be assigned on webpage/homework/class

Lecture Hour: MW 10:30 AM - 11:45 AM Place: DH615 Office Hour: 9:30 PM ‐ 10:30 PM, Wednesday 12:00-13:00 Tuesday Place: MSJ’s Office (DH621) METR215 I will meet with you for extra office hour whenever you need. send for appointment.

TA Henry Bartholomew

Extra Help Dr. Martin leach – guest lecture on optics and aerosols Departmental Seminars

Homework: 20% Midterm Exam 1: 15% Midterm Exam 2: 15% Midterm 3: 15% Class Participation 5% Research Project: 15% Final Exam: 15% Scale: 90+ A, 80’s B, 70’s C, 60’s D, <60 F Homework will be assigned on Tuesdays in class collected in discussions on two weeks later.

Learning Contract Instructor –On time and prepared. –Answers questions. –Approachable and friendly. –Fair with assignments and grades. –Genuinely concerned about your learning and intellectual development.

Learning Contract Students –Make every effort to arrive on time; and if late, enter class quietly. – Preserve a good classroom learning environment by a) refraining from talking when other people are talking b) turning off cell phones. –Be courteous to other students and the instructor. –Aware that learning is primarily their responsibility. –Aware of universities policy on academic integrity and pledge to abide by them at all times. –Have read and understand what plagiarism is and know how to cite sources properly.

Academic Integrity Integrity of university, its courses and degrees relies on academic standards. Cheating: –Copying from another’s test, cheatsheet etc. –Sitting an exam by, or as, a surrogate. –Submitting work for another Plagiarism: –Representing the work of another as one’s own (without giving appropriate credit)

Plagiarism Judicial Affairs Look at the Student Code of Conduct Read through SJSU library site on Plagiarism

GreenSheet (see handout) Homework turn-in on time, will be stated in the homework, in general, 1 week after the assignment Class Participation Research Project Final grade

Let’s see where this class stands in the big picture….. Chapter 1 Petty

One World

PHYS Clouds, spring ‘04, lect. 1, Platnick Earth’s Radiation Budget - Schematic

Radiative Components Net short-wave radiation = short-wave down - short-wave up Net long-wave radiation = long-wave down - long-wave up Net radiation (R net) = net short-wave radiation + net long-wave radiation Positive values represent energy moving towards the surface, negative values represent energy moving away from the surface.

the latitude (distance from the Equator) what season it is the time of day cloudiness How much radiation reaches any given spot depends on

Atmosphere Composition and Structure

Table 1: Composition of the Atmosphere Gas Percentage by Volume Nitrogen78.08 Oxygen Argon 0.93 Trace Gases Carbon dioxide Methane Ozone Chlorofluorocarbons Water vaporHighly variable (0-4%)

Vertical Layers of the Lower Atmosphere

Pressure in the Atmosphere Atmospheric pressure can be imagined as the weight of the overlying column of air.weight pressure decreases exponentially with altitude. but 80 percent of the atmosphere’s mass is contained within the 18 kmmass closest to the surface. measured in millibars (mb) At sea level, pressure ranges from about 960 to 1,050 mb, with an average of 1,013 mb.

1. Evaporation, transpiration (plants) 2. Atmospheric transport (vapor) 3. Condensation (liquid water, ice) 4. Precipitation 5. Surface transport (continental rivers, aquifers and ocean currents) Earth’s Hydrological Cycle - Schematic PHYS Clouds, spring ‘04, lect. 1, Platnick

Why Clouds? Weather –Dynamics: Latent heat and/or radiative effects impacting atmospheric stability/instability, atmospheric heating/cooling –Radiation (e.g., surface heating) Chemical processes Climate –General circulation –Hydrological cycle –Radiation budget  Clouds are a critical component of climate models (for reasons cited above) and therefore also to climate change studies Not well-represented in climate models Climate change: cloud-climate feedback, cloud-aerosol interactions (to be discussed), etc. PHYS Clouds, spring ‘04, lect. 1, Platnick

Cold front - steep frontal slopes Warm front - shallow frontal slopes Convective development (mesoscale, local) Synoptic development PHYS Clouds, spring ‘04, lect. 1, Platnick

Relevance for Remote Sensing

Absorption (attenuation) The process in which incident radiant energy is retained by a substance. –A further process always results from absorption: The irreversible conversion of the absorbed radiation goes into some other form of energy (usually heat) within the absorbing medium.

substance (air, water, ice, smog, etc.) incident radiation absorption transmitted radiation

Atmospheric Constituents: empty space molecules dust and pollutants salt particles volcanic materials cloud droplets rain drops ice crystals

Optical phenomena process + atmospheric constituent optical phenomena atmospheric structure light

Atmospheric Structure temperature gradient humidity gradient clouds layers of stuff - pollutants, clouds

Optical phenomena process + atmospheric constituent optical phenomena atmospheric structure light

White clouds scattering off cloud droplets ~ 20 microns

Dark clouds scattering and attenuation from larger cloud droplets and raindrops

Atmosphere Window

GOES-8/10 diagram

Channel 1:  m (Visible) –Clouds –Pollution –Haze –Severe storms

Channel 2:  m (Shortwave infrared) –Nighttime fog –Nighttime SSTs –Liquid vs. ice clouds –Fires and volcanoes

Channel 3:  m (Upper-level water vapor) –Standard water vapor –Mid-level moisture –Mid-level motion

Channel 4:  m (Longwave infrared) –Standard IR channel –Winds –Severe storms –Heavy rainfall

Channel 5:  m (Infrared/water vapor) –Low-level moisture –SSTs –Volcanic dust or ash

Sounder IR bands 2, 3, 4 and 5 (temperature)

Sounder IR bands 8, 10, 11 and 12 (water vapor)

EOS A-train The Afternoon Train, or "A-Train", for short, is a constellation of satellites that travel one behind the other, along the same track, as they orbit Earth. Four satellites currently fly in the A-Train - Aqua, CloudSat, CALIPSO, and Aura. Glory, GCOM-W1, and OCO-2 are scheduled to join the configuration in 2011, 2012, and 2013, respectively. The A-Train satellites cross the equator within a few minutes of each other at around 1:30 p.m. local time. By combining different sets of nearly simultaneous observations from these satellites, scientists are able to study important parameters related to climate change.