1. Air – Sea Measurements from Ships: Fluxes, Time Series, Remote Sensing Dr. Jeff Hare CIRES – University of Colorado and NOAA Earth Systems Research Lab jeff.hare@noaa.gov CSU ATS 650 Measurements Systems and Theory

3. Fasullo and Trenberth, J.Clim. 2008 SI = Solar Insulation ASR = Absorbed Solar OLR = Outgoing Longwave F S = Net Surface Flux R T = Net Radiation F A = Energy transport (atm)

6. NOAA Ship Ronald H. Brown

7. Turbulent fluxes (direct covariance) Latent heatρL v [W/m 2 ] Sensible heatρC p [W/m 2 ] Momentumρ [N/m 2 ] Gas (etc) Instruments: Sonic anemometer (wind, temperature) Infrared gas analyzer (humidity, CO2, etc) Motion (roll, pitch, yaw, heave, surge, sway) GPS/Compass/Doppler speed

8. t 1 = L / (c + v) ; t 2 = L / (c - v); v = 0.5 L (1/t 1 – 1/t 2 ); c = 0.5 L (1/t 1 + 1/t 2 ); T s = c 2 / 403; T = T s / (1 + 0.32 e / p) L = path length t = time of flight c = speed of sound v = wind velocity T = temperature T s = “virtual” temp p = pressure e = water vapor pressure

9. Absorptance of a particular gas α = 1 – A / A o A = power received at absorbing wavelength A o = power received at non-absorbing wavelength ρ = P e f(α / P e ) [mol m -3 ] number density ρ = P e f([1 – z A / A o ] S / P e ); P e is equivalent pressure S is ‘span’ Channels available for water vapor and CO 2 Infrared Gas Analyzer (IRGA)

10. Ƭ = ρ + ρ + ρ streamwise transverse wave stress U = + u’ + u ~ V = + v’ + v ~ W = + w’ + w ~ Wind stress (momentum flux) drives currents and waves, thus driving heat transport in the ocean. Wind Stress

11. H s = ρ C p Sensible heat flux H L = ρ L v Latent heat flux T = + θ’ Q = + q’ Heat transfer between the sea surface and atmosphere is another primary driver of ocean circulation Heat Fluxes

12. Using advanced techniques for direct measurement of air-sea fluxes, we have obtained data from oceans around the world. This data has been used to develop parameterizations to estimate air-sea fluxes from mean state variables (wind speed, air temperature, sea temperature, humidity, etc). Air-sea fluxes of heat (latent/sensible) are also fundamental to cloud development (hence, surface energy budget, precipitation, etc).

13. Ron Brown Mast

14. NOAA/ESRL Turbulent Flux System

15. Example of power spectra for wind velocity components

16. Flow distortion study

17. Energy Budget Q NET = Q S ↑ + Q S ↓ + Q L ↑ + Q L ↓ + H S + H L + Storage Net at the surface Shortwave up/down (albedo) Longwave up/down Sensible turbulent heat flux Latent turbulent heat flux Q L ↑ = ε(σT 4 -Q L ↓)

18. Surface energy budget study from Stratus 2003

19. Radiative fluxes / Clouds / Water vapor / Boundary layer profiles Downwelling solar Downwelling IR Cloud base height, cloud fraction T / RH / wind profiles Instruments Pyrgeometer (PSP) Pyranometer (PIR) Ceilometer 60 GHz scanning microwave radiometer C-band radar Wind profiling radar (915 MHz) Cloud radars (35 GHz [K a ], 94 GHz [W])

20. Eppley PIR (longwave) Eppley PSP (shortwave) Issues with roll, pitch of ship are resolved with stabilized platform

23. TAO/PACS Heat Fluxes 95 & 110˚W Model TAO buoy WHOI (1984-2002) [Yu and Weller 2007] CORE (1984-2004) [Large and Yeager 2004] NOAA ship observations (1999-2002) [Fairall et al. 2008] GFDL CM2.1 latent sensible longwave solar net IROAM -12-8-404812 -160 -120 -80 -40 0 -12-8-404812 -20 -10 0 -12-8-404812 -75 -50 -25 0 -12-8-404812 100 150 200 250 300 -12-8-404812 -100 -50 0 50 100 150 200 north latitude -12-8-404812 -160 -120 -80 -40 0 -12-8-404812 -20 -10 0 -12-8-404812 -75 -50 -25 0 -12-8-404812 100 150 200 250 300 -12-8-404812 -100 -50 0 50 100 150 200

25. NOAA Ship Ronald H. Brown

26. Ron Brown C-band Radar reflectivity 08:00 UTC 08/01/2004

27. Ron Brown C-band Precip Radar

30. Radiometers and raingauge Radiosonde launch can be difficult

31. ceilometer Radiometers 23 – 32 GHz Passive “Mailbox” -> integrated water vapor, liquid, brightness temperature

32. Radiometrics Model 1500 22-30 GHz Continuous water vapor profiles up to 10km, integrated liquid water. NOAA ESRL also has a Model WVR-1100 (mailbox)

35. TeraScan visible image with Stratus Buoy (NOAA-18, 20:43 UTC 10/19/2006) GOES, NOAA, DMSP, SeaWiFS, Aqua, etc

36. Ron Brown 915-MHz Wind Profiler

37. Water-side measurements Currents Temperature and salinity profiles Wave measurement systems Instruments Conductivity temperature depth (CTD) Acoustic Doppler current profiler (ADCP) WAMOS Laser altimeter

38. CTD Strain gauge pressure sensor Thermistor to measure temperature Conductivity = Current / Voltage (1/R) Uses a bridge circuit to detect small changes in resistance

39. CTD and water sampling bottle array ADCP

41. WAMOS (Wave and Surface Current Monitoring System)

44. Significant wave height (height of the highest 1/3 of waves) H s = 4 1/2 ζ is the standard deviation of surface displacement. ω = 2 π f ω is wave frequency (f is in Hz) ω = 2 π / TT is wave period k = 2 π / LL is wave length ω 2 = g kDeep water c = (g/k) 1/2 Phase velocity

45. PACS Synthesis Examples

46. Liquid and vapor water column diurnal sampling

47. diurnal sampling 250 618 12 0 25 618 12 0 25 618 12 0 25 618 12 0 50 618 12 0 -85-82.5-80-77.5-75 0 0.5 1 1.5 2 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 5 55 5 5 5 5 5 5 5 5 5 5 5 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 7 7 7 77 7 7 7 7 7 7 7 7 7 7 degrees longitude height (km) surface LCL cloud base cloud top Cloud height

48. cloud base 10% higher than LCL Cloud base above 900 m decoupled from surface layer Effect of stratification and mixing on cloud base

49. “Sea Snake” Surface temperature measurement