lidar observations of the mlt metal layer and temperatures at (and with) the arecibo observatory

17 May 2007

Lidar observations of the MLT metal layer and temperatures at

(and with) the Arecibo Observatory

Jonathan FriedmanArecibo Observatory

17 May 2007

17 May 2007

Outline

• Arecibo’s lidars• Results

– Ion-neutral interactions … sporadic layers

– Micrometeors and the metal layer topside

– MLT temperature measurements & solar influence

17 May 2007

Arecibo Observatory Lidars

• Two broadband resonance density lidars (any 2 of Na, Ca, Ca+, Fe)

• Narrowband K Doppler lidar• Four 80-cm diameter cassegrain telescopes, fiber coupled to detectors.

• Seven independent channels with PMT detectors, APD channels under development.

• Daylight capability for K lidar being implemented

17 May 2007

K lidar Transmitter & Receiver

17 May 2007

Some Results

1. Summary of some past results• Sporadic layers• Temperatures, inversion layers, and Gravity

Wave events2. Ongoing projects

• Metal layer topside and micrometeoroids• Seasonal thermal structure of the Arecibo

mesopause.

17 May 2007

Sporadic layer event during the 1998 Coquí II sounding

rocket campaign

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17 May 2007

Tepley et al., 2003

Ca+

e-

K

17 May 2007

Ducted waves and temperature inversions

17 May 2007

Arecibo and SABER inversion measurement

17 May 2007

The Metal Layer Topside: A direct

measure of micrometeor input?

17 May 2007

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Metal Layer Topside

0.1/cc

100/cc10/cc

1/cc

17 May 2007

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Metal abundance ratios

17 May 2007

An example from Kühlungsborn (1/2)

Plotted are ratios of metal atom densities (K/Fe), K/Ca, and Fe/Ca from Kühlungsborn, 27 Oct 97.

17 May 2007

Example from Kühlungsborn (2/2)

17 May 2007

[K/Na] example for Arecibo

17 May 2007

Comparisons with K

17 May 2007

Seasonal Climatology of the tropical MLT

17 May 2007

Seasonal Climatology and how the mesopause above Arecibo fits into the

global picture

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17 May 2007

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78°N, SpitsbergenHöffner, 2006

Latitude Comparison

35°N, Albuquerque, NM (Starfire)Chu et al., 2005

18°N, Arecibo, PRFriedman and Chu, 2007

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21°N, Maui, HIFriedman and Chu, 2006

17 May 2007

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Comparing specific altitudes

17 May 2007

12-tidal oscillationsa work in progress

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17 May 2007

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January 12-h Analysis

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17 May 2007

Including the 24-h tide from GSWM

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Summary• Arecibo has multiple resonance lidars to investigate the properties of the mesospheric metal layer

• The K lidar is a Doppler lidar for temperature measurements.

• We have studied sporadic layers in conjunction with the ionospheric radar.

• We work together with visiting instruments to study transient phenomena.

• We participate in the study of the meteoric input to the atmosphere, and how micrometeoroids may produce the topside.

• We study thermal structure & oscillations

• Full daylight capabilities imminent.

17 May 2007

Additional slides

17 May 2007

Tracking Ks layers

17 May 2007

Tracking ion layers