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Proposal Identification No.:

T2163

Date Received:

2005-Sep-19 18:00:24

Technical Page
Proposal Type: General Category: Sub-Category: Observation Category: Total Time Requested: Prop osal Title: Regular Terrestrial Aeronomy Radar Thermosphere 288 Hours

A Proposal for Radar Meteor Observations during the Seasonal Minimum of the Sporadic Activity at Arecibo: A Crucial Need for the Confirmation of Modeled Predictions and its Relation to the Atmospheric Ca, Ca+ and K Layers
ABSTRACT:
We request observing time with the 430 MHz radar b efore, during and after the spring solstice op erated in high resolution meteor detection mo de. These observations will b e used to address several scientific and engineering pro jects with the involvement of three graduate students. Preliminary results from a recently started mo deling effort predict a seasonal minimum of the diurnal micrometeor rate over Arecib o during this p erio d. This prediction is supp orted by early meteor observations which showed that the meteor rates observed during the night of March 25, 2002 is at least 2 times lower than any other month during the same year (Janches and Chau, 2005; Janches et al., 2005). The observations prop osed here will confirm the theoretical predictions providing the necessary data to understand and mo del the Micrometeor Input Function (MIF) in the Mesosphere/Lower Thermosphere (MLT) region. Understanding accurately the MIF is required to completely account for the sources of meteoric material in the upp er atmosphere which is resp onsible for the formation of metallic layers observed by lidars. We also prop ose simultaneous lidar observations to investigate the relationship b etween the MIF and the Ca and Ca+ layers. These layers are characterized by two unique prop erties: 1) A very significant lack of Ca in the atmosphere, when compared with meteorite comp osition; and b) the ratio Ca+/Ca is much higher (by ab out 1 order of magnitude) than the corresp onding ratios that have b een measured for other meteoric metals found in the upp er atmosphere.. We b elieve this b ehavior is directly connected to the observed high velo city micrometeor flux, since Ca is amongst the most refractory of the meteoritic constituents. We will complement these simultaneous observations with the K lidar. The prop osed simultaneous campaigns will continue an ongoing observational program at the observatory (Tepley et al., 2003; Raizada et al., 2004). The data pro duced by these observations will also b e used for a statistical study of sp oradic E layers and to finalize the testing and the full characterization of the digital receiver for the 430 MHz radar.

Name Diego Janches

Institution NorthWest Reasearch Assoc./CoRA Div.

E-mail diego@cora.nwra.com

Phone 303-4159701x228

Student no

1


Service Observing Request

Remot e Observing Request

X

None All of the observing run. Part of the observing run. Queue Observing

X

No Maybe Yes

Instrument Setup
430 CH receiver 430 CH radar Atmospheric Observation Instruments: Lidar Sp ecial Equipment or setup: none

RFI Considerations Frequency Ranges Planned

2