1 / 9

Multi-satellite Precipitation Analysis (MPA)

Multi-satellite Precipitation Analysis (MPA). George Huffman, Bob Adler, Dave Bolvin, Eric Nelkin NASA/GSFC. Theory / Schematic. Algorithm Inputs. Calibrate High-Quality (HQ) Estimates to “Best”. Instant-aneous SSM/I TRMM AMSR AMSU. 30-day HQ coefficients. Merge HQ Estimates.

thora
Télécharger la présentation

Multi-satellite Precipitation Analysis (MPA)

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Multi-satellite Precipitation Analysis (MPA) George Huffman, Bob Adler, Dave Bolvin, Eric Nelkin NASA/GSFC

  2. Theory / Schematic • Algorithm Inputs

  3. Calibrate High-Quality (HQ) Estimates to “Best” Instant-aneous SSM/I TRMM AMSR AMSU 30-day HQ coefficients Merge HQ Estimates 3-hourly merged HQ Match IR and HQ, generate coeffs 3-hourly IR Tb 30-day IR coefficients Apply IR coefficients Hourly HQ-calib IR precip Merge IR, merged HQ estimates 3-hourly multi-satellite (MS) Compute monthly satellite-gauge combination (SG) Monthly gauges Monthly SG Rescale 3-hourly MS to monthly SG Rescaled 3-hourly MS Theory / Schematic (cont.) • Algorithm Process • The “real” MPA is the post-real-time Version 6 3B42 • The current real-time 3B42RT that runs 10 hr after real time is a first look • We plan to replace the 10-hr run with a 4-hr “early” and 7-hr “final” to better support operations

  4. Theory / Schematic (cont.) • IR Calibration Data Cube • 3-hr/0.25° matched HQ and IR, aggregated for a month on overlapping 3°x3° blocks

  5. Theory / Schematic (cont.) • Strengths and Weaknesses of Underlying Assumptions • “All” MW are used • Aggregating MW to 3-hr maps introduces time errors at fine scale • Intercalibration of MW and cal. of IR to MW traceable; good, except bad if the calibrator goes bad • Different calibrators are used for RT (TMI) and V.6 (TCI and gauge) • VAR scheme for IR assumes that instantaneously colder clouds rain more • VAR scheme for IR takes calibration from a month of data; stable, but stiff • HQ-VAR combination scheme is priority - HQ, else VAR; minimum assumptions, but introduces boundaries

  6. Theory / Schematic (cont.) • Planned Modifications / Improvements Current (3 February) • Update the RT VAR calibration coefficients every 3 hr (vs. 5 days) • Introduce AMSR, AMSU in RT in addition to TMI, SSM/I • Just recomputed February–May due to programming, uh, feature Short-term • 10-hr latency lowered to 7-hr in RT (the “final”) • Introduce “early” 4-hr RT Long-term • Approximate TCI and gauge calibrations for RT (so closer to V.6) • Ameliorate or audit out deficient input data in light-rain, cold-surface areas • High-latitude estimates based on NASA SRT TOVS and AIRS • Fine-scale error estimates (REM2D?) • Evaluate CST to replace VAR • Evaluate B1 (and TOVS, OPI) data to extend back in time

  7. Algorithm Output Information • Spatial Resolution 0.25°x0.25° • Spatial Coverage 50°N-S (60° possible) • Update Frequency 3-hr (RT), monthly (V.6) • Data Latency 10 hr (RT; plan move to 7 & 4), 2 weeks after month (V.6)

  8. Algorithm Output Information (cont.) • Source of Real-Time Data • Source of Archive Data

  9. Algorithm Output Information (cont.) • Capability of Producing Retrospective Data (data and resources required / available) • Currently 1/98-present (but already based on heterogeneous input data) • Could go back to 10/96 with current data sets • Likely able to go back to 1/91 by employing B1 data • Figuring out how to handle the F8 drop-out would allow us to go back to 7/87 • Properly handling TOVS and/or OPI as calibrators might take us back to 1983 • At coarser resolution, might be able to go back to 1979

More Related