Brief Discussion of Current Aerosol Events (Ordered from newest to oldest) (Those with their own Case Study page have asterisk) 19990407-08 - Sahara - dust from 19990404-05 event emerging from coast and heading north along 27W. NOAA AOD and TOMS AI both show this tongue, captured by NAAPS. NOAA AOD as high as 0.7. NAAPS has similar values. 19990404 - Gobi: moderate mobilization event at 12Z. See world sfc obs. loop, and China sfc obs. loop See NOGAPS China loop: short wave traveling down backside of very broad trough centered over Sea of Okhotsk gives large friction velocity over Gobi at 06Z See TOMS dateline loop - 04th image shows event over Yellow Sea and Sea of Japan See NAAPS China loop (or NAAPS/TOMS combo loop): shows event over Yellow Sea and Sea of Japan 19990404 - Sahara - beginning of large event at 12Z on 4th. Expanded on 5th, reaching from Chad to nearly the coast. Dyanmics: surface high builds over NW Africa beginning on 3rd, continues through 4th and 5th resulting in large area of high winds over Sahara and Sahel from Chad, including Libya Egypt, and Sudan at times. 19990403 - Caspian: a few surface observations at 12Z and 18Z 1999032406-1999032412 - Mongolia - High amplitude 500mb wave with intense cold front swings SE across Mongolia. Small patch of dust storm observations and NW winds of 10-20 kts centered around Dalanzadgad. NOGAPS shows moderate area of high friction velocities streched along cold front. NAAPS captures this event. 1999032406-1999032412 - Tatla Makan - High amplitude 500mb wave with intense cold front swings SE across Mongolia. In front of building surface high, small patch of dust storm observations and NE winds of 10-20 kts entering and across Tatla Makan Basin NOGAPS shows area of high friction velocities streched along Tatla Makan. NAAPS captures this event. 1999032306 - Zhuangaerpendi (Northwestern-most China) - High amplitude 500mb wave with intense cold front swings SE across Zhuangaerpendi region (basin north of Tatla Makan). Small patch of severe dust storm observations and W winds of 20-30 kts. Small area of high friction velocity in NOGAPS but no dust lifted in NAAPS because NOGAPS ground wetness is around 0.6. 1999031800-1999032100 - Eastern Mediterrranean - Strong low transiting the N. Africa coastline injects moderate dust along Libya and Egypt coast (on 18th), and into Israel, Jordan and Syria on 19th-21st and Saudi Arabia and Iraq on 20-22nd. *1999031000-1999032000 - South China/Viet Nam - Plume of Unknown Type, Surface Observations show no smoke, dust, or haze observations in the region. NOAA Aerosol Retrieval Loop shows some evidence of a plume over the South China Sea. GSFC TOMS Aerosol Residual Loop shows high residual values popping up on the 10th in southern China and northern North Viet Nam. Omar Torres says high values have been seen periodically since February, suggest plume is probably from biomass buring. NAAPS World Loop indicates that the plume is not dust or anthropogenic sulfate *1999031506-1999031512 - China - Weak wave at 500 mb on pure zonal flow, amplified at 700mb, leads to high winds near 40-45N, 100-105E. Surface observations of dust storms. Captured by NAAPS. *1999022006-1999022018 - Egypt - Strong pressure gradient between high (bulding along Med coastline) and low (over Sinai) yield strong N flow (20-30 kts) in central Egypt. Duststorms reported. Captured by NOGAPS and NAAPS, though may be too extensive. *1999022012-1999022112 - Sahara - Strong high along N. Africa coast yields strong ENE flow over Mali and Mauritania. Dust lifted 1999022012, reaching coast at 1999022112. Captured by NOGAPS and NAAPS. 1999021706-1999021800 - East Med - Low of 19990216 continues eastward, with 25 kt winds in N. Egypt, Israel, Syria, etc. NAAPS captures event. 1999021512-1999021612 - Mongolia - A number of dust obs across western, southern, and then central Mongolia in NW flow behind deep low associated with broad, high-amplitude wave. Captured by NAAPS. 19990216 - Sahara - moderate SW winds ahead of Algerian low as it moves ENE towards Crete. A few dust obs in Libya and Egypt 19990215 - Sahara - strong NE winds over Northern Algeria in response to high off NW Africa and low over Southen Algria. Some dust obs in Northern Algeria. Dust hits coast at 1999021712. 1999021018-1999021100 - Agrentina - A few dust obs along coast and 5 deg inland in SW winds behind cold front associated with baroclinic wave. Not captured by NAAPS since no source areas there: The sparse grassland is not allowed as a source, except in Mongolia.